LDMOS

LDMOS (laterally-diffused metal-oxide semiconductor)[1] is a planar double-diffused MOSFET (metal–oxide–semiconductor field-effect transistor) used in amplifiers, including microwave power amplifiers, RF power amplifiers and audio power amplifiers. These transistors are often fabricated on p/p+ silicon epitaxial layers. The fabrication of LDMOS devices mostly involves various ion-implantation and subsequent annealing cycles.[1] As an example, The drift region of this power MOSFET is fabricated using up to three ion implantation sequences in order to achieve the appropriate doping profile needed to withstand high electric fields.

The silicon-based RF LDMOS (radio-frequency LDMOS) is the most widely used RF power amplifier in mobile networks,[2][3][4] enabling the majority of the world's cellular voice and data traffic.[5] LDMOS devices are widely used in RF power amplifiers for base-stations as the requirement is for high output power with a corresponding drain to source breakdown voltage usually above 60 volts.[6] Compared to other devices such as GaAs FETs they show a lower maximum power gain frequency.

Manufacturers of LDMOS devices and foundries offering LDMOS technologies include TSMC, LFoundry, Tower Semiconductor, GLOBALFOUNDRIES, Vanguard International Semiconductor Corporation, STMicroelectronics, Infineon Technologies, RFMD, Freescale Semiconductor, NXP Semiconductors, SMIC, MK Semiconductors, Polyfet and Ampleon.

History[edit]

The invention of the metal–oxide–semiconductor field-effect transistor (MOSFET) by Mohamed M. Atalla and Dawon Kahng at Bell Labs in 1959 was a breakthrough in power electronics. Generations of power MOSFETs enabled power designers to achieve performance and density levels not possible with bipolar transistors.[7] In 1969, the DMOS (double-diffused MOSFET) with self-aligned gate was first reported by Y. Tarui, Y. Hayashi and Toshihiro Sekigawa of the Electrotechnical Laboratory (ETL).[8][9]

In 1977, Hitachi introduced the LDMOS, a planar type of DMOS. Hitachi was the only LDMOS manufacturer between 1977 and 1983, during which time LDMOS was used in audio power amplifiers from manufacturers such as HH Electronics (V-series) and Ashly Audio, and were used for music, high-fidelity (hi-fi) equipment and public address systems.[10]

RF LDMOS[edit]

In the early 1990s, RF LDMOS (radio-frequency LDMOS) was introduced, as RF power amplifiers for cellular network infrastructure. They eventually displaced RF bipolar transistors, because RF LDMOS provided superior linearity, efficiency and gain along with lower costs.[11][4] With the introduction of the 2G digital mobile network, LDMOS became the most widely used RF power amplifier technology in 2G and then 3G mobile networks.[2] By the late 1990s, the RF LDMOS had become the dominant RF power amplifier in markets such as cellular base stations, broadcasting, radar, and Industrial, Scientific and Medical band applications.[12] LDMOS has since enabled the majority of the world's cellular voice and data traffic.[5]

In the mid-2000s, RF power amplifiers based on single LDMOS devices suffered from relatively low efficiency when used in 3G and 4G (LTE) networks, due to the higher peak-to-average power of the modulation schemes and CDMA and OFDMA access techniques used in these communication systems. In 2006, the efficiency of LDMOS power amplifiers was boosted using typical efficiency enhancement techniques, such as Doherty topologies or envelope tracking.[13]

As of 2011, RF LDMOS is the dominant device technology used in high-power RF power amplifier applications for frequencies ranging from 1 MHz to over 3.5 GHz, and is the dominant RF power device technology for cellular infrastructure.[11] As of 2012, RF LDMOS is the leading technology for a wide range of RF power applications.[4] As of 2018, LDMOS is the de facto standard for power amplifiers in mobile networks such as 4G and 5G.[3][5]

Applications[edit]

Common applications of LDMOS technology include the following.

RF LDMOS[edit]

Common applications of RF LDMOS technology include the following.

