The
sensitivity of an electronic device, such as a
communications systemIn telecommunication, a communications system is a collection of individual communications networks, transmission systems, relay stations, tributary stations, and data terminal equipment usually capable of interconnection and interoperation to form an integrated whole...
receiver, or
detectionIn general, detection is the extraction of particular information from a larger stream of information without specific cooperation from or synchronization with the sender....
device, such as a
PIN diodeA PiN diode is a diode with a wide, lightly doped 'near' intrinsic semiconductor region between a p-type semiconductor and an n-type semiconductor regions. The p-type and n-type regions are typically heavily doped because they are used for ohmic contacts....
, is the minimum
magnitudeThe magnitude of a mathematical object is its size: a property by which it can be compared as larger or smaller than other objects of the same kind; in technical terms, an ordering of the class of objects to which it belongs....
of
inputInput is the term denoting either an entrance or changes which are inserted into a system and which activate/modify a process. It is an abstract concept, used in the modeling, system design and system expwdlfhaslfnasl'fnsfasnfloitation...
signal required to produce a specified
outputOutput is the term denoting either an exit or changes which exit a system and which activate/modify a process. It is an abstract concept, used in the modeling, system design and system exploitation.-In control theory:...
signal having a specified
signal-to-noise ratioSignal-to-noise ratio is an electrical engineering measurement, also used in other fields , defined as the ratio of a signal power to the noise power corrupting the signal...
, or other specified criteria.
Sensitivity is sometimes improperly used as a synonym for
responsivityResponsivity measures the input–output gain of a detector system. For a system that responds linearly to its input, there is a unique responsivity. For nonlinear systems, the responsivity is the local slope ....
.
MicrophoneA microphone, colloquially called a mic or mike , is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. In 1876, Emile Berliner invented the first microphone used as a telephone voice transmitter...
s
- The sensitivity of a microphone
A microphone, colloquially called a mic or mike , is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. In 1876, Emile Berliner invented the first microphone used as a telephone voice transmitter...
is usually expressed as the soundSound is a travelling wave which is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.- Perception of sound...
field strengthIn physics, the field strength of a field is the magnitude of its vector value.In theoretical physics, field strength is another name for the curvature form...
in decibelThe decibel is a logarithmic unit of measurement that expresses the magnitude of a physical quantity relative to a specified or implied reference level. Since it expresses a ratio of two quantities with the same unit, it is a dimensionless unit...
s (dB) relative to 1 VThe volt is the SI derived unit of electromotive force, commonly called "voltage". It is also the unit for the related but slightly different quantity electric potential difference...
/PaThe pascal is the SI derived unit of pressure, stress, Young's modulus and tensile strength. It is a measure of force per unit area, defined as one newton per square metre...
(Pa = N/m2) or as the transfer factor in millivolts per pascalThe pascal is the SI derived unit of pressure, stress, Young's modulus and tensile strength. It is a measure of force per unit area, defined as one newton per square metre...
(mV/Pa) into an open circuitThe term Open circuit may refer to:*Open-circuit voltage, the difference of electrical potential between two terminals of a device when there is no external load connected...
or into a 1 kilohm load.
LoudspeakerA loudspeaker is an electroacoustic transducer that converts an electrical signal into sound. The speaker pulses in accordance with the variations of an electrical signal and causes sound waves to propagate through a medium such as air or water.Loudspeakers are the most variable elements in a...
s
- The sensitivity of a loudspeaker
A loudspeaker is an electroacoustic transducer that converts an electrical signal into sound. The speaker pulses in accordance with the variations of an electrical signal and causes sound waves to propagate through a medium such as air or water.Loudspeakers are the most variable elements in a...
is usually expressed as dB / 2.83 VRMS at 1 meter.
The
sensitivity of an electronic device, such as a
communications systemIn telecommunication, a communications system is a collection of individual communications networks, transmission systems, relay stations, tributary stations, and data terminal equipment usually capable of interconnection and interoperation to form an integrated whole...
receiver, or
detectionIn general, detection is the extraction of particular information from a larger stream of information without specific cooperation from or synchronization with the sender....
device, such as a
PIN diodeA PiN diode is a diode with a wide, lightly doped 'near' intrinsic semiconductor region between a p-type semiconductor and an n-type semiconductor regions. The p-type and n-type regions are typically heavily doped because they are used for ohmic contacts....
