Implementing a passive rotating harmonic rejection mixer (RHRM) for a TV tuner in an integrated circuit

An apparatus comprising:

• a master radio frequency (RF) device to receive an incoming single-ended RF signal and provide first and second RF currents;
• a master local oscillator (LO) device coupled to an output of the master RF device, the master LO device to receive the first and second RF currents and mix each of the first and second RF currents with a master clock signal of a first polarity and a second polarity to obtain a mixed signal pair;
• a rotating switch coupled to the master LO device to cyclically switch the mixed signal pair to one of a plurality of virtual ground nodes at an output of the rotating switch;
• a plurality of operational amplifiers each having a first input terminal coupled to one of the plurality of virtual ground nodes, each of the plurality of operational amplifiers having a feedback filter coupled thereto;
• and
• a plurality of gain stages each coupled to one of the plurality of operational amplifiers to weight the output of the corresponding operational amplifiers.

A system comprising:

• an antenna to receive a radio frequency (RF) signal;
• a passive rotating harmonic rejection mixer (RHRM) coupled directly to the antenna to receive and downconvert the RF signal to a second frequency signal, the passive RHRM comprising:
• a transconductor stage to receive the RF signal and convert the RF signal to an RF current pair;
• a mixing stage to downconvert the RF current pair to a second frequency current pair;
• a passive switch stage to receive the second frequency current pair and to cyclically rotate the second frequency current pair to a plurality of virtual ground nodes;
• and
• a load stage having a plurality of operational amplifiers each coupled to a corresponding one of the virtual ground nodes;
• second frequency circuitry to receive and process the second frequency signal;
• and
• a demodulator coupled to the second frequency circuitry to demodulate the processed second frequency signal to obtain a demodulated signal.