A GaAs IC broadband variable ring oscillator and arbitrary integer divider

A monolithic broadband variable ring oscillator is described. The single GaAs IC performs as a broadband variable ring oscillator and arbitrary integer frequency divider. The oscillator, a ring of inverters with a variable delay feature, covers two octaves in the 0.4-1.6-GHz range. The oscillator tuning range can be increased by extending the basic topology. A provision for external signal injection permits injection locking. Frequency division was achieved with a selectable arbitrary division ratio by tuning the oscillator to near the desired submultiple of the input signal. Spurious-free output with a constant amplitude was maintained independently of the divide ratio.<>