Electromagnetism

• Electricity
  Electricity
  Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
  
  
• Magnetism
  Magnetism
  Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well...
  
  
• Electromagnetic spectrum
  Electromagnetic spectrum
  The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object....
  
  
  • Optical spectrum
• Electrostatics
  Electrostatics
  Electrostatics is the branch of physics that deals with the phenomena and properties of stationary or slow-moving electric charges....
  
  
  • Electric charge
    Electric charge
    Electric charge is a physical property of matter that causes it to experience a force when near other electrically charged matter. Electric charge comes in two types, called positive and negative. Two positively charged substances, or objects, experience a mutual repulsive force, as do two...
    
    
  • Coulomb's law
    Coulomb's law
    Coulomb's law or Coulomb's inverse-square law, is a law of physics describing the electrostatic interaction between electrically charged particles. It was first published in 1785 by French physicist Charles Augustin de Coulomb and was essential to the development of the theory of electromagnetism...
    
    
  • Electric field
    Electric field
    In physics, an electric field surrounds electrically charged particles and time-varying magnetic fields. The electric field depicts the force exerted on other electrically charged objects by the electrically charged particle the field is surrounding...
    
    
  • Gauss's law
    Gauss's law
    In physics, Gauss's law, also known as Gauss's flux theorem, is a law relating the distribution of electric charge to the resulting electric field. Gauss's law states that:...
    
    
  • Electric potential
    Electric potential
    In classical electromagnetism, the electric potential at a point within a defined space is equal to the electric potential energy at that location divided by the charge there...
    
    
• Magnetostatics
  Magnetostatics
  Magnetostatics is the study of magnetic fields in systems where the currents are steady . It is the magnetic analogue of electrostatics, where the charges are stationary. The magnetization need not be static; the equations of magnetostatics can be used to predict fast magnetic switching events that...
  
  
  • Electric current
    Electric current
    Electric current is a flow of electric charge through a medium.This charge is typically carried by moving electrons in a conductor such as wire...
    
    
  • Ampère's law
    Ampère's law
    In classical electromagnetism, Ampère's circuital law, discovered by André-Marie Ampère in 1826, relates the integrated magnetic field around a closed loop to the electric current passing through the loop...
    
    
  • Magnetic field
    Magnetic field
    A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
    
    
  • Magnetic moment
    Magnetic moment
    The magnetic moment of a magnet is a quantity that determines the force that the magnet can exert on electric currents and the torque that a magnetic field will exert on it...
    
    
• Electrodynamics
  • Lorentz force law
  • Electromotive force
    Electromotive force
    In physics, electromotive force, emf , or electromotance refers to voltage generated by a battery or by the magnetic force according to Faraday's Law, which states that a time varying magnetic field will induce an electric current.It is important to note that the electromotive "force" is not a...
    
    
  • Electromagnetic induction
    Electromagnetic induction
    Electromagnetic induction is the production of an electric current across a conductor moving through a magnetic field. It underlies the operation of generators, transformers, induction motors, electric motors, synchronous motors, and solenoids....
    
    
  • Faraday-Lenz law
  • Displacement current
    Displacement current
    In electromagnetism, displacement current is a quantity that is defined in terms of the rate of change of electric displacement field. Displacement current has the units of electric current density, and it has an associated magnetic field just as actual currents do. However it is not an electric...
    
    
  • Maxwell's equations
    Maxwell's equations
    Maxwell's equations are a set of partial differential equations that, together with the Lorentz force law, form the foundation of classical electrodynamics, classical optics, and electric circuits. These fields in turn underlie modern electrical and communications technologies.Maxwell's equations...
    
    
  • Electromagnetic field
    Electromagnetic field
    An electromagnetic field is a physical field produced by moving electrically charged objects. It affects the behavior of charged objects in the vicinity of the field. The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction...
    
    
  • Electromagnetic radiation
    Electromagnetic radiation
    Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
    
    
• Electrical circuits
  • Electrical resistance
    Electrical resistance
    The electrical resistance of an electrical element is the opposition to the passage of an electric current through that element; the inverse quantity is electrical conductance, the ease at which an electric current passes. Electrical resistance shares some conceptual parallels with the mechanical...
    
    
  • Capacitance
    Capacitance
    In electromagnetism and electronics, capacitance is the ability of a capacitor to store energy in an electric field. Capacitance is also a measure of the amount of electric potential energy stored for a given electric potential. A common form of energy storage device is a parallel-plate capacitor...
    
    
  • Inductance
    Inductance
    In electromagnetism and electronics, inductance is the ability of an inductor to store energy in a magnetic field. Inductors generate an opposing voltage proportional to the rate of change in current in a circuit...
    
