Low loss low cost microstrip millimeter wave mixers at 94 GHz

In recent years both military (sensors, seekers) and commercial (automotive) millimeter waves applications have emerged which involve mass production. These applications usually require both good performance and very low cost. In this paper we present two types of mixers at 94 GHz, which were specifically designed for low cost with minimal sacrifice in performance. The components are intended for integration in a 94 GHz front end, and thus are constructed in microstrip on 5 mil duroid substrate. A subharmonic mixer operating at 4th LO harmonic and using commercial Ka band anti-parallel diode pair has a conversion loss of 15 dB and a balanced mixer has a net conversion loss of 6 dB. These results are the best reported so far for low cost W-band printed circuit components.