Abstract: A calibration system may be provided for calibrating wireless communications circuitry in an electronic device during manufacturing. The calibration system may include data acquisition equipment and calibration computing equipment for receiving and processing test and calibration signals from wireless communications circuitry to be calibrated. During testing and calibration operations, a device may be provided with initial pre-distortion calibration values. The initial pre-distortion calibration values may be generated at least in part based on calibration operations performed for other wireless electronic devices. The device may generate a test signal using the initial pre-distortion calibration values. The calibration system may determine whether the test signal is within an acceptable range of a known reference signal.

Abstract: Electronic devices with wireless communications capabilities are provided. The electronic device may include storage and processing circuitry, power amplifier circuitry, power supply circuitry, etc. The storage and processing circuitry may direct the power amplifier circuitry to operate using a desired gain mode, in a particular radio channel, and at a given output power level. The power supply circuitry may bias the power amplifier circuitry with a power supply voltage. The performance of the power amplifier circuitry may be characterized by an adjacent channel leakage ratio (ACLR) margin. The power consumption of the power amplifier circuitry may be characterized by a current savings ratio. A cost function may be calculated by taking the product of the ACLR margin and current savings ratio. A minimum point for each cost function curve may be determined. It is desirable to bias the power amplifier circuitry with a supply voltage corresponding to the minimum point.

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 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.

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: Calibration equipment for calibrating multiple test stations in a test system is provided. Each test station may include a test unit, a test chamber with an over-the-air antenna, and a radio-frequency (RF) cable that connects the test unit to the test chamber. Reference devices under test (DUTs) may be used to calibrate uplink and downlink path loss (e.g., OTA path loss, RF cable path loss, and variations of the test unit) associated with each test station. The reference DUTs may calibrate each test station at desired frequencies to generate a path loss table. Once calibrated, the test chambers may be used during production testing to test factory DUTs. During production testing, the transmit/receive power efficiency of each factory DUT may be calculated based on values in the path loss table to determine whether a particular production DUT is a passing or failing DUT according to pass/fail criteria.

Abstract: A calibration system may be provided for calibrating wireless communications circuitry in an electronic device during manufacturing. The calibration system may include data acquisition equipment and calibration computing equipment for receiving and processing test and calibration signals from wireless communications circuitry to be calibrated. During testing and calibration operations, a device may be provided with initial pre-distortion calibration values. The initial pre-distortion calibration values may be generated at least in part based on calibration operations performed for other wireless electronic devices. The device may generate a test signal using the initial pre-distortion calibration values. The calibration system may determine whether the test signal is within an acceptable range of a known reference signal.

Abstract: Electronic devices with wireless communications capabilities are provided. The electronic device may include storage and processing circuitry, power amplifier circuitry, power supply circuitry, etc. The storage and processing circuitry may direct the power amplifier circuitry to operate using a desired gain mode, in a particular radio channel, and at a given output power level. The power supply circuitry may bias the power amplifier circuitry with a power supply voltage. The performance of the power amplifier circuitry may be characterized by an adjacent channel leakage ratio (ACLR) margin. The power consumption of the power amplifier circuitry may be characterized by a current savings ratio. A cost function may be calculated by taking the product of the ACLR margin and current savings ratio. A minimum point for each cost function curve may be determined. It is desirable to bias the power amplifier circuitry with a supply voltage corresponding to the minimum point.

Abstract: Test systems are provided for performing testing and calibration operations on wireless circuitry in electronic devices. The electronic devices may include cellular telephones and other portable electronic devices. Wireless circuitry in a device may include a radio-frequency transceiver that is controlled based on radio-frequency transceiver control signals. The wireless circuitry may also include power amplifier circuitry. The power amplifier circuitry may receive radio-frequency signals from the transceiver and may produce correspondingly amplified radio-frequency output signals for wireless transmission with an antenna. The power amplifier circuitry may be powered by a bias voltage. The test systems may provide the electronic device with a transmit power request that directs the electronic device to produce a desired output power. The test systems may measure the actual resulting power.

Abstract: Wireless circuitry in an electronic device may contain radio-frequency transceiver circuitry and power amplifier circuitry that transmits radio-frequency signals through an antenna. A tap and power detector that are interposed in the radio-frequency signal path between the power amplifier circuitry and the antenna may be used to make output power measurements. Control circuitry may control the wireless circuitry in an open-loop control regime in which output power adjustments are based on a requested power without using the output power measurements. The control circuitry may also control the wireless circuitry in a closed-loop control regime in which the output power measurements serve as a source of real time feedback to determine whether to increase or decrease the output power. The output power may be controlled using linear transition zone power control curves in a transition zone between the open-loop regime and the closed-loop regime.

Abstract: Calibration equipment for calibrating multiple test stations in a test system is provided. Each test station may include a test unit, a test chamber with an over-the-air antenna, and a radio-frequency (RF) cable that connects the test unit to the test chamber. Reference devices under test (DUTs) may be used to calibrate uplink and downlink path loss (e.g., OTA path loss, RF cable path loss, and variations of the test unit) associated with each test station. The reference DUTs may calibrate each test station at desired frequencies to generate a path loss table. Once calibrated, the test chambers may be used during production testing to test factory DUTs. During production testing, the transmit/receive power efficiency of each factory DUT may be calculated based on values in the path loss table to determine whether a particular production DUT is a passing or failing DUT according to pass/fail criteria.

