NONLINEAR DESIGN OF MULTIPLE-CAVITY SWITCHABLE DIELECTRIC-RESONATOR OSCILLATORS

The application of nonlinear CAD techniques to the design of multiple- cavity dielectric-resonator oscillators is demonstrated. The circuit t opology consists of an FET oscillator which can be coupled to one of s everal dielectric resonators by means of a diode switching network. Th e circuit is numerically designed as a whole making use of a novel bro adband optimisation technique especially devised for autonomous nonlin ear circuits. At each fundamental frequency of interest the steady sta te of oscillation is determined by harmonic-balance analysis, and at t he same time the oscillator is tuned to the prescribed frequency by ch anging a parameter of the corresponding resonator. The electrical perf ormance is simultaneously specified at all the fundamentals, and the o ptimisation is carried out with respect to the circuit parameters of t he frequency-invariant part of the network.