Method and apparatus for transmitter calibration

A method of calibrating a transmitter comprising:

• attenuating transmitter output signals as controlled by an output control signal, ensuring that an average power of the transmitter output signals is below a threshold level;
• performing calibration of the transmitter at periods of time in which the output control signal is attenuating the transmitter output signals a lesser amount;
• wherein performing a calibration comprises an LO feed through calibration comprising adjusting a D.C. potential input to an LO mixer and monitoring the LO feed through;
• and
• wherein monitoring the LO feed through comprises frequency down-converting transmitter output signals with a down conversion chain of a receiver, and sampling the frequency down-converted signal.

A transmitter, comprising:

• a frequency up-converting LO mixer for frequency upconverting baseband signals, generating transmitter output signals;
• a transmitter antenna for transmitting the transmitter output signals;
• control circuitry for controlling attenuating the transmitter output signals during a calibration of the transmitter;
• wherein
• a duty cycle of first and second portions of the control signal is set to ensure that an average power of the transmitter signals is maintained below a threshold level.