A compact and low-radiation CPW probe pad using CBCPW-to-microstrip transitions for V-band LTCC applications

Abstract

In this paper, a compact and low-radiation coplanar waveguide lines (CPW) probe pad using vialess conductor-backed coplanar waveguide (CBCPW)-to-microstrip transitions is presented for V-band low-temperature cofired ceramic (LTCC) applications. To reduce the radiation loss due to open-end and transition discontinuities, a vialess CBCPW structure with a edge cut back is proposed. The back pad and an optimum transition length suppress the radiation loss of the standard CPW probe pad by 30% and 10%, respectively, compared to a conventional vialess transition. In particular, at 66 GHz, radiation is completely suppressed for the proposed transition and its insertion loss is -0.15 dB at that frequency.