Abstract: A duplexer may be used to isolate a transmitter and a receiver that share a common antenna. By using impedance gradients to provide impedances that cause balance-unbalance transformers (balun) of the duplexer to cut-off access to the common antenna rather than duplicate the antenna impedance, the duplexer is balanced. Such cut-offs may have a lower insertion loss than a duplexer that merely duplicates the antenna impedance to separate the differential signals of the receiver and transmitter from the common mode signal.

Abstract: An electrical balance duplexer has multiple impedance gradients and multiple impedance tuners. The electrical balance duplexer transmits an outgoing signal from a transmitter during a transmission mode when a first set of impedance gradients of the multiple impedance gradients is operating in a first impedance state and a first set of impedance tuners of the multiple impedance tuners is operating in a second state. The electrical balance duplexer isolates the outgoing signal from a receiver during the transmission mode when a second set of impedance gradients of the multiple impedance gradients and a second set of impedance tuners of the multiple impedance tuners are operating in the second impedance state.

Abstract: Embodiments disclosed herein relate to reducing or substantially eliminating an insertion loss caused by isolating a transmit circuit from a receive circuit of an electronic device. To do so, an isolation circuit may be disposed between the transmit circuit and the receive circuit. The isolation circuit may have a first signal path and a second signal path. A first portion of the signal may propagate along the first signal path and a second portion of the signal may propagate along the second signal path. A phase shifter may be disposed on the first signal path to shift a phase of the first portion to match a phase of the second portion. The phase-shifted first portion may be combined with the second portion to reduce or substantially eliminate an insertion loss caused by the isolation circuit.

Abstract: Systems and method are described for improving electrical isolation between a transmission signal and receiver circuitry of a transceiver communicating over one or more wireless networks via one or more shared antennas. The transceiver may include isolation circuitry to facilitate isolation of the transmission signal from the receiver circuitry. However, a leakage current of the transmission signal and noise signals may appear at the receiver circuitry. Presence of the leakage current or the noise signals in the receiver circuitry may cause interference with the reception signal. As such, the isolation circuitry may benefit from additional isolation between the transmission signal and the receiver circuitry to reduce an effect of the leakage current and the noise signals on the reception signal.

Abstract: An electronic device may include wireless circuitry with one or more antennas that transmit radio-frequency signals and that receive corresponding reflected signals. The wireless circuitry may detect a range to an external object based on the transmitted and received signals. The wireless circuitry may include a receive path having a mixer, an analog-to-digital converter (ADC), and a filter between the mixer and the ADC. The receive path may include a bypass path with a switch coupled around the filter. The wireless circuitry may detect the range to the external object within an ultra-short range (USR) domain when the switch is closed, thereby bypassing the filter in the receive path. The wireless circuitry may detect the range to the external object within a far-field domain when the switch is open. The filter may filter the reflected signals to remove undesired leakage and maximize dynamic range.

Abstract: An electronic device may include wireless circuitry with a transmit antenna that transmits signals and a receive antenna that receives reflected signals. The wireless circuitry may detect a range between the device and an external object based on the transmitted signals and the reflected signals. When the range exceeds a first threshold, the wireless circuitry may use the transmitted signals and received signals to record background noise. When the range is less than a second threshold value, the wireless circuitry may detect the range based on the reflected signals and the recorded background noise. This may allow the range to be accurately measured within an ultra-short range domain even when the device is placed in different device cases, placed on different surfaces, etc.

Abstract: An electronic device may include wireless circuitry with one or more antennas that transmit radio-frequency signals and that receive corresponding reflected signals. The wireless circuitry may detect a range to an external object based on the transmitted and received signals. The wireless circuitry may include a receive path having a mixer, an analog-to-digital converter (ADC), and a filter between the mixer and the ADC. The receive path may include a bypass path with a switch coupled around the filter. The wireless circuitry may detect the range to the external object within an ultra-short range (USR) domain when the switch is closed, thereby bypassing the filter in the receive path. The wireless circuitry may detect the range to the external object within a far-field domain when the switch is open. The filter may filter the reflected signals to remove undesired leakage and maximize dynamic range.

