A high frequency circuit includes a transistor having an input electrode that inputs a high frequency signal and an output electrode that outputs the high frequency signal, a transmission line that is connected to any one of the input electrode and the output electrode, and transmits the high frequency signal, a coupling line electrically separated from the transmission line to an extent that an electromagnetic field coupling is enabled with the transmission line, and a resonance circuit that is connected between a first end of the coupling line and a reference potential, and minimizes an impedance between the first end and the reference potential at a resonance frequency.

An amplifying system is provided for use as a high sensitivity receive booster or replacement for a low noise amplifier in a receive chain of a communication device. The amplifying system includes an amplifying circuit configured to receive an input signal having a first frequency and generate an oscillation based on the input signal, a sampling circuit coupled to the amplifying circuit and configured to terminate the oscillation based on a predetermined threshold to periodically clamp and restart the oscillation to generate a series of pulses modulated by the oscillation and by the input signal, and one or more resonant circuits coupled with the amplifying circuit and configured to establish a frequency of operation and to generate an output signal having a second frequency, the second frequency being substantially the same as the first frequency.

An amplifying system is provided for use as a high sensitivity receive booster or replacement for a low noise amplifier in a receive chain of a communication device. The amplifying system includes an amplifying circuit configured to receive an input signal having a first frequency and generate an oscillation based on the input signal, a sampling circuit coupled to the amplifying circuit and configured to terminate the oscillation based on a predetermined threshold to periodically clamp and restart the oscillation to generate a series of pulses modulated by the oscillation and by the input signal, and one or more resonant circuits coupled with the amplifying circuit and configured to establish a frequency of operation and to generate an output signal having a second frequency, the second frequency being substantially the same as the first frequency.

The present disclosure relates to a power amplifier (PA) system provided in a semiconductor device and having feed forward gain control. The PA system comprises a transmit path and control circuitry. The transmit path is configured to amplify an input radio frequency (RF) signal and comprises a first tank circuit and a PA stage. The control circuitry is configured to detect a power level associated with the input RF signal and control a first bias signal provided to the PA stage based on a first function of the power level and control a quality factor (Q) of the first tank circuit based on a second function of the power level.

A communication module includes a first input terminal to which a first signal of a first frequency band is input, a second input terminal to which a second signal of a second frequency band is input, an amplifier that outputs an amplified signal which is obtained by amplifying the first signal, a diplexer that receives the amplified signal and/or the second signal and that outputs an output signal of the first and/or second frequency band, and a harmonic termination circuit that short-circuits a harmonic of the second signal. The harmonic termination circuit has an end connected between the second input terminal and the diplexer, and another end grounded at a ground position. A distance in plan view between the first input terminal and the ground position of the harmonic termination circuit is longer than a distance in plan view between the first input terminal and the second input terminal.

An RF amplifier includes an amplifier input, a transistor die with a transistor and a transistor input terminal, a fundamental frequency impedance matching circuit coupled between the amplifier input and the transistor input terminal, and a harmonic frequency termination circuit coupled between the transistor input terminal and a ground reference node. The harmonic frequency termination circuit includes a first inductance coupled between the transistor input terminal and a first node, and a tank circuit coupled between the first node and the ground reference node. The tank circuit includes a first capacitance coupled between the first node and the ground reference node, and a second inductance coupled between the first node and the ground reference node. The tank circuit is configured to shunt signal energy at or near a second harmonic frequency, while appearing as an open circuit to signal energy at a fundamental frequency of operation of the RF amplifier.

A logarithmic detector amplifying (LDA) system is provided for use as a high sensitivity receive booster or replacement for a low noise amplifier in a receive chain of a communication device. The LDA system includes an amplifying circuit configured to receive an input signal having a first frequency and generate an oscillation based on the input signal, a sampling circuit coupled to the amplifying circuit and configured to terminate the oscillation based on a predetermined threshold to periodically clamp and restart the oscillation to generate a series of pulses modulated by the oscillation and by the input signal, and one or more resonant circuits coupled with the amplifying circuit and configured to establish a frequency of operation and to generate an output signal having a second frequency, the second frequency being substantially the same as the first frequency.

A high-frequency signal amplifier circuit is used in a front-end circuit configured to propagate a high-frequency transmission signal and a high-frequency reception signal, and includes an amplifier transistor configured to amplify the high-frequency transmission signal; a bias circuit configured to supply a bias to a signal input end of the amplifier transistor; and a ferrite bead, one end of which is connected to a bias output end of the bias circuit and the other end of which is connected to the signal input end of the amplifier transistor, having characteristics in which impedance in a difference frequency band between the high-frequency transmission signal and the high-frequency reception signal is higher than impedance in DC.

A logarithmic detector amplifying (LDA) system is provided for use as a high sensitivity receive booster or replacement for a low noise amplifier in a receive chain of a communication device. The LDA system includes an amplifying circuit configured to receive an input signal having a first frequency and generate an oscillation based on the input signal, a sampling circuit coupled to the amplifying circuit and configured to terminate the oscillation based on a predetermined threshold to periodically clamp and restart the oscillation to generate a series of pulses modulated by the oscillation and by the input signal, and one or more metamaterial (MTM) resonant circuits coupled in shunt with an RF path that couples the amplifying circuit in series and configured to establish a frequency of operation and a phase response to output a signal having RF frequencies with a ultra-wide bandwidth.

A radio frequency (RF) amplifier and a bias circuit are provided. The RF amplifier includes an amplifier, a first inductive-capacitive resonance circuit, and a first bias circuit. The amplifier includes an input terminal configured to receive an incoming RF signal through a first RF path. The first inductive-capacitive resonance circuit includes a first terminal coupled to a first reference voltage. A second terminal of the first inductive-capacitive resonance circuit is coupled to the first RF path. In response to the first reference voltage being at a first reference level, the RF amplifier is enabled; in response to the first reference voltage being at a second reference level, the RF amplifier is disabled. The first bias circuit includes a first terminal configured to be coupled to the first reference voltage and a second terminal coupled to the input terminal of the amplifier to provide a first direct current (DC) component.