Measurement of Admittances of Microwave Oscillators with Injection Locking

A new method of measuring admittances of microwave oscillators is proposed. In a usual method, changes of the output power of the oscillator and the oscillation frequency are measured by varying the admittance of a passive load. However, in a new method the variable passive load is replaced by an isolator and another oscillator (a signal generator) and even a positive admittance of the oscillator can be measured. A measurable range by this method is also discussed compared with that by the usual method.