Study on linearization of Ka-band wideband traveling-wave tube amplifer

Abstract

Linearizer is a key component in the millimeter-wave communication system, it plays an important role in improving the linearity performance of amplifier and communication quality. At present, the development of traveling-wave tube amplifier (TWTA) linearization technology cannot meet the application requirements of communication technology, therefore, the research of linearization technology is very important. In this paper we propose a kind of a new wide-band analog pre-distortion structure used to improve the nonlinear characteristics of Ka-band TWTA. The simulation results show that when the input power changes from −20 to 10 dBm in the frequency range of 26−30 GHz, the gain expansion of the linearizer is greater than 5.08 dB, and the phase expansion exceeds 64.81°. The linearizer and the TWTA are cascaeded for testing. The test results show that the gain compression and phase compression of center frequence is less than 3.12 dB and 2.31° respectively, and the third-order intermodulation (IMD3) improves significantly.