Harmonic Feedback Circuit Effects on Intermodulation Products and Adjacent Channel Leakage Power in HBT Power Amplifier for 1.95GHz Wide-Band CDMA Cellular Phones (Special Issue on Low Distortion Technology for Microwave Devices and Circuits)

概要

論文の詳細を見る
Second harmonic signal feedback technique is applied to an HBT power amplifier for Wide-band CDMA (W-CDMA) mobile communication system to improve its linearity and efficiency. This paper describes the feedback effect of the 2nd harmonic signal from the output of the amplifier to the input on the 3rd order intermodulation distortion (IMD) products and Adjacent Channel leakage Power (ACP) of the power amplifier. The feedback amplifier, using an InGaP/GaAs HBT with 48 fingers of 3×20 μm emitter, exhibits a 10 dB reduction in the level of the 3rd order IMD products. In addition, an ACP improvement of 7 dB for the QPSK modulation signal with a chip rate of 4.096 Maps at 1.95 GHz was realized. As a result, the amplifier achieves a power-added efficiency of 41.5%, gain of 15.3 dB, and ACP of -43.0 dBc at a 5 MHz offset frequency and output power of 27.5 dBm. At the output power of 28dBm, the power-added efficiency increases to 43.3% with an ACP of -40.8 dBc.
社団法人電子情報通信学会の論文
1999-05-25