A transceiver that allows dynamic high-pass filter (HPF) cut-off frequency adjustment may include a mixer circuit to mix a local oscillator (LO) signal with a receive (RX) signal received from a transmitter to generate a baseband signal. The transceiver may further include a high-pass filter (HPF) having an adjustable cut-off frequency that is used to reduce a DC offset of the baseband signal. A control circuit can dynamically control components of the HPF to set the adjustable cut-off frequency at a first frequency during a first time period and at a second frequency during a second time period.

A method and apparatus for RF ripple correction in an antenna aperture are described. In one embodiment, the antenna comprises: an array of antenna elements having liquid crystal (LC); drive circuitry coupled to the array and having a plurality of drivers, each driver of the plurality of drivers coupled to an antenna element of the array and operable to apply a drive voltage to the antenna element; and radio-frequency (RF) ripple correction logic coupled to the drive circuitry to adjust drive voltages to compensate for ripple.

A method and apparatus for DC offset correction in an antenna aperture are described. In one embodiment, the antenna comprises: an array of antenna elements having liquid crystal (LC); drive circuitry coupled to the array and having a plurality of drivers, each driver of the plurality of drivers coupled to an antenna element of the array and operable to apply a drive voltage to the antenna element; and voltage correction logic coupled to the drive circuitry adjust drive voltages to compensate for an offset between a first magnitude of a first voltage applied to the LC of each antenna element during a first interval of drive polarity and a second magnitude of a second voltage applied to the LC of said each antenna element during a second interval of drive polarity opposite the drive polarity of the first interval.

Local oscillator (LO) leakage and Image are common and undesirable effects in typical transmitters. Typically, fairly complex hardware and algorithms are used to calibrate and reduce these impairments. A single transistor that draws essentially no dc current and occupies a very small area detects the LO leakage and Image signals. The single transistor operating as a square-law device is used to mix the signals at the input and output ports of a power amplifier. The mixed signal generated by the single transistor enables the simultaneous calibration of the LO leakage and Image Rejection.

A system for reducing a local oscillator leakage component. The system includes a transmitter channel to transmit data modulated using a transmitter local oscillator frequency. A transmitted signal includes a transmitter local oscillator leakage component. The system also includes a receiver channel to receive the transmitted signal using a receiver local oscillator signal having a frequency offset from the transmitter local oscillator frequency. The received signal includes the transmitter local oscillator leakage component isolated from one or more receiver impairments. The system further includes a feedback loop from the receiver channel to the transmitter channel to identify a power of the isolated transmitter local oscillator leakage component and to generate a local oscillator leakage cancellation signal based on the identified power.

A device for determining a DC component in a zero-IF radio receiver comprises an input configured to receive a complex baseband signal; and an analyzer configured to analyze the complex baseband signal to determine a DC component in the complex baseband signal by selecting at least three samples of the complex baseband signal and determining the intersection of at least two perpendicular bisectors of at least two straight lines, each straight line running through a different pair of two of said selected samples, said intersection representing the DC component. Further, a corresponding method, a radar device and a radar method are disclosed.

The disclosure relates to a module for a radio receiver. The module comprises an input terminal; an output terminal; a main signal path for communicating in-phase and quadrature signals between the input terminal and the output terminal; and a second signal path. The second signal path is connected in parallel with the main signal path and is configured to: extract in-phase and quadrature signals from the main signal path; filter the extracted in-phase and quadrature signals; detect an error in the filtered, extracted in-phase and quadrature signals; and apply a correction to in-phase and quadrature signals on the main signal path based on the error.

Faults in a periodically oscillating MEMS mass are detected by processing a position signal, having an amplitude and oscillation frequency, generated as a function of mass position. First and second reference signals formed by samples of quadrature sinusoids at the oscillation frequency are generated. First and second multipliers generate a first product signal and a second product signal, respectively, via multiplication of the position signal by the first and second reference signals. The first and second product signals are low pass filtered to generate first and second filtered signals, respectively. An estimator circuit determines estimates of the amplitude as a function of the first and second filtered signals. A decision circuit detects the presence of faults on the basis of a comparison of the estimates with a range of values.

Method embodiments are provided herein for dynamically calibrating and adjusting a direct conversion receiver system. One embodiment includes applying one or more gain control signals to one or more gain elements of a receiver system, where the applying one or more gain control signals results in a gain change to the receiver system; in response to the gain change, determining whether the receiver system exhibits a DC (direct conversion) offset; and in response to a determination that the receiver system exhibits the DC offset, applying one or more DC offset correction control signals to one or more gain elements of the receiver system, where the one or more DC offset correction signals are configured to correct the DC offset.

In accordance with an embodiment, a circuit includes a mixer having a signal input port, a local oscillator input port and an output port, a lowpass filter circuit having an input coupled to the output port of the mixer and a terminal configured to be connected to a shunt capacitor, and a difference circuit having a first input coupled to the output port of the mixer, and a second input coupled to an output of the lowpass filter. The output of the difference circuit substantially rejects a DC signal component at the output port of the mixer.