Analysis of Internally Bandlimited Multistage Cubic-Term Generators for RF Receivers
Adaptive feedforward error cancellation applied to correct distortion arising from third-order nonlinearities in RF receivers requires low-noise low-power reference cubic nonidealities. Multistage cubic-term generators utilizing cascaded nonlinear operations are ideal in this regard, but the frequency response of the interstage circuitry can introduce errors into the cubing operation. In this paper, an overview of the use of cubic-term generators in receivers relative to other applications is presented. An interstage frequency response plan is presented for a receiver cubic-term generator and is shown to function for arbitrary three-signal third-order intermodulation generation. The noise of such circuits is also considered and is shown to depend on the total incoming signal power across a particular frequency band. Finally, the effects of the interstage group delay are quantified in the context of a relevant communication standard requirement.
© Copyright 2009 IEEE. Manuscript received April 07, 2008; revised August 08, 2008. First published October 31, 2008; current version published August 21, 2009. This work was supported in part by the Lee Center for Advanced Networking and in part by a National Defense Science and Engineering Graduate Fellowship. This paper was recommended by Associate Editor E. A. M. Klumperink.
Published - Keehr2009p5923Ieee_T_Circuits-I.pdf