A TX/RX switch includes a power amplifier (PA), a Low Noise Amplifier (LNA), and an antenna connection. The PA is connected to a PA matching network that has a PA network impedance and a common PA-LNA impedance connected in one or more series-parallel combinations in different embodiments in a transmitting mode. The LNA is connected to a LNA matching network that has a LNA network impedance and the same common PA-LNA impedance connected in one or more series-parallel combinations in a receive mode. A mode switch can connect the common PA-LNA impedance in different configurations to enable the transmitting and receiving mode respectively. In some embodiments, the mode switch can short or open circuit the connection of the PA matching circuit or the LNA matching circuit to the antenna. In some embodiments, the mode switch can also turn power on or off to the PA or the LNA when the switch is in a mode where the respective amplifier is not selected. Accordingly, with specific design limitations on the common PA-LNA impedance combined with different mode switch configurations of the TX/RX switch components in either the TX or RX mode, the TX/RX switch operates within a design bandwidth without transmission lines embedded in the TX/RX switch circuitry and provides optimum power transfer from/to the antenna at the antenna connection with reduced noise.

An electronic device includes a network monitor configured to acquire network environment information related to a radio frequency (RF) transmission signal; a transceiver configured to generate an envelope signal of the RF transmission signal; a transmission (Tx) module including a power amplifier for receiving the RF transmission signal from the transceiver and amplifying the RF transmission signal; and an envelope tracking (ET) modulator configured to receive the envelope signal from the transceiver and to provide a bias of a power amplifier to correspond to the envelope signal, wherein the ET modulator determines a magnitude of the bias of the power amplifier based on the network environment information acquired by the network monitor.

A working state adjustment method is applied to a terminal. A power amplifier (PA) is arranged on the terminal. The method includes: determining a target channel bandwidth in which the terminal works; determining a target working state in which the PA works among optional working states according to the target channel bandwidth, in which the optional working states correspond to at least two types of working modes respectively; and adjusting the PA to work in the target working state.

A working state adjustment method is applied to a terminal. A power amplifier (PA) is arranged on the terminal. The method includes: determining a target channel bandwidth in which the terminal works; determining a target working state in which the PA works among optional working states according to the target channel bandwidth, in which the optional working states correspond to at least two types of working modes respectively; and adjusting the PA to work in the target working state.

A receiving circuit may include a first amplifying circuit, a second amplifying circuit, a third amplifying circuit, and a feedback circuit. The first amplifying circuit amplifies a first input signal and a second input signal to generate a first amplified signal and a second amplified signal, respectively. The second amplifying circuit amplifies the first amplified signal and the second amplified signal to generate a first preliminary output signal and a second preliminary output signal, respectively. The third amplifying circuit amplifies the first preliminary output signal and the second preliminary output signal to generate a first output signal and a second output signal, respectively. The feedback circuit changes voltage levels of the first amplified signal and the second amplified signal based on a current control signal, the first output signal, and the second output signal.

A broadband choke inductor is used in a bias circuit for broadband high-power distributed amplifiers.

A broadband choke inductor is used in a bias circuit for broadband high-power distributed amplifiers.

Provided are an interstage matching circuit and a push-pull power amplifier circuit. The push-pull power amplifier circuit comprises a pre-stage push-pull amplifier circuit and a post-stage push-pull amplifier circuit. The interstage matching circuit comprises a first matching capacitor connected in series between the pre-stage push-pull amplifier circuit and the post-stage push-pull amplifier circuit; and a second matching capacitor connected in series between the pre-stage push-pull amplifier circuit and the post-stage push-pull amplifier circuit; a first matching inductor is connected with a connection node between the pre-stage push-pull amplifier circuit and the first matching capacitor, the first matching inductor is connected with a second matching inductor, the second matching inductor is connected with a connection node between the pre-stage push-pull amplifier circuit and the second matching capacitor, and a connection node between the first matching inductor and the second matching inductor is used for connecting with a feed power supply.

Provided are an interstage matching circuit and a push-pull power amplifier circuit. The push-pull power amplifier circuit comprises a pre-stage push-pull amplifier circuit and a post-stage push-pull amplifier circuit. The interstage matching circuit comprises a first matching capacitor connected in series between the pre-stage push-pull amplifier circuit and the post-stage push-pull amplifier circuit; and a second matching capacitor connected in series between the pre-stage push-pull amplifier circuit and the post-stage push-pull amplifier circuit; a first matching inductor is connected with a connection node between the pre-stage push-pull amplifier circuit and the first matching capacitor, the first matching inductor is connected with a second matching inductor, the second matching inductor is connected with a connection node between the pre-stage push-pull amplifier circuit and the second matching capacitor, and a connection node between the first matching inductor and the second matching inductor is used for connecting with a feed power supply.

An amplifier includes: a high-frequency input terminal; a high-frequency output terminal; a multistage circuit provided between the high-frequency input terminal and the high-frequency output terminal and including two or more amplifiers and connected in series, each amplifier including an input matching circuit, a transistor, and an output matching circuit; a stabilizing circuit provided in at least two of the amplifiers and including a bandpass filter and a resistor connected in parallel; and a band-rejection filter provided between the at least two of amplifiers and eliminating a frequency lower than an operation frequency of the amplifier. The stabilizing circuit and the band-rejection filter are provided between an output terminal of the transistor of the amplifier and the output matching circuit or provided in the output matching circuit. The closer to the high-frequency input terminal the bandpass filter is, the lower a resonance frequency of the bandpass filter is.