Spur suppression for millimeter wave (mmW) receiver

A millimeter wave (mmW) receiver comprising:

• a local oscillator (LO) generator;
• a splitter coupled to the LO generator configured to output a first LO signal from a first output and a second LO signal from a second output;
• a 90-degree phase shifter having an output and an input coupled to the second output of the splitter;
• a radio frequency (RF) input;
• a first mixer having an output, a first input coupled to the RF input, and a second input coupled to the first output of the splitter;
• a second mixer having an output, a first input coupled to the RF input, and a second input coupled to the output of the 90-degree phase shifter;
• a 180-degree phase shifter having an output, and an input coupled to the output of the second mixer;
• a combiner element having an output, a first input coupled to the output of the first mixer, and a second input coupled to the output of the 180-degree phase shifter;
• a first switch coupled between the RF input and the input of the second mixer;
• and
• a second switch coupled between the output of the 180-degree phase shifter and the second input of the combiner element.

A wireless communication apparatus, comprising:

• a local oscillator (LO) source having an LO output for an LO signal;
• phase shifting circuitry having an input coupled to the LO output, and a plurality of outputs, the plurality of outputs including at least a first output for a first LO signal, and a second output for a second LO signal, wherein each output of the plurality of outputs other than the first output is configured with a signal out of phase with the first LO signal;
• a plurality of LO drivers, each LO driver of the plurality of LO drivers comprising a corresponding LO driver input coupled to a corresponding output of the plurality of outputs of the phase shifting circuitry;
• and
• one or more power connections coupled between groupings of outputs of the plurality of LO drivers, wherein the one or more power connections provide spur suppression associated with a phase difference between the outputs of the plurality of LO drivers in an associated grouping.

A method comprising:

• generating a first LO signal at a first millimeter wave (mmW) frequency;
• generating a second LO signal at the first mmW frequency, wherein the second LO signal is out of phase with the first LO signal;
• generating a harmonic of the first LO signal;
• and
• generating a harmonic of the second LO signal such that the harmonic of the second LO signal is 180 degrees out of phase with the harmonic of the first LO signal with an approximately matching amplitude,
• wherein the first LO signal and the second LO signal are generated using a quadrature generation circuit having an input coupled to an LO output of an LO generator, a first output for the first LO signal, and a second output for the second LO signal, wherein the second LO signal is 90 degrees out of phase with the first LO signal, and
• wherein the harmonic of the first LO signal and the harmonic of the second LO signal are generated using:
• a first LO driver having a first LO output and a first LO input, wherein the first LO input is coupled to the first output of the quadrature generation circuit;
• a second LO driver having a second LO output and a second LO input, wherein the second LO input is coupled to the second output of the quadrature generation circuit;
• a first mixer having a first mixer LO input, a first mixer radio frequency (RF) input, and a first mixer output, wherein the first mixer LO input is coupled to the first LO output, and wherein the first mixer RF input is coupled to an RF signal source;
• and
• a second mixer having a second mixer LO input, a second mixer RF input, and a second mixer output, wherein the second mixer LO input is coupled to the second LO output, and wherein the first mixer RF input is coupled to a dummy RF load.