Power-Recycling Microwave Mixer With Wide Linear Instantaneous Bandwidth

A self-embedded power-recycling technique in microwave mixers is proposed and presented for radio frequency (RF) and microwave multiple-input multiple-output (MIMO) systems. The novelty of the proposed power-recycling technique stems from a distinct concept of harnessing direct current (dc) signal rectified by mixing elements in the course of a frequency translation. The large-signal model of a nonlinear mixing element coupled with electromagnetic simulations is used to understand and examine the contribution of the dc signal in the overall transceiver energy efficiency. A single-balanced (SB) diode-switching mixer integrated with a diplexer bank is prototyped using off-the-shelf components to validate the power-recycling technique, which can be extended for an IC implementation. The measurement results show that about 30% of the driving signal power is directly present in the form of a dc signal at the power-recycling port under the maximum conversion efficiency condition. Furthermore, wide linear instantaneous bandwidth performance is shown with a resistive termination of sum–product signal in a downconverter.