    
  • Impedance
    Electrical impedance
    Electrical impedance, or simply impedance, is the measure of the opposition that an electrical circuit presents to the passage of a current when a voltage is applied. In quantitative terms, it is the complex ratio of the voltage to the current in an alternating current circuit...
    
    
  • Resonant cavity
  • Waveguide
    Waveguide
    A waveguide is a structure which guides waves, such as electromagnetic waves or sound waves. There are different types of waveguides for each type of wave...
    
    

Physical laws

• Ampère's law
  Ampère's law
  In classical electromagnetism, Ampère's circuital law, discovered by André-Marie Ampère in 1826, relates the integrated magnetic field around a closed loop to the electric current passing through the loop...
  
  
• Coulomb's law
  Coulomb's law
  Coulomb's law or Coulomb's inverse-square law, is a law of physics describing the electrostatic interaction between electrically charged particles. It was first published in 1785 by French physicist Charles Augustin de Coulomb and was essential to the development of the theory of electromagnetism...
  
  
• Faraday's law of induction
  Faraday's law of induction
  Faraday's law of induction dates from the 1830s, and is a basic law of electromagnetism relating to the operating principles of transformers, inductors, and many types of electrical motors and generators...
  
  /Farady-Lenz law
• Gauss's law
  Gauss's law
  In physics, Gauss's law, also known as Gauss's flux theorem, is a law relating the distribution of electric charge to the resulting electric field. Gauss's law states that:...
  
  
• Kirchhoff's circuit laws
  Kirchhoff's circuit laws
  Kirchhoff's circuit laws are two equalities that deal with the conservation of charge and energy in electrical circuits, and were first described in 1845 by Gustav Kirchhoff...
  
  
  • Current law
  • Voltage law
• Maxwell's equations
  Maxwell's equations
  Maxwell's equations are a set of partial differential equations that, together with the Lorentz force law, form the foundation of classical electrodynamics, classical optics, and electric circuits. These fields in turn underlie modern electrical and communications technologies.Maxwell's equations...
  
  
  • Gauss's law
    Gauss's law
    In physics, Gauss's law, also known as Gauss's flux theorem, is a law relating the distribution of electric charge to the resulting electric field. Gauss's law states that:...
    
    
  • Faraday's law of induction
    Faraday's law of induction
    Faraday's law of induction dates from the 1830s, and is a basic law of electromagnetism relating to the operating principles of transformers, inductors, and many types of electrical motors and generators...
    
    
  • Ampère's law
    Ampère's law
    In classical electromagnetism, Ampère's circuital law, discovered by André-Marie Ampère in 1826, relates the integrated magnetic field around a closed loop to the electric current passing through the loop...
    
    
• Ohm's law
  Ohm's law
  Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference across the two points...
  
  

Control engineering

• Control Theory
  Control theory
  Control theory is an interdisciplinary branch of engineering and mathematics that deals with the behavior of dynamical systems. The desired output of a system is called the reference...
  
  
  • Adaptive control
    Adaptive control
    Adaptive control is the control method used by a controller which must adapt to a controlled system with parameters which vary, or are initially uncertain. For example, as an aircraft flies, its mass will slowly decrease as a result of fuel consumption; a control law is needed that adapts itself...
    
    
  • Control theory
    Control theory
    Control theory is an interdisciplinary branch of engineering and mathematics that deals with the behavior of dynamical systems. The desired output of a system is called the reference...
    
    
  • Digital control
    Digital control
    Digital control is a branch of control theory that uses digital computers to act as system controllers.Depending on the requirements, a digital control system can take the form of a microcontroller to an ASIC to a standard desktop computer....
    
    
  • Nonlinear control
    Nonlinear control
    Nonlinear control is the area of control engineering specifically involved with systems that are nonlinear, time-variant, or both. Many well-established analysis and design techniques exist for LTI systems ; however, one or both of the controller and the system under control in a general control...
    
    
  • Optimal control
    Optimal control
    Optimal control theory, an extension of the calculus of variations, is a mathematical optimization method for deriving control policies. The method is largely due to the work of Lev Pontryagin and his collaborators in the Soviet Union and Richard Bellman in the United States.-General method:Optimal...
    
    
  • Intelligent control
    Intelligent control
    Intelligent control is a class of control techniques, that use various AI computing approaches like neural networks, Bayesian probability, fuzzy logic, machine learning, evolutionary computation and genetic algorithms.- Overview :...
    
