Broadband, electrically long vertical waveguideinterconnect

A bandwidth optimised vertical interconnect using a rectangular waveguide to couple two microstrip lines is presented. The electrically long interconnect gives low insertion loss and large bandwidth, in contrast to other indirectly and directly coupled interconnects. Experimental results show < 1.5 dB insertion loss and > 20 dB return loss over a wide bandwidth 8.1 – 10.7 GHz.