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 the radio 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 first cancellation signal to substantially cancel second order intermodulation components by superimposing the amplified radio frequency receive signal weighted by a cancellation value, so as to alter its amplitude, on the local oscillator signal;
• 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, and a third terminal adapted to receive the first 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 first cancellation signal provided as input at the third 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 first cancellation signal to substantially cancel second order intermodulation components by superimposing the amplified intermediate frequency signal or baseband signal weighted by a cancellation value, so as to alter its amplitude, on the local oscillator signal;
• 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 a radio frequency transmit signal, and a third terminal adapted to receive the first 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 first cancellation signal provided as input at the third terminal.

A method, performed by a passive mixer, of converting a first signal having a first frequency into a second signal having a second frequency by using a third signal having a third frequency, comprising:

• receiving, at a first terminal of a mixing component, the first signal;
• receiving, at a third terminal of the mixing component, a first cancellation signal;
• sensing, by a first sensing component, a voltage at the first terminal;
• adapting a cancellation value based on the sensed voltage at the first terminal;
• generating, by a cancellation component, the first cancellation signal to substantially cancel second order intermodulation components by superimposing the first signal weighted by the cancellation value, so as to alter its amplitude, on the third signal;
• and
• outputting, at a second terminal of the mixing component, the second signal by mixing the first signal provided as input at the first terminal and the first cancellation signal provided as input at the third terminal.