    
  • Neural networks
    Neural Networks
    Neural Networks is the official journal of the three oldest societies dedicated to research in neural networks: International Neural Network Society, European Neural Network Society and Japanese Neural Network Society, published by Elsevier...
    
    
  • Fuzzy control
  • Model predictive control
    Model predictive control
    Model Predictive Control, or MPC, is an advanced method of process control that has been in use in the process industries such as chemical plants and oil refineries since the 1980s...
    
    
• System Properties:
  • Exponential stability
  • Marginal stability
    Marginal stability
    In the theory of dynamical systems, and control theory, a continuous linear time-invariant system is marginally stable if and only if the real part of every eigenvalue in the system's transfer-function is non-positive, and all eigenvalues with zero real value are simple roots...
    
    
  • BIBO stability
    BIBO stability
    In electrical engineering, specifically signal processing and control theory, BIBO stability is a form of stability for linear signals and systems that take inputs. BIBO stands for Bounded-Input Bounded-Output...
    
    
  • Lyapunov stability
    Lyapunov stability
    Various types of stability may be discussed for the solutions of differential equations describing dynamical systems. The most important type is that concerning the stability of solutions near to a point of equilibrium. This may be discussed by the theory of Lyapunov...
    
     (i.e., asymptotic stability)
  • Input-to-state (ISS) stability
  • Controllability
    Controllability
    Controllability is an important property of a control system, and the controllability property plays a crucial role in many control problems, such as stabilization of unstable systems by feedback, or optimal control....
    
    
  • Observability
    Observability
    Observability, in control theory, is a measure for how well internal states of a system can be inferred by knowledge of its external outputs. The observability and controllability of a system are mathematical duals. The concept of observability was introduced by American-Hungarian scientist Rudolf E...
    
    
  • Negative feedback
    Negative feedback
    Negative feedback occurs when the output of a system acts to oppose changes to the input of the system, with the result that the changes are attenuated. If the overall feedback of the system is negative, then the system will tend to be stable.- Overview :...
    
    
  • Positive feedback
    Positive feedback
    Positive feedback is a process in which the effects of a small disturbance on a system include an increase in the magnitude of the perturbation. That is, A produces more of B which in turn produces more of A. In contrast, a system that responds to a perturbation in a way that reduces its effect is...
    
    
• System Modeling:
  • System identification
    System identification
    In control engineering, the field of system identification uses statistical methods to build mathematical models of dynamical systems from measured data...
    
    
  • State observer
    State observer
    In control theory, a state observer is a system that models a real system in order to provide an estimate of its internal state, given measurements of the input and output of the real system. It is typically a computer-implemented mathematical model....
    
    
  • First principles modeling
    First principles
    In philosophy, a first principle is a basic, foundational proposition or assumption that cannot be deduced from any other proposition or assumption. In mathematics, first principles are referred to as axioms or postulates...
    
    
  • Least squares
    Least squares
    The method of least squares is a standard approach to the approximate solution of overdetermined systems, i.e., sets of equations in which there are more equations than unknowns. "Least squares" means that the overall solution minimizes the sum of the squares of the errors made in solving every...
    
    
  • Artificial neural networks
• Controllers:
  • Closed-loop controller
  • PID controller
    PID controller
    A proportional–integral–derivative controller is a generic control loop feedback mechanism widely used in industrial control systems – a PID is the most commonly used feedback controller. A PID controller calculates an "error" value as the difference between a measured process variable and a...
    
    
  • Programmable logic controller
    Programmable logic controller
    A programmable logic controller or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines...
    
    
  • Embedded controller
    Embedded system
    An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
    
    
• Control Applications:
  • Industrial Control Systems
    Industrial Control Systems
    Industrial control system is a general term that encompasses several types of control systems used in industrial production, including supervisory control and data acquisition systems, distributed control systems , and other smaller control system configurations such as skid-mounted programmable...
    
    
  • Process Control
    Process control
    Process control is a statistics and engineering discipline that deals with architectures, mechanisms and algorithms for maintaining the output of a specific process within a desired range...
    
    
  • Distributed Control System
    Distributed control system
    A distributed control system refers to a control system usually of a manufacturing system, process or any kind of dynamic system, in which the controller elements are not central in location but are distributed throughout the system with each component sub-system controlled by one or more...
    
    
  • Mechatronics
    Mechatronics
    Mechatronics is the combination of mechanical engineering, electronic engineering, computer engineering, software engineering, control engineering, and systems design engineering in order to design, and manufacture useful products. Mechatronics is a multidisciplinary field of engineering, that is...
    
