Design of stub loaded transmission line matching circuit for series fed patch array

A stub loaded transmission line based matching circuit is designed for the series fed patch array antenna with Dolph-Tschebyshev amplitude tapering at 78.675 GHz. The short-circuited stub loaded transmission line is designed to replace the quarter wave transformer with unrealizably small width. The designed antenna array is matched well at 78.675 GHz. The 10 dB bandwidth is from 78.12 GHz to 79.2 GHz and the co-polarized gain is 9.277 dB.