Apple Inc.

Adil Syed

Justin Lawrence Gregg

Tomoki Takeya

Vishwanath Venkataraman

Jason S Sloey

Joshua G Nickel

Jonathan M Haylock

David A Donovan

Thomas W Chang

Fernando Urioste

Song Liu

Wireless electronic devices may include wireless communications circuitry such as a transceiver, antenna, and other wireless circuitry. The transceiver may be coupled to the antenna through a bidirectional switch connector. The switch connector may mate with a corresponding radio-frequency test probe that is connected to radio-frequency test equipment. When the test probe is mated with the switch connector, the transceiver may be decoupled from the antenna. During transceiver testing, radio-frequency test signals may be conveyed between the test unit and the transceiver using the test probe. During antenna testing, radio-frequency test signals may be conveyed between the test unit and the antenna using the test probe. Transceiver testing and antenna testing may, if desired, be conducted in parallel using the test probe.

Bidirectional radio-frequency probing

A test system may include test equipment for testing the radio-frequency performance of wireless electronic devices. The test equipment may provide radio-frequency downlink signals to a wireless electronic device under test (DUT). The test equipment may perform a power sweep by stepping down the downlink signals in signal power level to test receiver sensitivity for the DUT. The DUT may gather measurement data from the downlink signals. The test equipment may retrieve measurement data from the DUT after downlink signal transmission has ended. The test equipment may identify a trigger in the retrieved measurement data to ensure that the data is synchronized with the power sweep in the transmitted downlink signals. The test equipment may identify path loss information associated with the test system. The test equipment may compute receiver sensitivity values for the DUT based on the path loss information and retrieved measurement data.

Methods for testing receiver sensitivity of wireless electronic devices

Calibration equipment for calibrating multiple test stations in a test system is provided. Each test station may include a test unit, a test fixture, and a radio-frequency (RF) cable that connects the test unit to the test fixture. A control test setup may be used to calibrate uplink and downlink characteristics associated with each test station (e.g., to determine path loss associated with the RF cable and test fixture and variations associated with the test unit). The control test setup may calibrate each test station at desired frequencies to generate a test station error (offset) table. The test unit of each test station may be individually configured based on the test station error table so that offset is minimized among the different stations and so that the test stations may reliably measure hundreds or thousands of wireless electronic devices during product testing.

Methods for calibration of radio-frequency path loss in radio-frequency test equipment

A test station may include a test host, a signal generator, and a test chamber. Multiple devices under test (DUTs) may be placed in the test chamber during production testing. Radio-frequency signals may be conveyed from the signal generator to the multiple DUTs using a conducted arrangement through a radio-frequency signal splitter circuit or using a radiated arrangement through an antenna in the test chamber. The signal generator may broadcast initialization downlink signals. The multiple DUTs may synchronize with the initialing downlink signals. The signal generator may broadcast test downlink signals at a target output power level. The multiple DUTs may receive the test downlink signals and compute a corresponding downlink transmission performance level based on the received downlink signals. A given DUT is marked as a passing DUT if the downlink performance level is satisfactory. A given DUT may be retested if the downlink performance level fails design criteria.

Simultaneous downlink testing for multiple devices in radio-frequency test systems

A method for testing wireless devices under test (DUTs) in a wireless test station is provided. Each test station may include a test unit, a test chamber with an antenna, and a radio-frequency (RF) cable that connects the test unit to the test chamber. Reference DUTs may be used to calibrate each test station to compute a corrected linear equation based on a nominal path loss value. Over-the-air (OTA) path loss of each test station may not be directly measured. Once calibrated, the test chambers may be used during product testing to test factory DUTs to determine whether a particular factory DUT satisfies pass/fail criteria. During product testing, measured output power levels may be compared with expected output power levels computed using the corrected linear equation. The amount of error between the measured and expected output power levels will determine whether a production DUT satisfies the pass/fail criteria.

Methods of testing wireless devices in over-the-air radio-frequency test systems without path loss characterization

A test station may include a test host, a signal generator, and a test chamber. Multiple devices under test (DUTs) may be placed in the test chamber during device characterization operations. Radio-frequency signals may be conveyed from the signal generator to the multiple DUTs using a radiated arrangement through an antenna in the test chamber. The signal generator may broadcast downlink test signals. The DUTs may synchronize with the downlink test signals and measure radio-frequency performance levels while receiving the downlink test signals. The test host may direct the signal generator to gradually lower its output power level. The DUTs may be used to determine downlink sensitivity by monitoring the measured radio-frequency performance levels as the output power level of the signal generator is lowered. Downlink sensitivity testing may be performed across any desired radio-frequency bands and channels.

Simultaneous sensitivity testing for multiple devices in radio-frequency test systems

A test station may include a test host, a tester, and a test chamber. Multiple devices under test (DUTs) may be placed in the test chamber during device characterization operations. Radio-frequency signals may be conveyed from the tester to the multiple DUTs using a radiated arrangement through an antenna in the test chamber. The tester may broadcast downlink test signals in parallel to the multiple DUTs. The DUTs may simultaneously synchronize with the downlink test signals and measure radio-frequency performance levels while receiving the downlink test signals. The test host may direct the tester to gradually lower its output power level. The DUTs may be used to determine downlink sensitivity by monitoring the measured radio-frequency performance levels as the output power level of the tester is lowered. Simultaneously downlink sensitivity testing may be performed for multiple modulation schemes and data rates for any communications protocol.

Simultaneous downlink sensitivity testing for multiple modulation schemes in a wireless test system

A test system may include multiple test stations. Electronic devices may be tested using the test system. Each test station may include a test unit such as a radio-frequency tester that can make wireless and wired radio-frequency signal measurements on devices under test. The test stations may be configured to perform pass-fail testing on devices under test during manufacturing. One or more selected devices under test that have passed the pass-fail tests may be retested using the test stations. Multiple tests may be performed at a given test station using the same selected device under test. Gathered test data may be analyzed to determine whether the test stations have sufficient accuracy and precision or need to be recalibrated or taken offline.

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Santa Clara, CA, United States of America

Adil Syed