Measurements of millimeter wave test structures for high speed chip testing

This paper presents the frequency domain characterization of very high bandwidth connectorized traces and a millimeter wave rat race coupler. These connectorized differential grounded coplanar waveguide traces, essential for the testability of high speed integrated circuits, have a measured flat frequency response up to 67 GHz which indicates correct connector footprint and transmission line design. The differential traces narrow down to a chip scale pitch of 150 μm allowing direct flip chip connections. This enabling the testing of millimeter wave integrated circuits without the need for probing. Furthermore, a 50 GHz rat race coupler was fabricated to generate a differential clock from a single ended clock source.