A radio-frequency module includes a module substrate, a power amplifier, and a control circuit configured to control the power amplifier. The control circuit includes a temperature sensor. The power amplifier and the control circuit are stacked one on top of another on a principal surface of the module substrate.

A radio-frequency circuit is provided that includes a power amplifier, a control circuit, an on-off switch, a connection terminal, and a mount board. The power amplifier supports an APT system and an ET system. The control circuit controls the power amplifier by using the APT system and the ET system. The on-off switch is connected in series to a capacitive element connected between a path and the ground. The connection terminal is connected to the capacitive element. Moreover, the control circuit overlies the connection terminal in plan view in the thickness direction of the mount board.

A transceiver interface for a phased array element includes a first magnetic circuit having a primary coil and a secondary coil, a second magnetic circuit having a primary coil, a secondary coil and a tertiary coil, a main amplifier path and an auxiliary amplifier path, the main amplifier path coupled to the primary coil of the second magnetic circuit and configured to receive a quadrature signal, the main amplifier path configured to provide a quadrature output signal, the auxiliary amplifier path coupled to the primary coil of the first magnetic circuit and configured to receive an in-phase signal, the auxiliary amplifier path configured to provide an in-phase output signal, a selectable output circuit configured to selectively combine the in-phase output signal and the quadrature output signal, and a low noise amplifier (LNA) coupled to the tertiary coil of the second magnetic circuit.

A circuit for downlink/uplink operational mode switching in a TDD wireless communication system comprises a field-effect transistor operatively connected to a power amplifier on the downlink path of a RF front-end apparatus in a TDD wireless communication system, a first voltage generator connected to a large-value first resistor, a second voltage generator connected to a second resistor, a large-value hold capacitor, and a sample-and-hold circuit configured to be switched between a reception configuration, wherein the first voltage generator is connected to the gate of the field-effect transistor and the large-value capacitor is connected to the first voltage generator through the first resistor, and a transmission configuration, wherein the gate of the field-effect transistor is connected to the hold capacitor and the hold capacitor is connected to the second voltage generator through the second resistor.

A circuit for downlink/uplink operational mode switching in a TDD wireless communication system comprises a field-effect transistor operatively connected to a power amplifier on the downlink path of a RF front-end apparatus in a TDD wireless communication system, a first voltage generator connected to a large-value first resistor, a second voltage generator connected to a second resistor, a large-value hold capacitor, and a sample-and-hold circuit configured to be switched between a reception configuration, wherein the first voltage generator is connected to the gate of the field-effect transistor and the large-value capacitor is connected to the first voltage generator through the first resistor, and a transmission configuration, wherein the gate of the field-effect transistor is connected to the hold capacitor and the hold capacitor is connected to the second voltage generator through the second resistor.

An output switch includes; a plurality of input terminals and output terminals each of the plurality of input terminals is electrically connected to at least one of the plurality of output terminals; a first low noise amplifier that amplifies a signal of a predetermined frequency band input through an antenna and outputs a first signal to a first input terminal among the plurality of input terminals, and a second low noise amplifier that amplifies a signal of a predetermined frequency band input through an antenna and outputs a second signal to a second input terminal different from the first input terminal among the plurality of input terminals. A filter that attenuates a signal of a frequency band higher than a frequency band of the second signal is electrically connected between the second input terminal and the second low noise amplifier.

An output switch includes; a plurality of input terminals and output terminals each of the plurality of input terminals is electrically connected to at least one of the plurality of output terminals; a first low noise amplifier that amplifies a signal of a predetermined frequency band input through an antenna and outputs a first signal to a first input terminal among the plurality of input terminals, and a second low noise amplifier that amplifies a signal of a predetermined frequency band input through an antenna and outputs a second signal to a second input terminal different from the first input terminal among the plurality of input terminals. A filter that attenuates a signal of a frequency band higher than a frequency band of the second signal is electrically connected between the second input terminal and the second low noise amplifier.

Methods and devices to support multiple gain states in amplifiers are described. The methods and devices are based on implementing a feedback element in the amplifier and adjusting the impedance of the feedback element to provide a desired gain while maintaining the overall performance of the amplifier and reducing degradation of the S12 parameter. The feedback element includes an adjustable attenuator and a tunable resistive element. The adjustable attenuator is provided in a path that is common to the feedback path and the bypass path of the amplifier. Exemplary implementations of adjustable attenuators are also presented.

A front end module (FEM) integrated circuit (IC) architecture that uses the same LNA in each of several frequency bands extending over a wide frequency range. In some embodiments, switched impedance circuits distributed throughout the front end circuit allow selection of the frequency response and impedances that are optimized for particular performance parameters targeted for a desired device characteristic. Such switched impedance circuits tune the output and input impedance match and adjust the gain of the LNA for specific operating frequencies and gain targets. In addition, adjustments to the bias of the LNA can be used to optimize performance trade-offs between the total direct current (DC) power dissipated versus radio frequency (RF) performance. By selecting appropriate impedances throughout the circuit using switched impedance circuits, the LNA can be selectively tuned to operate optimally at a selected bias for operation within selected frequency bands.

A front end module (FEM) integrated circuit (IC) architecture that uses the same LNA in each of several frequency bands extending over a wide frequency range. In some embodiments, switched impedance circuits distributed throughout the front end circuit allow selection of the frequency response and impedances that are optimized for particular performance parameters targeted for a desired device characteristic. Such switched impedance circuits tune the output and input impedance match and adjust the gain of the LNA for specific operating frequencies and gain targets. In addition, adjustments to the bias of the LNA can be used to optimize performance trade-offs between the total direct current (DC) power dissipated versus radio frequency (RF) performance. By selecting appropriate impedances throughout the circuit using switched impedance circuits, the LNA can be selectively tuned to operate optimally at a selected bias for operation within selected frequency bands.