MM-Wave Super Harmonic Injection Locked Frequency Dividers

This paper describes the design of a mm-wave super-harmonic injection locked (SHIL) analogue frequency divide-by-2 circuit. The technique exploits the case whereby a saturated amplifier can become unstable and oscillate at exactly half the input frequency. This particular design example operates at an input frequency of 35 GHz, but the technique is viable to frequencies approaching the Fmax of the amplifier transistor.