Circuits and methods for performing harmonic rejection mixing

摘要

Circuits and methods for performing harmonic rejection mixing are provided. In some embodiments, the circuit comprises: a first amplifier that amplifies a received signal at a first gain; a second amplifier that amplifies the received signal at a fraction of the first gain; a mixer that receives a local oscillator signal having a first fundamental frequency and the first amplifier output, and outputs a first mixed signal; a second mixer that receives a second local oscillator signal having a fundamental frequency that is a multiple of the first fundamental frequency and the second amplifier output, and outputs a second mixed signal; and an output stage that receives the first and second mixed signals and outputs a sum of the first and second mixed signals.

主权项

1. A circuit for performing harmonic rejection mixing, the circuit comprising:
a first amplifier that outputs a first amplified signal by amplifying a received signal using a first gain; a second amplifier that outputs a second amplified signal by amplifying the received signal using a second gain that is a fraction of the first gain; a third amplifier that outputs a third amplified signal by amplifying the received signal using a third gain that is a second fraction of the first gain; a first mixer that receives (i) a first local oscillator signal having a first fundamental frequency and (ii) the first amplified signal of the first amplifier, and outputs a first mixed signal created by mixing the first local oscillator signal with the first amplified signal of the first amplifier; a second mixer that receives (iii) a second local oscillator signal having a second fundamental frequency that is a multiple of the first fundamental frequency and that is different from the first fundamental frequency and (iv) the second amplified signal of the second amplifier, and outputs a second mixed signal created by mixing the second local oscillator signal with the second amplified signal of the second amplifier; a third mixer that receives (v) a third local oscillator signal having a third fundamental frequency that is a second multiple of the first fundamental frequency and (vi) the third amplified signal of the third amplifier, and outputs a third mixed signal created by mixing the third local oscillator signal with the third amplified signal of the third amplifier, wherein a rising edge of the second local oscillator signal and a rising edge of the third local oscillator signal are substantially aligned with a falling edge of the first local oscillator signal; and an output stage that receives the first mixed signal, the second mixed signal and the third mixed signal, and outputs a combined signal that includes a sum of the first mixed signal and the second mixed signal.