Characterizing the effects of nonlinear amplifiers on linear modulation for digital portable radio communications

Abstract

The design and performance of linear modulation techniques and RF power amplifiers for digital portable radio communications are discussed. Various types of power amplifiers are used in the comparison of out-of-band radiation and power efficiency simulation. The designs focus on high-frequency silicon bipolar power amplifiers suitable for portable radio applications. Two different 4-ary quadrature amplitude modulation schemes are compared. It is shown that power efficiency as high as 40% can be achieved using a dynamically biased amplifier operating near saturation. The effects of nonlinear distortions from power amplifiers on adjacent interference as well as bit and block error rate performance are also investigated.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>