A 60dB harmonic mixing reduction mixer for wideband applications

Abstract

Mixers will suffer from harmonic mixing problem in wideband applications because these harmonics may be the inband interferences after down-conversion. In this paper, a linear current steering is used for harmonic mixing reduction instead of a RF tracking filter or poly-phase down-conversions. A simple but effective circuit topology we proposed can solve the harmonic mixing problem with less trade-off in linearity and noise figure. This circuit was realized in TSMC 0.18μm CMOS technology with 4.8mW power consumption. Measurement results indicate that the down-converted third-order harmonic interference can be rejected as large as 60 dB without any filters. Compared to conventional switching type, the proposed mixer has 43dB rejection improvement. © 2008 IEEE.