Abstract: In one embodiment, a lidar system includes a light source configured to emit local-oscillator (LO) light and pulses of light, the emitted pulses of light including a first emitted pulse of light, where an optical frequency of the first emitted pulse of light is offset from an optical frequency of the LO light by a first frequency offset. The lidar system further includes a receiver configured to detect the LO light and a first received pulse of light, the first received pulse of light including light from the first emitted pulse of light scattered by a target located a distance from the lidar system. The receiver includes a detector, where: the LO light and the first received pulse of light are coherently mixed together at the detector, and the detector is configured to produce a photocurrent signal corresponding to the coherent mixing.

Abstract: A system includes a light source, an optical splitter, and a pulse-energy measurement circuit. The light source is configured to generate an emitted beam of light that includes an emitted pulse of light. The optical splitter is configured to split the emitted beam of light to produce at least (i) a test beam of light that includes a test pulse of light, the test pulse of light including a first portion of the emitted pulse of light and (ii) an output beam of light that includes an output pulse of light, the output pulse of light including a second portion of the emitted pulse of light allowed to at least in part exit the system. The pulse-energy measurement circuit is configured to receive the test pulse of light and determine a numerical value corresponding to an individual energy amount of the test pulse of light.

Abstract: A method and system performs antenna tuning using detected changes in antenna self-capacitance in a wireless communication device. A modem detects changes in antenna self-capacitance by utilizing multiple antenna elements. The modem determines a current antenna loading condition using the detected changes in antenna self-capacitance. The modem determines appropriate tuning states for each antenna matching and tuning circuit (AMTC) associated with a respective antenna element. In order to determine the appropriate tuning states, the modem utilizes pre-established antenna self-capacitance information which is mapped to antenna tuning states. The antenna tuning states which are respectively mapped to pre-established antenna self-capacitance are empirically pre-determined by correlating antenna self-capacitance changes to antenna impedance changes.

Abstract: A method and system performs antenna tuning which enhances radio frequency (RF) tuner reliability within a wireless communication device (WCD). The WCD, in response to receiving a request to change an active RF tuning state, retrieves component usage data corresponding to components of a tuning circuit that is tunable to an RF operating channel. The WCD selectively determines, using device environment state data and/or RF state data and the component usage data, an RF tuning state tuned to the RF operating channel. The selected RF tuning state (a) satisfies tuning performance specifications and (b) enhances component reliability performance by minimizing an operational wear on tuning circuit components. The WCD configures the tuning circuit using the selected RF tuning state and tracks session parameter values for tuning circuit components during a corresponding communication session.

Abstract: A method and system performs antenna tuning which enhances radio frequency (RF) tuner reliability within a wireless communication device (WCD). The WCD, in response to receiving a request to change an active RF tuning state, retrieves component usage data corresponding to components of a tuning circuit that is tunable to an RF operating channel. The WCD selectively determines, using device environment state data and/or RF state data and the component usage data, an RF tuning state tuned to the RF operating channel. The selected RF tuning state (a) satisfies tuning performance specifications and (b) enhances component reliability performance by minimizing an operational wear on tuning circuit components. The WCD configures the tuning circuit using the selected RF tuning state and tracks session parameter values for tuning circuit components during a corresponding communication session.

Abstract: A method and system performs antenna tuning using detected changes in antenna self-capacitance in a wireless communication device. A modem detects changes in antenna self-capacitance by utilizing multiple antenna elements. The modem determines a current antenna loading condition using the detected changes in antenna self-capacitance. The modem determines appropriate tuning states for each antenna matching and tuning circuit (AMTC) associated with a respective antenna element. In order to determine the appropriate tuning states, the modem utilizes pre-established antenna self-capacitance information which is mapped to antenna tuning states. The antenna tuning states which are respectively mapped to pre-established antenna self-capacitance are empirically pre-determined by correlating antenna self-capacitance changes to antenna impedance changes.

Abstract: A transmitter (100) includes a fractional N synthesizer, a baseband digital modulation stage coupled to the fractional N synthesizer in a first modulation mode, and a baseband I/Q modulation stage also coupled to the fractional N synthesizer and reusing the fractional N synthesizer in a second modulation mode. A method (300) of operating a transmitter includes transmitting a first signal from a transmitter using the fractional N synthesizer and the baseband digital modulation stage to modulate the first signal according to a first wireless protocol. The method (300) also includes transmitting a second signal from the transmitter using the baseband I/Q modulation stage and the fractional N synthesizer to modulate the second signal according to a second wireless protocol.

Abstract: An isolator eliminator for a linear transmitter receives a plurality of digital samples of an information signal and a drive signal sampled from a feedback loop at periodic time intervals and, responsive to processing the digital samples, provides high accuracy phase and level correction signals to the feedback loop. The phase and level correction signals maintain stable, linear operation of the feedback loop and limit splatter. In a preferred embodiment, the isolator eliminator includes a digital signal processor such that multiple communication protocols may be accommodated by changing software code executed by the processor.

