This embodiment discloses a dual-band signal booster for a public safety radio network. The signal booster disclosed herein performs a low-noise amplification and a frequency down/up conversion on a radio frequency signal received from a donor antenna, amplifies the amplified and converted signal to a high-power level, and transmits the amplified signal to a service antenna. Further, the signal booster disclosed herein performs the low-noise amplification and the frequency down/up conversion on a radio frequency signal received from the service antenna, amplifies the amplified and converted signal to a high-power level, and transmits the amplified signal to the donor antenna. According to this embodiment, it is possible to simultaneously service a plurality of channels to increase a communication capacity. Further, it is possible to variably set a class, frequency and bandwidth of each channel as needed, which makes it possible to provide communication qualities optimized according to installation field conditions.

A feedforward echo cancellation device includes: a first impedance circuit for responding to a transmission current to output a first current to a node; an echo cancellation current generating circuit for drawing an echo cancellation current from the node; a circuit module that is coupled to the echo cancellation current generating circuit and the node has a first impedance value adjusted based on a system convergence index of a communication device, where the first impedance value is used to determine a gain of a programmable gain amplifier in the communication device; and a second impedance circuit for responding to the transmission current to output a second current to the node, where a second impedance value of the second impedance circuit is adjusted based on the first impedance value of the circuit module accordingly. Specifically, the node is coupled to an input terminal of the programmable gain amplifier.

A feed forward echo cancellation device includes a first impedance circuit, a second impedance circuit, and an echo cancellation current generator circuit. The first impedance circuit is configured to output a first current to a node in response to a transmission current. The second impedance circuit is configured to output a second current to a node in response to the transmission current. The echo cancellation current generator circuit is configured to drain an echo cancellation current from the node. The node is connected to an input terminal of a programmable gain amplifier circuit via a gain control circuit, and the gain control circuit is configured to set a gain of the programmable gain amplifier circuit.

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.

Provided is a high frequency communication apparatus and method for vehicle. The high frequency communication apparatus for vehicle includes a communication module configured to process a radio frequency (RF) signal; a cable having one end connected to the communication module; and an antenna module connected to the other end of the cable and configured to transmit through an antenna the RF signal delivered from the communication module, the antenna module including a compensator configured to compensate for a loss of the RF signal in the cable and a controller configured to determine an amount of compensation for the loss in the cable based on power of the RF signal transmitted from the compensator.

Disclosed in the present invention are a radio frequency power amplifier, a radio frequency front-end module, and a communication terminal. The power amplifier includes a control unit, a power amplification unit, a detection and comparison unit, and a gain adjustment unit. According to a function relationship between the gain of the power amplification unit and the output power of the power amplification unit in different frequency bands and different power level modes, the control unit adjusts a function relationship between an adjustment current generated by the gain adjustment unit and a bias current of the power amplification unit; then the detection and comparison unit compares the bias current, of the power amplification unit with a reference current; according to the comparison result, the control unit controls whether the gain adjustment unit needs to generate an adjustment current and output the same to the power amplification unit.

In an electronic device and an operation method of the electronic device according to various embodiments, a communication circuit of the electronic device may comprise: a first transmission chain which outputs a first transmission signal through a first antenna; a second transmission chain which outputs a second transmission signal through a second antenna; a first amplifier which is electrically connected to the first transmission chain, and amplifies the first transmission signal output from the first transmission chain; and a second amplifier which is electrically connected to the second transmission chain, and amplifies the second transmission signal output from the second transmission chain, where the second amplifier is configured to have an output end connected to an output end of the first amplifier through a transmission line, and output the second transmission signal received from the second transmission chain to the first antenna through the transmission line. Various other embodiments may be possible.

In some examples, a system includes a transceiver configured to transmit a first surveillance message at a first power level at or below a first maximum power level. The system also includes processing circuitry coupled to the transceiver, the processing circuitry configured to determine that a threshold condition exists. The processing circuitry is also configured to determine a second maximum power level in response to determining that the threshold condition exists, where the second maximum power level is lower than the first maximum power level. The transceiver is configured to transmit, in response to the processing circuitry determining that the threshold condition exists, a second surveillance message at a second power level, wherein the second power level is at or below the second maximum power level.

A power radio frequency (RF) switch used in wireless communication is disclosed. A boosted switching control signal, which swings between a boosted supply voltage in which a system supply voltage is boosted and a negative supply voltage in which a polarity of the system supply voltage is inverted, is applied to a gate of a high-voltage transistor. Further, a substrate control signal which is synchronized with the boosted switching control signal, and swings between the negative supply voltage and a reference voltage may be applied to a substrate of the high-voltage transistor thereof.

Disclosed is an envelope tracking (ET) system having a transmit (TX) section, a power amplifier (PA), a fast switched-mode power supply (Fast SMPS), and control circuitry. The TX section receives an input signal and provides a modulated signal to the PA. The TX section also generates an ET signal based on a modulation envelope of the modulated signal. The TX section provides an envelope control (EC) signal based on the ET signal to modulate a supply signal provided to the PA by the Fast SMPS. The control circuitry provides a transmit TX gain signal and an ET gain signal to the TX section based on a PA temperature signal, a TX temperature signal, a target power signal, a measured power signal. The control circuitry is configured to maintain the efficiency and linearity of the PA over a wide operating temperature range.