Generation of constant envelope signals

A modification is presented of a technique for the generation of a constant envelope signal by the addition of separately generated in-phase and quadrature signals. The original scheme, developed by Yazdani et al. (1980), utilizes a nonlinear approximation to the quadrature signal and requires hard limiting to achieve a constant envelope. A modified technique is developed which does not require hard limiting and, thus, eliminates the spectral spreading associated with the limiting process. Important waveforms, such as the multiplier output and the quadrature modulator input and output, are presented in order to illustrate the operation of the constant envelope modulator.