Abstract: Radio-frequency performance of wireless communications circuitry on an electronic device under test (DUT) may be tested without external test equipment such as signal analyzers or signal generators. A first DUT may transmit test signals to a second DUT. External attenuator circuitry interposed between the DUTs may attenuate the test signals to desired power levels. The second DUT may characterize and/or calibrate receiver performance by generating wireless performance metric data based on the attenuated test signals. A single DUT may transmit test signals to itself via corresponding transmit and receive ports coupled together through the attenuator. The DUT may generate performance metric data based on the test signals. The DUT may include feedback receiver circuitry coupled to an output of a transmitter via a feedback path and may characterize and/or calibrate transmit performance using test signals transmitted by the transmitter and received by the feedback receiver.

Abstract: Systems and method for improving operation of a radio frequency system are provided. One embodiment includes instructions to execute a coarse calibration to associate a first output power with a first operational parameter set; instruct the radio frequency system to transmit a signal based at least in part on the first operational parameter set and a base detrough function; determine performance metrics resulting from transmission of the signal; determine changes in the performance metrics resulting from operating the radio frequency based at least in part on the first operational parameter set and each of a plurality of augmented detrough functions; and associate a second operational parameter set with a second output power, in which the second operational parameter set includes one of the plurality of augmented detrough functions selected based at least in part on the changes that reduce margin between the performance metrics and performance metric thresholds.

Abstract: An electronic device may include wireless communications circuitry that has first and second digital predistortion circuits. The first predistortion circuit receives a first signal at a first frequency while the second predistortion circuit receives a second signal at a second frequency. The first circuit may perform predistortion operations on the first signal using non-unity predistortion coefficients to generate a predistorted signal. The second circuit may apply unity predistortion coefficients to the second signal to generate an undistorted signal. An adder may combine the predistorted and undistorted signals to generate a combined signal that is amplified by amplifier circuitry. An antenna may transmit the amplified signal.

Abstract: An electronic device may include wireless communications circuitry that has first and second digital predistortion circuits. The first predistortion circuit receives a first signal at a first frequency while the second predistortion circuit receives a second signal at a second frequency. The first circuit may perform predistortion operations on the first signal using non-unity predistortion coefficients to generate a predistorted signal. The second circuit may apply unity predistortion coefficients to the second signal to generate an undistorted signal. An adder may combine the predistorted and undistorted signals to generate a combined signal that is amplified by amplifier circuitry. An antenna may transmit the amplified signal.

Abstract: Wireless communications circuitry in an electronic device may include power amplifier circuitry that is powered using a bias voltage supplied by adjustable power supply circuitry. The power supply circuitry may include envelope tracking circuitry that continuously adjusts the bias voltage. The wireless communications circuitry may generate test signals and may generate performance metric data from the test signals. Processing circuitry may generate bias voltage calibration data based on the performance metric data and may provide the calibration data to the envelope tracking circuitry. After the calibration data has been generated, the envelope tracking circuitry may continuously select bias voltages to provide to the amplifier based on the magnitude of signals that are transmitted and the calibration data. By actively adjusting the bias voltage in this way, power consumption may be minimized without generating undesirable harmonics or other radio-frequency performance requirement violations.

Abstract: Wireless communications circuitry in an electronic device may include power amplifier circuitry that is powered using a bias voltage supplied by adjustable power supply circuitry. The power supply circuitry may include envelope tracking circuitry that continuously adjusts the bias voltage. The wireless communications circuitry may generate test signals and may generate performance metric data from the test signals. Processing circuitry may generate bias voltage calibration data based on the performance metric data and may provide the calibration data to the envelope tracking circuitry. After the calibration data has been generated, the envelope tracking circuitry may continuously select bias voltages to provide to the amplifier based on the magnitude of signals that are transmitted and the calibration data. By actively adjusting the bias voltage in this way, power consumption may be minimized without generating undesirable harmonics or other radio-frequency performance requirement violations.

