Waveguide-to-coax-to-microstrip transitions for millimeter-wave monolithic circuits

It is believed that the single-sided, planar, monolithic circuit chip employing quasi-TEM transmission lines and semiconductor devices represents the future of developments in the microwave frequency range, and that it may also have a similar importance for the millimeter-wave frequency range up to a few hundred gigahertz. Methods are, however, needed for gaining access to the small circuits in order to test them. Attention is given to transitions which have been developed to go from a WR10 waveguide to UT-20 coaxial cable. The transitions are used over the full 75 to 110 GHz band. The UT-20 coax transitions to microstrip on the monolithic chip. The chip thickness being employed is 50 microns (0.002 in.). The monolithic circuits which are being designed for use on this substrate thickness are all octave bandwidth designs for 75 to 150 GHz operation.