    
  • Motion control
    Motion control
    Motion control is a sub-field of automation, in which the position or velocity of machines are controlled using some type of device such as a hydraulic pump, linear actuator, or an electric motor, generally a servo...
    
    
  • Supervisory control (SCADA)
    SCADA
    SCADA generally refers to industrial control systems : computer systems that monitor and control industrial, infrastructure, or facility-based processes, as described below:...
    
    

Electronics

• Electrical network
  Electrical network
  An electrical network is an interconnection of electrical elements such as resistors, inductors, capacitors, transmission lines, voltage sources, current sources and switches. An electrical circuit is a special type of network, one that has a closed loop giving a return path for the current...
  
  /Circuit
  • Circuit laws
    • Kirchhoff's circuit laws
      Kirchhoff's circuit laws
      Kirchhoff's circuit laws are two equalities that deal with the conservation of charge and energy in electrical circuits, and were first described in 1845 by Gustav Kirchhoff...
      
      
      • Current law
      • Voltage law
    • Y-delta transform
    • Ohm's law
      Ohm's law
      Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference across the two points...
      
      
  • Electrical element
    Electrical element
    Electrical elements are conceptual abstractions representing idealized electrical components, such as resistors, capacitors, and inductors, used in the analysis of electrical networks...
    
    /Discretes
    • Passive elements:
      • Capacitor
        Capacitor
        A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
        
        
      • Inductor
        Inductor
        An inductor is a passive two-terminal electrical component used to store energy in a magnetic field. An inductor's ability to store magnetic energy is measured by its inductance, in units of henries...
        
        
      • Resistor
        Resistor
        A linear resistor is a linear, passive two-terminal electrical component that implements electrical resistance as a circuit element.The current through a resistor is in direct proportion to the voltage across the resistor's terminals. Thus, the ratio of the voltage applied across a resistor's...
        
        
      • Hall effect sensor
        Hall effect sensor
        A Hall effect sensor is a transducer that varies its output voltage in response to a magnetic field. Hall effect sensors are used for proximity switching, positioning, speed detection, and current sensing applications....
        
        
    • Active elements:
      • Microcontroller
        Microcontroller
        A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...
        
        
      • Operational amplifier
        Operational amplifier
        An operational amplifier is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output...
        
        
    • Semiconductor
      Semiconductor
      A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
      
      s:
      • Diode
        Diode
        In electronics, a diode is a type of two-terminal electronic component with a nonlinear current–voltage characteristic. A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material connected to two electrical terminals...
        
        
        • Zener diode
          Zener diode
          A Zener diode is a special kind of diode which allows current to flow in the forward direction in the same manner as an ideal diode, but will also permit it to flow in the reverse direction when the voltage is above a certain value known as the breakdown voltage, "Zener knee voltage" or "Zener...
          
          
        • Light-emitting diode
          Light-emitting diode
          A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting...
          
          
        • PIN diode
          PIN diode
          A PIN diode is a diode with a wide, lightly doped 'near' intrinsic semiconductor region between a p-type semiconductor and an n-type semiconductor region. The p-type and n-type regions are typically heavily doped because they are used for ohmic contacts....
          
          
        • Schottky diode
          Schottky diode
          The Schottky diode is a semiconductor diode with a low forward voltage drop and a very fast switching action...
          
          
        • Avalanche diode
          Avalanche diode
          In electronics, an avalanche diode is a diode that is designed to go through avalanche breakdown at a specified reverse bias voltage. The junction of an avalanche diode is designed to prevent current concentration at hot spots, so that the diode is undamaged by the breakdown...
          
          
        • Laser diode
          Laser diode
          The laser diode is a laser where the active medium is a semiconductor similar to that found in a light-emitting diode. The most common type of laser diode is formed from a p-n junction and powered by injected electric current...
          
          
        • DIAC
          DIAC
          The DIAC, or 'diode for alternating current', is a diode that conducts current only after its breakover voltage has been reached momentarily....
          
          
      • Thyristor
        Thyristor
        A thyristor is a solid-state semiconductor device with four layers of alternating N and P-type material. They act as bistable switches, conducting when their gate receives a current trigger, and continue to conduct while they are forward biased .Some sources define silicon controlled rectifiers and...
        
        
      • Transistor
        Transistor
        A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
        
        
        • Bipolar transistor (BJT)
        • Field effect transistor (FET)
        • Darlington transistor
          Darlington transistor
          In electronics, the Darlington transistor is a compound structure consisting of two bipolar transistors connected in such a way that the current amplified by the first transistor is amplified further by the second one...
          
          
        • IGBT
      • Triac
        Triac
        Triac may refer to:* TRIAC , an electronics component* Triac , a green vehicle* Tiratricol, a common thyroid hormone analogue used for treating thyroid hormone resistance syndrome...
        