See also[edit]

References[edit]

  1. ^ a b A. Elhami Khorasani, IEEE Electron Dev. Lett., vol. 35, pp. 1079-1081, 2014
  2. ^ a b c d e f Baliga, Bantval Jayant (2005). Silicon RF Power MOSFETS. World Scientific. pp. 1–2. ISBN 9789812561213.
  3. ^ a b c d e f g h i Asif, Saad (2018). 5G Mobile Communications: Concepts and Technologies. CRC Press. p. 134. ISBN 9780429881343.
  4. ^ a b c d e f g h i j k l m n Theeuwen, S. J. C. H.; Qureshi, J. H. (June 2012). "LDMOS Technology for RF Power Amplifiers" (PDF). IEEE Transactions on Microwave Theory and Techniques. 60 (6): 1755–1763. doi:10.1109/TMTT.2012.2193141. ISSN 1557-9670.
  5. ^ a b c d e f g h i j k l m "LDMOS Products and Solutions". NXP Semiconductors. Retrieved 4 December 2019.
  6. ^ van Rijs, F. (2008). "Status and trends of silicon LDMOS base station PA technologies to go beyond 2.5 GHz applications". Radio and Wireless Symposium, 2008 IEEE. Orlando, FL. pp. 69–72. doi:10.1109/RWS.2008.4463430.
  7. ^ "Rethink Power Density with GaN". Electronic Design. 21 April 2017. Retrieved 23 July 2019.
  8. ^ Tarui, Y.; Hayashi, Y.; Sekigawa, Toshihiro (September 1969). "Diffusion Self-Aligned MOST; A New Approach for High Speed Device". Proceedings of the 1st Conference on Solid State Devices. doi:10.7567/SSDM.1969.4-1.
  9. ^ McLintock, G. A.; Thomas, R. E. (December 1972). "Modelling of the double-diffused MOST's with self-aligned gates". 1972 International Electron Devices Meeting: 24–26. doi:10.1109/IEDM.1972.249241.
  10. ^ a b c Duncan, Ben (1996). High Performance Audio Power Amplifiers (PDF). Elsevier. pp. 177–8, 406. ISBN 9780080508047.
  11. ^ a b c "White Paper – 50V RF LDMOS: An ideal RF power technology for ISM, broadcast and commercial aerospace applications" (PDF). NXP Semiconductors. Freescale Semiconductor. September 2011. Retrieved 4 December 2019.
  12. ^ Baliga, Bantval Jayant (2005). Silicon RF Power MOSFETS. World Scientific. p. 71. ISBN 9789812561213.
  13. ^ Draxler, P.; Lanfranco, S.; Kimball, D.; Hsia, C.; Jeong, J.; De Sluis, J.; Asbeck, P. (2006). "High Efficiency Envelope Tracking LDMOS Power Amplifier for W-CDMA". 2006 IEEE MTT-S International Microwave Symposium Digest. pp. 1534–1537. doi:10.1109/MWSYM.2006.249605. ISBN 978-0-7803-9541-1.
  14. ^ a b c "L-Band Radar". NXP Semiconductors. Retrieved 9 December 2019.
  15. ^ a b c d "Avionics". NXP Semiconductors. Retrieved 9 December 2019.
  16. ^ a b c d e f "RF LDMOS Transistors". ST Microelectronics. Retrieved 2 December 2019.
  17. ^ a b c d e f g h i j "ISM & Broadcast". ST Microelectronics. Retrieved 3 December 2019.
  18. ^ a b "RF Cellular Infrastructure". NXP Semiconductors. Retrieved 12 December 2019.
  19. ^ "450 - 1000 MHz". NXP Semiconductors. Retrieved 12 December 2019.
  20. ^ "3400 - 4100 MHz". NXP Semiconductors. Retrieved 12 December 2019.
  21. ^ a b c d "RF Aerospace and Defense". NXP Semiconductors. Retrieved 7 December 2019.
  22. ^ a b "Communications and Electronic Warfare". NXP Semiconductors. Retrieved 9 December 2019.
  23. ^ "1-600 MHz – Broadcast and ISM". NXP Semiconductors. Retrieved 12 December 2019.
  24. ^ a b c Torres, Victor (21 June 2018). "Why LDMOS is the best technology for RF energy". Microwave Engineering Europe. Ampleon. Retrieved 10 December 2019.
  25. ^ a b c d e f g "Mobile & Wideband Comms". ST Microelectronics. Retrieved 4 December 2019.
  26. ^ "RF Cellular Infrastructure". NXP Semiconductors. Retrieved 7 December 2019.
  27. ^ a b "RF Mobile Radio". NXP Semiconductors. Retrieved 9 December 2019.
  28. ^ a b "S-Band Radar". NXP Semiconductors. Retrieved 9 December 2019.
  29. ^ a b "915 MHz RF Cooking". NXP Semiconductors. Retrieved 7 December 2019.
  30. ^ a b c "RF Defrosting". NXP Semiconductors. Retrieved 12 December 2019.
  31. ^ "HF, VHF and UHF Radar". NXP Semiconductors. Retrieved 7 December 2019.

External links[edit]