A Wideband Contactless CPW to $W$ -Band Waveguide Transition

A wideband, contactless, coplanar waveguide (CPW) to rectangular waveguide transition integrated with an
$E$
-plane bend at a
${W}$
-band is proposed. The transition utilizes a four-step Chebyshev ridge waveguide impedance transformer and a
$\lambda _{g}$
/4 matching stub over the quartz CPW to ensure the wider impedance matching and to maintain a good electrical contact, without any soldering or gluing. The novel transition has a simple structure and a low insertion loss. The back-to-back prototype is fabricated and measured, and the measured reflection coefficient remains better than −10-dB over the entire
${W}$
-band, while the insertion loss is on average 1.2 dB in the range of 80–109 GHz (31.5% bandwidth). Also, the design is fully scalable to any other frequency band of interest.