ABSTRACT
Most of today’s transceivers are designed with passive mixers, which is the motivation behind dedicating this chapter to analyze and understand their operation fundamentals. We study transceivers designed with passive mixers driven by 50% and 25% duty-cycle clocks. It is shown that due to lack of reverse isolation between RF and IF ports, the passive mixer holds a property called impedance transformation. This property of the passive mixers can be utilized to frequency-shift low-Q baseband impedances to synthesize on-chip high-Q filters with center frequencies precisely controlled by the local oscillator (LO) clock, a useful feature to design blocker-resilient receivers. It is also revealed how this lack of reverse isolation can cause problems such as IQ cross talk and different high-and low-side conversion gains. This chapter discusses how to design a receiver or a transmitter with passive mixers for the best gain and linearity performance.