Abstract: Systems and method for improving operation of a radio frequency system are provided. One embodiment includes instructions to execute a coarse calibration to associate a first output power with a first operational parameter set; instruct the radio frequency system to transmit a signal based at least in part on the first operational parameter set and a base detrough function; determine performance metrics resulting from transmission of the signal; determine changes in the performance metrics resulting from operating the radio frequency based at least in part on the first operational parameter set and each of a plurality of augmented detrough functions; and associate a second operational parameter set with a second output power, in which the second operational parameter set includes one of the plurality of augmented detrough functions selected based at least in part on the changes that reduce margin between the performance metrics and performance metric thresholds.

Abstract: Radio-frequency performance of wireless communications circuitry on an electronic device under test (DUT) may be tested without external test equipment such as signal analyzers or signal generators. A first DUT may transmit test signals to a second DUT. External attenuator circuitry interposed between the DUTs may attenuate the test signals to desired power levels. The second DUT may characterize and/or calibrate receiver performance by generating wireless performance metric data based on the attenuated test signals. A single DUT may transmit test signals to itself via corresponding transmit and receive ports coupled together through the attenuator. The DUT may generate performance metric data based on the test signals. The DUT may include feedback receiver circuitry coupled to an output of a transmitter via a feedback, path and may characterize and/or calibrate transmit performance using test signals transmitted by the transmitter and received by the feedback receiver.

Abstract: A device under test (DUT) may be tested using a test station having a test host, a non-signaling tester, and a test cell. During testing, the DUT may be placed within the test cell, and the DUT may be coupled to the test host and the tester. In one suitable arrangement, the DUT may be loaded with a predetermined test sequence. The predetermined test sequence may configure the DUT to transmit test signals using different network access technologies without synchronizing with the tester. The tester may receive corresponding test signals and perform desired radio-frequency measurements. In another suitable arrangement, the tester may be loaded with the predetermined test sequence. The predetermined test sequence may configure the tester to generate test signals using different network access technologies without establishing a protocol-compliant data link with the DUT. The DUT may receive corresponding test signals and compute receive signal quality.

Abstract: A calibration system for calibrating wireless circuitry in an electronic device is provided. The test system may include test equipment, a computer, and a device under test (DUT). The test equipment may measure the output power of the DUT. The DUT may include power amplifier circuitry that is provided with a power supply voltage supplied by power supply circuitry. A list mode sequence of commands may be provided to the DUT and the test equipment to calibrate the power amplifier circuitry. The list of commands may be processed by the DUT to produce radio-frequency signals. The list of commands may be simultaneously processed by the test equipment to perform measurements on the radio-frequency signals. The computer may retrieve measurement data from the test equipment after testing is complete. The computer may subsequently determine calibrated control settings for the DUT that reduce power consumption while ensuring satisfactory adjacent channel leakage performance.

Abstract: Wireless test equipment may be used to perform over-the-air testing of user equipment. The user equipment may contain an antenna and a receiver. The wireless test equipment may contain a call box that performs network-level testing by sending and receiving protocol-compliant network messages. The call box may transmit a radio-frequency test signal at a predetermined power. The antenna in the user equipment may receive the radio-frequency test signal and may provide the received radio-frequency test signal to the input of the receiver. The call box may send a network message such as a code-division-multiple-access intercode handover command to the user equipment to direct the user equipment to measure the received radio-frequency test signal power at the input of the receiver. The measured power may be transmitted to the call box as part of a pilot measurement message indicator, using an intercode handover command, or using other network messages.

Abstract: A test system for testing wireless circuitry in an electronic device is provided. The test system may include a test host and a tester. The tester may provide radio-frequency test signals to a device under test (DUT). The DUT may include radio-frequency decoding circuitry that processes the test signals using a communications protocol and digital demodulator circuitry that processes the test signals without using the communications protocol. The digital demodulator circuitry may include transformation circuitry that performs fast Fourier transforms on the test signals to create frequency-domain performance data. The test host may compute a noise floor and signal-to-noise ratio based on the frequency-domain performance data. The test host may compare the computed noise floor and signal-to-noise ratio to predetermined thresholds to characterize the radio-frequency performance of the wireless circuitry.

