A fire detector is connected to a loop transmission line connected to a receiver. When the loop transmission line is normal, a transmission unit is connected to the fire detector. When a disconnection failure occurs, a disconnection monitoring unit turns on switching circuits to connect the end of the loop transmission line to the transmission unit, and the receiver connects to the fire detector from both ends of the loop transmission line. An input/output switching booster is inserted and connected in the middle of the loop transmission line, and when the start side transmission line is disconnected and the switching circuits are turned on, the input/output is switched. Accordingly, the input/output switching booster amplifies the down signal input from the terminal side transmission line and outputs it to the start side transmission line and at the same time amplifies the up signal input from the start side transmission line.

A fire detector is connected to a loop transmission line connected to a receiver. When the loop transmission line is normal, a transmission unit is connected to the fire detector. When a disconnection failure occurs, a disconnection monitoring unit turns on switching circuits to connect the end of the loop transmission line to the transmission unit, and the receiver connects to the fire detector from both ends of the loop transmission line. An input/output switching booster is inserted and connected in the middle of the loop transmission line, and when the start side transmission line is disconnected and the switching circuits are turned on, the input/output is switched. Accordingly, the input/output switching booster amplifies the down signal input from the terminal side transmission line and outputs it to the start side transmission line and at the same time amplifies the up signal input from the start side transmission line.

Systems and methods are provided herein that include an improved RF switch assembly. In at least one embodiment, the RF switch assembly may have an optimized topology including a common node shared by each signal path, reducing the size and cost of the RF switch assembly and providing improved performance.

Systems and methods are provided herein that include an improved RF switch assembly. In at least one embodiment, the RF switch assembly may have an optimized topology including a common node shared by each signal path, reducing the size and cost of the RF switch assembly and providing improved performance.

A communication system has a galvanic isolation link coupling a first circuit to a second circuit. The first circuit transmits first data signals to the second circuit and receives second data signals from the second circuit in response to the first data signals. The data signals are transmitted in consecutive time slots of a determined time duration via the galvanic isolation link. The first data signals include polling signals transmitted from the first circuit to the second circuit during consecutive time slots, and on-demand access requests transmitted from the first circuit to the second circuit. The second data signals include status response signals transmitted from the second circuit to the first circuit in response to polling signals received from the first circuit, and access response signals transmitted from the second circuit to the first circuit in response to access requests received from the first circuit.

A communication system has a galvanic isolation link coupling a first circuit to a second circuit. The first circuit transmits first data signals to the second circuit and receives second data signals from the second circuit in response to the first data signals. The data signals are transmitted in consecutive time slots of a determined time duration via the galvanic isolation link. The first data signals include polling signals transmitted from the first circuit to the second circuit during consecutive time slots, and on-demand access requests transmitted from the first circuit to the second circuit. The second data signals include status response signals transmitted from the second circuit to the first circuit in response to polling signals received from the first circuit, and access response signals transmitted from the second circuit to the first circuit in response to access requests received from the first circuit.

A radio-frequency PA Mid device has a transmitting port and a plurality of antenna ports, and includes: a power amplifier having an input terminal connected to the transmitting port to perform a power amplification processing on a received radio-frequency signal; a first filtering unit connected to an output terminal of the power amplifier to perform a filtering processing on the received radio-frequency signal; and a multi-channel selection switch including at least one first terminal and a plurality of second terminals. One first terminal is connected to the first filtering unit, and the second terminals are connected to the antenna ports in a one-to-one correspondence to selectively switch on a transmitting path between the transmitting port and any one of the plurality of antenna ports, for transmitting the radio-frequency signal and supporting a function of polling transmission of a Sounding Reference Signal among the plurality of antenna ports.

A radio-frequency PA Mid device has a transmitting port and a plurality of antenna ports, and includes: a power amplifier having an input terminal connected to the transmitting port to perform a power amplification processing on a received radio-frequency signal; a first filtering unit connected to an output terminal of the power amplifier to perform a filtering processing on the received radio-frequency signal; and a multi-channel selection switch including at least one first terminal and a plurality of second terminals. One first terminal is connected to the first filtering unit, and the second terminals are connected to the antenna ports in a one-to-one correspondence to selectively switch on a transmitting path between the transmitting port and any one of the plurality of antenna ports, for transmitting the radio-frequency signal and supporting a function of polling transmission of a Sounding Reference Signal among the plurality of antenna ports.

A circuit portion for a radio transceiver comprises: a power amplifier for use when the transceiver operates in a transmission mode, a low-noise amplifier for use when the transceiver operates in a reception mode, a voltage control circuit portion, and a transformer. The transformer comprises a primary winding with a terminal for connecting to an antenna, and a secondary winding comprising a first terminal, a second terminal and a third terminal located between the first and second terminals. The power amplifier is connected to the secondary winding, the low-noise amplifier is connected to both the primary and secondary windings and the voltage control circuit portion is connected to the third terminal of the secondary winding. The voltage control circuit portion applies a first voltage to the third terminal when the transceiver operates in the transmission mode and applies a second, different voltage when the transceiver operates in the reception mode.

A multi-band radio frequency device uses a single tuning inductor and a multiple pole switch that switches small inductors in series with the tuning inductor provide tuning capability for the antenna switching module to operate over different frequency bands. The single tuning inductor replaces individual tuning inductors for each frequency band.