Wireless signal processing may be improved by using a configurable baseband filter (BBF) in the receive path of a transceiver. A configurable BBF may accommodate processing of different wireless signals in a single integrated circuit (IC) chip. For example, a single IC may support processing of 5G mmWave RF signals and 5G sub-7 GHz RF signals by reconfiguring the BBF with settings appropriate for the different wireless signals. The reconfiguring of the BBF may include adjusting a bandwidth of the BBF and/or adjusting a filter order of the BBF. The reconfiguring of the BBF may be performed in response to detection of jammer signals to improve rejection of the jammer signals.

A circuit includes a filter, a first inverter, and a second inverter. The filter is coupled to an input of the first inverter. The second inverter includes an input and an output. The input of the second inverter is coupled to the output of the first inverter. The output of the second inverter is coupled to the input of the first inverter. The filter includes a notch filter and a bandpass filter.

In some examples, a circuit includes an amplifier, a resistor, and a damping network. The amplifier has an amplifier output and first and second amplifier inputs. The first amplifier input is adapted to be coupled to a first terminal, and the second amplifier input is configured to receive a reference voltage. The resistor is coupled between the amplifier output and the first amplifier input. The damping network is coupled between the amplifier output and the first terminal.

The present disclosure provides an audio amplifying circuit and a playing device, including: N-order filters and an integrated circuit; after an original audio signal passes through the N-order filters, a filtered signal is obtained; after the filtered signal passes through the integrated circuit, a corresponding digital signal is output; where the number of operational amplifiers adopted in the N-order filters is smaller than N, and N is a natural number greater than 1.

Examples provide a method and apparatus for an analog bi-quad infinite impulse response (IIR) filter. An amplifier generates a positive output signal corresponding to a received RF signal and a negative output signal. A set of selectively switchable time-delay circuits associated with a positive arm of the filter causes a predetermined delay corresponding to a desired sample frequency. A first set of configurable variable gain amplifiers amplify the positive output signal to establish a set of positive coefficients. A set of selectively switchable time-delay circuits associated with a negative arm of the filter causes a predetermined delay. A delayed negative output signal is generated which is amplified by a second set of configurable variable gain amplifiers to establish a set of negative coefficients. A set of power combiners function as sum junctions to combine the delayed positive output signals and the delayed negative output signals into a single output signal.

In some examples, a circuit includes an amplifier, a resistor, and a damping network. The amplifier has an amplifier output and first and second amplifier inputs. The first amplifier input is adapted to be coupled to a first terminal, and the second amplifier input is configured to receive a reference voltage. The resistor is coupled between the amplifier output and the first amplifier input. The damping network is coupled between the amplifier output and the first terminal.

In an illustrative example, a device includes an operational amplifier of an active bandpass filter circuit. The device further includes an adjustable resistance device configured to adjust a center frequency associated with the active bandpass filter circuit. The device further includes an adjustable capacitance device configured to adjust the center frequency and a bandwidth associated with the active bandpass filter circuit.

An aspect includes a filtering method including operating a first filter to filter a first input signal to generate a first output signal; operating a second filter to filter a second input signal to generate a second output signal; and merging at least a portion of the second filter with the first filter to filter a third input signal to generate a third output signal. Another aspect includes a filtering method including operating switching devices to configure a filter with a first set of pole(s); filtering a first input signal to generate a first output signal with the filter configured with the first set of pole(s); operating the switching devices to configure the filter with a second set of poles; and filtering a second input signal to generate a second output signal with the filter configured with the second set of poles.

A circuit includes a filter, a first inverter, and a second inverter. The filter is coupled to an input of the first inverter. The second inverter includes an input and an output. The input of the second inverter is coupled to the output of the first inverter. The output of the second inverter is coupled to the input of the first inverter. The filter includes a notch filter and a bandpass filter.

An audio filter and corresponding method with through-zero linearly variable resonant frequency are described. An example method includes receiving an input signal; receiving one or more control input signals; and providing a resonant filter for electronic music for processing the input signal. The resonant filter can include an exponential times linear multiplication to produce the resonant frequency control responsive to control voltages exponentially for musical octave/semitone control, and linearly for timbre modulation, the waveform being invariant over corresponding exponential changes in pitch of both input signal and filter resonance. The linear modulation can include inverting the sign of a bandpass feedback based on the sign of the resonant frequency variable so as to maintain stability. In the example method, to prevent a glitch on the output when frequency changes sign, a separate highpass output signal may be generated.