We have designed a new photomixer using a uni-traveling carrier photodiode (UTC-PD) for generation of W-band radiation. The UTC-PD is integrated on a InP chip with DC and RF circuits and the chip is mounted upside down on a fused quartz substrate which is placed in a microstrip channel across a quarter-height W-band waveguide. A simple cross-shaped microstrip-waveguide transition printed on the quartz substrate is used to couple power into the waveguide. From the simulation it is found that this microstrip-waveguide transition can give better than -15 dB return loss over 75--120 GHz. The UTC-PD is irradiated by combined two lasers from the back side of the InP chip. We have successfully produced difference-frequency radiation at 100 GHz with a power level of 1 mW by the photomixer.
View a pdf version of ALMA Memo 399.
Last modified: 2001-11-19
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