A 90 GHz Broadband Balanced 8-Way Power Amplifier for High Precision FMCW Radar Sensors in 65-nm CMOS

Abstract

We present a W-band 8-way wideband power amplifier (PA) for a high precision frequency modulated continuous wave (FMCW) radar in 65-nm CMOS technology. To achieve a broadband operation with an improved output power for a high range resolution and high distance coverage of FMCW radar sensors, a balanced architecture is employed with the Lange coupler which naturally combines the output powers from two 4-way push-pull PAs. By utilizing a transformer-based push-pull structure with a cross-coupled capacitive neutralization technique, the gate-drain capacitance of the 4-way PA is compensated for the stabilization with an improved power gain. Interstage matching was performed with transformers for a reduced loss from the matching network and minimal area occupation. The implemented balanced 8-way PA achieved a saturated output power (Psat) of 16.5 dBm, a 1-dB compressed output power (OP1dB) of 13.3 dBm, a power-added efficiency (PAE) of 9.9% at 90 GHz and 3-dB power bandwidth was 20.4 GHz (79.2–99.6 GHz).

Catalyzing satellite communication: A 20W Ku-Band RF front-end power amplifier design and deployment

“…Meanwhile, owing to challenges in current PA research, particularly around modular design, researchers have proposed various new ideas and approaches, such as the design concept of the combination of discrete and integrated modules. These approaches can enhance the balance of power amplification, matching, and stability considerations [ 32 – 36 ]. Research on low-noise techniques and modulation approaches for PAs has also garnered significant attention [ 37 – 40 ].…”