Various data transmission detection systems are described. A receiver input through which a wireless data transmission signal is received may be present. A plurality of mixers in communication with the receiver input may be present, which may be digitally implemented. A data transmission detector may be present that receives a mixed wireless data transmission signal from each mixer and creates a plurality of scores. A match detection module may be present that receives the scores and identifies a highest score. The signal mapped to the highest score to be selected for further processing.

A circuit includes a radio frequency (RF) channel including an input node and an output node and being configured to receive an RF oscillator signal at the input node and to provide an RF output signal at the output node; a mixer configured to mix an RF reference signal and an RF test signal representative of the RF output signal to generate a mixer output signal; an analog-to-digital converter configured to sample the mixer output signal in order to provide a sequence of sampled values; and a control circuit configured to provide a sequence of phase offsets by phase-shifting at least one of the RF test signal and the RF reference signal using one or more phase shifters, calculate a spectral value from the sequence of sampled values; and calculate estimated phase information indicating a phase of the RF output signal based on the spectral value.

In tuning a radio frequency (RF) module including a non-volatile tunable RF filter, a desired frequency and an undesired frequency being provided by an amplifier of the RF module are detected. The non-volatile tunable RF filter is coupled to an output of the amplifier of the RF module. A factory setting of an adjustable capacitor in the non-volatile tunable RF filter is changed by factory-setting a state of a non-volatile RF switch, such that the non-volatile tunable RF filter substantially rejects the undesired frequency and substantially passes the desired frequency. The adjustable capacitor includes the non-volatile RF switch, and the factory setting of the adjustable capacitor corresponds to a factory-set state of the non-volatile RF switch. An end-user is prevented access to the non-volatile RF switch, so as prevent the end-user from modifying the factory-set state of the non-volatile RF switch.

This disclosure is directed to power gain variation compensation of Radio Frequency (RF) receivers based on temperature variations. An RF receiver may include amplification circuitry having a chain of multiple amplifiers and/or passive elements. Multiple distributed and/or lumped attenuators disposed at different points between amplifiers and/or passive elements of the chain may attenuate a received RF signal to compensate for gain variations of the multiple amplifiers and/or passive elements caused by a temperature change. Accordingly, the distributed and/or lumped attenuators may improve linear response of the amplifiers and/or passive elements and signal-to-noise and distortion ratio of RF signals received at the receiver.

An integrated circuit and a method of performing a built-in-self-test (BIST) procedure in an integrated circuit. The integrated circuit includes a plurality of radio circuits and a switching network for performing a built-in-self-test (BIST) procedure. The switching network includes a plurality of combiners, a plurality of transmitter connection switches, a combiner switch, a splitter switch, a plurality of splitters and a plurality of receiver connection switches. The switching network may also include a splitter bypass switch and/or a combiner bypass switch. The components of the switching network may operate to route signals between outputs and inputs of the radio circuit to implement the built-in-self-test procedure in one or more modes involving either parallel or sequential testing of the components of the radio circuits. A diagnostic mode is also envisaged.

On-chip multi-band equalizers for adjusting signal strength for a receiver receiving multi-band frequency signals are provided. An example multi-band equalizer comprises multiple series connected tapped LC resonators. The tapped LC resonator may be capacitive tapping or inductive tapping, where both frequency and gain of the frequency bands of interest may be programmed by tuning the capacitances of the programmable capacitors and/or selecting the tapped-out terminals of the inductors. The multi-band equalizer may be connected to a signal node, for instance between two amplifiers in the receiver.

Aspects of the disclosure provide an apparatus for receiving a circularly polarized signal by linearly polarized antennas. A horizontally polarized antenna and a vertically polarized antenna of the apparatus receive a circularly polarized signal that is transmitted based on a transmitted baseband signal vector. A radio frequency (RF) module of the apparatus generates a first baseband signal vector based on the received circularly polarized signal. The first baseband signal vector includes a product of the transmitted baseband signal vector and a receiving polarization vector of the transmitted baseband signal vector. Processing circuitry of the apparatus estimates the receiving polarization vector of the transmitted baseband signal vector based on the first baseband signal vector. The processing circuitry derives a second baseband signal vector based on the estimated receiving polarization vector and the first baseband signal vector.

A method for front-end filtering frequency selection for a communication receiver is provided. The method includes: disposing a reference oscillator working at a preset frequency associated with a frequency to be received by the communication receiver, where the preset frequency and the frequency to be received can be accurately converted and expressed by a formula; and transmitting the frequency to be received to a front-end filtering frequency selector to realize accurate tuning. The frequency of the front-end filtering frequency selector is a required tuning frequency based on the device parameter relationship between the reference oscillator and the front-end filtering frequency selector.

Radio frequency front end modules implementing coexisting time division duplexing and frequency division duplexing are provided. In one aspect, a front end system includes a time-division duplexing transmit terminal, a time-division duplexing receive terminal, a frequency division duplexing terminal, and an antenna terminal. The front end system further includes first, second, and third switches configured to selectively connect the terminals to either a node or the antenna. The front end system also includes a controller configured to provide delays between disconnecting the terminals from the antenna and connecting the terminals to the node.

Embodiments of this disclosure may include a receiver with a reconfigurable processing path for different signal conditions. Such a receiver may reconfigure between a mixer-first configuration and an amplifier-first configuration. In the mixer-first configuration, an RF input signal is not passed through an LNA for amplification before processing the RF input signal for downconversion to baseband and eventual extraction of the information in the signal. In the amplifier-first configuration, an RF input signal is passed through an LNA for amplification before processing the RF input signal for downconversion to baseband and eventual extraction of the information in the signal. Reconfiguring the receiver between mixer-first and amplifier-first configurations may be performed based on detection of jammer signals and/or measurement of signal-to-noise ratio (SNR).