V-Band Solid-State Power Amplifiers for SATCOM Downlinks

TECHNOLOGY AREA(S): Space Platforms
OBJECTIVE: Develop linear-efficient V-band solid-state power amplifiers for high-data-rate communication downlinks.
DESCRIPTION: Linear, efficient 71-76 GHz downlink solid-state power amplifiers (SSPAs) are required to meet future millimeter-wave satellite communications (satcom) transmit power requirements. This new frequency spectrum will support advanced high-data-rate satcom concepts. Although solid-state transistor, circuit, and power combiner technologies have demonstrated the potential to meet V-band power and linearity requirements, amplifier power-added efficiency goals have proven more challenging. Approaches for linear-efficient V-band solid-state power performance should address both improved, innovative high-performance millimeter-wave transistor approaches and low-loss power combiner approaches. The SSPA should address the following challenging performance goals. The amplifier’s linearity should support adjacent channel power ratios and intermodulation distortion consistent with 16 Quadrature Amplitude Modulation (QAM) operation for a power-combined output power greater than 30 watts with power-added efficiency greater than 30%. Additional goals include an operating temperature range of -40 degrees to +85 degrees Celsius, as well as power gain greater than 20 dB and power gain variation less than ±1 dB across the 71-76 GHz band (5 GHz bandwidth). The selected solid-state power amplifier approach should support reliable space operation and operation in radiation environments. Radiation hardening goals include greater than 1 Mrad total dose radiation tolerance.
PHASE I: Concept design and circuit simulations of the linear-efficient 71-76 GHz microwave monolithic integrated circuit (MMIC) power amplifier based on a suitable, high-performance millimeter-wave transistor process, as well as the integrated design of the power-combined SSPA.
PHASE II: Fabrication of the linear-efficient prototype power amplifiers (MMICs, power combiner, integrated SSPA) according to the Phase I design. Characterization of the MMICs, combiner and SSPA for linearity, output power, and efficiency under typical signal and environmental conditions.
PHASE III: Military: Military high power amplifier applications include V-band communications downlink electronics for future V/W-band downlink/uplink high-data-rate satcom concepts. Commercial: Commercial V-band high power amplifier applications include ground/airborne/space electronics where millimeter-wave power sources are required. Technologies and methodologies under this effort will further benefit commercial communication networks in nearby frequency bands.
REFERENCES: 1: K. Tsukashima, et al., An E-band 1 W-class PHEMT Power Amplifier MMIC, Microwave Integrated Circuits Conference Digest, 2015 10th European Microwave Integrated Circuits Conference.2: A. Brown, et al., High Power, High Efficiency E-Band GaN Amplifier MMICs, Wireless Information and Systems Digest, 2012 IEEE International Conference on Wireless Information Technology and Systems.KEYWORDS: V-band, Solid-state Power Amplifier, Power-added Efficiency, Satellite Communications
CONTACT(S):
Lois Kehias (AFRL/RY)
(937) 713-8702
lois.kehias@us.af.mil