, is the minimum
magnitudeThe magnitude of a mathematical object is its size: a property by which it can be compared as larger or smaller than other objects of the same kind; in technical terms, an ordering of the class of objects to which it belongs....
of
inputInput is the term denoting either an entrance or changes which are inserted into a system and which activate/modify a process. It is an abstract concept, used in the modeling, system design and system expwdlfhaslfnasl'fnsfasnfloitation...
signal required to produce a specified
outputOutput is the term denoting either an exit or changes which exit a system and which activate/modify a process. It is an abstract concept, used in the modeling, system design and system exploitation.-In control theory:...
signal having a specified
signal-to-noise ratioSignal-to-noise ratio is an electrical engineering measurement, also used in other fields , defined as the ratio of a signal power to the noise power corrupting the signal...
, or other specified criteria.
Sensitivity is sometimes improperly used as a synonym for
responsivityResponsivity measures the input–output gain of a detector system. For a system that responds linearly to its input, there is a unique responsivity. For nonlinear systems, the responsivity is the local slope ....
.
MicrophoneA microphone, colloquially called a mic or mike , is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. In 1876, Emile Berliner invented the first microphone used as a telephone voice transmitter...
s
- The sensitivity of a microphone
A microphone, colloquially called a mic or mike , is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. In 1876, Emile Berliner invented the first microphone used as a telephone voice transmitter...
is usually expressed as the soundSound is a travelling wave which is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.- Perception of sound...
field strengthIn physics, the field strength of a field is the magnitude of its vector value.In theoretical physics, field strength is another name for the curvature form...
in decibelThe decibel is a logarithmic unit of measurement that expresses the magnitude of a physical quantity relative to a specified or implied reference level. Since it expresses a ratio of two quantities with the same unit, it is a dimensionless unit...
s (dB) relative to 1 VThe volt is the SI derived unit of electromotive force, commonly called "voltage". It is also the unit for the related but slightly different quantity electric potential difference...
/PaThe pascal is the SI derived unit of pressure, stress, Young's modulus and tensile strength. It is a measure of force per unit area, defined as one newton per square metre...
(Pa = N/m2) or as the transfer factor in millivolts per pascalThe pascal is the SI derived unit of pressure, stress, Young's modulus and tensile strength. It is a measure of force per unit area, defined as one newton per square metre...
(mV/Pa) into an open circuitThe term Open circuit may refer to:*Open-circuit voltage, the difference of electrical potential between two terminals of a device when there is no external load connected...
or into a 1 kilohm load.
LoudspeakerA loudspeaker is an electroacoustic transducer that converts an electrical signal into sound. The speaker pulses in accordance with the variations of an electrical signal and causes sound waves to propagate through a medium such as air or water.Loudspeakers are the most variable elements in a...
s
- The sensitivity of a loudspeaker
A loudspeaker is an electroacoustic transducer that converts an electrical signal into sound. The speaker pulses in accordance with the variations of an electrical signal and causes sound waves to propagate through a medium such as air or water.Loudspeakers are the most variable elements in a...
is usually expressed as dB / 2.83 VRMS at 1 meter. This is not the same as the electrical efficiencyThe efficiency of an entity in electronics and electrical engineering is defined as useful power output divided by the total electrical power consumed , typically denoted by the Greek letter small Eta .- Efficiency of typical electrical devices :Efficiency should not be confused with...
; see Efficiency vs Sensitivity.
HydrophoneNot to be confused with hydraulophone, a musical instrument.A hydrophone is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates electricity when subjected to a pressure change...
s
- The sensitivity of a hydrophone
Not to be confused with hydraulophone, a musical instrument.A hydrophone is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates electricity when subjected to a pressure change...
is usually expressed as dB re 1 V/µPa.
Sensitivity in a receiver is normally defined as the minimum input signal required to produce a specified signal-to-noise S/N ratio at the output port of the receiver and is defined as the mean noise power at the input port of the receiver times the minimum required signal-to-noise ratio at the output of the receiver:
where
= sensitivity [W]
k
= Boltzmann's constant = equivalent noise temperature in [K] of the source (e.g. antenna) at the input of the receiver = equivalent noise temperature in [K] of the receiver referred to the input of the receiver
B
= bandwidth [Hz] = Required SNR at output [-]
Because receive sensitivity indicates how faint an input signal can be successfully received by the receiver, the lower power level, the better. Lower power for a given S/N ratio means better sensitivity since the receiver's contribution is smaller. When the power is expressed in dBm the larger the absolute value of the negative number, the better the receive sensitivity. For example, a receiver sensitivity of -98
dBmFor other uses, see DBM dBm is an abbreviation for the power ratio in decibels of the measured power referenced to one milliwatt . It is used in radio, microwave and fiber optic networks as a convenient measure of absolute power because of its capability to express both very large and very small...
is better than a receive sensitivity of -95 dBm by 3 dB, or a factor of two. In other words, at a specified data rate, a receiver with a -98 dBm sensitivity can hear signals that are half the power of those heard by a receiver with a -95 dBm receiver sensitivity.
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