Patent ID: 8275338
Filing Date: 2012-09-25
Classification: H03D

Abstract:
1. A passive image reject mixer (IRM) comprising: a first MOS multiplier enabled to receive RF+ and RF− input signals forming differential radio frequency input signal and LO+ and LO− input signals forming a differential local oscillator input signal, and further enabled to output an intermediate frequency I IF+ and I IF− differential output signal; a second MOS multiplier; a passive phase shifter coupled to said differential local oscillator input signal and enabled to output to said second MOS multiplier said differential local oscillator input signal phase shifted ninety degrees; the second MOS multiplier enabled to receive said differential radio frequency input signal and the output of the passive phase shifter, and further enabled to output an intermediate frequency (IF) Q IF+ and Q IF− differential output signal; a first lumped-element hybrid coupled to receive said I IF+ output signal of said first MOS multiplier and said Q IF+ output signal of said second MOS multiplier, said first lumped-element hybrid being enabled to output an IF+ output signal responsive to whether a frequency of said radio frequency input signal is greater or less than a frequency of said first differential local oscillator input signal; and a second lumped-element hybrid coupled to receive said I IF− output signal of said first MOS multiplier and said Q IF− output signal of said second MOS multiplier, said second lumped-element enabled to output an IF− output signal responsive to whether a frequency of said radio frequency input signal is greater or less than a frequency of said first differential local oscillator input signal; said first MOS multiplier and said second MOS multiplier both being operative in deep triode region.