Abstract: In a general aspect, a radio frequency (RF) measurement device includes first and second mode converters, each configured to convert a mode of the RF electromagnetic wave between a first RF waveguide mode and a second RF waveguide mode. The RF measurement device also includes an internal cavity between the first and second mode converters that contains a vapor or a source of the vapor. The vapor includes Ryberg atoms or molecules. The RF measurement device additionally includes an RF waveguide extending between the first and second mode converters and configured to carry the second RF waveguide mode through the internal cavity. In some variations, the RF waveguide includes first and second longitudinal portions disposed on respective, opposite sides of the device and configured to establish a target RF profile in an interaction region of the internal cavity.

Abstract: In a general aspect, a system for measuring radio frequency (RF) electromagnetic waves includes a laser system configured to generate plurality of input optical signals. The system also includes an RF measurement device having first and second mode converters and an internal cavity therebetween. The internal cavity contains a vapor that is configured to produce an output optical signal based on the plurality of input optical signals. The RF measurement device also includes an RF waveguide that extends between the first and second mode converters and is configured to carry the second RF waveguide mode through the internal cavity. The system also includes an optical detector system configured to generate a detector signal in response to receiving the output optical signal. The system additionally includes a signal processing system configured to generate data in response to receiving the detector signal.

Abstract: In a general aspect, a radio frequency (RF) measurement device includes first and second mode converters, each configured to convert a mode of the RF electromagnetic wave between a first RF waveguide mode and a second RF waveguide mode. The RF measurement device also includes an internal cavity between the first and second mode converters that contains a vapor or a source of the vapor. The vapor includes Ryberg atoms or molecules. The RF measurement device additionally includes an RF waveguide extending between the first and second mode converters and configured to establish a circular polarization of the RF electromagnetic wave in the internal cavity.

Abstract: In a general aspect, radio frequency (RF) electromagnetic radiation can be detected using vapor cell sensors. In some aspects, a system includes a laser system that is configured to generate laser signals that comprise first and second laser signals. The system also includes an optical comb generator and a vapor cell sensor. The optical comb generator is configured to generate a comb spectrum based on the first laser signal. The comb spectrum includes comb lines at respective comb frequencies. The vapor cell sensor contains a vapor and is configured to generate an optical spectrum based on interactions of the vapor with the comb spectrum and the second laser signal. The system also includes an optical detector that is configured to detect the property of the optical spectrum at one or more of the comb frequencies.

Abstract: In a general aspect, a system for sensing pulses of radio frequency (RF) fields includes a laser system and a vapor cell sensor. The laser system is configured to generate beams of light that include a probe beam of light. The vapor cell sensor has a vapor therein and is configured to allow the beams of light to pass through the vapor. The system also includes an optical detector configured to generate a detector signal based on the probe beam of light. The system includes a signal processing system configured to perform operations that include receiving the detector signal from the optical detector over a time period. The operations also include generating a digital signal based on the detector signal and applying a matched filter to the digital signal to generate a filtered signal. The filtered signal is processed to determine properties of an RF field experienced by the vapor.

Abstract: In a general aspect, radio frequency (RF) electromagnetic radiation can be detected using vapor cell sensors. In some aspects, a system includes a laser system that is configured to generate laser signals that comprise first and second laser signals. The system also includes an optical comb generator and a vapor cell sensor. The optical comb generator is configured to generate a comb spectrum based on the first laser signal. The comb spectrum includes comb lines at respective comb frequencies. The vapor cell sensor contains a vapor and is configured to generate an optical spectrum based on interactions of the vapor with the comb spectrum and the second laser signal. The system also includes an optical detector that is configured to detect the property of the optical spectrum at one or more of the comb frequencies.

Abstract: In a general aspect, a system for sensing pulses of radio frequency (RF) fields includes a laser system and a vapor cell sensor. The laser system is configured to generate beams of light that include a probe beam of light. The vapor cell sensor has a vapor therein and is configured to allow the beams of light to pass through the vapor. The system also includes an optical detector configured to generate a detector signal based on the probe beam of light. The system includes a signal processing system configured to perform operations that include receiving the detector signal from the optical detector over a time period. The operations also include generating a digital signal based on the detector signal and applying a matched filter to the digital signal to generate a filtered signal. The filtered signal is processed to determine properties of an RF field experienced by the vapor.

Abstract: In a general aspect, a radar system includes a vapor cell sensor system and a radio frequency (RF) optic. The vapor cell sensor system includes a vapor cell sensor, and the RF optic is configured to direct an RF field onto the vapor cell sensor. The RF field includes one or more RF pulses that define a radar signal. The radar system also includes a signal processing system configured to perform operations that include generating a digital signal based on a signal from the vapor cell sensor system. The digital signal represents a measured response of the vapor to the RF field over a time period. The operations also include applying a matched filter to the digital signal to generate a filtered signal and processing the filtered signal to determine properties of the RF field sensed by the vapor cell sensor over the time period.

Abstract: In a general aspect, a radar system includes a vapor cell sensor system and a radio frequency (RF) optic. The vapor cell sensor system includes a vapor cell sensor, and the RF optic is configured to direct an RF field onto the vapor cell sensor. The RF field includes one or more RF pulses that define a radar signal. The radar system also includes a signal processing system configured to perform operations that include generating a digital signal based on a signal from the vapor cell sensor system. The digital signal represents a measured response of the vapor to the RF field over a time period. The operations also include applying a matched filter to the digital signal to generate a filtered signal and processing the filtered signal to determine properties of the RF field sensed by the vapor cell sensor over the time period.