Abstract: An electronic device may include wireless circuitry. The wireless circuitry may include a quadratic phase generator for outputting a perfectly interpolated constant amplitude zero autocorrelation (CAZAC) sequence for a transmit path. The quadratic phase generator may include a numerically controlled oscillator, a switch controlled based on a value output from the numerically controlled oscillator, a first integrator stage, and a second integrator stage connected in series with the first integrator stage. The numerically controlled oscillator may receive as inputs a chirp count and a word length. The switch may be configured to switchably feed one of two input values that are a function of the chirp count and the word length to the first integrator stage. The quadratic phase generator may output full-bandwidth chirps or reduced-bandwidth chirps. Bandwidth reduction can be achieved by scaling the two input values of the switches.

Abstract: Embodiments disclosed herein relate to reducing or substantially eliminating an insertion loss caused by isolating a transmit circuit from a receive circuit of an electronic device. To do so, an isolation circuit may be disposed between the transmit circuit and the receive circuit. The isolation circuit may have a first signal path and a second signal path. A first portion of the signal may propagate along the first signal path and a second portion of the signal may propagate along the second signal path. A phase shifter may be disposed on the first signal path to shift a phase of the first portion to match a phase of the second portion. The phase-shifted first portion may be combined with the second portion to reduce or substantially eliminate an insertion loss caused by the isolation circuit.

Abstract: Embodiments disclosed herein relate to improving an available bandwidth for a transceiver of an electronic device and to reducing a footprint of an associated integrated circuit of the electronic device. To do so, an isolation circuit is disposed between a transmit circuit and a receive circuit. The isolation circuit has first and second signal paths. A first portion of the signal propagates along the first signal path and a second portion of the signal propagates along the second signal path. A non-reciprocal phase shifter is disposed on the first signal path to shift a phase of the first portion to match a phase of the second portion and improve isolation between the transmit circuit and the receive circuit. The phase-shifted first portion may be combined with the second portion to reduce or substantially eliminate an insertion loss caused by the isolation circuit.

Abstract: This disclosure provides techniques for impedance matching. A radio frequency (RF) device includes a power detector to determine a transmitter leakage and a post-processing unit to determine a receiver leakage, and determines if isolation is acceptable based on the leakages. The RF device may include a device for measuring antenna impedance. Otherwise, the RF device may select multiple tuner settings (e.g., capacitor values) for test signals to be transmitted and received at a target frequency, determine multiple sets of leakage values, determine multiple reflection coefficients based on the multiple sets of leakage values, and determine an estimated antenna impedance at the target frequency based on the reflection coefficients. The RF device then determines impedance tuner settings based on the measured or estimated antenna impedance. Alternatively, the RF device determines impedance tuner settings using an inverse machine-learning model based on a determined matching impedance.

Abstract: An electronic device may include a processor and wireless circuitry with transmit and receive antennas. Radar circuitry may use the transmit and receive antennas to perform spatial ranging on external objects farther than a threshold distance (e.g., 1-2 cm) from the transmit antenna. The wireless circuitry may include a voltage standing wave ration (VSWR) sensor coupled to the transmit antenna to detect the presence of objects within the threshold distance from the transmit antenna. This may serve to cover a blind spot for the radar circuitry near to the transmit antenna. The VSWR sensor may gather background VSWR measurements when other wireless performance metric data for the wireless circuitry is within a predetermined range of satisfactory values. The background VSWR measurements may be subtracted from real time VSWR measurements to perform accurate and robust ultra-short range object detection near to the transmit antenna.

Abstract: An electrical balance duplexer (EBD) may be used to isolate a transmitter and receiver that share a common antenna. By using impedance gradients to provide impedances that cause balance-unbalance transformers (balun) of the EBD to cut-off access to the common antenna rather than duplicate the antenna impedance, the EBD is balanced. Such cut-offs may have a lower insertion loss than an EBD that merely duplicates the antenna impedance to separate the differential signals of the receiver/transmitter from the common mode signal.

