A Very High-Order Subharmonically Injection-Locked Oscillator Using a Resonant-Tunneling HEMT

Abstract

A novel high-order subharmonically injection-locked oscillator (ILO) using a resonant-tunnelingHEMT (RTHEMT) is presented. Due to the strong nonlinear characteristic of RTHEMT's, the monolithic ILO can be locked for higher-ordersubharmonics as highas 128. The ILO exhibits an adjacent spur levelas low as -30 dBc for all subharmonic factors. In addition, the degradation rate of phase noise against subharmonic factors is close to 6 dB/octave, the same as that ofideal frequency multipliers. This is the highest-order subharmonically injection-locked oscillator yet reported.