A bandpass filter that provides a wide gain control range is provided. The bandpass filter performs channel filtering and gain control while maintaining the bandpass characteristic of the bandpass filter. The bandpass filter enables gain control for a wide signal amplitude range while maintaining performance characteristics, such as an out-of-band attenuation ratio capable of high linearity and good pass-band flatness.

The present invention discloses a gain-boosted n-path passive-mixer-first receiver. According to another aspect of the present disclosure, a gain-boosted n-path passive-mixer-first receiver is provided. The receiver includes a number n of switch-capacitor (sc) sets, a resistor, and a transconductance amplifier. The sc sets connect in parallel, and the sc sets have a first node and a second node. The resistor connects to the first node. The transconductance amplifier connects to the resistor and the second node.

According to another aspect of the present disclosure, a radio-frequency-to-baseband-function-reuse receiver with shared amplifiers for common-mode and differential-mode amplification is provided. The receiver includes two set networks connected in parallel. The set networks includes a first and a second input capacitors, a first and a second output capacitors, a first transconductance amplifier having an input terminal, a second transconductance amplifier having an input terminal, a first switch, and a second switch. The first and the second input capacitors connect to a first node. The first and the second output capacitors connect to a second node. The first transconductance amplifier connects between the first input capacitor and the first output capacitor. The second transconductance amplifier connects between the second input capacitor and the second output capacitor. The first switch connects between the input terminal of the first transconductance amplifier and the second node. The second switch connects between the input terminal of the second transconductance amplifier and the second node.

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.

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.

A high- and low-pass network circuit with integrated amplitude-phase regulation, including a high- and low-pass network phase-shift unit circuit and amplitude modulation unit subcircuits each including an amplitude modulation switch transistor and a resistor connected in parallel. The high- and low-pass network phase-shift unit circuit includes high-pass and low-pass network subcircuits. A first end of the high-pass network subcircuit is connected to a first end of the low-pass network subcircuit through phase modulation switch transistors M1 and M3. A second end of the high-pass network subcircuit is connected to a second end of the low-pass network subcircuit through phase modulation switch transistors M2 and M4. Body ends of M1 and M2 are connected through two amplitude modulation unit subcircuits. Body ends of M3 and M4 are connected through another two amplitude modulation unit subcircuits. A method for controlling such network circuit is also provided.