Abstract: An electronic device may include signal transmission circuitry such as wireless circuitry having a signal source, a signal path, and an output node coupled to an output load. The signal source may transmit a signal to the output load over the signal path. The output load may have an impedance characterized by a first reflection coefficient. A signal coupler may be disposed on the signal path. A power detector coupled to a coupled node of the signal coupler may measure a voltage at the third node. A termination coupled to an isolated node of the signal coupler may include components that cause the termination to exhibit a second reflection coefficient. The second reflection coefficient may be selected to configure the voltage at the third node to track a power wave at the output load to within a constant that is invariant as the first reflection coefficient changes over time.

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 electronic device may include signal transmission circuitry such as wireless circuitry having a signal source, a signal path, and an output node coupled to an output load. The signal source may transmit a signal to the output load over the signal path. The output load may have an impedance characterized by a first reflection coefficient. A signal coupler may be disposed on the signal path. A power detector coupled to a coupled node of the signal coupler may measure a voltage at the third node. A termination coupled to an isolated node of the signal coupler may include components that cause the termination to exhibit a second reflection coefficient. The second reflection coefficient may be selected to configure the voltage at the third node to track a power wave at the output load to within a constant that is invariant as the first reflection coefficient changes over time.

Abstract: An electronic device may include signal transmission circuitry having a signal path and a signal source that transmits a signal on the signal path. First and second signal couplers may be coupled to the signal path. Control circuitry may use the first signal coupler to measure the signal at a first reference plane and may use the second signal coupler to concurrently measure the signal at a second reference plane. The signal measurements may include power wave, forward wave, reverse wave, impedance, and/or delivered power measurements. Terminations in the signal couplers may be adjusted to dynamically shift the reference planes. The first and second signal couplers may be formed from first and third metallization layers on a stacked dielectric substrate, where the signal path is formed from a second metallization layer. Additional signal couplers may be coupled to the signal path for concurrently measuring additional reference planes.

Abstract: An electronic device may include signal transmission circuitry such as wireless circuitry having a signal source, a signal path, and an output node coupled to an output load. The signal source may transmit a signal to the output load over the signal path. The output load may have an impedance characterized by a first reflection coefficient. A signal coupler may be disposed on the signal path. A power detector coupled to a coupled node of the signal coupler may measure a voltage at the third node. A termination coupled to an isolated node of the signal coupler may include components that cause the termination to exhibit a second reflection coefficient. The second reflection coefficient may be selected to configure the voltage at the third node to track a power wave at the output load to within a constant that is invariant as the first reflection coefficient changes over time.

Abstract: An electronic device may include signal transmission circuitry having a signal path and a signal source that transmits a signal on the signal path. First and second signal couplers may be coupled to the signal path. Control circuitry may use the first signal coupler to measure the signal at a first reference plane and may use the second signal coupler to concurrently measure the signal at a second reference plane. The signal measurements may include power wave, forward wave, reverse wave, impedance, and/or delivered power measurements. Terminations in the signal couplers may be adjusted to dynamically shift the reference planes. The first and second signal couplers may be formed from first and third metallization layers on a stacked dielectric substrate, where the signal path is formed from a second metallization layer. Additional signal couplers may be coupled to the signal path for concurrently measuring additional reference planes.

Abstract: An electronic device may include signal transmission circuitry such as wireless circuitry having a signal source, a signal path, and an output node coupled to an output load. The signal source may transmit a signal to the output load over the signal path. The output load may have an impedance characterized by a first reflection coefficient. A signal coupler may be disposed on the signal path. A power detector coupled to a coupled node of the signal coupler may measure a voltage at the third node. A termination coupled to an isolated node of the signal coupler may include components that cause the termination to exhibit a second reflection coefficient. The second reflection coefficient may be selected to configure the voltage at the third node to track a power wave at the output load to within a constant that is invariant as the first reflection coefficient changes over time.

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 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.