Passive mixer with reduced second order intermodulation

A transceiver apparatus comprising a transmitter adapted to transmit a radio frequency transmit signal and a receiver adapted to receive a radio frequency receive signal, wherein the receiver comprises:

• a low noise amplifier adapted to amplify a high frequency receive signal;
• and
• a passive mixer comprising:
• a local oscillator adapted to generate a local oscillator signal;
• a cancellation component adapted to generate a second cancellation signal to substantially cancel second order intermodulation components by superimposing the amplified radio frequency receive signal weighted by a cancellation value on a bias voltage;
• and
• a mixing component having a first terminal adapted to receive the amplified radio frequency receive signal, a second terminal adapted to output one of an intermediate frequency signal and a baseband signal, a third terminal adapted to receive the local oscillator signal, and a fourth terminal adapted to receive the second cancellation signal, wherein the mixing component is adapted to provide one of the intermediate frequency signal and the baseband signal as output at the second terminal by mixing the amplified radio frequency receive signal provided as input at the first terminal and the local oscillator signal provided as input at the third terminal together with the second cancellation signal provided as input at the fourth terminal.

A transceiver apparatus comprising a transmitter adapted to transmit a radio frequency transmit signal and a receiver adapted to receive a radio frequency receive signal, wherein the transmitter comprises:

• an amplifier adapted to amplify one of an intermediate frequency signal and a baseband signal to be transmitted;
• and
• a passive mixer comprising:
• a local oscillator adapted to generate a local oscillator signal;
• a cancellation component adapted to generate a second cancellation signal to substantially cancel second order intermodulation components by superimposing the amplified intermediate frequency signal or baseband signal weighted by a cancellation value on a bias voltage;
• and
• a mixing component having a first terminal adapted to receive the amplified intermediate frequency signal or baseband signal, a second terminal adapted to output the radio frequency transmit signal, a third terminal adapted to receive the local oscillator signal, and a fourth terminal adapted to receive the second cancellation signal, wherein the mixing component is adapted to provide the radio frequency transmit signal as output at the second terminal by mixing the amplified intermediate frequency signal or baseband signal provided as input at the first terminal and the local oscillator signal provided as input at the third terminal together with the second cancellation signal provided as input at the fourth terminal.

A method for converting an input signal having one of a Radio Frequency (RF) or Intermediate Frequency (IF) into an output signal having the other of the RF or IF by using a Local Oscillator (LO) signal having a frequency intermediate to the RF and IF, comprising:

• receiving, at a drain terminal of a mixing component comprising a field effect transistor switch, the input signal;
• receiving, at a gate terminal of the mixing component, the LO signal;
• sensing, by a first sensing component, a voltage at the drain terminal;
• adapting a cancellation value based on the sensed voltage;
• generating, by a cancellation component, a second cancellation signal operative to substantially cancel second order intermodulation components by superimposing the input signal weighted by the cancellation value on a bias voltage;
• receiving, at a bulk terminal of the mixing component, the second cancellation signal;
• and
• outputting, at a source terminal of the mixing component, the output signal by mixing the input signal and the LO signal together with the second cancellation signal.