A V-Band Power Amplifier With Integrated Wilkinson Power Dividers-Combiners and Transformers in 0.18- $\mu$ m SiGe BiCMOS

A high output power fully integrated V-band power amplifier (PA) is developed using a 0.18-μm SiGe BiCMOS technology. The developed PA makes use of four-way parallel power dividing and combining structures to feed and combine powers from four identical unit-PA cells, respectively. Especially, the parallel power combiner and divider are developed by integrating a low-loss wideband Wilkinson structure and two transformers connected in parallel, which achieve broad bandwidth and minimum phase and amplitude mismatches between ports. The unit-PA is designed as a pseudo-differential two-stage cascode amplifier, which employ transformers for both matching and impedance transformation. The PA achieves measured broadband small-signal gain of 19 dB at 60 GHz and 3-dB bandwidth of 56.8-67.5 GHz, which encompasses the overall unlicensed Vband spectrum (57-64 GHz). In addition, it delivers 18.8 dBm of saturated output power and 15.3 dBm of output 1-dB compressed power at 60 GHz. Across 55 to 65 GHz, the PA achieves a very flat power performance with maximum output power between 17-19.1 dBm.