A method comprises: measuring reflected and forward power at a power amplifier output; determining if the reflected power equals to or exceeds a first level; if the reflected power is equal to or exceeds the first level, then reduce power of a power amplifier input signal; determining if a standing wave ratio at the power amplifier output equals or exceeds a second level; if the standing wave ratio at the power amplifier output equals or exceeds the second level, then reducing the power amplifier input signal power level and/or sending an alarm; determining if the power amplifier output power equals or exceeds a third level; and if the power output from the power amplifier equals or exceeds the third level, then reducing the power amplifier input signal power level until such power level is less than or equal to the third level and/or sending an alarm.

A passive intermodulation detection system is provided to remotely identify passive intermodulation at a base station site and diagnose the type of intermodulation and location of the non-linearity that is the source of the passive intermodulation. A passive intermodulation cancelation system can generate an equivalent signal to a received interference signal and use the equivalent signal to generate an error signal. The error signal can then be used to reinforce a learning system and converge on a steady state of the interference signal to cancel other interference signals.

A transmitter circuit includes an amplifier configured to output a radio frequency (RF) signal on an output node, a power detection circuit coupled with the output node and configured to generate an output voltage having a first component based on a power level of the RF signal, and a reference voltage generator configured to generate a reference voltage. A comparator is configured to receive the output voltage and the reference voltage, an analog-to-digital converter (ADC) is coupled between the comparator and the amplifier, and the amplifier is configured to adjust the power level of the RF signal responsive to an output of the ADC.

A system includes a plurality of digital-to-analog converter (DAC) channels. Each DAC channel includes a current control circuit which receives a start limit signal or an end limit signal. The current control circuit reduces an output current limit of the channel responsive to the start limit signal and increases the output current limit responsive to the end limit signal. Each channel includes a current sensor circuit adapted to measure the output current of the channel and provide a channel over-current alert signal if the output current rises above a high current limit. The system includes a controller which asserts the start limit signal if the number of channels exceeding the high current limit is greater than a maximum allowable number and asserts the end limit signal if the number of channels exceeding the high current limit is less than the maximum allowable number minus a hysteresis value.

In accordance with one or more embodiments, a communication device includes a dual-band antenna array configured to communicate RF signals in an RF band and to communicate MMW signals in a MMW frequency band with a remote device. At least one transceiver is configured to generate the RF signals conveying a command to the remote device to transmit probe signals in the MMW frequency band, to receive the probe signals via the dual-band antenna in the MMW frequency band, and is initialized with first antenna beam steering parameters to facilitate a first antenna beam of the dual-band antenna array for the operation in the MMW frequency band. A controller is configured to generate the first antenna beam steering parameters based on the probe signals and to generate the control signal to switch the dual-band antenna array to the operation in the MMW frequency band after transmission of the RF signals.

Disclosed is an electronic device is provided. The electronic device includes a first substrate, a second substrate arranged to be spaced apart from the first substrate, a first cable electrically connecting a first point on the first substrate and a second point on the second substrate, and a second cable electrically connecting a third point on the first substrate and a fourth point on the second substrate. The first substrate may include a first communication circuit, a second communication circuit, a detection circuit, a voltage application unit, and a ground unit, and a second substrate may include a first antenna, a first capacitive element, a second antenna, a second capacitive element, and an isolation circuit. The isolation circuit may isolate a radio frequency (RF) signal between the first path and the second path, and electrically connect the detection circuit to the ground unit through the first cable and the second cable.

A power amplifier overcurrent protection circuit is provided. The overcurrent protection circuit protects a power amplifier that receives a bias current from a bias circuit and amplifies an input radio frequency (RF) signal. The current protection circuit includes an envelope detector configured to detect an envelope for a first voltage corresponding to an input radio frequency (RF) signal, a first transistor configured to receive a value of the envelope through a control terminal of the first transistor and turn on based on the value of the envelope to sink a current from a first node of a bias circuit, and a second transistor connected between a power source and the first transistor and including a control terminal connected to the first node of the bias circuit.

A system can comprise a radio unit comprising a transmitter, a receiver, and a power amplifier. The system can further comprise a hardware loopback that communicatively couples the transmitter and the receiver via an analog section of the radio unit, wherein the hardware loopback is selected at a component disposed between the transmitter and the power amplifier. The system can further comprise a hardware component that is configured to transmit a signal from the transmitter to the receiver via the hardware loopback.

A passive intermodulation detection system is provided to remotely identify passive intermodulation at a base station site and diagnose the type of intermodulation and location of the non-linearity that is the source of the passive intermodulation. A passive intermodulation cancelation system can generate an equivalent signal to a received interference signal and use the equivalent signal to generate an error signal. The error signal can then be used to reinforce a learning system and converge on a steady state of the interference signal to cancel other interference signals.

The present disclosure relates to a radio frequency (RF) communications system including an RF power amplifier (PA), a bias circuit, and a protection circuit. The RF PA has an amplifier control terminal and a power supply terminal, the bias circuit is coupled to the amplifier control terminal, and the protection circuit is coupled between the bias circuit and the power supply terminal. Herein, the protection circuit is configured to reduce a current through the power supply terminal using the bias circuit via the amplifier control terminal when the RF PA is in an operation mode and a magnitude of a voltage at the power supply terminal exceeds a protection threshold. Further, the protection circuit is configured to be open and does not allow a current to pass through when the RF PA is in a standby mode.