New Technique for Synthesizing Concurrent Dual-Band Impedance-Matching Filtering Networks and ${\hbox{0.18-}}\mu{\hbox {m}}$ SiGe BiCMOS 25.5/37-GHz Concurrent Dual-Band Power Amplifier

New technique for synthesizing concurrent dual-band impedance-matching filtering networks is presented. The technique enables the design of concurrent dual-band impedance-matching filtering networks that provide not only simultaneous matching of two arbitrary loads to two arbitrary sources at two different frequencies, but also dual-bandpass filtering response capable of suppressing unwanted signals like the harmonics and inter-modulation products in nonlinear circuits, such as power amplifiers (PAs). A new 0.18-μm SiGe BiCMOS concurrent dual-band PA was designed based on the developed dual-band matching filtering technique around 25.5 and 37 GHz, which works in the concurrent dual-band mode (25.5 and 37 GHz), as well as single-band mode (25.5 or 37 GHz). The measured results show that, in the single-band mode, the dual-band PA exhibits gain of 21.4 and 17 dB, maximum output power of 16 and 13 dBm, and maximum power-added efficiency (PAE) of 10.6% and 4.9% at 25.5 and 37 GHz, respectively. In the dual-band mode, the maximum output power is 13 and 9.5 dBm at 25.5 and 37 GHz, respectively, and the total maximum PAE is 7.1%. The designed concurrent dual-band PA has a chip size of 1.3×0.68 mm2 and consumes a dc current of 120 mA from a 3-V supply voltage.