A method for providing IQ mismatch (IQMM) compensation includes: sending a single tone signal at an original frequency; determining a first response of an impaired signal at the original frequency and a second response of the impaired signal at a corresponding image frequency; determining an estimate of a frequency response of the compensation filter at the original frequency based on the first response and the second response; repeating the steps of sending the single tone signal, determining the first response and the second response, and determining the estimate of the frequency response of the compensation filter by sweeping the single tone signal at a plurality of steps to determine a snapshot of the frequency response of the compensation filter; converting the frequency response of the compensation filter to a plurality of time-domain filter taps of the compensation filter by performing a pseudo-inverse of a time-to-frequency conversion matrix; and determining a time delay that provides a minimal LSE for the corresponding time domain filter taps.

A method for providing IQ mismatch (IQMM) compensation includes: sending a single tone signal at an original frequency; determining a first response of an impaired signal at the original frequency and a second response of the impaired signal at a corresponding image frequency; determining an estimate of a frequency response of the compensation filter at the original frequency based on the first response and the second response; repeating the steps of sending the single tone signal, determining the first response and the second response, and determining the estimate of the frequency response of the compensation filter by sweeping the single tone signal at a plurality of steps to determine a snapshot of the frequency response of the compensation filter; converting the frequency response of the compensation filter to a plurality of time-domain filter taps of the compensation filter by performing a pseudo-inverse of a time-to-frequency conversion matrix; and determining a time delay that provides a minimal LSE for the corresponding time domain filter taps.

A method for providing IQ mismatch (IQMM) compensation includes: estimating an overall frequency response of a compensation filter by stepping through a frequency range starting at an initial frequency and performing (1) through (3) at each step, a selected frequency at each step being a multiple of a subcarrier frequency of the initial frequency: (1) sending a single tone signal at the selected frequency, (2) determining a first response of a mismatched signal at the selected frequency and a second response of the mismatched signal at an image frequency of the selected frequency, and (3) estimating a frequency response of the compensation filter at the selected frequency based on the first response and the second response; generating time-domain filter taps based on the estimated overall frequency response of the compensation filter; determining a time delay based on the time-domain filter taps; and generating a compensated signal based on the time delay.

A radio frequency (RF) device includes a plurality of mixers, each of the plurality of mixers having a first input terminal, a second input terminal, and an output terminal; and a self-test circuit. The self-test circuit includes a buffer having an input terminal and an output terminal, the buffer configured to buffer a reference signal from a local oscillator (LO) to produce a first RF signal at a first frequency; and a plurality of delay elements having different respective transmission delays, the delay elements each having a first end coupled to the output terminal of the buffer and a second end configured to provide a respective delayed signal based on the first RF signal, where the self-test circuit is configured to, in a test mode, couple the second ends of the delay elements to respective first input terminals of the plurality of mixers to provide each mixer with the respective delayed signal, and where the second input terminals of the mixer are configured to receive a second RF signal having the first frequency.

A method for providing IQ mismatch (IQMM) compensation includes: sending a single tone signal at an original frequency; determining a first response of an impaired signal at the original frequency and a second response of the impaired signal at a corresponding image frequency; determining an estimate of a frequency response of the compensation filter at the original frequency based on the first response and the second response; repeating the steps of sending the single tone signal, determining the first response and the second response, and determining the estimate of the frequency response of the compensation filter by sweeping the single tone signal at a plurality of steps to determine a snapshot of the frequency response of the compensation filter; converting the frequency response of the compensation filter to a plurality of time-domain filter taps of the compensation filter by performing a pseudo-inverse of a time-to-frequency conversion matrix; and determining a time delay that provides a minimal LSE for the corresponding time domain taps.

An apparatus and method are provided for setting a local oscillator duty ratio based on an image distortion level. A first signal is transmitted utilizing a first X-phase path of a transmitter. Further, an image distortion level is measured in connection with the first signal. Based on the measurement, a duty ratio of a local oscillator is set, for reducing a distortion in connection with a transmission of a second signal utilizing a second Y-phase path of the transmitter.

An apparatus and method. The method includes filtering an output of an in-phase (I-mixer); filtering an output of a quadrature-mixer (Q-mixer); converting an output of a first low pass filter (LPF); converting an output of a second LPF; buffering an output of a first analog-to-digital converter (ADC); buffering an output of a second ADC; buffering a transmitter signal; generating a reference signal from an output of a transmitter (TX) data capture buffer; removing DC from the reference signal; and adaptively tuning an I-mixer digital-to-analog (DAC) code and a Q-mixer DAC code from an output of a first receiver (RX) data capture buffer, an output of a second RX data capture buffer, an output of a DC removal unit, and a predetermined step size for each of the I-mixer DAC code and the Q-mixer DAC code.

An apparatus is disclosed for oscillator leakage calibration. In example aspects, the apparatus includes a mixer circuit and calibration circuitry. The mixer circuit has a first stage including at least one transistor coupled between a mixer input and a mixer output and a second stage including one or more transistors coupled between the at least one transistor and the mixer output. The mixer circuit also has tuning circuitry coupled to the at least one transistor. The calibration circuitry includes at least one resistor coupled between a power distribution node and at least one mixer node, with the at least one mixer node coupled between the at least one transistor and the one or more transistors, and at least one switch coupled between the power distribution node and the at least one mixer node. The calibration circuitry also includes controller circuitry coupled between the mixer node and the tuning circuitry.