An electronic device includes: an antenna, a PAM including a PA configured to amplify a transmitting signal and a protection circuit, a PMIC configured to supply voltage to the PA, and at least one processor is configured to: provide a first signal, to a NAND gate in the protection circuit, provide to a AND gate in the protection circuit, a second signal indicating a result of a logical operation between the first signal and a bias enable signal for the PA, provide to the AND gate, a third signal indicating whether the transmitting signal is input to the PAM, provide to a switching circuit, a fourth signal indicating a result of logical operation between the second signal and the third signal, identify whether to apply a bias voltage to the PA based on the fourth signal, and transmit the transmitting signal, to the external electronic device, via the antenna.

An acoustic wave device includes a piezoelectric substrate including a support substrate and a piezoelectric layer on the support substrate, the piezoelectric substrate including a first principal surface on the piezoelectric layer side, and a second principal surface on the support substrate side, an IDT electrode on the first principal surface, a support layer on the support substrate, a cover on the support layer, a through-via electrode provided through the support substrate and electrically connected to the IDT electrode, a first wiring electrode on the second principal surface of the piezoelectric substrate and electrically connected to the through-via electrode, and a protective film on the second principal surface to cover at least a portion of the first wiring electrode. The protective film is provided on an inner side of the support layer when viewed in a direction normal or substantially normal to the second principal surface.

A radio frequency module includes: a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; a power amplifier configured to amplify a transmission signal; a first circuit component; and a power amplifier (PA) control circuit configured to control the power amplifier. The power amplifier and the PA control circuit are stacked on the first principal surface, and the first circuit component is disposed on the second principal surface.

A radio frequency circuit includes a power amplifier configured to selectively amplify one of a first radio frequency signal and a second radio frequency signal that have different bandwidths, and when the first radio frequency signal is input to the power amplifier, a first bias signal is applied to the power amplifier, and when the second radio frequency signal is input to the power amplifier, a second bias signal different from the first bias signal is applied to the power amplifier.

A receiver front end having low noise amplifiers (LNAs) is disclosed herein. A cascode having a “common source” configured input FET and a “common gate” configured output FET can be turned on or off using the gate of the output FET. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input FET of each LNA. A drain switch is provided between the drain terminals of input FETs to place the input FETs in parallel. This increases the g.sub.m of the input stage of the amplifier, thus improving the noise figure of the amplifier.

In a high-frequency module, a plurality of filters are connected to a first switch. A plurality of amplifiers are connected to a second switch. A first inductor is disposed on a common path between a second common terminal of the second switch and a first common terminal of the first switch. A plurality of second inductors are disposed, on a one-to-one correspondence, in sections different from the common path, the sections being included in the plurality of respective signal paths. The first inductor is a surface mount inductor located on a first main surface of a mounting substrate. The plurality of second inductors are each an inductor disposed within an IC chip including the plurality of amplifiers or an inductor including a conductive pattern formed in or on the mounting substrate.

Disclosed is a radio frequency circuit, a method of transmitting and receiving radio frequency signals, and a wireless communication device. The radio frequency circuit includes a first radio frequency amplifier, a second radio frequency amplifier, a first channel switch, a first low noise amplifier, a second low noise amplifier, and a second channel switch; the first radio frequency amplifier and the second radio frequency amplifier are connected with a plurality of antennas through the first channel switch, respectively, and are connected with a plurality of SRS antennas through an SRS switch in the first channel switch; the first low noise amplifier and the second low noise amplifier are connected with the plurality of antennas through the first channel switch, respectively, and are connected with a receiver through the second channel switch, respectively; wherein, the first radio frequency amplifier or the second radio frequency amplifier transmits one channel of radio frequency transmission signals to realize one-channel transmission, and the first low noise amplifier and the second low noise amplifier simultaneously receive radio frequency reception signals to realize two-channel reception.

A shunt switch. In some embodiments, the shunt switch includes a transistor stack including a first transistor and a capacitor. The transistor stack may have a first end terminal and a second end terminal, the first transistor being connected to the first end terminal, the first end terminal being connected to a switching terminal of the shunt switch. The capacitor may have a first terminal connected to the second end terminal of the transistor stack, and a second terminal connected to a low-impedance node.

A radio frequency module includes: a first terminal to which a signal of a first frequency band is inputted, the first frequency band being at least a portion of an unlicensed band higher than or equal to 5 GHz; a second terminal to which a signal of a second frequency band is inputted, the second frequency band being at least a portion of a licensed band lower than 5 GHz; a first amplifier configured to amplify a signal of the first frequency band inputted to the first terminal; and a second amplifier configured to amplify a signal of the second frequency band inputted to the second terminal. In the radio frequency module, the first amplifier and the second amplifier are disposed in one package.

A multi-band power amplifier module includes at least one transmission input terminal, at least one power amplifier circuit that receives a first transmission signal and a second transmission signal through the at least one transmission input terminal, a first filter circuit that allows the first transmission signal to pass therethrough, a second filter circuit that allows the second transmission signal to pass therethrough, at least one transmission output terminal through which the first and second transmission signals output from the first and second filter circuits are output, a transmission output switch that outputs each of the first and second transmission signals output from the at least one power amplifier circuit to the first filter circuit or the second filter circuit, and a first tuning circuit that adjusts impedance matching between the at least one power amplifier circuit and the at least one transmission output terminal.