Abstract: An outdoor microwave radio, which supports two channels aggregation, includes a cable interface, a radio frequency processing section, and an antenna coupling section. The cable interface includes two cables, each cable configured to receive an analog intermediate frequency signal from a modem output at a remote indoor microwave radio. The radio frequency processing section configured to process the two analog intermediate frequency signals into one analog radio frequency signal. The antenna coupling section includes a co-plane circulator for connecting to an antenna and transmitting the analog radio frequency signal using the antenna.

Abstract: A method for biasing a power amplifier using a transmission signal having a time-varying envelope is provided. The method comprises producing a time-varying signal indicative of an amplitude of the envelope of the transmission signal and comparing the time-varying signal to a plurality of distinct threshold voltages. The method further comprises, for each of the plurality of distinct threshold voltages exceeded by the time-varying signal, providing a respective bias voltage to a respective input of a summing device and producing, using the summing device, an output bias voltage that is at least a sum of the respective bias voltages provided to the respective inputs of the summing device. The method further comprises biasing the power amplifier with the output bias voltage and amplifying the transmission signal using the power amplifier biased at the output bias voltage.

Abstract: An antenna coupling unit (ACU) is provided. The ACU includes a transmitter port, a receiver port, and an antenna port; a circulator isolating the transmitter port from the receiver port; a first waveguide coupling the transmitter port with the circulator. The transmitter port receives an outgoing from first external circuitry. The first waveguide includes a first filter that filters the outgoing before routing the outgoing signal to the antenna port. The ACU further includes a second waveguide coupling the circulator with the receiver port. The second waveguide includes a second filter that filters an incoming received through the antenna port before routing the incoming signal to the receiver port. The receiver port provides the filtered incoming to second external circuitry. The ACU further includes a third waveguide coupling the antenna port with the circulator. At least one of the first filter and the second filter is a tunable filter.

Abstract: A digital microwave radio system includes a splitter that splits a common baseband input into two baseband outputs, first and second transmitters, each transmitter electrically connected to a baseband output of the splitter via a mixer, a common local oscillator electrically connected to the mixer of the first transmitter and the mixer of the second transmitter via an adjustable phase shifter, respectively, and a combiner. The common local oscillator is configured to up-convert each baseband output into a radio-frequency signal using a corresponding mixer. The combiner combines the two radio-frequency signals into a 0-degree phase-shift output and a 180-degree phase-shift output, respectively. A phase error control loop adjusts the phase shifter to minimize the 180-degree phase-shift radio-frequency output. A combiner gain control loop adjusts the output power level of the two transmitters in accordance with an actual power detector reading at the 0-degree phase-shift radio-frequency output.

Abstract: A method for biasing a power amplifier using a transmission signal having a time-varying envelope is provided. The method comprises producing a time-varying signal indicative of an amplitude of the envelope of the transmission signal and comparing the time-varying signal to a plurality of distinct threshold voltages. The method further comprises, for each of the plurality of distinct threshold voltages exceeded by the time-varying signal, providing a respective bias voltage to a respective input of a summing device and producing, using the summing device, an output bias voltage that is at least a sum of the respective bias voltages provided to the respective inputs of the summing device. The method further comprises biasing the power amplifier with the output bias voltage and amplifying the transmission signal using the power amplifier biased at the output bias voltage.

Abstract: A digital microwave radio system includes a splitter that splits a common baseband input into two baseband outputs, first and second transmitters, each transmitter electrically connected to a baseband output of the splitter via a mixer, a common local oscillator electrically connected to the mixer of the first transmitter and the mixer of the second transmitter via an adjustable phase shifter, respectively, and a combiner. The common local oscillator is configured to up-convert each baseband output into a radio-frequency signal using a corresponding mixer. The combiner combines the two radio-frequency signals into a 0-degree phase-shift output and a 180-degree phase-shift output, respectively. A phase error control loop adjusts the phase shifter to minimize the 180-degree phase-shift radio-frequency output. A combiner gain control loop adjusts the output power level of the two transmitters in accordance with an actual power detector reading at the 0-degree phase-shift radio-frequency output.

