Abstract
A high-power digital transmitter (DTX) concept, targeting future low-cost, highly-integrated and energy-efficient mMIMO base stations, is presented. The proposed approach bridges the 'historical' gap between low-voltage high-speed digital and high-voltage high-power RF devices. The resulting combination allows for a complete replacement of the traditional TX line-up, which includes signal-generation, up-conversion, and analog pre-drivers and power amplifier (PA), as such, facilitating drastic energy savings. The DTX principles are demonstrated by a dual TX line-up implemented in a dedicated VT-shifted LDMOS technology. Each 11-bit DTX line-up features 15 thermometer and 7 binary-weighted LDMOS output-stage segments, which are individually controlled by digital logic and high-speed drivers implemented in 40 nm CMOS technology. The realized DTX prototype exploits a 2.1 GHz centered class-BE output matching network and provides, at 20 V drain supply, 18.5 W (CW) output power with 66.7 % drain and 60.4 % system efficiencies. The suitability of the concept to handle modulated signals is demonstrated for a two-tone signal (Δf = 80 kHz), yielding an 1M3 < -51.4dBc and a 10MHz 256-QAM signal, achieving an ACLR of -46.1 dBc and 1.2 % EVM.
Original language | English |
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Title of host publication | 2020 IEEE/MTT-S International Microwave Symposium (IMS) |
Place of Publication | Los Angeles, CA, USA, USA |
Publisher | Institute of Electrical and Electronics Engineers (IEEE) |
Chapter | Th1G |
Pages | 1113-1116 |
Number of pages | 4 |
Volume | 2020 |
ISBN (Electronic) | 978-1-7281-6815-9 |
ISBN (Print) | 978-1-7281-6816-6 |
DOIs | |
Publication status | Published - Aug 2020 |
Event | IMS 2020: International Microwave Symposium - Los Angeles, United States Duration: 21 Jun 2020 → 26 Jun 2020 |
Conference
Conference | IMS 2020: International Microwave Symposium |
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Abbreviated title | IMS 2020 |
Country/Territory | United States |
City | Los Angeles |
Period | 21/06/20 → 26/06/20 |
Bibliographical note
Virtual/online event due to COVID-19Keywords
- digital transmitter
- CMOS RFIC
- LDMOS
- polar transmitter
- digital pre-distortion (DPD)
- power RFDAC
- digital power amplifier
- efficiency