Abstract:
An electronic device may be provided with an antenna. The antenna may have an antenna resonating element and an antenna ground. An adjustable inductor may be coupled between the antenna resonating element and the antenna ground. An antenna feed may have a positive feed terminal coupled to the antenna resonating element and a ground antenna feed coupled to the antenna ground. The adjustable inductor may have first and second inductors coupled to respective first and second ports of a switch. The switch may have a third port coupled to the antenna ground. A capacitor may have a first terminal coupled to ground and a second terminal coupled to the first inductor at the first port of the switch. An inductor may be coupled between the antenna resonating element and antenna ground at a location between the adjustable inductor and the antenna feed.
Abstract:
Electronic devices may be provided that include radio-frequency transceiver circuitry and antennas. An antenna may be formed from an antenna resonating element and an antenna ground. The antenna resonating element may have a shorter portion that resonates at higher communications band frequencies and a longer portion that resonates at lower communications band frequencies. An extended portion of the antenna ground may form an inverted-F antenna resonating element portion of the antenna resonating element. The antenna resonating element may be formed from a peripheral conductive electronic device housing structure that is separated from the antenna ground by an opening. A first antenna feed may be coupled between the peripheral conductive electronic device housing structures and the antenna ground across the opening. A second antenna feed may be coupled to the inverted-F antenna resonating element portion of the antenna resonating element.
Abstract:
An electronic device may be provided with shared antenna structures that can be used to form both a near-field-communications antenna such as a loop antenna and a non-near-field communications antenna such as an inverted-F antenna. The antenna structures may include conductive structures such as metal traces on printed circuits or other dielectric substrates, internal metal housing structures, or other conductive electronic device housing structures. A main resonating element arm may be separated from an antenna ground by an opening. A non-near-field communications antenna return path and antenna feed path may span the opening. A balun may have first and second electromagnetically coupled inductors. The second inductor may have terminals coupled across differential signal terminals in a near-field communications transceiver. The first inductor may form part of the near-field communications loop antenna.
Abstract:
An electronic device may be provided with a housing. The 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 a slot. An antenna feed may have a positive antenna terminal coupled to the peripheral metal member and a ground terminal coupled to the ground and may feed both an inverted-F antenna structure that is formed from the peripheral metal member and the ground and a slot antenna structure that is formed from the slot. Control circuitry may tune the antenna by controlling adjustable components that are coupled to the peripheral metal member. The adjustable components may include adjustable inductors and adjustable capacitors.
Abstract:
Radio frequency test systems for characterizing antenna performance in various radio coexistence scenarios are provided. In one suitable arrangement, a test system may be used to perform passive radio coexistence characterization. During passive radio coexistence characterization, at least one signal generator may be used to feed aggressor signals directly to antennas within an electronic device under test (DUT). The aggressor signals may generate undesired interference signals in a victim frequency band, which can then be received and analyzed using a spectrum analyzer. During active radio coexistence characterization, at least one radio communications emulator may be used to communicate with a DUT via a first test antenna. While the DUT is communicating with the at least one radio communications emulator, test signals may also be conveyed between DUT 10 and a second test antenna. Test signals conveyed through the second test antenna may be used in obtaining signal interference level measurements.
Abstract:
An electronic device may be provided with peripheral conductive housing structures having first and second segments. The device may include an antenna having a resonating arm formed from the first segment, an antenna ground, and a tuning element. The tuning element may have first, second, and third terminals. The first terminal may be coupled to the second segment. The antenna may have a switchable loop path that includes a first path from the second terminal to the first segment, a second path from first segment to a first point on the antenna ground, a portion of the antenna ground from the first point to a second point, and a third path from the second point to the third terminal. The tuning element may selectively activate the switchable loop path to boost performance of the antenna in a frequency band between 3300 MHz and 5000 MHz when needed.
Abstract:
An electronic device may include an antenna disposed on a substrate. The antenna may include a ring of conductive traces, a fed arm, and an unfed arm. The fed arm and the unfed arm may extend from opposing segments of the ring. The ring may be coupled to ground by fences of conductive vias extending through the substrate. The first arm may have a first radiating edge. The second arm may have a second radiating edge. The first radiating edge may be separated from the second radiating edge by a gap. The first arm may indirectly feed the second arm via near-field electromagnetic coupling across the gap. The first and second arms may collectively radiate in an ultra-wideband (UWB) frequency band.
Abstract:
An electronic device may be provided with a first antenna fed by a first path and a second antenna fed by a second path. A first coupler may be disposed on the first path, a second coupler may be disposed on the second path, and a feedback path may couple the couplers to a receiver. A low-pass filter may be disposed on the second path. The first antenna may transmit signals in a low band. Some of the signals may couple onto the second antenna. The second coupler may pass the coupled signals to the receiver. Control circuitry may generate a scattering parameter value characterizing the coupling of the signals from the first antenna onto the second antenna. The scattering parameter value may be used to determine when to switch the first antenna out of use and the second antenna into use for covering the low band.
Abstract:
An electronic device may be provided with peripheral conductive housing structures having a first segment and a second segment. First and second antenna feeds may be coupled between the first segment and the ground structures. The first feed may convey signals in a first band and the second feed may convey signals in a second band. The first segment may be near-field coupled to a slot between the second segment and the ground structures. A first tuner may be coupled between the second segment and the ground structures and may adjust a resonance of the first segment in the first and second bands. A second tuner coupled to the first feed may perform impedance matching in the first band and aperture tuning in the second band. A third tuner coupled to the second feed may perform impedance matching in the second band and aperture tuning in the first band.
Abstract:
An electronic device may include first and second antennas formed from respective first and second segments of a housing. The first antenna may have a first feed coupled to the first segment by a first switch and coupled to the first segment by a first conductive trace. The second antenna may have a second feed coupled to the second segment by a second switch and coupled to the second segment by a second conductive trace. The first segment may be separated from the second segment by a single gap, a data connector may pass through the second segment, and the antennas may selectively cover a low band. Alternatively, the first segment may be separated from the second segment by a third segment and two gaps, the data connector may pass through the third segment, and the first and second antennas may concurrently cover the low band.