LDMOS
Encyclopedia
LDMOS transistors are used in RF/microwave power amplifiers. These transistors are fabricated via an epitaxial silicon layer on a more highly doped silicon substrate.
Such silicon-based FET
s are widely used in power amplifiers for base-stations where the requirement is for high output power with a corresponding drain to source breakdown voltage
usually above 60 volt
s, but have lower maximum power gain frequency compared to other devices such as GaAs
FETs.
Manufacturers of LDMOS devices include TSMC
, Infineon Technologies
, RFMD
, Freescale Semiconductor
, NXP Semiconductors and Polyfet.
Single LDMOS devices suffer from relatively poor efficiency when used in 3G and 4G (LTE) networks, due to the higher peak-to-average power of the waveforms used. The efficiency of LDMOS power amplifiers can be boosted using Doherty or Envelope Tracking
techniques.
Such silicon-based FET
Fet
Fet is a municipality in Akershus county, Norway. It is part of the Romerike traditional region. The administrative centre of the municipality is the village of Fetsund.Fet was established as a municipality on 1 January 1838...
s are widely used in power amplifiers for base-stations where the requirement is for high output power with a corresponding drain to source breakdown voltage
Breakdown voltage
The breakdown voltage of an insulator is the minimum voltage that causes a portion of an insulator to become electrically conductive.The breakdown voltage of a diode is the minimum reverse voltage to make the diode conduct in reverse...
usually above 60 volt
Volt
The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...
s, but have lower maximum power gain frequency compared to other devices such as GaAs
Gaas
Gaas is a commune in the Landes department in Aquitaine in south-western France....
FETs.
Manufacturers of LDMOS devices include TSMC
TSMC
Taiwan Semiconductor Manufacturing Company, Limited or TSMC is the world's largest dedicated independent semiconductor foundry, with its headquarters and main operations located in the Hsinchu Science Park in Hsinchu, Taiwan.-Overview:...
, Infineon Technologies
Infineon Technologies
Infineon Technologies AG is a German semiconductor manufacturer and was founded on April 1, 1999, when the semiconductor operations of the parent company Siemens AG were spun off to form a separate legal entity. , Infineon has 25,149 employees worldwide...
, RFMD
RF Micro Devices
RF Micro Devices is involved in the design and manufacture of high-performance radio frequency systems and solutions for applications that drive wireless and broadband communications....
, Freescale Semiconductor
Freescale Semiconductor
Freescale Semiconductor, Inc. is a producer and designer of embedded hardware, with 17 billion semiconductor chips in use around the world. The company focuses on the automotive, consumer, industrial and networking markets with its product portfolio including microprocessors, microcontrollers,...
, NXP Semiconductors and Polyfet.
Single LDMOS devices suffer from relatively poor efficiency when used in 3G and 4G (LTE) networks, due to the higher peak-to-average power of the waveforms used. The efficiency of LDMOS power amplifiers can be boosted using Doherty or Envelope Tracking
Envelope Tracking
Envelope tracking describes an approach to RF amplifier design in which the power supply voltage applied to the power amplifier is constantly adjusted to ensure that the amplifier is operating at peak efficiency for the given instantaneous output power requirements....
techniques.