A mobile device may be configured to perform concurrent Satellite Positioning System and communication system operation, e.g. enabling an SPS receiver to continue to receive SPS signals in frequency bands that are interfered with due to aggressor transmission signals. A controllable filter, such as a selectable and/or tunable notch or lowpass filter is used to reject the aggressor transmission signals. The controllable filter may also attenuate some, but not all, frequencies in the SPS L1 band. To avoid losing complete access to these filtered SPS signal frequencies, the controllable filter is controlled, e.g., selected or tuned to these frequencies only when the aggressor transmission signal is active, and is otherwise turned off or tuned away from the SPS signal frequencies.

A controller is configured to control the adaptive notch filter and to execute a search technique (e.g., artificial intelligence (AI) search technique) to converge on filter coefficients and to recursively adjust the filter coefficients of the adaptive notch filter in real time to adaptively adjust one or more filter characteristics (e.g., maximum notch depth or attenuation, bandwidth of notch, or general magnitude versus frequency response of notch).

Aspects of this disclosure relate to a radio frequency system with tunable notch filtering. The radio frequency system includes a first tunable filter and a second tunable filter. The first tunable filter is coupled between an output of a power amplifier and a radio frequency switch. The second tunable filter is coupled between an antenna switch and an antenna node. The second tunable filter has a notch at a lower frequency than a notch of the first tunable filter. Related methods and wireless communication devices are also disclosed.

Aspects of this disclosure relate to a radio frequency system with tunable notch filtering. The radio frequency system includes a first tunable filter and a second tunable filter. The first tunable filter is coupled between an output of a power amplifier and a radio frequency switch. The second tunable filter includes mutually coupled inductors and a tunable impedance circuit electrically connected to at least one of the mutually coupled inductors. The second tunable filter is coupled between an antenna switch and an antenna node. Related methods and wireless communication devices are also disclosed.

A method for real-time processing of a detection signal, wherein signal processing is respectively performed when a detection signal is converted from a high level to a low level or vice versa. A moment at which a level of the detection signal is converted is recorded as a start point. A status of the detection signal is then detected in real time at a current moment. A current time width is compared to a maximum interval width of pre-set interference signals, and signal levels are determined and recorded from the start point to the current moment. Using characteristics of different interference signals, anti-interference processing is performed by using a targeted edge positioning and width recognition method, so that the delay impact of filtering on signals is avoided, improving both the recognition precision of weighing data of a checkweigher and the overall performance of the checkweigher.

A radio frequency (RF) filter includes a signal conditioning circuit and a bandstop filter. The signal conditioning circuit receives a broadband RF signal that includes both a jamming signal at a jamming frequency and a signal of interest and generates a plurality of clock signals. Each of the plurality of clock signals has a substantially same frequency as the jamming frequency, but a different phase shift. The bandstop filter receives the RF signal and the plurality of clock signals. The bandstop filter attenuates signals within a bandstop centered at the frequency of the plurality of clock signals. A self-tuning N-path filter is provided.

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.

A receiver circuit includes an interleaved ADC, a first delay circuit, a second delay circuit, a first processing channel, a second processing channel, and an interleaving ADC timing error detector circuit. The interleaved ADC includes a first ADC and a second ADC in parallel. The first delay circuit delays a first clock signal provided to the first ADC. The second delay circuit delays a second clock signal provided to the second ADC. The first processing channel processes data samples provided by the first ADC, and includes a first slicer. The second processing channel processes data samples provided by the second ADC, and includes a second slicer. The interleaving ADC timing error detector circuit controls delay of the first delay circuit and the second delay circuit based on an output signal of the first slicer, and an output signal or an input signal of the second slicer.

A receiver circuit includes an ADC, a processing channel, and an interference detection path. The processing channel is configured to process data samples provided by the ADC, and includes a notch filter. The interference detection path is configured to detect interference in the data samples, and includes a slicer, a slicer error circuit, and an interference detection circuit. The slicer is configured to slice input of the notch filter. The slicer error circuit is configured to compute an error of the slicer. The interference detection circuit configured to detect an interference signal in the error of the slicer, and set the notch filter to attenuate the interference signal.

A communication device is provided that includes a receiver configured to receive a signal. The communication device further includes a circuit configured to determine an interference reference signal based on an interference signal, to multiply the received signal with the interference reference signal in the time domain to form a multiplication signal and to filter the multiplication signal to form a filtered signal.