        
      • Mosfet
        MOSFET
        The metal–oxide–semiconductor field-effect transistor is a transistor used for amplifying or switching electronic signals. The basic principle of this kind of transistor was first patented by Julius Edgar Lilienfeld in 1925...
        
        

Power engineering

• Generation
  Electricity generation
  Electricity generation is the process of generating electric energy from other forms of energy.The fundamental principles of electricity generation were discovered during the 1820s and early 1830s by the British scientist Michael Faraday...
  
  
  • Electrical generator
    Electrical generator
    In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...
    
    
  • Renewable electricity
  • Hydropower
    Hydropower
    Hydropower, hydraulic power, hydrokinetic power or water power is power that is derived from the force or energy of falling water, which may be harnessed for useful purposes. Since ancient times, hydropower has been used for irrigation and the operation of various mechanical devices, such as...
    
    
• Transmission
  Electric power transmission
  Electric-power transmission is the bulk transfer of electrical energy, from generating power plants to Electrical substations located near demand centers...
  
  
  • Electricity pylon
    Electricity pylon
    A transmission tower is a tall structure, usually a steel lattice tower, used to support an overhead power line. They are used in high-voltage AC and DC systems, and come in a wide variety of shapes and sizes...
    
    
  • Transformer
    Transformer
    A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...
    
    
  • Transmission line
    Transmission line
    In communications and electronic engineering, a transmission line is a specialized cable designed to carry alternating current of radio frequency, that is, currents with a frequency high enough that its wave nature must be taken into account...
    
    
• Distribution
  Electricity distribution
  File:Electricity grid simple- North America.svg|thumb|380px|right|Simplified diagram of AC electricity distribution from generation stations to consumers...
  
  
• Processes:
  • Alternating current
    Alternating current
    In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....
    
    
  • Direct current
    Direct current
    Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...
    
    
  • Single-phase electric power
    Single-phase electric power
    In electrical engineering, single-phase electric power refers to the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when loads are mostly lighting and heating, with few large electric motors...
    
    
  • Two phase
    Two phase
    Two-phase electrical power was an early 20th century polyphase alternating current electric power distribution system. Two circuits were used, with voltage phases differing by 90 degrees. Usually circuits used four wires, two for each phase. Less frequently, three wires were used, with a common...
    
    
  • Three-phase power
  • Ward Leonard control
    Ward Leonard control
    Ward Leonard Control, also known as the Ward Leonard Drive System, was a widely used DC motor speed control system introduced by Harry Ward Leonard in 1891. In early 1900s, the control system of Ward Leonard was adopted by the U.S. Navy and also used in passenger lift of large mines...
    
    

Electric vehicles

• Electric motor
  Electric motor
  An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
  
  
• Hybrid electric vehicle
  Hybrid electric vehicle
  A hybrid electric vehicle is a type of hybrid vehicle and electric vehicle which combines a conventional internal combustion engine propulsion system with an electric propulsion system. The presence of the electric powertrain is intended to achieve either better fuel economy than a conventional...
  
  
• Plug-in hybrid
• Rechargeable battery
  Rechargeable battery
  A rechargeable battery or storage battery is a group of one or more electrochemical cells. They are known as secondary cells because their electrochemical reactions are electrically reversible. Rechargeable batteries come in many different shapes and sizes, ranging anything from a button cell to...
  
  
• Vehicle-to-grid
  Vehicle-to-grid
  Vehicle-to-grid describes a system in which plug-in electric vehicles, such as electric cars and plug-in hybrids , communicate with the power grid to sell demand response services by either delivering electricity into the grid or by throttling their charging rate.Vehicle-to-grid can be used with...
  
  

Signal processing

• Analog signal processing
  Analog signal processing
  Analog signal processing is any signal processing conducted on analog signals by analog means. "Analog" indicates something that is mathematically represented as a set of continuous values. This differs from "digital" which uses a series of discrete quantities to represent signal...
  
  
• Digital signal processing
  Digital signal processing
  Digital signal processing is concerned with the representation of discrete time signals by a sequence of numbers or symbols and the processing of these signals. Digital signal processing and analog signal processing are subfields of signal processing...
  
  
  • Quantization
    Quantization (signal processing)
    Quantization, in mathematics and digital signal processing, is the process of mapping a large set of input values to a smaller set – such as rounding values to some unit of precision. A device or algorithmic function that performs quantization is called a quantizer. The error introduced by...
    
