Reduced spurious signals in an injection-locked oscillator by using combining technique

An injection-locked oscillator technique has been used in order to improve phase noise in the oscillating signal. A single-ended injection-locked oscillator in subharmonic mode provides the unwanted signals due to the nonlinear properties. These unwanted signals can be suppressed by using power combiner technique. A cascaded oscillator using power combining technique was tested. As a result, it is found that the spurious signals caused by the injection locking phenomenon in subharmonic mode reduce by more than 25 dB