A selective filtering module is arranged to filter or process the digital baseband signal consistent with a target receiving bandwidth, where the selective filtering module comprises a narrowband rejection filter and wide-band filter configured to reject an interference component that interferes with the received radio frequency signal. The narrowband rejection filter is configured to reject a first interference component, where the narrowband rejection filter comprises an adaptive notch filter (NF). The wide band rejection filter is configured to reject a second interference component in accordance with a pulse blanking technique. An electronic data processor is adapted to control one or more filter coefficients of narrowband rejection filter and the wide band rejection filter in accordance with one or more strategic filter control factors among ADC saturation, activation/deactivation of the notch filter, and a wide-band spectrum analysis.

Systems, methods, and computer program product embodiments are disclosed for removing any fixed frequency interfering signal from an input signal without introducing artifacts that are not part of the original signal of interest. An embodiment operates by using a virtual buffer with a length that matches a length of one cycle of an interfering signal. The embodiment extracts the interfering signal into the virtual buffer. For a sample in the next cycle of the interfering signal that corresponds to a virtual memory location for the virtual buffer, the embodiment can update one or more physical memory locations of the virtual buffer that are in the vicinity of the virtual memory location. This use of virtual buffer can remove any interfering signal without creating the artifacts associated with conventional notch filters.

The present technology relates to a notch filter capable of easily obtaining a desired frequency characteristic.

In an N-path filter unit, any one of a plurality of N capacitors is selected as a signal path through which a signal passes, so that the capacitor serving as the signal path is temporally switched. A plurality of N-path filter units is cascade-connected and a capacitor is inserted to a connection point between the N-path filter units. The present technology may be applied to the notch filter which eliminates a blocker and the like, for example.

In some examples, a system includes at least two antennas configured to receive signals encoding first, second, and third messages in first, second, and third frequency bands. The system also includes a set of splitters configured to generate separate signals in the first, second, and third frequency bands. The system further includes a set of combiners, wherein each combiner of the set of combiners is configured to combine two or more of the separate signals. The system includes a set of mixers configured to down-convert the combined signals and at least one analog-to-digital converter configured to sample the down-converted signals. The system also includes processing circuitry configured to determine data in the first, second, and third messages based on an output of the at least one analog-to-digital converter.

Disclosed is a frequency selective limiter with a switched multiplexer filter bank having a plurality of filters coupled between antenna and receiver ports, wherein the switched multiplexer filter bank is configured to enable and disable selected ones of the plurality of filters in response to control signals. First detector circuitry is coupled to the antenna port and configured to detect signal voltage at the antenna port and generate a first detector voltage. Second detector circuitry is coupled to the receiver port and configured to detect signal voltage at the receiver port and generate a second detector voltage, and a digital controller is coupled between the first detector circuitry, the second detector circuitry, and a control interface, wherein the digital controller is configured to limit interfering signals by sending control signals to the switched multiplexer filter bank in response to the first detector voltage and the second detector voltage.

Apparatus and methods for envelope controlled radio frequency (RF) switches are provided. In certain embodiments, a power amplifier provides an RF signal to an antenna by way of an RF switch. Additionally, the envelope signal is used not only to control a power amplifier supply voltage of the power amplifier, but also to control a regulated voltage used to turn on the RF switch. For example, a level shifter can use a regulated voltage from charge pump circuitry to turn on the RF switch, and the envelope signal can be provided to the charge pump circuitry and used to control the voltage level of the regulated voltage over time.

Radio frequency (RF) acoustic wave resonator (AWR) filter circuits and methods. Embodiments essentially de-couple the stopband or notch characteristics of an RF filter from the passband characteristics. Accordingly, the de-coupled parameters can be individually designed to meet the specifications of a particular application. Partially-hybridized or fully-hybridized series-arm and parallel-arm AWR filter building blocks enable “de-coupled” RF filters having (1) wideband and low insertion loss passbands and (2) wideband deep notches (stopbands) with a specifically placed notch center frequency, without compromising the passband characteristics. The AWR filter building blocks include an inductance L that matches (resonates with) the electrostatic capacitance CO of the corresponding AWR within a desired passband. The resonance and anti-resonance frequencies of the building block AWRs are selected to be spaced apart from the specified passband in order to provide independent stopband or notch characteristics without substantially affecting the passband characteristics.

An electronic device includes an antenna configured to receive a wireless transmission. The wireless transmission includes noise and data to be received. The electronic device includes a signal splitter that splits the wireless transmission into a first signal and a second signal. The electronic device includes a filter configured to filter the data to be received in the first signal. Furthermore, the electronic device includes merging circuitry configured to subtract the first signal from the second signal to reduce the noise in the second signal.

Method and multi carrier receiver for removing interference from a RF-signal. In a multi carrier receiver with a heterodyne receiver structure, the RF-signal is received from a multi carrier transmitting entity. The RF-signal comprises a data part an interference part. The interference part is detected by means of the interference unit, and a frequency and a power level of the interference part is determined. A frequency of a first LO is adjusted, such that an output signal of a first mixer is frequency shifted towards an upper edge or a lower edge of a first IF bandpass filter when the determined power level exceeds a predetermined threshold. By detecting an interference part of an incoming RF-signal and controlling a local oscillator based on the detected interference, an effective and flexible solution is achieved for removing interference from the RF-signal.

A multiplexer device includes an antenna node connected to an antenna for at least one of receiving and transmitting signals; multiple band pass filters connected to the antenna node, each band pass filter having a different passband; and multiple notch filters connected in to the antenna node and the multiple band pass filters, each notch filter having a different stopband corresponding to one of the passbands of the band pass filters. The notch filters are connected in parallel with one another in order to reduce insertion loss.