Patent ID: 8487710

Claim:
A pulse width modulator comprising: a first rotary traveling wave oscillator oscillating at a predetermined frequency and having an oscillator signal at a first output tap and a feedback tap with a first phase; a second rotary traveling wave oscillator oscillating at a second frequency and having an oscillator signal at a second output tap and a feedback tap with a second phase; a voltage controlled capacitance device, receiving a voltage control signal that alters the capacitance of said device, said device connected to the second rotary traveling wave oscillator such that the capacitance of said device affects the frequency and phase of said second oscillator; a phase detector that connects to the feedback taps from the first and second rotary traveling wave oscillators to determine any difference between the first phase and the second phase; a time-to-voltage converter that converts any difference from the phase detector into a voltage; an error amplifier that receives the voltage output of the time-to-voltage converter and an external input voltage to generate an error signal; a low pass filter that filters the error signal from the error amplifier to generate the voltage control signal that tends to make the second frequency substantially the same as the predetermined frequency and the second phase adjustably offset from the first phase; and a pulse width device that combines the oscillator signal at the first output tap and the oscillator signal at the second output tap to create a pulse whose width is a function of the input voltage.