The Harmonic-Rejection Mixer [A Circuit for All Seasons]

The harmonic-rejection mixer (HRM) dates back to 2001 [1] but has been finding increasingly wider application in radio-frequency (RF) transceivers [2]-[4]. The popularity of HRMs stems from two trends in RF design: the incentive to minimize the number of high-frequency filters and the demand for wide-band radios. In this article, we study the HRM's operation principle and design issues.