Automatic quadrature network with phase and amplitude detection

摘要

An automatic quadrature network with amplitude and phase detection produces quadrature signals for an input oscillator signal, the quadrature signals being equal in amplitude and having ideal quadrature phase between them. An RC circuit provides one quadrature path, and a CR circuit provides another quadrature path. The outputs from the RC/CR circuits are amplitude detected to produce an amplitude control signal. The outputs also are amplitude limited, and the phase between the limiter outputs is detected to produce a phase control signal. The amplitude and phase control signals are combined to generate respective control signals for the RC/CR circuits to automatically align them so that the quadrature signals are of equal amplitude and ideal quadrature phase.

主权项

1. An automatic quadrature network that produces a pair of output quadrature signals having equal amplitude and ideal phase quadrature for a desired frequency signal comprising:
a pair of quadrature signal paths having the desired frequency signal as an input to produce a pair of interim quadrature signals at respective outputs; means for detecting respective amplitudes of the interim quadrature signals to produce an amplitude control signal; means for detecting a phase difference between the interim quadrature signals to produce a phase control signal; means for combining the amplitude and phase control signals to produce respective quadrature control signals; and means for aligning the pair of quadrature signal paths using the respective quadrature control signals to produce the pair of output quadrature signals having equal amplitudes and ideal phase quadrature.