Abstract:
Electronic devices may be provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and antenna structures. The antenna structures may form a dual arm inverted-F antenna. The antenna may have a resonating element formed from portions of a peripheral conductive electronic device housing member and may have an antenna ground that is separated from the antenna resonating element by a gap. A short circuit path may bridge the gap. An antenna feed may be coupled across the gap in parallel with the short circuit path. Low band tuning may be provided using an adjustable inductor that bridges the gap. The antenna may have a slot-based parasitic antenna resonating element with a slot formed between portions of the peripheral conductive electronic device housing member and the antenna ground. An adjustable capacitor may bridge the slot to provide high band tuning.
Abstract:
Electronic devices may include antenna structures. The antenna structures may form an antenna having first and second feeds at different locations. Transceiver circuitry for transmitting and receiving radio-frequency antenna signals may be mounted on one end of a printed circuit board. Transmission line structures may be used to convey signals between an opposing end of the printed circuit board and the transceiver circuitry. The printed circuit board may be coupled to an antenna feed structure formed from a flexible printed circuit using solder connections. The flexible printed circuit may have a bend and may be screwed to conductive electronic device housing structures using one or more screws at one or more respective antenna feed terminals. Electrical components such as an amplifier circuit and filter circuitry may be mounted on the flexible printed circuit.
Abstract:
Electronic device antenna structures may include first and second antennas. A housing may have a periphery that is surrounded by peripheral conductive structures such as a segmented peripheral metal member. A segment of the peripheral metal member may be separated from a ground by an opening. An antenna feed for the first antenna may have a positive antenna terminal coupled to the peripheral metal member and a ground terminal coupled to the ground. A return path for the first antenna may span the opening in parallel with the antenna feed. A plastic carrier may be mounted to a printed circuit and a metal housing structure using screws. The plastic carrier may support an antenna resonating element for the second antenna and may support the return path for the first antenna. The screws may short metal structures on the plastic carrier to the metal structures and traces on the printed circuit.
Abstract:
Electronic devices may include radio-frequency transceiver circuitry and antenna structures. The antenna structures may include an inverted-F antenna resonating element and an antenna ground that form an inverted-F antenna having first and second antenna ports. The antenna structures may include a slot antenna resonating element. The slot antenna resonating element may serve as a parasitic antenna resonating element for the inverted-F antenna at frequencies in a first communications band and may serve as a slot antenna at frequencies in a second communications band. The slot antenna may be directly fed using a third antenna port. An adjustable capacitor may be coupled to the first port to tune the inverted-F antenna. The inverted-F antenna may also be tuned using an adjustable capacitor bridging the slot antenna resonating element.
Abstract:
An electronic device has wireless communications circuitry including an adjustable antenna system coupled to a radio-frequency transceiver. The adjustable antenna system may include one or more adjustable electrical components that are controlled by storage and processing circuitry in the electronic device. The adjustable electrical components may include switches and components that can be adjusted between numerous different states. The adjustable electrical components may be coupled between antenna system components such as transmission line elements, matching network elements, antenna elements and antenna feeds. By adjusting the adjustable electrical components, the storage and processing circuitry can tune the adjustable antenna system to ensure that the adjustable antenna system covers communications bands of interest.
Abstract:
A wireless electronic device may be provided with antenna structures. The antenna structures may be formed from an antenna ground and an array of antenna resonating elements formed along its periphery. The antenna resonating elements may be formed from metal traces on a dielectric support structure that surrounds the antenna ground. The electronic device may be tested using a test system for detecting the presence of manufacturing/assembly defects. The test system may include an RF tester and a test fixture. The device under test (DUT) may be attached to the test fixture during testing. Multiple test probes arranged along the periphery of the DUT may be used to transmit and receive RF test signals for gathering scattering parameter measurements on the device under test. The scattering parameter measurements may then be compared to predetermined threshold values to determine whether the DUT contains any defects.
Abstract:
Electronic devices may include radio-frequency transceiver circuitry and antenna structures. The antenna structures may include a dual arm inverted-F antenna resonating element and an antenna ground. An antenna feed may be coupled between the inverted-F antenna resonating element and the antenna ground. An adjustable component such as an adjustable inductor may be coupled between the inverted-F antenna resonating element and the antenna ground in parallel with the antenna feed. The adjustable component may be operable in multiple states such as an open circuit state, a short circuit state, and a state in which the adjustable component exhibits a non-zero inductance. Antenna bandwidth can be broadened by coupling a loop antenna resonating element across the antenna feed. A portion of the antenna ground may overlap the loop antenna resonating element to further enhance antenna bandwidth.
Abstract:
Electronic devices may include radio-frequency transceiver circuitry and antenna structures. The antenna structures may form a dual arm inverted-F antenna and a monopole antenna sharing a common antenna ground. The antenna structures may have three ports. A first antenna port may be coupled to an inverted-F antenna resonating element at a first location and a second antenna port may be coupled to the inverted-F antenna resonating element at a second location. A third antenna port may be coupled to the monopole antenna. Tunable circuitry can be used to tune the antenna structures. An adjustable capacitor may be coupled to the first port to tune the inverted-F antenna. An additional adjustable capacitor may be coupled to the third port to tune the monopole antenna. Transceiver circuitry for supporting wireless local area network communications, satellite navigation system communications, and cellular communications may be coupled to the first, second, and third antenna ports.
Abstract:
A test system may include test stations for testing the radio-frequency performance of wireless electronic devices. A reference test station may perform test measurements on a group of wireless electronic devices under test (DUTs) to select a reference DUT. The reference test station may gather radio-frequency measurements at a number of test frequencies from the group of DUTs. The reference test station may compute statistical data associated with the gathered measurements. The reference test station may compute weight values associated with each test frequency based on the statistical parameters. The reference test station may compute a weighted mean square error value for each DUT based on the weight values and the statistical data. The reference test station may select a DUT having a minimum weighted mean square error value to serve as the reference DUT, which may be used to calibrate test stations in the test system.
Abstract:
An electronic device may be provided with wireless communications circuitry and control circuitry. The wireless communications circuitry may include centimeter and millimeter wave transceiver circuitry and a phased antenna array. A dielectric cover may be formed over the phased antenna array. The phased antenna array may transmit and receive wireless radio-frequency signals through the dielectric cover. The dielectric cover may have first and second opposing surfaces. The second surface may face the phased antenna array and may have a curvature. The curvature of the second surface may include one or more recessed regions of the dielectric cover. The one or more recessed regions of the second surface may serve to maximize and broaden the coverage area for the phased antenna array. The first surface may be conformal to other structures in the electronic device.