Abstract: A low-power scouting receiver is presented that provides an ability perform low-power scouting functions at a relatively low power. The low-power scouting functions determine context information for the receiver and enable fine-tuning of other receiver operations based on the context information. The low-power scouting functions include receiver control and switching, jammer detection, self-interference detection, or other context-dependent radio parameters.

Abstract: A user equipment (UE) device may communicate according to a new device category satisfying specified QoS (quality of service) requirements while also satisfying specified link budget requirements, and/or additional optimization requirements. The UE device may communicate with a cellular base station according to a first mode of operation associated with the new device category, and may switch to communicating with the cellular base station according to a second mode of operation associated with a second (pre-existing) device category in response to the link budget requirements exceeding a specified value and the quality of service requirements not being sensitive.

Abstract: Electronic devices may be provided that include mechanical and electronic components. Connectors may be used to interconnect printed circuits and devices mounted to printed circuits. Printed circuits may include rigid printed circuit boards and flexible printed circuit boards. Heat sinks and other thermally conductive structures may be used to remove excess component heat. Structures may also be provided in an electronic device to detect moisture. Integrated circuits and other circuitry may be mounted on a printed circuit board under a radio-frequency shielding can.

Abstract: A wireless electronic device may include antennas formed at different locations on the device. The wireless electronic device may include transceivers that are used to wirelessly communicate in different frequency bands by transmitting and receiving radio-frequency signals in the frequency bands. The transceivers may include Wi-Fi® transceivers and cellular transceivers such as Long Term Evolution transceivers. The wireless electronic device may include antenna switching circuitry interposed between the transceivers and the antennas. The wireless electronic device may include control circuitry that controls the antenna switching circuitry to ensure that radio-frequency transmissions in adjacent frequency bands are routed to different antennas. By routing radio-frequency transmissions in adjacent frequency bands to different antennas, self-interference between communications in the adjacent frequency bands may be reduced.

Abstract: An electronic device has wireless communications circuitry that includes transmitters and receivers. Antenna structures may be coupled to the transmitters and receivers to support radio-frequency signal transmission and radio-frequency signal reception operations. Switching circuitry such may be used to support multiple communications bands of interest. One or more low band receivers may be associated with the first switch and one or more high band receivers may be associated with the second switch. The switches can be configured in real time to switch a desired communications band into use. A diplexer may be used to simultaneously pass low bands to the first receiver and high bands to the second receiver. In this way, a data stream in the low band may be simultaneously received with a data stream in the high band.

Abstract: Electronic devices with wireless communications capabilities are provided. The electronic device may include storage and processing circuitry, power amplifier circuitry, power supply circuitry, etc. The storage and processing circuitry may direct the power amplifier circuitry to operate using a desired power mode, in allocated resource blocks within a particular frequency channel, and at a given output power level. The power supply circuitry may bias the power amplifier circuitry with a power supply voltage. The electronic device may be subject to in-band emissions requirements and adjacent channel leakage requirements that restrict the power levels produced by the device on frequencies that are not allocated to the device. The electronic device may optimize the power amplifier supply voltage based on allocated resource blocks by minimizing the supply voltage to reduce power consumption while ensuring that emissions requirements are satisfied.

Abstract: An electronic device may be located in a geographical cell that is served by a base station. The electronic device may communicate with the base station on a frequency band. The frequency band may be subject to adjacent band emissions requirements to help prevent interference with wireless devices that are operating in adjacent frequency bands. The adjacent band emission requirements may vary based on the frequency band used to communicate with the base station, the geographical cell, and/or the presence of public safety radios. To satisfy the adjacent band emissions requirements while minimizing power consumption, the electronic device may receive cell information from the base station and adjust power amplifier linearity based on the received information.

