Devices, systems, and methods for multi-channel common-mode coupled alternating current (AC) gain amplifiers (MC-CM-AC Amp) are disclosed. The MC-CM-AC Amp can comprise a first operational amplifier including: a first non-inverting input port configured to be coupled to a first input signal, and a first inverting input port configured to be coupled to a first capacitor. The MC-CM-AC Amp can comprise a second operational amplifier including a second non-inverting input port configured to be coupled to a second input signal, and a second inverting input port configured to be coupled to a second capacitor. The MC-CM-AC Amp can comprise one or more gain-setting resistors configured to be coupled between the first capacitor and the second capacitor.

A program gain amplifier includes an operational amplifier and a capacitor array. The capacitor array includes a first, second, and third capacitors selectively coupled to the operational amplifier or ground according to a first, second, and third switches, respectively. The first, second, and third capacitors have a first, second, and third capacitance, respectively. The third capacitance equals a sum of the first and second capacitance. In a first configuration, the first and second switches are operated at a first conductive state, and the third switch is operated at a second conductive state. When converting to a second configuration from the first configuration, the third switch is operated at the first conductive state, and the first and second switches are operated at the second conductive state. The gain being provided to an input signal in the first and second configurations are the same.

Devices, systems, and methods for multi-channel common-mode coupled alternating current (AC) gain amplifiers (MC-CM-AC Amp) are disclosed. The MC-CM-AC Amp can comprise a first operational amplifier including: a first non-inverting input port configured to be coupled to a first input signal, and a first inverting input port configured to be coupled to a first capacitor. The MC-CM-AC Amp can comprise a second operational amplifier including a second non-inverting input port configured to be coupled to a second input signal, and a second inverting input port configured to be coupled to a second capacitor. The MC-CM-AC Amp can comprise one or more gain-setting resistors configured to be coupled between the first capacitor and the second capacitor.

An apparatus includes an input terminal to receive a radio frequency (RF) signal and to communicate the RF signal to a low noise amplifier (LNA) via an input signal path, and a capacitor attenuator coupled to the input terminal to attenuate the RF signal by a controllable amount and having a first portion controllable to include a used part configured on the input signal path and an unused part coupled between the input signal path and an AC reference node, and a second portion coupled between the LNA and the AC reference node.

Quadrature error correction (QEC) for radio transceivers are provided herein. In certain embodiments, a transceiver includes an in-phase (I) signal path including a first controllable amplifier coupled to a first data converter, and a quadrature-phase (Q) signal path including a second controllable amplifier coupled to a second data converter. The transceiver further includes a QEC circuit operable to correct for a quadrature error between the I signal path and the Q signal path by adjusting a gain of the first controllable amplifier and/or a gain of the second controllable amplifier.

Processes and systems for producing glass fibers having regions devoid of glass using submerged combustion melters, including feeding a vitrifiable feed material into a feed inlet of a melting zone of a melter vessel, and heating the vitrifiable material with at least one burner directing combustion products of an oxidant and a first fuel into the melting zone under a level of the molten material in the zone. One or more of the burners is configured to impart heat and turbulence to the molten material, producing a turbulent molten material comprising a plurality of bubbles suspended in the molten material, the bubbles comprising at least some of the combustion products, and optionally other gas species introduced by the burners. The molten material and bubbles are drawn through a bushing fluidly connected to a forehearth to produce a glass fiber comprising a plurality of interior regions substantially devoid of glass.

A logarithmic amplifier includes programmable gain amplifiers each having a different gain, wherein an input of each of the programmable gain amplifiers is coupled to an input of the logarithmic amplifier; and a summing circuit having inputs coupled to a corresponding output of each of the programmable gain amplifiers and an output coupled to an output of the logarithmic amplifier, wherein the summing circuit generates a logarithmic transfer function having piecewise linear segments.

Quadrature error correction (QEC) for radio transceivers are provided herein. In certain embodiments, a transceiver includes an in-phase (I) signal path including a first controllable amplifier coupled to a first data converter, and a quadrature-phase (Q) signal path including a second controllable amplifier coupled to a second data converter. The transceiver further includes a QEC circuit operable to correct for a quadrature error between the I signal path and the Q signal path by adjusting a gain of the first controllable amplifier and/or a gain of the second controllable amplifier.

A push-pull dynamic amplifier is operable in reset and amplification phases. The amplifier includes first NMOS and PMOS input transistors that are electrically coupled to a first input terminal and a first output terminal. Second NMOS and PMOS input transistors are electrically coupled to a second input terminal and a second output terminal. First and second reset switches are electrically coupled to the first and second output terminals, respectively. A power supply switch is electrically coupled to the first and the second PMOS transistors, and a ground switch is electrically coupled to the first and the second NMOS transistors. During the reset phase, the reset switches are closed and the power supply switch and the ground switch are opened. During the amplification phase, the reset switches are opened and the power supply switch and the ground switch are closed.

A signal receiving device includes a first amplifier, a duty cycle adjuster and a common mode feedback circuit. The first amplifier receives an input signal, a reference voltage and a bias voltage. The first amplifier generates a first common current based on the bias voltage and, based on the first common current, generates a first output signal and a second output signal complementary to each other by comparing the input signal and the reference voltage. The duty cycle adjuster charges and discharges a selected capacitor according to the first output signal or the second output signal to generate a sensing voltage, and generates a common reference voltage according to the sensing voltage. The common mode feedback circuit generates the bias voltage by comparing the common reference voltage and the reference voltage.