Abstract: A calibration system for calibrating wireless circuitry in an electronic device is provided. The test system may include test equipment, a computer, and a device under test (DUT). The test equipment may measure the output power of the DUT. The DUT may include power amplifier circuitry that is provided with a power supply voltage supplied by power supply circuitry. A list mode sequence of commands may be provided to the DUT and the test equipment to calibrate the power amplifier circuitry. The list of commands may be processed by the DUT to produce radio-frequency signals. The list of commands may be simultaneously processed by the test equipment to perform measurements on the radio-frequency signals. The computer may retrieve measurement data from the test equipment after testing is complete. The computer may subsequently determine calibrated control settings for the DUT that reduce power consumption while ensuring satisfactory adjacent channel leakage performance.

Abstract: A device under test (DUT) may be tested using a test station having a test host, a non-signaling tester, and a test cell. During testing, the DUT may be placed within the test cell, and the DUT may be coupled to the test host and the tester. In one suitable arrangement, the DUT may be loaded with a predetermined test sequence. The predetermined test sequence may configure the DUT to transmit test signals using different network access technologies without synchronizing with the tester. The tester may receive corresponding test signals and perform desired radio-frequency measurements. In another suitable arrangement, the tester may be loaded with the predetermined test sequence. The predetermined test sequence may configure the tester to generate test signals using different network access technologies without establishing a protocol-compliant data link with the DUT. The DUT may receive corresponding test signals and compute receive signal quality.

Abstract: A test station may include a test host, a test unit, and a test chamber. Multiple devices under test (DUTs) may be placed in the test chamber during wireless testing. Radio-frequency signals may be conveyed between the test unit and the multiple DUTs using a conducted arrangement through a splitter-combiner circuit or using a radiated arrangement through a test antenna in the test chamber. The multiple DUTs may be synced to the test unit one DUT at a time (in series) or in parallel. The test host may direct the test unit to broadcast downlink signals at a given channel. The test host my direct a selected DUT to transmit uplink signals at the given channel or at a selected channel that is different from the given channel. The test unit may be used to perform desired measurement on the uplink signals transmitted from the selected DUT.

Abstract: A method for contemporaneously testing multiple digital data packet transceivers using predefined UL test sequences of synchronized data packets by pre-configuring test measurements, and multiplexing and interleaving portions of the data packets from the devices under test (DUTs).

Abstract: Wireless test equipment may be used to perform over-the-air testing of user equipment. The user equipment may contain an antenna and a receiver. The wireless test equipment may contain a call box that performs network-level testing by sending and receiving protocol-compliant network messages. The call box may transmit a radio-frequency test signal at a predetermined power. The antenna in the user equipment may receive the radio-frequency test signal and may provide the received radio-frequency test signal to the input of the receiver. The call box may send a network message such as a code-division-multiple-access intercode handover command to the user equipment to direct the user equipment to measure the received radio-frequency test signal power at the input of the receiver. The measured power may be transmitted to the call box as part of a pilot measurement message indicator, using an intercode handover command, or using other network messages.

Abstract: A method for contemporaneously testing multiple digital data packet transceivers using predefined UL test sequences of synchronized data packets by pre-configuring test measurements, and multiplexing and interleaving portions of the data packets from the devices under test (DUTs).

Abstract: A method and apparatus for testing a data signal amplifier having an output signal power dependent upon multiple signal power control parameters, e.g., signal gain control and amplifier bias current control.

Abstract: A method for testing a radio frequency (RF) receiver as a device under test (DUT) with one or more test instruments to provide a plurality of relative power correction factors, a plurality of received signal strength indication (RSSI) calibration factors, or both.