Abstract: An electronic device may include antenna structures. Wireless transmitter circuitry such as cellular telephone transmitter circuitry and wireless local area network circuitry may transmit signals using the antenna structures. A wireless receiver may receive signals from the antenna structures through an adjustable-linearity amplifier. The wireless receiver may operate in a receive band such as a satellite navigation system receive band. During operation of the electronic device, control circuitry in the device may analyze the frequencies and powers of the transmitted signals to determine whether there is a potential for interference for the receive band to be generated in the adjustable-linearity amplifier. In response to determining that there is a potential for interference, the control circuitry may increase the linearity of the adjustable-linearity amplifier.

Abstract: An electronic device has wireless communications circuitry that includes transmitters and receivers. Antenna structures may be coupled to the transmitters and receivers to support radio-frequency signal transmission and radio-frequency signal reception operations. Switching circuitry such as first and second radio-frequency switches may be used to support multiple communications bands of interest. A low band set of transmitters may be associated with the first switch and a high band set of transmitters may be associated with the second switch. The switches can be configured in real time to switch a desired communications band into use. As transmitted signals at frequency f pass through the switches, harmonics at 2f, 3f, and other integral multiples of the transmitted signals may be produced. A diplexer may be interposed between the switching circuitry and the antenna structures that prevents the harmonics from reaching the antenna structures.

Abstract: An electronic device has wireless communications circuitry including a triplexer. The wireless communications circuitry may be used in first and second modes. In the first mode, the device communicates in a first communications band using a transmitter in a first uplink frequency range associated with the first communications band and using a receiver in a first downlink frequency range associated with the first communications band. In the second mode, the device communicates in a second communications band using a transmitter to transmit in a second uplink frequency range associated with the second communications band and using the receiver to receive in a second downlink frequency range associated with the second communications band. Signals in the two downlink frequency ranges may pass through a common bandpass filter in the triplexer. Two additional bandpass filters in the triplexer may be used to respectively handle the two uplink frequency ranges.

Abstract: An electronic device has wireless communications circuitry that supports communications using multiple radio access technologies. The electronic device may gather information such as data rate values, power consumption values, and other data for a currently active radio access technology and an alternative radio access technology. The electronic device may automatically switch between the currently active radio access technology and the alternative radio access technology based on a value of a data rate efficiency metric. The data rate efficiency metric may represent how efficiently each radio access technology is capable of using power to convey a given amount of data per unit time. The data rate efficiency metric may be evaluated using measured power consumption data, measured data rate values, and operating parameters such as signal strength and transmitted power parameters.

Abstract: An electronic device may include antenna structures. Wireless transmitter circuitry such as cellular telephone transmitter circuitry and wireless local area network circuitry may transmit signals using the antenna structures. A wireless receiver may receive signals from the antenna structures through an adjustable-linearity amplifier. The wireless receiver may operate in a receive band such as a satellite navigation system receive band. During operation of the electronic device, control circuitry in the device may analyze the frequencies and powers of the transmitted signals to determine whether there is a potential for interference for the receive band to be generated in the adjustable-linearity amplifier. In response to determining that there is a potential for interference, the control circuitry may increase the linearity of the adjustable-linearity amplifier.

Abstract: An electronic device may be located in a geographical cell that is served by a base station. The electronic device may communicate with the base station on a frequency band. The frequency band may be subject to adjacent band emissions requirements to help prevent interference with wireless devices that are operating in adjacent frequency bands. The adjacent band emission requirements may vary based on the frequency band used to communicate with the base station, the geographical cell, and/or the presence of public safety radios. To satisfy the adjacent band emissions requirements while minimizing power consumption, the electronic device may receive cell information from the base station and adjust power amplifier linearity based on the received information.

Abstract: Electronic devices with wireless communications capabilities are provided. The electronic device may include storage and processing circuitry, power amplifier circuitry, power supply circuitry, etc. The storage and processing circuitry may direct the power amplifier circuitry to operate using a desired power mode, in allocated resource blocks within a particular frequency channel, and at a given output power level. The power supply circuitry may bias the power amplifier circuitry with a power supply voltage. The electronic device may be subject to in-band emissions requirements and adjacent channel leakage requirements that restrict the power levels produced by the device on frequencies that are not allocated to the device. The electronic device may optimize the power amplifier supply voltage based on allocated resource blocks by minimizing the supply voltage to reduce power consumption while ensuring that emissions requirements are satisfied.