Abstract: An antenna RSSI meter includes a microcontroller unit for digitizing an antenna receiver voltage signal, converting the digitized antenna receiver voltage signal into a receiver signal level in accordance with a predefined antenna specification, and converting the receiver signal level into the antenna tuning signal in accordance with the predefined antenna specification. The antenna RSSI meter includes an input communication port for receiving the antenna receiver voltage signal from an antenna and providing the antenna receiver voltage signal to the microcontroller unit, The antenna RSSI meter also includes an output communication port for receiving the antenna tuning signal from the microcontroller unit and providing the antenna tuning signal to an antenna auto-aligning mechanism for adjusting position and orientation of the antenna.

Abstract: A microwave radio receiver includes a first down-converter, a second down-converter, and a combined receiver signal level (RSL) and interference detector. The first down-converter is configured to convert a RF signal into a first IF signal. The second down-converter is configured to convert the first IF signal into a second IF signal. The combined RSL and interference detector is configured to determine one or more RSLs and generate an interference indicator based on the first IF signal from the first down-converter and a control signal from the second down-converter.

Abstract: A method for performing digital predistortion to a microwave radio transceiver in response to an increase/decrease of transmit power level is disclosed. If the new transmit power level is higher than the current transmit power level, a set of digital predistortion (DPD) coefficients is applied to the transceiver before the issuance of a transmit power level increase command to the transceiver. Otherwise, a transmit power level decrease command is issued to the transceiver before the application of the set of DPD coefficients to the transceiver. Determining the set of DPD coefficients for the transceiver involves two stages: (i) calibrating the transceiver at a room temperature under predefined conditions and generating a DPD lookup table including DPD coefficients at a plurality of predefined temperatures other than the room temperature and (ii) determining the set of DPD coefficients for a given set of operating conditions using entries in the DPD lookup table.

Abstract: A method of providing multiple voltage references to a radio-frequency device using a single analog line includes the steps of setting the analog line voltage level to be a first reference voltage signal; instructing a first voltage reference device to memorize the first reference voltage signal by sending a first digital control signal to a digital line; providing the first reference voltage signal to the RF device via the first voltage reference device; re-setting the analog line voltage level to be a second reference voltage signal; instructing a second voltage reference device to memorize the second reference voltage signal by sending a second digital control signal to the digital line, the second digital control signal being different from the first digital control signal; and providing the second reference voltage signal to the RF device via the second voltage reference device.

Abstract: A transceiver used in a radio unit for wireless communication, comprises: a circuitry board including a transmitter and a receiver; a first connector on a first side of the circuitry board, wherein the first connector is configured to be connected to an interface card; a second connector on a second side of the circuitry board, wherein the second side is opposite the first side and the second connector is configured to be connected to a digital card via a flexible circuit; and a pair of transmit port and receive port located on the second side of the circuitry board, wherein the transmit port is coupled to the transmitter and the receive port coupled to the receiver, respectively. When the transceiver is part of a split-mount radio unit (SRU), the first connector is connected to the interface card and the second connector is not in use. When the transceiver is part of an all-outdoor radio unit (AOU), the second connector is connected to the digital card and the first connector is not in use.

Abstract: A method of providing multiple voltage references to a radio-frequency device using a single analog line includes the steps of setting the analog line voltage level to be a first reference voltage signal; instructing a first voltage reference device to memorize the first reference voltage signal by sending a first digital control signal to a digital line; providing the first reference voltage signal to the RF device via the first voltage reference device; re-setting the analog line voltage level to be a second reference voltage signal; instructing a second voltage reference device to memorize the second reference voltage signal by sending a second digital control signal to the digital line, the second digital control signal being different from the first digital control signal; and providing the second reference voltage signal to the RF device via the second voltage reference device.

