Technique for harmonic minimisation in high-power MMIC antenna switches using load-pull tuners

Abstract

Harmonic suppression in front-end monolithic microwave integrated circuit (MMIC) antenna switches for multi-band mobile phones is critical, and achieving sufficiently low values is challenging to meet. This study presents a novel technique for harmonic minimisation based on harmonically matching the input impedance of the relevant transmit port. It is shown how a load-pull system with an appropriate setup can be used for this purpose. This technique was successfully implemented on a single-pole-four-through switch, and harmonics were significantly reduced to values well below the specifications. Information extracted from the load-pull analysis was then used to design discrete matching networks as part of the application solution in commercial applications.