A Subharmonic Injection-Locked Self-Oscillating Mixer

Abstract

A subharmonic injection-locked self-oscillating mixer (s-ILSOM) at 1 GHz is reported in this paper. The proposed circuit which combines both injection-locking and mixing functions is described theoretically and experimentally. In contrast to previously reported works, only one input port is required for both the RF/IF signal and the injection signal. Furthermore, the injection signal which is used to stabilize the oscillation is at a subharmonic of the oscillation frequency (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LO</sub> /4), with a power level as low as -20 dBm. Phase noise calculations and mixing characteristics are reported, indicating a noise improvement, and a high up-conversion gain for both fundamental and harmonic mixing. The circuit is implemented, using a GaAs FET, exhibiting an up-conversion gain of 13 dB, a phase noise of -93 dBc/Hz at 100 KHz offset, a P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub> of -18 dBm, an IP3 of -5 dBm, and a power consumption of 24 mW.