75 GHz InP HBT distributed amplifier with record figures of merit and low power dissipation for OEIC applications

We present an InP HBT distributed amplifier with a bandwidth of 75 GHz, gain of 14 dB, and power consumption of 78 mW. The HBTs had a 600 nm thick collector, and hence relatively low f_T and f_MAX of 84 GHz and 150 GHz respectively. The thick collector is a tradeoff required in optoelectronic integrated receivers, in which the PIN diode layers are the same as the base collector layers. To obtain high PEN diode responsivity, the collector layer needs to be thicker than in optimized HBTs. The amplifier topology comprises an emitter follower at the input and a cascode stage, with a resistor and inductance at the emitter follower output, and a peaking line between the HBTs in the cascode stage. The amplifier exhibits matching at the input better than -10 dB up to 85 GHz. The chip contains 16 HBTs and it size is 1.7mm times 0.9 mm