An example circuit includes: an inverter-based filter; a voltage regulator having an input and an output, the output of the voltage regulator providing a supply voltage to bias the inverter-based filter; a ring oscillator having a supply input and an output, the supply input of the ring oscillator coupled to the output of the voltage regulator; a control circuit coupled to the output of the ring oscillator and the input of the voltage regulator, the control circuit configured detect an oscillation frequency of the ring oscillator and to adjust the voltage regulator in response to the oscillator frequency.

Active feedback is used with two electrodes of a four-electrode capacitive-gap transduced wine-glass disk resonator to enable boosting of an intrinsic resonator Q and to allow independent control of insertion loss across the two other electrodes. Two such Q-boosted resonators configured as parallel micromechanical filters may achieve a tiny 0.001% bandwidth passband centered around 61 MHz with only 2.7 dB of insertion loss, boosting the intrinsic resonator Q from 57,000, to an active Q of 670,000. The split capacitive coupling electrode design removes amplifier feedback from the signal path, allowing independent control of input-output coupling, Q, and frequency. Controllable resonator Q allows creation of narrow channel-select filters with insertion losses lower than otherwise achievable, and allows maximizing the dynamic range of a communication front-end without the need for a variable gain low noise amplifier.

A calibration method and a tuning method for an on-chip differential active RC filter are provided. The calibration method comprises: obtaining zero-crossing time of a differential signal outputted by a single-pole point real number filter by analyzing the single-pole point real number filter; setting a reference clock period according to the relationship between the zero-crossing time and the bandwidth of the single-pole point real number filter, and setting a calibration working time sequence according to the reference clock period; and scanning an RC configuration of an RC array according to the calibration working time sequence to realize calibration of the RC array.

Active feedback is used with two electrodes of a four-electrode capacitive-gap transduced wine-glass disk resonator to enable boosting of an intrinsic resonator Q and to allow independent control of insertion loss across the two other electrodes. Two such Q-boosted resonators configured as parallel micromechanical filters may achieve a tiny 0.001% bandwidth passband centered around 61 MHz with only 2.7 dB of insertion loss, boosting the intrinsic resonator Q from 57,000, to an active Q of 670,000. The split capacitive coupling electrode design removes amplifier feedback from the signal path, allowing independent control of input-output coupling, Q, and frequency. Controllable resonator Q allows creation of narrow channel-select filters with insertion losses lower than otherwise achievable, and allows maximizing the dynamic range of a communication front-end without the need for a variable gain low noise amplifier.

A method includes forming a resonator comprising a plurality of switched impedances spatially distributed within the resonator, selecting a resonant frequency for the resonator, and distributing two or more transconductance elements within the resonator based on the selected resonant frequency. Distributing the two or more transconductance elements may include non-uniformly distributing the two or more transconductance elements within the resonator.

A method includes forming a resonator comprising a plurality of switched impedances spatially distributed within the resonator, selecting a resonant frequency for the resonator, and distributing two or more transconductance elements within the resonator based on the selected resonant frequency. Distributing the two or more transconductance elements may include non-uniformly distributing the two or more transconductance elements within the resonator.

A voltage and current generator (1) includes an operation interface (11) that receives an operation from a user, an output stage (16) that outputs an electrical signal to a load (30), detectors (17, 18) that detect a measured value of the electrical signal outputted by the output stage (16), and a control calculator (15) that controls operation of the output stage (16), based on the deviation between a target value of the electrical signal as set by the user via the operation interface (11) and the measured value of the electrical signal as detected by the detector, so that the measured value of the electrical signal approaches the target value. The control calculator (15) performs control, including a compensation operation to cancel a low-pass filter effect in output resistance of the output stage (16) and the load (30), based on an impedance of the load (30) as set by the user via the operation interface (11).

A coupling module can be used to communicate high speed signals between an optical transceiver and a processing module of an optical communication device, such as an optical line termination (OLT) or an optical network unit (ONU). The coupling module can adjust the DC offset voltage level of the signal output by the optical transceiver to the DC offset voltage level required by the processing module. In addition, the coupling module splits the output signal from the optical transceiver and passes the signal to both a high pass filter and a low pass filter that are connected in parallel. The outputs of the high pass filter and the low pass filter are then combined and provided to the processing module. The high pass filter and the low pass filter can be configured such that all frequencies of the signal from the optical transceiver are provided to the processing module.

A tunable multi-path filter, a method for filtering a radio frequency signal with the tunable multi-path filter, and a communication device including the tunable multi-path filter. In one embodiment, the tunable multi-path filter includes a voltage controlled current source, an oscillator source, and at least two filter paths. The voltage controlled current source for receiving a radio frequency (RF) signal and generating a current signal. The oscillator source for generating a tunable clock signal. Each of the at least two filter paths are coupled to the voltage controlled current source and the oscillator source, and are configured to generate an output voltage signal based at least in part on the current signal and the tunable clock signal. In some embodiments, the tunable multi-path filter further includes a carrier signal rejection component that is configured to reduce the carrier feedthrough in the output voltage signals.

A method includes forming a resonator comprising a plurality of switched impedances spatially distributed within the resonator, selecting a resonant frequency for the resonator, and distributing two or more transconductance elements within the resonator based on the selected resonant frequency. Distributing the two or more transconductance elements may include non-uniformly distributing the two or more transconductance elements within the resonator.