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US 8,275,338 B2Granted
Passive high frequency image reject mixer
AssigneeTheta S.A.
InventorIoannis Papananos
Life of this patent
Estimating the term…
Abstract
The apparatus is a complete passive implementation of an image reject mixer (IRM) that is capable of operating at very high frequency. Using a hybrid as part of the IRM circuit enables operation at very high frequencies that also employs a high intermediate frequency (IF). All the components of the design are passive and implementable in MOS technologies providing significant cost and implementation advantages. Furthermore, the apparatus is operative at frequencies that are higher than several tens of GHz.
Claims23
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.
5 more elements
A passive image reject mixer (IRM) comprising:
- a differential radio frequency input signal having RF+ and RF− input signals;
- a first differential local oscillator input signal having LO+ and LO− input signals;
- a second differential local oscillator signal phase shifted with respect of said first differential local oscillator input signal, the second differential local oscillator signal providing phase shifted LO+ and LO− signals;
- a first passive multiplier responsive to said RF+ and said RF− input signals, said LO+ and said LO− input signals, and outputting I IF+ and an “I IF− output signals;
- a second passive multiplier responsive to said RF+ and said RF− input signals, said phase shifted LO+ and said phase shifted LO− signals, and outputting a Q IF+ and Q IF− output signals;
- a first passive filter for filtering said I IF+ and said Q IF+ output signals and generating an IF+ output signal;
- and
- a second passive filter filtering said I IF− and said Q IF− signals and generating an IF− output signal.
5 more elements
Dependencies are inferred from the claim text.