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| A Predistortion Linearizer for Ku-band Traveling Wave Tube Amplifier |
| Liu Jie①② Hu Bo-xiong① Wang Gang① Su Xiao-bao① |
①(Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China)
②(University of Chinese Academy of Sciences, Beijing 100039, China) |
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Abstract With the development of communication technology, the requirements of power amplifier linearity are increasing. This paper presents a kind of two-branch predistortion circuit which contains the main branch and the auxiliary branch. The main branch is a diode based nonlinear generator and the auxiliary branch consists of variable attenuator and nonlinear generator. Compared with single nonlinear generator, this two-branch predistortion circuit increases the slope of amplitude characteristic. The ADS co-simulation of Traveling Wave Tube Amplifier (TWTA) and new predistorion circuit show the improvement of linearity. Based on the analysis and simulation, a Ku-band practically predistortion cuicuit is designed and tested with the TWTA. The results of experiments show that, the Carrier to Intermodulation (C/IM3) at TWTA Input Power Back Off (IPBO) of 3 dB can reach 12.92 dB, C/IM3 at TWTA IPBO of 6 dB can reach 22.8 dB. With the linearizer, the linearity of TWTA is clearly improved.
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Received: 20 November 2013
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Corresponding Authors:
Liu Jie
E-mail: lj_ant@sina.com
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2014, Vol. 36 
