A 20-dB gain W-band InP DHBT power amplifier

A two-stage double heterojunction bipolar transistor (DHBT) power MMIC fabricated in InP technology is realized using coplanar waveguide structure. The output cell unit consists of four parallel cascode fingers. Sixteen fingers are at output stage from which the power is combined. Broad-band, low-loss matching networks lead to high gain and high combining efficiency. The chip area is 1.5×1.7 mm². Measurements show that small signal gain is above 20 dB over 75.5 GHz ~ 84.5 GHz frequency band. Simulated saturated power is 19.7 dBm @ 89 GHz and the actual output power is to be measured once the W-band power source arrive.