Rectangular waveguide to coplanar stripline transition based on a unilateral finline

Abstract

In this paper we present a wideband rectangular waveguide to coplanar stripline (WG-to-CPS) transition that spans the frequency range 52–89 GHz. The transition has a relative bandwidth of about 52 % with respect to 15 dB return loss and an insertion loss in the range of 0.3–1 dB. The transition is based on a unilateral finline and it can be employed in other frequency bands as well. The transition converts the TE <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</inf> dominant mode to a differential CPS mode and has a negligible coupling to the common mode. Several samples were fabricated and measured over the V-band and W-band. The comparison between simulation and measurement results demonstrates a good agreement.