V-band Flip-Chip pHEMT Balanced Power Amplifier with CPWG-MS-CPWG Topology and CPWG Lange Couplers

Abstract

A V-band balanced two-stage power amplifier MMICs with Lange couplers is demonstrated using 0.15 mu m GaAs pHEMT technology in this paper. A CPWG-MS-CPWG topology with via holes at the transistors as the transition between coplanar waveguide with backside ground (CPWG) and microstrip (MS) is employed for the two-stage amplifier. CPWG is applied to realize the flip-chip transition interface for both input and output ports of the amplifier and inter-stage MS matching has the advantage of small size. The structure parameters of the CPWG Lange coupler and matching network are designed and optimized for power combining. Finally, a 60-GHz balanced two-stage power amplifier using a CPWG-MS-CPWG structure delivers the small signal gain of 18 dB, OP1dB of 12 dBm and P-sat of 15 dBm.