Intermediate matching cascode core를 이용한 H-band 광대역 증폭기 설계

Abstract

This paper discusses the design of fourth order filters, suitable for THz-Wave broadband power amplifiers (PAs) in compound semiconductor process. One key issue of the PA is the ability to handle fractional bandwidths in the order of 20%, for achieving large data rates. Conventional LC matching networks are not suitable for THz wideband amplifier designs where available device gain is relatively low, as bandwidth has a tradeoff with power gain. In this work, we exploit inter-stage coupling realizing fourth-order filters where wide bandwidth is achieved at the expense of in-band gain ripple only. In this paper, inter-stage matching using a capacitively coupled resonator is examined and a design formula is provided. Experiments performed on TSC 250 nm InP DGBT prototypes provide: 5.5 dBm maximum saturated power at 275 GHz, a small-signal gain of 23 dB with 3dB bandwidth of 42 GHz while consuming 84 mW.