A multi-band radio frequency front-end device, a multi-band receiver, and a multi-band transmitter, the multi-band radio frequency front-end device including a first radio frequency front-end circuit, where the first radio frequency front-end circuit works on a first band, a second radio frequency front-end circuit, where the second radio frequency front-end circuit works on a second band, a first input/output matching network, and a second input/output matching network, where routing of the first input/output matching network and routing of the second input/output matching network on a layout are annular and nested.

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 mechanism is proposed to reduce overhead at the expense of increasing latency for UEs with weak link gain, while the latency for most UEs may remain the same. In one aspect of this disclosure, a UE may determine the number of attempts for transmitting a RACH signal based on one or more of path loss, the transmit power of the UE, the beam correspondence at the UE, or the power of signals received during the synchronization subframe. The UE may transmit the RACH signal in the determined number of attempts. In another aspect of the disclosure, a base station may combine signals of one or more RACH attempts to decode a RACH signal. The base station may inform a UE regarding the number of RACH subframes that the base station uses for decoding the RACH signal through a random access response message.

A radio frequency module includes a module board, a transmission power amplifier, a first inductance element mounted on a first principal surface and connected to an output terminal of the transmission power amplifier, a reception low-noise amplifier, and a second inductance element mounted on a first principal surface connected to an input terminal of the reception low-noise amplifier. In a plan view of the module board, a conductive member mounted on the first principal surface is disposed between the first inductance element and the second inductance element.

A selective filtering module is arranged to filter or process the digital baseband signal consistent with a target receiving bandwidth, where the selective filtering module comprises a narrowband rejection filter and wide-band filter configured to reject an interference component that interferes with the received radio frequency signal. The narrowband rejection filter is configured to reject a first interference component, where the narrowband rejection filter comprises an adaptive notch filter (NF). The wide band rejection filter is configured to reject a second interference component in accordance with a pulse blanking technique. An electronic data processor is adapted to control one or more filter coefficients of narrowband rejection filter and the wide band rejection filter in accordance with one or more strategic filter control factors among ADC saturation, activation/deactivation of the notch filter, and a wide-band spectrum analysis.

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.

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 signal feedback gain circuit is disclosed. The signal feedback gain circuit includes a signal input terminal, a summing point, a gain module, a signal output terminal and a plurality of feedback paths. The signal input terminal is for inputting a transmission signal. The summing point is connected to the signal input terminal. The gain module is connected to the summing point to input and adjust the gain of the transmission signal. The signal output terminal is for receiving the transmission signal and outputting it to an electronic module. The plurality of feedback paths are connected in parallel to the signal output terminals so as to input the transmission signal and are further connected in parallel to the summing point so as to feedback the transmission signal to the summing point. Accordingly, the plurality of feedback paths can adjust a gain curve of the transmission signal.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may adjust an amplifier of the UE to a highest gain state after a downlink period and before an uplink period. Additionally, the UE may adjust the amplifier of the UE to a lower gain state after the uplink period and before a subsequent downlink period. Numerous other aspects are described.

A radio frequency module includes a first transmission power amplifier configured to amplify a radio frequency signal of a first communication band, a second transmission power amplifier configured to amplify a radio frequency signal of a second communication band, and a module board which includes a first principal surface and a second principal surface on opposite sides of the module board, and on which the first transmission power amplifier and the second transmission power amplifier are mounted. The first transmission power amplifier is disposed on the first principal surface, and the second transmission power amplifier is disposed on the second principal surface.