William R. Panton

Effects of nonlinear distortion on CDMA communication systems

We report a rigorous approach to analyze the effects of nonlinear distortion on code division multiple access (CDMA) wireless communication systems based on time-domain analysis and band-pass nonlinearity theory. Given AM-AM and AM-PM characteristics of a nonlinear device, this technique is capable of predicting adjacent channel power rejection (ACPR), power compression, and base-band signal vector constellation at the output of the nonlinear device. To demonstrate and verify the capability of this technique, an L-band power amplifier was designed, built, tested with CDMA waveforms, and compared with the simulated results. Excellent agreement between the measured and predicted results has been achieved.

A high linearity, 35 dBm L-band power amplifier for Globalstar applications

A high linearity, class A power amplifier has been designed for the Globalstar transmit band. The power amplifier provides 40 dB of gain at a Pout of 35 dBm (CDMA) at 1610.73 MHz with 30% efficiency with <-75 dBW/MHz ACP at 1605 MHz, thus exceeding the ETSI emissions requirement in the GLONASS band (1585-1605 MHz). The design has been verified from -30/spl deg/C to +70/spl deg/C.