Abstract: In a general aspect, a laser system includes a laser and a frequency comb generator system. The laser is configured to generate a laser signal, and the frequency comb generator system is configured to generate a frequency comb based on the laser signal. The frequency comb includes frequency comb signals at respective comb frequencies. The laser system also includes a frequency comb dispersion system configured to spatially separate the frequency comb signals onto respective optical channels of the frequency comb dispersion system. The laser system additionally includes a frequency selector system configured to generate a selected frequency signal from the frequency comb signals after separation. The selected frequency signal includes a target separated frequency comb signal. The laser system also includes a frequency shifter configured to alter the selected frequency signal toward a target output frequency of the laser system.

Abstract: A communications device, in one aspect as a portable wireless communications device, includes an in-phase modulator and power amplifier that receives a baseband I signal and modulates and amplifies the I signal. A quadrature modulator and power amplifier receives a baseband Q signal and modulates and amplifies the Q signal. A power combiner sums and outputs the I and Q signals. An I demodulator circuit receives a signal fed back from the I power amplifier and demodulates the fed back signal to produce demodulated I signals. A Q demodulator circuit receives a signal fed back from the Q power amplifier and demodulates the fed back signal to produce demodulated Q signals. A processor compares the digital, baseband I and Q signals with a demodulated I and Q signals to compensate for amplitude, frequency and phase modulation errors.

Abstract: The disclosure relates to an electronic circuit for reducing leakage of radio frequency signals from a power amplifier of a wireless communication device is provided.

Abstract: A system and method for managing battery slump in a battery-powered communications device including: an input configured for receiving battery voltage level information; an output configured for sending a signal for terminating a transmission; and a controller connected to the input and the output and configured to receive the battery voltage level information from the input; monitor the battery voltage level information; and send a signal via the output to terminate a transmission if the battery voltage level information crosses a predetermined threshold during the transmission. In particular, the system and method may further include an input connected to the controller and configured for receiving a signal indicating when a transmission is beginning or occurring and the controller is further configured to receive and monitor the battery voltage level information only when the transmission is occurring.

Abstract: A communications device may include an In-phase (I) circuit having an In-phase modulator and mixer circuit, and an I power amplifier circuit coupled thereto, the I circuit configured to modulate and amplify a digital baseband I signal to generate an amplified I signal, and a Quadrature (Q) circuit having a Q modulator and mixer circuit, and a Q power amplifier circuit coupled thereto, the Q circuit configured to modulate and amplify a digital baseband Q signal to generate an amplified Q signal separate from the amplified I signal. A processor selectively switches the digital baseband I signal and the digital baseband Q signal between the I and Q signal inputs to provide selective phase shifting for the digital baseband I and Q signals.

Abstract: A communications device, in one aspect as a portable wireless communications device, includes an in-phase modulator and power amplifier that receives a baseband I signal and modulates and amplifies the I signal. A quadrature modulator and power amplifier receives a baseband Q signal and modulates and amplifies the Q signal. A power combiner sums and outputs the I and Q signals. An I demodulator circuit receives a signal fed back from the I power amplifier and demodulates the fed back signal to produce demodulated I signals. A Q demodulator circuit receives a signal fed back from the Q power amplifier and demodulates the fed back signal to produce demodulated Q signals. A processor compares the digital, baseband I and Q signals with a demodulated I and Q signals to compensate for amplitude, frequency and phase modulation errors.

Abstract: The disclosure relates to an electronic circuit for reducing leakage of radio frequency signals from a power amplifier of a wireless communication device is provided.

Abstract: The disclosure relates to a printed circuit board (PCB) for an electronic circuit for a power amplifier of a wireless communication device. The PCB comprises: a substrate; a ground reference in the substrate; first through fourth locations and first and second pads in the substrate; and first and second electrical tracks in the substrate. The locations are for components for the PCB, including a 0 ohm component, and pads connect tracks to the components. The first pad is for a high band power input terminal of the amplifier. The first track connects the first pad to the second location. The third location is in the first track for placement of a first capacitor in a circuit between the first pad and ground. The second pad is for an output terminal of the amplifier. The second track connects the second pad to an output stage circuit of the amplifier.

Abstract: A communications device may include an In-phase (I) circuit having an In-phase modulator and mixer circuit, and an I power amplifier circuit coupled thereto, the I circuit configured to modulate and amplify a digital baseband I signal to generate an amplified I signal, and a Quadrature (Q) circuit having a Q modulator and mixer circuit, and a Q power amplifier circuit coupled thereto, the Q circuit configured to modulate and amplify a digital baseband Q signal to generate an amplified Q signal separate from the amplified I signal. A processor selectively switches the digital baseband I signal and the digital baseband Q signal between the I and Q signal inputs to provide selective phase shifting for the digital baseband I and Q signals.

Abstract: A communications device, in one aspect as a portable wireless communications device, includes an in-phase modulator and power amplifier that receives a baseband I signal and modulates and amplifies the I signal. A quadrature modulator and power amplifier receives a baseband Q signal and modulates and amplifies the Q signal. A power combiner sums and outputs the I and Q signals. An I demodulator circuit receives a signal fed back from the I power amplifier and demodulates the fed back signal to produce demodulated I signals. A Q demodulator circuit receives a signal fed back from the Q power amplifier and demodulates the fed back signal to produce demodulated Q signals. A processor compares the digital, baseband I and Q signals with a demodulated I and Q signals to compensate for amplitude, frequency and phase modulation errors.