A method of frequency-converting a received radio frequency (RF) signal includes frequency mixing a received RF signal with a first local oscillator (LO) signal to generate a first intermediate frequency (IF) signal, where the first IF signal is a mixed signal of a desired signal and an image signal. The method further includes frequency mixing the RF signal with a second LO signal to generate a second IF signal, where the second LO signal has a same frequency as the first LO signal, and the second LO signal has a 90 degree phase shift relative to the first LO signal. The method further includes analog-to-digital converting the first IF signal to a first digital signal and the second IF signal to a second digital signal, down-converting the first digital signal to a first digital baseband signal and the second digital signal to a second digital baseband signal, calibrating the first and second digital baseband signals for the 90 degree phase shift, and the separating the calibrated first and second digital baseband signals to obtain the desired signal and the image signal.

A method of frequency-converting a received radio frequency (RF) signal includes frequency mixing a received RF signal with a first local oscillator (LO) signal to generate a first intermediate frequency (IF) signal, where the first IF signal is a mixed signal of a desired signal and an image signal. The method further includes frequency mixing the RF signal with a second LO signal to generate a second IF signal, where the second LO signal has a same frequency as the first LO signal, and the second LO signal has a 90 degree phase shift relative to the first LO signal. The method further includes analog-to-digital converting the first IF signal to a first digital signal and the second IF signal to a second digital signal, down-converting the first digital signal to a first digital baseband signal and the second digital signal to a second digital baseband signal, calibrating the first and second digital baseband signals for the 90 degree phase shift, and the separating the calibrated first and second digital baseband signals to obtain the desired signal and the image signal.

A receiver circuit includes a mixer receiving an RF signal encoding an information signal. The mixer receives a number of multiphase oscillator signals and generates multiphase baseband signals. The receiver circuit also includes a variable gain circuit receives the multiphase baseband signals, generates a first output signal having a first distortion, and a second output signal having a second distortion. The variable gain circuit is configured to generate a reduced distortion output signal based on the first and second output signals.

A receiver circuit includes a mixer receiving an RF signal encoding an information signal. The mixer receives a number of multiphase oscillator signals and generates multiphase baseband signals. The receiver circuit also includes a variable gain circuit receives the multiphase baseband signals, generates a first output signal having a first distortion, and a second output signal having a second distortion. The variable gain circuit is configured to generate a reduced distortion output signal based on the first and second output signals.

A signal mixing circuit device includes a first mixer, a second mixer and a signal amplifying circuit serially connected to the first mixer; the first mixer includes an RF signal input terminal for receiving an RF signal, LO signal input terminals for sampling a first and second LO signals, a first mixed-signal output terminal for outputting a first mixed signal and a second mixed-signal output terminal for outputting a second mixed signal; the second mixer includes an input terminal connected to a capacitor, two mixed-signal output terminals respectively connected to the first and second mixed-signal output terminals of the first mixer, LO signal input terminals for inversely sampling the first and second LO signals. With the double-balance nature of the second mixer core, the noise at the LO signal input terminals of the first mixer can be cancelled. A receiver includes the signal mixing circuit device is also disclosed.

A signal mixing circuit device includes a first mixer, a second mixer and a signal amplifying circuit serially connected to the first mixer; the first mixer includes an RF signal input terminal for receiving an RF signal, LO signal input terminals for sampling a first and second LO signals, a first mixed-signal output terminal for outputting a first mixed signal and a second mixed-signal output terminal for outputting a second mixed signal; the second mixer includes an input terminal connected to a capacitor, two mixed-signal output terminals respectively connected to the first and second mixed-signal output terminals of the first mixer, LO signal input terminals for inversely sampling the first and second LO signals. With the double-balance nature of the second mixer core, the noise at the LO signal input terminals of the first mixer can be cancelled. A receiver includes the signal mixing circuit device is also disclosed.

A method of pre-compensating for transmitter in-phase (I) and quadrature (Q) mismatch (IQMM) may include sending a signal through an up-converter of a transmit path to provide an up-converted signal, determining the up-converted signal, determining one or more IQMM parameters for the transmit path based on the determined up-converted signal, and determining one or more pre-compensation parameters for the transmit path based on the one or more IQMM parameters for the transmit path. In some embodiments, the up-converted signal may be determined through a receive feedback path. In some embodiments, the up-converted signal may be determined through an envelope detector.

A full duplex, low latency, near field data link controls a resonant induction, wireless power transfer system for recharging batteries. In an electric vehicle embodiment, an assembly is aligned with respect to a ground assembly to receive a charging signal. The vehicle assembly includes one or more charging coils and a first full duplex inductively coupled data communication system that communicates with a ground assembly including one or more charging coils and a second full duplex inductively coupled data communications system. The charging coils of the ground assembly and the vehicle assembly are selectively enabled based on geometric positioning of the vehicle assembly relative to the ground assembly for charging. As appropriate, the transmit/receive system of the ground assembly and/or the vehicle assembly are adjusted to be of the same type to enable communication of charging management and control data between the ground assembly and the vehicle assembly during charging.

A full duplex, low latency, near field data link controls a resonant induction, wireless power transfer system for recharging batteries. In an electric vehicle embodiment, an assembly is aligned with respect to a ground assembly to receive a charging signal. The vehicle assembly includes one or more charging coils and a first full duplex inductively coupled data communication system that communicates with a ground assembly including one or more charging coils and a second full duplex inductively coupled data communications system. The charging coils of the ground assembly and the vehicle assembly are selectively enabled based on geometric positioning of the vehicle assembly relative to the ground assembly for charging. As appropriate, the transmit/receive system of the ground assembly and/or the vehicle assembly are adjusted to be of the same type to enable communication of charging management and control data between the ground assembly and the vehicle assembly during charging.

Example signal processing methods and apparatus are described. The signal processing apparatus includes a first power amplifier, a second power amplifier, a first filter, a second filter, and a combiner. The first filter filters a second signal obtained by the first power amplifier to obtain a first sub-signal belonging to a first frequency band and a second sub-signal belonging to a second frequency band. The second filter filters a fourth signal obtained by the second power amplifier to obtain n sub-signals including at least a third sub-signal belonging to a third frequency band. The combiner combines the first sub-signal and i sub-signals in the n sub-signals based on a preset condition to obtain a first combined signal. The communication module sends the first combined signal by using a first port, and sends the second sub-signal by using a second port.