V-band Six-Port Down-conversion Techniques

This paper presents comparative down-conversion results using two different topologies. The conventional approach using anti-parallel diodes acting as LO-driven switches is compared with the six-port one. The proposed down-converter which provides an intermediate frequency of 900 MHz uses a six-port circuit and two pairs of parallel Schottky diodes acting as power detectors connected to two differentials amplifiers. Simulation results of down-converter passive circuits in terms of I/Q IF power and phase are presented and discussed. In addition, comparative analyses are performed in terms of local oscillator and RF power required for the frequency conversion and phase stability. These results show the advantages of the proposed frequency conversion six-port technique.