    
  • Sampling
    • Analog-to-digital converter
      Analog-to-digital converter
      An analog-to-digital converter is a device that converts a continuous quantity to a discrete time digital representation. An ADC may also provide an isolated measurement...
      
      , Digital-to-analog converter
      Digital-to-analog converter
      In electronics, a digital-to-analog converter is a device that converts a digital code to an analog signal . An analog-to-digital converter performs the reverse operation...
      
      
    • Continuous signal
      Continuous signal
      A continuous signal or a continuous-time signal is a varying quantity whose domain, which is often time, is a continuum . That is, the function's domain is an uncountable set. The function itself need not be continuous...
      
      , Discrete signal
      Discrete signal
      A discrete signal or discrete-time signal is a time series consisting of a sequence of qualities...
      
      
    • Downsampling
      Downsampling
      In signal processing, downsampling is the process of reducing the sampling rate of a signal. This is usually done to reduce the data rate or the size of the data....
      
      
    • Nyquist frequency
      Nyquist frequency
      The Nyquist frequency, named after the Swedish-American engineer Harry Nyquist or the Nyquist–Shannon sampling theorem, is half the sampling frequency of a discrete signal processing system...
      
      
    • Nyquist-Shannon sampling theorem
    • Oversampling
      Oversampling
      In signal processing, oversampling is the process of sampling a signal with a sampling frequency significantly higher than twice the bandwidth or highest frequency of the signal being sampled...
      
      
    • Sample and hold
      Sample and hold
      In electronics, a sample and hold circuit is an analog device that samples the voltage of a continuously varying analog signal and holds its value at a constant level for a specified minimal period of time. Sample and hold circuits and related peak detectors are the elementary analog memory...
      
      
    • Sampling frequency
    • Undersampling
      Undersampling
      In signal processing, undersampling or bandpass sampling is a technique where one samples a bandpass filtered signal at a sample rate below the usual Nyquist rate In signal processing, undersampling or bandpass sampling is a technique where one samples a bandpass filtered signal at a sample rate...
      
      
    • Upsampling
      Upsampling
      Upsampling is the process of increasing the sampling rate of a signal. For instance, upsampling raster images such as photographs means increasing the resolution of the image....
      
      
  • Audio signal processing
    Audio signal processing
    Audio signal processing, sometimes referred to as audio processing, is the intentional alteration of auditory signals, or sound. As audio signals may be electronically represented in either digital or analog format, signal processing may occur in either domain...
    
    
    • Audio noise reduction
    • Speech processing
      Speech processing
      Speech processing is the study of speech signals and the processing methods of these signals.The signals are usually processed in a digital representation, so speech processing can be regarded as a special case of digital signal processing, applied to speech signal.It is also closely tied to...
      
      
    • Equalization
      Equalization
      Equalization, is the process of adjusting the balance between frequency components within an electronic signal. The most well known use of equalization is in sound recording and reproduction but there are many other applications in electronics and telecommunications. The circuit or equipment used...
      
      
  • Digital image processing
    Digital image processing
    Digital image processing is the use of computer algorithms to perform image processing on digital images. As a subcategory or field of digital signal processing, digital image processing has many advantages over analog image processing...
    
    
    • Geometric transformation
      Euclidean geometry
      Euclidean geometry is a mathematical system attributed to the Alexandrian Greek mathematician Euclid, which he described in his textbook on geometry: the Elements. Euclid's method consists in assuming a small set of intuitively appealing axioms, and deducing many other propositions from these...
      
      
    • Color
      Color
      Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...
      
       correction
    • Computer vision
      Computer vision
      Computer vision is a field that includes methods for acquiring, processing, analysing, and understanding images and, in general, high-dimensional data from the real world in order to produce numerical or symbolic information, e.g., in the forms of decisions...
      
      
    • Image noise reduction
    • Edge detection
      Edge detection
      Edge detection is a fundamental tool in image processing and computer vision, particularly in the areas of feature detection and feature extraction, which aim at identifying points in a digital image at which the image brightness changes sharply or, more formally, has discontinuities...
      
      
    • Image editing
      2D computer graphics
      2D computer graphics is the computer-based generation of digital images—mostly from two-dimensional models and by techniques specific to them...
      
      
    • Segmentation
      Segmentation (image processing)
      In computer vision, segmentation refers to the process of partitioning a digital image into multiple segments . The goal of segmentation is to simplify and/or change the representation of an image into something that is more meaningful and easier to analyze...
      
      
  • Data compression
    Data compression
    In computer science and information theory, data compression, source coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use....
    
    
    • Lossless data compression
      Lossless data compression
      Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. The term lossless is in contrast to lossy data compression, which only allows an approximation of the original data to be reconstructed, in exchange...
      
