A 70-GHz Bandwidth and 9-dB Gain Travelling Wave Amplifier Using 0.15-μm Gate InGaP/InGaAs HEMTs with Coplanar Transmission Line Technology

We developed a technique to reduce gain variations over a wide frequency range for an ultra-broadband travelling wave amplifier (TWA) that employs a cascode configuration using 0.15-μm gate InGaP/InGaAs HEMTs. Using this technique, we achieved gain variations within 1.5 dB for frequencies up to 70 GHz with a 9-dB gain. The agreement of measured S-parameters with simulated results demonstrates that the proposed technique is suitable for broadband amplifier design.