A New Approach to the Design of a Phase Modulator with Low Nonlinear Distortion

Phase modulation can most directly be effected by a device whose output is a sinusoidal function of its input. In this paper a phase modulator is described in which a linear segmental approximation of the sinusoidal function is used. Performance results in terms of a phase difference from perfect linearity (
\Delta \Phi
) and signal-to-distortion ratio (SDR) are given. For eight-segment approximation
\Delta \Phi
is 0.06° and SDR is 62.3 dB in the range
\pm90\deg
.