90-nm CMOS for microwave power applications

We report, for the first time, the experimental evaluation of a very short channel 90-nm CMOS transistor under RF over-voltage conditions. At 9 GHz and 1.5 V supply a 40 μm gate width device is able to deliver 370 mW/mm output power with a PAE of 42% and a transducer power gain of 15 dB. Measurement results at 3 and 6 GHz is also presented. The transistor does not show any degradation in either dc or RF performance after prolonged operation at 1 and 6 dB compression. Simulation show, that the peak voltage, V/sub ds/ at this condition is 3.0 V, while the maximum allowed dc supply voltage is limited by the design rules to 1.2 V. We show for the first time that nanometer-scale CMOS can be used for microwave power applications with severe RF over-voltage conditions without any observable degradation.