Abstract: An electronic device has wireless communications circuitry that supports communications using multiple radio access technologies. The electronic device may gather information such as data rate values, power consumption values, and other data for a currently active radio access technology and an alternative radio access technology. The electronic device may automatically switch between the currently active radio access technology and the alternative radio access technology based on a value of a data rate efficiency metric. The data rate efficiency metric may represent how efficiently each radio access technology is capable of using power to convey a given amount of data per unit time. The data rate efficiency metric may be evaluated using measured power consumption data, measured data rate values, and operating parameters such as signal strength and transmitted power parameters.

Abstract: An electronic device has wireless communications circuitry that includes transmitters and receivers. Antenna structures may be coupled to the transmitters and receivers to support radio-frequency signal transmission and radio-frequency signal reception operations. Switching circuitry such may be used to support multiple communications bands of interest. One or more low band receivers may be associated with the first switch and one or more high band receivers may be associated with the second switch. The switches can be configured in real time to switch a desired communications band into use. A diplexer may be used to simultaneously pass low bands to the first receiver and high bands to the second receiver. In this way, a data stream in the low band may be simultaneously received with a data stream in the high band.

Abstract: Wireless circuitry in an electronic device may contain output power amplifier circuitry for amplifying transmitted radio-frequency signals. The power amplifier circuitry may be powered using a bias voltage. The magnitude of the bias voltage can be selectively reduced to conserve power. Control circuitry can maintain a table of bias voltage settings to use under various conditions. These conditions may include required output powers as determined by link quality, transmission mode status, and required data rates. When link quality is low or when high data rates are required, the bias voltage can be maintained at a relatively high level to ensure that the power amplifier operates linearly and does not exhibit excessive noise. When link quality is high or when data rates are low as with voice calls, the bias voltage can be reduced to conserve power.

Abstract: An electronic device has wireless communications circuitry that includes transmitters and receivers. Antenna structures may be coupled to the transmitters and receivers to support radio-frequency signal transmission and radio-frequency signal reception operations. Switching circuitry such as first and second radio-frequency switches may be used to support multiple communications bands of interest. A low band set of transmitters may be associated with the first switch and a high band set of transmitters may be associated with the second switch. The switches can be configured in real time to switch a desired communications band into use. As transmitted signals at frequency f pass through the switches, harmonics at 2f, 3f, and other integral multiples of the transmitted signals may be produced. A diplexer may be interposed between the switching circuitry and the antenna structures that prevents the harmonics from reaching the antenna structures.

Abstract: An electronic device has wireless communications circuitry including a triplexer. The wireless communications circuitry may be used in first and second modes. In the first mode, the device communicates in a first communications band using a transmitter in a first uplink frequency range associated with the first communications band and using a receiver in a first downlink frequency range associated with the first communications band. In the second mode, the device communicates in a second communications band using a transmitter to transmit in a second uplink frequency range associated with the second communications band and using the receiver to receive in a second downlink frequency range associated with the second communications band. Signals in the two downlink frequency ranges may pass through a common bandpass filter in the triplexer. Two additional bandpass filters in the triplexer may be used to respectively handle the two uplink frequency ranges.

Abstract: Electronic devices may be provided that include mechanical and electronic components. Connectors may be used to interconnect printed circuits and devices mounted to printed circuits. Printed circuits may include rigid printed circuit boards and flexible printed circuit boards. Heat sinks and other thermally conductive structures may be used to remove excess component heat. Structures may also be provided in an electronic device to detect moisture. Integrated circuits and other circuitry may be mounted on a printed circuit board under a radio-frequency shielding can.