A Ka-Band Substrate Integrated Suspended Line to Rectangular Waveguide Transition

In this letter, a novel Ka-band transition from substrate integrated suspended line (SISL) to rectangular waveguide (RWG) is proposed. In order to broaden the bandwidth, a T-shaped patch is adopted. A back-to-back transition prototype has been designed and fabricated. From 24.6 to 38.5 GHz, i.e., a fractional bandwidth of 44%, the measured return loss is better than 12 dB and the insertion loss is less than 0.34 dB with a minimum of 0.11 dB. Fabricated by using a standard printed circuit board process, the proposed SISL-to-RWG transition has advantages of low manufacturing cost, compact size, lightweight, and self-packaging.