A W-Band Amplifier with a New Wide-Band Interstage Matching Technique Using Self-Resonance of a Microstrip-Coupled Line.

A new interstage matching technique is presented for design of a wide-band multi-stage amplifier using commercial 60 nm GaN-on-silicon technology in the W-band. The proposed interstage matching network is designed as a two-pole conjugated impedance matching approach for wideband characteristics using low-characteristic impedance transmission lines and an optimized microstrip-coupled line. In particular, the microstrip-coupled line provides strong resonance at the desired frequency, enabling optimal conjugate impedance matching of both edge and intermediate frequencies simultaneously. The implemented W-band three-stage amplifier using the proposed interstage matching technique exhibited a small-signal gain above 14.1 dB from 75 to 103 GHz. Also, the output power between 92-100 GHz was greater than 25 dBm, and the maximum output power at 96 GHz was 25.8 dBm. The W-band amplifier was designed with an area of 2 mm $\times1.2$ mm.