Abstract: A method and apparatus for frequency and phase error compensation in a synthesized oscillator is presented. A plurality of synthesizers (10, 20, N0) are connected in parallel and coherently combined. Each synthesizer employs a commonly referenced (42) feedback loop controlled oscillating source (12, 22, N2). Each synthesizer utilizes a phase shift detector (14, 24, N4) and in the path of each synthesizer is a time delay (16, 26, N6). The output of each synthesizer is modified by an amplitude control device (18, 28, N8). The plurality of synthesizers is coherently combined (40) at the output. When an internal or external physical event causes a phase or frequency error at the output of the oscillator, the phase and/or frequency error is detected by the phase shift detector. The phase shift detector disables the output of the synthesizer thereby preventing the phase and/or frequency error from propagating to the output of the circuit.