Useful Characteristics for Controlling the Cancellation Performance and Center Frequency of a Linearization Loop

  • Kang, Sang-Gee (Department of Electronics & Information Engineering, Kunsan National University) ;
  • Hong, Sung-Yong (Department of Radio Science and Engineering, Chungnam National University)
  • Received : 2004.10.18
  • Published : 2006.04.30

Abstract

The cancellation performance of a linearization loop is limited by the degree of an amplitude imbalance and a phase imbalance. A delay mismatch causes a phase variation as a function of frequency. Therefore, the cancellation performance and linearization bandwidth are limited by a delay mismatch. The expression for the effects of an amplitude imbalance, a phase imbalance, and a delay mismatch on the characteristics of a linearization loop is derived and analyzed. The simulation results are compared with the results obtained by means of using a commercial simulation tool and the exact agreement is reported. The derived equation could be used in designing a linearization loop and predicting the cancellation performance of the linearization loop usefully. Some useful characteristics, known from the simulation results obtained by using the derived equation, of a linearization loop for designing and implementing feedforward amplifiers are described in detail.

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