Ultra-broadband Nonlinear Microwave Monolithic Integrated Circuits in SiGe, GaAs and InP

Analog MMIC circuits with ultra-wideband operation are discussed in view of their frequency limitation and different circuit topologies. Results for designed and fabricated frequency converters in SiGe, GaAs, and InP technologies are presented in the paper. RF type circuit topologies exhibit a flat conversion gain with a 3 dB bandwidth of 10 GHz for SiGe and in excess of 20 GHz for GaAs processes. The concurrent LO-IF isolation is better than -25 dB, without including the improvement due to the combiner circuit. The converter circuits exhibit similar instantaneous bandwidth at IF and RF ports of >7.5 GHz and >10 GHz for SiGe BiCMOS and GaAs MMIC, respectively. Analysis of the frequency behaviour of frequency converting devices is presented for improved mixer design. Millimeter-wave front-end components for advanced microwave imaging and communications purposes have also been demonstrated. Analysis techniques and novel feedback schemes show improvement to the traditional circuit design. Subharmonic mixer measurements at 50 GHz RF signal agree very well with simulations, which manifests the broadband operating properties of these circuits.