Abstract: 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.

Abstract: Electronic devices with wireless communications capabilities are provided. The electronic device may include storage and processing circuitry, power amplifier circuitry, power supply circuitry, etc. The storage and processing circuitry may direct the power amplifier circuitry to operate using a desired gain mode, in a particular radio channel, and at a given output power level. The power supply circuitry may bias the power amplifier circuitry with a power supply voltage. The performance of the power amplifier circuitry may be characterized by an adjacent channel leakage ratio (ACLR) margin. The power consumption of the power amplifier circuitry may be characterized by a current savings ratio. A cost function may be calculated by taking the product of the ACLR margin and current savings ratio. A minimum point for each cost function curve may be determined. It is desirable to bias the power amplifier circuitry with a supply voltage corresponding to the minimum point.

Abstract: Test systems are provided for performing testing and calibration operations on wireless circuitry in electronic devices. The electronic devices may include cellular telephones and other portable electronic devices. Wireless circuitry in a device may include a radio-frequency transceiver that is controlled based on radio-frequency transceiver control signals. The wireless circuitry may also include power amplifier circuitry. The power amplifier circuitry may receive radio-frequency signals from the transceiver and may produce correspondingly amplified radio-frequency output signals for wireless transmission with an antenna. The power amplifier circuitry may be powered by a bias voltage. The test systems may provide the electronic device with a transmit power request that directs the electronic device to produce a desired output power. The test systems may measure the actual resulting power.

Abstract: Wireless circuitry in an electronic device may contain radio-frequency transceiver circuitry and power amplifier circuitry that transmits radio-frequency signals through an antenna. A tap and power detector that are interposed in the radio-frequency signal path between the power amplifier circuitry and the antenna may be used to make output power measurements. Control circuitry may control the wireless circuitry in an open-loop control regime in which output power adjustments are based on a requested power without using the output power measurements. The control circuitry may also control the wireless circuitry in a closed-loop control regime in which the output power measurements serve as a source of real time feedback to determine whether to increase or decrease the output power. The output power may be controlled using linear transition zone power control curves in a transition zone between the open-loop regime and the closed-loop regime.

Abstract: Method of masking one or more extremities of a cylinder bore from internal thermal spraying, when using a rotary gun inserted from one end of the bore, by essentially the steps of: (a) supporting one or more inflatable mask members adjacent an end of the bore wall; (b) pressurizing the inflatable mask member to expand and annularly engage an end of the bore, the mask being constituted of an inflatable and collapsible air tight bag of heat resistant (fiberglass) cloth coated on opposite sides with a sacrificial heat resistant non-stick coating (silicone). The inflatable characteristic of the mask member allows it to conform to the periphery of the cylinder bore extremities, and allows it to be easily installed in or through the component in its deflated condition. The mask is reusable by being comprised of coating material that may gradually be sacrificed to heat and wear of the over spray.

Abstract: Method of dimensionally stabilizing the interface between metal parts of differing thermal expansion characteristics (TEC), regardless of temperature variations under normal designed use of such parts, comprising: (a) hot extruding a mixture of ceramic fibers (i.e., Si.sub.3 N.sub.4, SiC, Al.sub.2 O.sub.3) and a powder of the metal having the higher TEC (i.e., Al, Ti, Mg) while aligning the fibers generally along the direction of extrusion, to form an insert; (b) shaping the insert to align its fibers generally in at least one direction of anticipated thermal growth that may interfere with the interface; (c) casting the insert in place within a first part compound of the higher TEC metal and with the insert's fibers (i) oriented as above, and (ii) preheated to a temperature no greater than 35-45% of the temperature of the molten light metal; and (d) bringing together the first metal part with a second part of lower TEC metal (i.e., Fe or steel) to form the interface.

Abstract: Stitch-machining the walls of a cylindrical blind cavity of a workpiece, the cavity being deep and narrow with respect to the axis of the cavity, is carried out by: (a) supporting a tubular housing for axial movement throughout substantially the axial extent of the cavity interior and in close-fitting tolerance to the walls of the cavity, the tubular housing having a free end; (b) rotationally driving a spindle (10,000-40,000 rpm) in the tubular housing for conjoint axial movement with the tubular housing, the spindle extending beyond the housing end for carrying a radially adjustable cutting tool; (c) inserting the tubular housing together with the rotationally driven spindle into the cavity (at lineal speeds of 400-800 inches/minute) with a cutting tool radially positioned for rough boring of the cavity walls, while guiding and steering the tubular housing and spindle to accurately concentrically position the cutting tool with respect to the cavity axis; (d) substantially immediately upon the execution of r

Abstract: Method and apparatus for conducting boring of a series of spaced walls on a workpiece using a self-adjusting boring bar.

Abstract: A shift lever and throttle lever coaxially mounted on the casing of an automatic transmission are engaged, respectively, by a lever mounted on each of two concentric shafts whose axes are aligned with the axis of the transmission levers. The shafts have torque sensors located between the levers carried by the shafts and bearings that support the shafts in rotation. The outer shaft has a radial positioning actuator which is hydraulically driven from a source of hydraulic pressure through a servo controlled valve that selectively opens and closes hydraulic passages. The actuator includes a vane fixed to the shaft and a stator that divides a cavity into two halves, each of which is pressurized selectively by operation of the servo.