A shaper circuit includes a first amplifier including an input and an output, the input being configured to receive an input signal, which includes one or more current pulses, a feedback component coupled to the output and to the input of the first amplifier thereby forming a feedback loop of the first amplifier, and an RC component coupled to the output of the first amplifier and to a reference potential terminal. Therein the shaper circuit is configured to provide an output signal as a function of the input signal, the output signal including one or more voltage pulses, and the RC component is configured to largely cancel a low frequency pole of the feedback loop of the first amplifier.

A load independent inverter comprises a switched mode zero-voltage switching (ZVS) amplifier. The switched mode ZVS amplifier comprising: a pair of circuits comprises: at least a transistor and at least a capacitor arranged in parallel; and at least an inductor arranged in series with the transistor and capacitor. The amplifier further comprises only one ZVS inductor connected to the pair of circuits; and at least a pair of capacitors connected to the ZVS inductor and arranged in series with at least an inductor and at least a resistor.

A room-temperature semiconductor maser, including a first matching network, a second matching network, a heterojunction-containing transistor, and a resonant network. The output end of the first matching network is connected to the drain of the heterojunction-containing transistor. The input end of the second matching network is connected to the source of the heterojunction-containing transistor. The gate of the heterojunction-containing transistor is connected to the resonant network. The pumped microwaves are fed into the input end of the first matching network.

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for a radio frequency (RF) receiver including a dual-mode low noise amplifier (LNA). One of the methods includes configuring the RF receiver to a wideband mode including operation over a multiple receive frequency (RX) bands including multiple frequencies, receiving, by the RF receiver, an input RF signal, scanning the multiple frequencies to detect a transmitted frequency of the input RF signal, configuring the RF receiver to narrowband mode including operation over a proper subset of the RX bands including a proper subset of the multiple frequencies, and tuning the RF receiver to the transmitted frequency.

A noise detecting circuit including an amplifier circuit amplifying an input signal indicating a noise level of a circuit to be detected and output an amplified signal; a filtering circuit receiving and filtering the amplified signal and output a filtered signal; and a comparing circuit receiving and compare the filtered signal to a reference voltage and output an output signal; wherein the filtering circuit includes: an output terminal; and a first filter selectively coupled to the output terminal, including: a sub-output terminal; a switch selectively coupling the sub-output terminal to the output terminal; a resistor, wherein a terminal of the resistor is coupled to the amplifier circuit and another terminal of the resistor is coupled to the sub-output terminal; and a capacitor, wherein a terminal of the capacitor is coupled to the sub-output terminal and another terminal of the capacitor is coupled to a reference voltage source.

A noise detecting circuit including an amplifier circuit amplifying an input signal indicating a noise level of a circuit to be detected and output an amplified signal; a filtering circuit receiving and filtering the amplified signal and output a filtered signal; and a comparing circuit receiving and compare the filtered signal to a reference voltage and output an output signal; wherein the filtering circuit includes: an output terminal; and a first filter selectively coupled to the output terminal, including: a sub-output terminal; a switch selectively coupling the sub-output terminal to the output terminal; a resistor, wherein a terminal of the resistor is coupled to the amplifier circuit and another terminal of the resistor is coupled to the sub-output terminal; and a capacitor, wherein a terminal of the capacitor is coupled to the sub-output terminal and another terminal of the capacitor is coupled to a reference voltage source.

Compact low noise amplifiers that have wide-band coverage while meeting necessary input matching and output matching characteristics. Embodiments include a wide-band, two-stage LNA with minimum degradation in performance compared to multiple narrow-band, single-stage LNAs. A generalized embodiment includes a first amplifier stage having a terminal coupled to a mutually coupled inductor circuit and to a second amplifier stage. The second amplifier stage includes a terminal coupled to the mutually coupled inductor circuit. The mutually coupled inductor circuit comprises electromagnetically coupled inductors L1, L2. Second terminals of the first and second amplifier stages are coupled to respective degeneration inductors. The electromagnetically coupled inductors L1, L2 of the inductor circuit substantially increase the output bandwidth of the LNA with minimum degradation in performance.

Compact low noise amplifiers that have wide-band coverage while meeting necessary input matching and output matching characteristics. Embodiments include a wide-band, two-stage LNA with minimum degradation in performance compared to multiple narrow-band, single-stage LNAs. A generalized embodiment includes a first amplifier stage having a terminal coupled to a mutually coupled inductor circuit and to a second amplifier stage. The second amplifier stage includes a terminal coupled to the mutually coupled inductor circuit. The mutually coupled inductor circuit comprises electromagnetically coupled inductors L1, L2. Second terminals of the first and second amplifier stages are coupled to respective degeneration inductors. The electromagnetically coupled inductors L1, L2 of the inductor circuit substantially increase the output bandwidth of the LNA with minimum degradation in performance.

Systems and methods for magnitude and phase trimming are provided. In one aspect, a radio frequency (RF) trimmer circuit includes an input terminal configured to receive an RF signal, an output terminal configured to output the RF signal, a control input configured to receive a control signal, at least one impedance element, and at least one transistor configured to selectively connect the impedance element onto a path between the input and output terminals. The selectively connecting the impedance element controls at least one of a magnitude trim and a phase trim of the RF signal.

Systems and methods for magnitude and phase trimming are provided. In one aspect, a radio frequency (RF) trimmer circuit includes an input terminal configured to receive an RF signal, an output terminal configured to output the RF signal, a control input configured to receive a control signal, at least one impedance element, and at least one transistor configured to selectively connect the impedance element onto a path between the input and output terminals. The selectively connecting the impedance element controls at least one of a magnitude trim and a phase trim of the RF signal.