A novel CAT system for millimeter-wave on-wafer measurement

A novel CAT system for millimeter-wave on-wafer measurement of S-parameter and NF has been developed. In the S-parameter test system, we have developed a holder setup for the waveguide T/R modules on a semi-automatic wafer prober so as to connect the T/R module to a probe-head with only a fixed waveguide, which has low insertion loss of no more than 2dB, from 75GHz to 98GHz. We have applied the system to the measurement of a co-planar offset short pattern, and a good agreement between the measured and calculated result has been achieved for both return loss and return phase. Meanwhile, a W-band NF test system, which has system noise of no more than 8dB, has been developed, and on-wafer NF measurement with the accuracy of ±0.3dB has been realized by that system. These test systems realize high-speed automatic MMIC testing up to W-band.