Abstract: A system includes a control board, a controlled board, and a connector connecting the control board to the controlled board. The control board includes a processing unit that configures the reference voltage signals, a non-volatile memory that stores information about the reference voltage signals, and a DAC that outputs the reference voltage signals in accordance with instructions from the processing unit. The controlled board includes: first and second voltage reference devices that receive first and second reference voltage signals, respectively, and a radio-frequency device that receives a first frequency signal and a second frequency signal and outputs a third frequency signal based on one of the first and second reference voltage signals. The connector includes an analog line for providing reference voltage signals to the first and second voltage reference devices and a digital line for providing control signals to activate one of the first and second voltage reference devices.

Abstract: A transceiver used in a radio unit for wireless communication, comprises: a circuitry board including a transmitter and a receiver; a first connector on a first side of the circuitry board, wherein the first connector is configured to be connected to an interface card; a second connector on a second side of the circuitry board, wherein the second side is opposite the first side and the second connector is configured to be connected to a digital card via a flexible circuit; and a pair of transmit port and receive port located on the second side of the circuitry board, wherein the transmit port is coupled to the transmitter and the receive port coupled to the receiver, respectively. When the transceiver is part of a split-mount radio unit (SRU), the first connector is connected to the interface card and the second connector is not in use. When the transceiver is part of an all-outdoor radio unit (AOU), the second con vector is connected to the digital card and the first connector is not in use.

Abstract: A microwave radio receiver includes a first down-converter, a second down-converter, and a combined receiver signal level (RSL) and interference detector. The first down-converter is configured to convert a RF signal into a first IF signal. The second down-converter is configured to convert the first IF signal into a second IF signal. The combined RSL and interference detector is configured to determine one or more RSLs and generate an interference indicator based on the first IF signal from the first down-converter and a control signal from the second down-converter.

Abstract: An antenna RSSI meter includes a microcontroller unit for digitizing an antenna receiver voltage signal, converting the digitized antenna receiver voltage signal into a receiver signal level in accordance with a predefined antenna specification, and converting the receiver signal level into the antenna tuning signal in accordance with the predefined antenna specification. The antenna RSSI meter includes an input communication port for receiving the antenna receiver voltage signal from an antenna and providing the antenna receiver voltage signal to the microcontroller unit, The antenna RSSI meter also includes an output communication port for receiving the antenna tuning signal from the microcontroller unit and providing the antenna tuning signal to an antenna auto-aligning mechanism for adjusting position and orientation of the antenna.

Abstract: A system includes a control board, a controlled board, and a connector connecting the control board to the controlled board. The control board includes a processing unit that configures the reference voltage signals, a non-volatile memory that stores information about the reference voltage signals, and a DAC that outputs the reference voltage signals in accordance with instructions from the processing unit. The controlled board includes: first and second voltage reference devices that receive first and second reference voltage signals, respectively, and a radio-frequency device that receives a first frequency signal and a second frequency signal and outputs a third frequency signal based on one of the first and second reference voltage signals. The connector includes an analog line for providing reference voltage signals to the first and second voltage reference devices and a digital line for providing control signals to activate one of the first and second voltage reference devices.

Abstract: A method for performing digital predistortion to a microwave radio transceiver in response to an increase/decrease of transmit power level is disclosed. If the new transmit power level is higher than the current transmit power level, a set of digital predistortion (DPD) coefficients is applied to the transceiver before the issuance of a transmit power level increase command to the transceiver. Otherwise, a transmit power level decrease command is issued to the transceiver before the application of the set of DPD coefficients to the transceiver. Determining the set of DPD coefficients for the transceiver involves two stages: (i) calibrating the transceiver at a room temperature under predefined conditions and generating a DPD lookup table including DPD coefficients at a plurality of predefined temperatures other than the room temperature and (ii) determining the set of DPD coefficients for a given set of operating conditions using entries in the DPD lookup table.