      
    • Lossy data compression
      Lossy data compression
      In information technology, "lossy" compression is a data encoding method that compresses data by discarding some of it. The procedure aims to minimize the amount of data that need to be held, handled, and/or transmitted by a computer...
      
      
• Filtering
  Filter (signal processing)
  In signal processing, a filter is a device or process that removes from a signal some unwanted component or feature. Filtering is a class of signal processing, the defining feature of filters being the complete or partial suppression of some aspect of the signal...
  
  
  • Analog filter
  • Audio filter
    Audio filter
    An audio filter is a frequency dependent amplifier circuit, working in the audio frequency range, 0 Hz to beyond 20 kHz. Many types of filters exist for applications including graphic equalizers, synthesizers, sound effects, CD players and virtual reality systems.Being a frequency dependent...
    
    
  • Digital filter
    Digital filter
    In electronics, computer science and mathematics, a digital filter is a system that performs mathematical operations on a sampled, discrete-time signal to reduce or enhance certain aspects of that signal. This is in contrast to the other major type of electronic filter, the analog filter, which is...
    
    
    • Finite impulse response
      Finite impulse response
      A finite impulse response filter is a type of a signal processing filter whose impulse response is of finite duration, because it settles to zero in finite time. This is in contrast to infinite impulse response filters, which have internal feedback and may continue to respond indefinitely...
      
      
    • Infinite impulse response
      Infinite impulse response
      Infinite impulse response is a property of signal processing systems. Systems with this property are known as IIR systems or, when dealing with filter systems, as IIR filters. IIR systems have an impulse response function that is non-zero over an infinite length of time...
      
      
  • Electronic filter
    Electronic filter
    Electronic filters are electronic circuits which perform signal processing functions, specifically to remove unwanted frequency components from the signal, to enhance wanted ones, or both...
    
    
  • Equalization filter
    • Band-pass filter
      Band-pass filter
      A band-pass filter is a device that passes frequencies within a certain range and rejects frequencies outside that range.Optical band-pass filters are of common usage....
      
      
    • Band-stop filter
      Band-stop filter
      In signal processing, a band-stop filter or band-rejection filter is a filter that passes most frequencies unaltered, but attenuates those in a specific range to very low levels. It is the opposite of a band-pass filter...
      
      
    • Butterworth filter
      Butterworth filter
      The Butterworth filter is a type of signal processing filter designed to have as flat a frequency response as possible in the passband so that it is also termed a maximally flat magnitude filter...
      
      
    • Chebyshev filter
      Chebyshev filter
      Chebyshev filters are analog or digital filters having a steeper roll-off and more passband ripple or stopband ripple than Butterworth filters...
      
      
    • High-pass filter
      High-pass filter
      A high-pass filter is a device that passes high frequencies and attenuates frequencies lower than its cutoff frequency. A high-pass filter is usually modeled as a linear time-invariant system...
      
      
    • Kalman filter
      Kalman filter
      In statistics, the Kalman filter is a mathematical method named after Rudolf E. Kálmán. Its purpose is to use measurements observed over time, containing noise and other inaccuracies, and produce values that tend to be closer to the true values of the measurements and their associated calculated...
      
      
    • Low-pass filter
      Low-pass filter
      A low-pass filter is an electronic filter that passes low-frequency signals but attenuates signals with frequencies higher than the cutoff frequency. The actual amount of attenuation for each frequency varies from filter to filter. It is sometimes called a high-cut filter, or treble cut filter...
      
      
    • Notch filter
    • Sallen Key filter
      Sallen Key filter
      The Sallen–Key topology is an electronic filter topology used to implement second-order active filters that is particularly valued for its simplicity. It is a degenerate form of a voltage-controlled voltage-source filter topology...
      
      
    • Wiener filter
      Wiener filter
      In signal processing, the Wiener filter is a filter proposed by Norbert Wiener during the 1940s and published in 1949. Its purpose is to reduce the amount of noise present in a signal by comparison with an estimation of the desired noiseless signal. The discrete-time equivalent of Wiener's work was...
      
      
• Transforms
  • Advanced Z-transform
    Advanced Z-transform
    In mathematics and signal processing, the advanced Z-transform is an extension of the Z-transform, to incorporate ideal delays that are not multiples of the sampling time...
    
    
  • Bilinear transform
    Bilinear transform
    The bilinear transform is used in digital signal processing and discrete-time control theory to transform continuous-time system representations to discrete-time and vice versa....
    