Abstract: Systems and methods for extracting polarized sub-signals from a dual-polarized signal includes isolating the polarized sub-signals using one or more filters. When a single filter is used to derive a first sub-signal, analog interference cancellation may be used to derive the second sub-signal. When two filters are used, the first and second sub-signals may each be derived using a corresponding filter.

Abstract: Embodiments disclosed herein relate to reducing or substantially eliminating an insertion loss caused by isolating a transmit circuit from a receive circuit of an electronic device. To do so, an isolation circuit may be disposed between the transmit circuit and the receive circuit. The isolation circuit may have a first signal path and a second signal path. A first portion of the signal may propagate along the first signal path and a second portion of the signal may propagate along the second signal path. A phase shifter may be disposed on the first signal path to shift a phase of the first portion to match a phase of the second portion. The phase-shifted first portion may be combined with the second portion to reduce or substantially eliminate an insertion loss caused by the isolation circuit.

Abstract: An electronic device may include wireless circuitry having a set of two or more antennas coupled to voltage standing wave ratio (VSWR) sensors. The VSWR sensors may gather VSWR measurements from radio-frequency signals transmitted using the set of antennas. The antennas may be disposed on one or more substrates and/or may be formed from conductive portions of a housing. Control circuitry may process the VSWR measurements to identify the ranges between each of the antennas in the set of antennas and an external object. The control circuitry may process the ranges to identify an angular location of the external object with respect to the device. The control circuitry may adjust subsequent communications based, adjust the direction of a signal beam produced by a phased antenna array, identify a user input, or perform any other desired operations based on the angular location.

Abstract: An electronic device may include a voltage standing wave ratio (VSWR) sensor disposed along a radio-frequency transmission line between a signal generator and an antenna. The VSWR sensor may gather VSWR measurements from radio-frequency signals transmitted by the signal generator over the transmission line. Control circuitry may identify a variation in the VSWR measurements over time and may compare the variation to a threshold value to determine whether an external object in the vicinity of the antenna is animate or inanimate. The control circuitry may reduce the maximum transmit power level of the antenna when the external object is animate and may maintain or increase the maximum transmit power level when the external object is inanimate. This may serve to maximize the wireless performance of the electronic device while also ensuring that the device complies with regulatory limits on radio-frequency energy exposure.

Abstract: An electrical balance duplexer has multiple impedance gradients and multiple impedance tuners. The electrical balance duplexer transmits an outgoing signal from a transmitter during a transmission mode when a first set of impedance gradients of the multiple impedance gradients is operating in a first impedance state and a first set of impedance tuners of the multiple impedance tuners is operating in a second state. The electrical balance duplexer isolates the outgoing signal from a receiver during the transmission mode when a second set of impedance gradients of the multiple impedance gradients and a second set of impedance tuners of the multiple impedance tuners are operating in the second impedance state.

Abstract: Systems and method are described for improving electrical isolation between a transmission signal and receiver circuitry of a transceiver communicating over one or more wireless networks via one or more shared antennas. The transceiver may include isolation circuitry to facilitate isolation of the transmission signal from the receiver circuitry. However, a leakage current of the transmission signal and noise signals may appear at the receiver circuitry. Presence of the leakage current or the noise signals in the receiver circuitry may cause interference with the reception signal. As such, the isolation circuitry may benefit from additional isolation between the transmission signal and the receiver circuitry to reduce an effect of the leakage current and the noise signals on the reception signal.

Abstract: Systems, methods, and devices for reducing insertion loss and/or swapping transmitter (TX) and receiver (RX) frequencies in an electrical balance duplexer (EBD) used in a transceiver device for frequency division duplexing (FDD) applications are provided. Feed-forward receiver path from the antenna to a low noise amplifier (LNA) and a feed-forward path from the antenna to a power amplifier (PA) of the EBD may be used for reducing insertion loss of the RX and TX signals. In some embodiments, switches may be used to selectively alter operational modes for varied levels of isolation and/or swapping of TX and RX frequencies.