In an embodiment, an amplifier circuit includes a second stage that includes a first switch circuit including first and second terminals, a plurality of resistive elements coupled between the first and second terminals of the first switch circuit, and a plurality of switches configured to control an equivalent resistance between the first and second terminals of the first switch circuit. During play mode, the second stage has a gain between the input of the second stage and the output of the second stage of a first value. During a transition from mute mode to play mode, the amplifier circuit is configured to progressively increase the gain of the second stage from a second value to the first value. During a transition from play mode to mute mode, the amplifier circuit is configured to progressively decrease the gain of the second stage from the first value to the second value.

An electronic device may include wireless circuitry with processor circuitry, a transceiver circuit, a front-end module, and an antenna. The front-end module may include amplifier circuitry such as low noise amplifier circuitry for amplifying received radio-frequency signals. The amplifier circuitry may include an amplifier having an input and an output, an adjustable load component coupled to the input, and an adjustable feedback component coupled across the input and output. A control circuit may simultaneously adjust the load and feedback components to tune the gain of the amplifier circuitry while maintaining the input resistance at a desired target level. The load and feedback components can be the same or different types of adjustable passive components.

To correct a difference in signal intensity due to a difference in hardware, for example, temporal deterioration of the hardware in the same device, or a difference in signal intensity between different devices. An adjustment method according to the disclosure specifies an amplification gain with which the same detection signal intensity as that of a comparison target is obtained by comparing correspondence relationships between the detection signal intensity and the amplification gain at different time points in the same charged particle beam device or among different charged particle beam devices.

A clamping circuit that may be used to provide efficient and effective voltage clamping in an RF front end. The clamping circuit comprises two series coupled signal path switches and a bypass switch coupled in parallel with the series coupled signal path switches. A diode is coupled from a point between the series coupled signal path switches to a reference potential. In addition, an output selection switch within an RF front end has integrated voltage clamping to more effectively clamp the output voltage from the RF front end. Additional output clamping circuits can be used at various places along a direct gain signal path, along an attenuated gain path and along a bypass path.

A variable gain amplifier includes input terminals configured to receive a differential input of the variable gain amplifier, output terminals configured to generate a differential output of the variable gain amplifier, the differential output having a gain applied by the variable gain amplifier to the differential input, and an impedance ladder circuit coupled to the input terminals, the impedance ladder circuit comprising a plurality of semiconductor switches configured to receive respective control signals based on a control voltage. The plurality of semiconductors switches are responsive to the respective control signals to adjust the gain of the variable gain amplifier and configured with a predetermined exponential scale such that the impedance ladder circuit causes a slope of the gain of the variable gain amplifier relative to the control voltage to be generally linear.

Optical network devices, optical receivers, Automatic Gain Control (AGC) circuits, and power detection systems are provided for detecting power of optical signals within an optical communication system. An optical network device, according to one implementation, includes a receiver configured to receive an optical signal. The optical network device also includes a low bandwidth path configured to detect a low-band power component of the optical signal within a channel of interest and a broad bandwidth path arranged in parallel with the low bandwidth path. The broad bandwidth path is configured to detect a broad-band power component of the optical signal within broad-band channels including at least the channel of interest. A power detection output is derived from the low-band power component and the broad-band power component.

Methods and systems for optimizing amplifier operations are described. The described methods and systems particularly describe a feed-forward control circuit that may also be used as a feed-back control circuit in certain applications. The feed-forward control circuit provides a control signal that may be used to configure an amplifier in a variety of ways.

Temperature compensation circuits and methods for adjusting one or more circuit parameters of a power amplifier (PA) to maintain approximately constant Gain versus time during pulsed operation sufficient to substantially offset self-heating of the PA. Some embodiments compensate for PA Gain “droop” due to self-heating using a Sample and Hold (S&H) circuit. The S&H circuit samples and holds an initial temperature of the PA at commencement of a pulse. Thereafter, the S&H circuit generates a continuous measurement that corresponds to the temperature of the PA during the remainder of the pulse. A Gain Control signal is generated that is a function of the difference between the initial temperature and the operating temperature of the PA as the PA self-heats for the duration of the pulse. The Gain Control signal is applied to one or more adjustable or tunable circuits within a PA to offset the Gain droop of the PA.

This disclosure relates to an apparatus and a method for adjusting a level of a low-noise amplifier (LNA), a terminal device, and a network-element device. The apparatus includes a LNA, a peak-to-average power ratio (PAPR) module, and an automatic gain control (AGC). The LNA is configured to amplify a received signal to obtain a first signal, where the received signal includes out-of-band interference and a target signal. The PAPR module is configured to measure a PAPR value of the first signal. The AGC module is configured to adjust a gain level of the LNA, according to the PAPR value, a maximum-linear-input-power point of the LNA, and a strength of the first signal.

An electronic device according to various embodiments of the present invention comprises: a housing; a plurality of antennas arranged on or inside the housing; a second communication circuit located inside the housing and electrically connected to the plurality of antennas; a first communication circuit, which is electrically connected to the second communication circuit, and generates a radio frequency (RF) signal or an intermediate frequency (IF) signal so as to transmit the RF or IF signal to the second communication circuit; a memory for storing at least one parameter set to correspond to the characteristic of the second communication circuit; and a control circuit electrically connected to the first communication circuit, wherein the control circuit can be set to transmit a control signal for controlling at least one amplifier included in the second communication circuit to the second communication circuit on the basis of the at least one parameter stored in the memory. Various embodiments of the present invention can be other embodiments.