Abstract:
Electronic devices may include antenna structures. The antenna structures may form an antenna having first and second feeds at different locations. A first transceiver may be coupled to the first feed using a first circuit. A second transceiver may be coupled to the second feed using a second circuit. The first and second feeds may be isolated from each other using the first and second circuits. The second circuit may have a notch filter that isolates the second feed from the first feed at operating frequencies associated with the first transceiver. The first circuit may include an adjustable component such as an adjustable capacitor. The adjustable component may be placed in different states depending on the mode of operation of the second transceiver to ensure that the first feed is isolated from the second feed.
Abstract:
A manufacturing system for assembling wireless electronic devices is provided. The manufacturing system may include test stations for testing the radio-frequency performance of components that are to be assembled within the electronic devices. A reference test station may be calibrated using calibration coupons having known radio-frequency characteristics. The calibration coupons may include transmission line structures. The reference test station may measure verification standards to establish baseline measurement data. The verification standards may include circuitry having electrical components with given impedance values. Many verification coupons may be measured to enable testing for a wide range of impedance values. Test stations in the manufacturing system may subsequently measure the verification standards to generate test measurement data. The test measurement data may be compared to the baseline measurement data to characterize the performance of the test stations to ensure consistent test measurements across the test stations.
Abstract:
A wireless electronic device may contain at least one adjustable antenna tuning element for use in tuning the operating frequency range of the device. The antenna tuning element may include radio-frequency switches, continuously/semi-continuously adjustable components such as tunable resistors, inductors, and capacitors, and other load circuits that provide desired impedance characteristics. A test system that is used for performing passive radio-frequency (RF) testing on antenna tuning elements in partially assembled devices is provided. The test system may include an RF tester and a test host. The tester may be used to gather scattering parameter measurements from the antenna tuning element. The test host may be used to ensure that power and appropriate control signals are being supplied to the antenna tuning element so that the antenna tuning element is placed in desired tuning states during testing.