    
  • Continuous Fourier transform
    Continuous Fourier transform
    The Fourier transform is a mathematical operation that decomposes a function into its constituent frequencies, known as a frequency spectrum. For instance, the transform of a musical chord made up of pure notes is a mathematical representation of the amplitudes of the individual notes that make...
    
    
  • Discrete cosine transform
    Discrete cosine transform
    A discrete cosine transform expresses a sequence of finitely many data points in terms of a sum of cosine functions oscillating at different frequencies. DCTs are important to numerous applications in science and engineering, from lossy compression of audio and images A discrete cosine transform...
    
    
  • Discrete Fourier transform
    Discrete Fourier transform
    In mathematics, the discrete Fourier transform is a specific kind of discrete transform, used in Fourier analysis. It transforms one function into another, which is called the frequency domain representation, or simply the DFT, of the original function...
    
    , Fast Fourier transform
    Fast Fourier transform
    A fast Fourier transform is an efficient algorithm to compute the discrete Fourier transform and its inverse. "The FFT has been called the most important numerical algorithm of our lifetime ." There are many distinct FFT algorithms involving a wide range of mathematics, from simple...
    
     (FFT)
  • Discrete sine transform
    Discrete sine transform
    In mathematics, the discrete sine transform is a Fourier-related transform similar to the discrete Fourier transform , but using a purely real matrix...
    
    
  • Fourier transform
    Fourier transform
    In mathematics, Fourier analysis is a subject area which grew from the study of Fourier series. The subject began with the study of the way general functions may be represented by sums of simpler trigonometric functions...
    
    
  • Hilbert transform
    Hilbert transform
    In mathematics and in signal processing, the Hilbert transform is a linear operator which takes a function, u, and produces a function, H, with the same domain. The Hilbert transform is named after David Hilbert, who first introduced the operator in order to solve a special case of the...
    
    
  • Laplace transform, Two-sided Laplace transform
    Two-sided Laplace transform
    In mathematics, the two-sided Laplace transform or bilateral Laplace transform is an integral transform closely related to the Fourier transform, the Mellin transform, and the ordinary or one-sided Laplace transform...
    
    
  • Z-transform
    Z-transform
    In mathematics and signal processing, the Z-transform converts a discrete time-domain signal, which is a sequence of real or complex numbers, into a complex frequency-domain representation....
    
    

Telecommunication

• Telephone
  Telephone
  The telephone , colloquially referred to as a phone, is a telecommunications device that transmits and receives sounds, usually the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other...
  
  
• Mobile phone
  Mobile phone
  A mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...
  
  
  • CDMA
  • CDMA2000
    CDMA2000
    CDMA2000 is a family of 3G mobile technology standards, which use CDMA channel access, to send voice, data, and signaling data between mobile phones and cell sites. The set of standards includes: CDMA2000 1X, CDMA2000 EV-DO Rev. 0, CDMA2000 EV-DO Rev. A, and CDMA2000 EV-DO Rev. B...
    
    
  • GSM
• Wireless network
  Wireless network
  Wireless network refers to any type of computer network that is not connected by cables of any kind. It is a method by which homes, telecommunications networks and enterprise installations avoid the costly process of introducing cables into a building, or as a connection between various equipment...
  
  
• Modulation
  Modulation
  In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...
  
  
  • Carrier wave
    Carrier wave
    In telecommunications, a carrier wave or carrier is a waveform that is modulated with an input signal for the purpose of conveying information. This carrier wave is usually a much higher frequency than the input signal...
    
    
• Channel (communications)
  Channel (communications)
  In telecommunications and computer networking, a communication channel, or channel, refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel...
  
  
• Information theory
  Information theory
  Information theory is a branch of applied mathematics and electrical engineering involving the quantification of information. Information theory was developed by Claude E. Shannon to find fundamental limits on signal processing operations such as compressing data and on reliably storing and...
  
  
  • Error correction and detection
• Digital television
  Digital television
  Digital television is the transmission of audio and video by digital signals, in contrast to the analog signals used by analog TV...
  
  
• Digital audio broadcasting
  Digital audio broadcasting
  Digital Audio Broadcasting is a digital radio technology for broadcasting radio stations, used in several countries, particularly in Europe. As of 2006, approximately 1,000 stations worldwide broadcast in the DAB format....
  
  
• Satellite radio
  Satellite radio
  Satellite radio is an analogue or digital radio signal that is relayed through one or more satellites and thus can be received in a much wider geographical area than terrestrial FM radio stations...
  
  
• Satellite
  Satellite
  In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
  
  

See also

• Outline of engineering
• List of electrical engineering topics (alphabetical)
• List of transforms