Abstract: A frequency generation circuit includes an oscillator (403), a comparator (413) coupled to the oscillator, a first divider (407) coupled to the comparator, a PLL (400) coupled to the first divider, a second divider (422) coupled to the PLL, a first multiplexor (409) coupled to the second divider, a third divider (408) coupled to the comparator and the first multiplexor, a second multiplexor (410) coupled to the comparator and the reference clock PLL, a fourth divider (411) coupled to the second multiplexor, a fifth divider (412) coupled to the comparator, and a seventh divider (450) coupled to the comparator. A method of operating a transceiver includes using the frequency generation circuit to provide a first clock signal, a second clock signal, a first reference frequency, and a second reference frequency for a first component, a second component, a third component, and a fourth component, respectively, of the transceiver.

Abstract: An isolator eliminator for a linear transmitter is disclosed. The isolator eliminator receives a plurality of digital samples of an information signal and a drive signal sampled from a feedback loop at periodic time intervals and, responsive to processing the digital samples, provides high accuracy phase and level correction signals to the feedback loop. The phase and level correction signals maintain stable, linear operation of the feedback loop and limit splatter. In a preferred embodiment, the isolator eliminator comprises a digital signal processor such that multiple communication protocols may be accommodated by changing software code executed by the processor.

Abstract: A system is provided which facilitates a single-channel signal processing system. The system includes a single mixing stage, wherein an RF input signal is mixed with an In-Phase and a Quadrature-Phase signal. The mixing stage generates a multiplexed output signal for subsequent signal processing.

Abstract: A phase lock loop (100) includes a dual-state charge pump (120) having a first current source (220), a second current source (230) coupled in series to the first current source, a third current source (240), a fourth current source (250) coupled in series to the third current source, and control circuitry (210) coupled to the first, second, third, and fourth current sources. The charge pump can be programmed to be in an adapt mode with large up and down currents or in a normal mode with small up and down currents. The duration of the adapt mode can be programmed by a timer. The phase lock loop has a wide loop bandwidth and a faster lock time during the adapt mode and a narrow loop bandwidth and less phase noise during the normal mode.

Abstract: The RF section of a communication device (100) includes a receiver (106), a transmitter (108), first injection frequency generation circuit (120), and an intermediate frequency (IF) generation circuit (124). The IF generation circuit has a shared output coupled to both the receiver and transmitter, as well as a control circuit (118) for feedback control purposes. The IF generation circuit is used to generate IF for both the receiver and transmitter, thus using fewer components that two separate IF generation circuits. It includes two differently tuned voltage controlled oscillators (202, 204) which are selectively and exclusively powered by first and second power switches (234, 236), respectively. The control circuit provides a single control voltage corresponding to a desired frequency pair to both VCOs at a common control input, then selects the appropriate VCO depending on whether the communication device is receiving or transmitting.

Abstract: A transmitter has a loop switch (132) and a feedback switch (127), which are operated by a control circuit (134). An unamplified value is obtained by connecting a cartesian demodulator (126) with the input to a power amplifier (118), applying a fixed baseband signal level to the input of the cartesian modulator, and measuring the output level of the cartesian demodulator. An amplified value is obtained by connecting the output of the power amplifier to the cartesian demodulator, again applying a fixed baseband signal level, and measuring the output of the demodulator. The amplified and unamplified values are compared by the control circuit, and the power amplifier gain is adjusted by varying the gain adjust signal (138), if necessary.

Abstract: An antenna coupling assembly (100) includes an stub section (107) for coupling radio frequency (RF) energy from an RF source to a radio antenna. An antenna coupler ground (113) is positioned adjacent to the stub section (107) and is electrically connected to the ground of the RF source (101). In accordance with the invention, a ground extension section (115,115',115") is attached to the antenna coupler ground (113) for electrically extending the physical length of the antenna coupler ground to enhance efficiency and overall performance of the antenna coupler.

Abstract: An active circuit includes an amplifying transistor (102), a voltage reference (208), and an active bias circuit. The active bias circuit controls the operating point of the amplifying transistor, and includes a bias transistor (224) which is controlled by the voltage reference and the collector current of the amplifying transistor. As the temperature of the amplifying transistor changes, the tendency of the collector current to change is counter-acted by the bias transistor and the voltage reference.

Abstract: A low loss electronic radio frequency (RF) switch (100) for switching RF energy between an antenna port (115), a receiver port (113) and a transmit port (101) used in a two-way radio transceiver. The RF switch includes a first diode (105) connected between the transmit port (101) and the antenna port (115). A first capacitor (103) is connected between the transmit port (101) and a ground potential while an inductor (107) and second capacitor (111) are serially connected between the antenna port (115) and a receive port (113). A second diode (109) is connected between the inductor (107) and the second capacitor (111) and the ground potential. The antenna port (115) is normally connected with the receive port (113) when idle. When direct current is applied to the transmit port (101) the first diode (105) and second diode (109) are biased into a low impedance state connecting the antenna port (115) to the transmit port (101) and isolating the receive port (113) from the antenna port (115).

Abstract: An antenna coupler (100) for use in a mobile adaptor (102, 300) transfers radio frequency (RF) energy between a portable radio antenna system (204) and an external antenna (124) with minimal coupling losses. The antenna coupler (100) includes a resonator patch (110) and an electromagnetic tuning element (112) forming side walls on a substrate for receiving the portable antenna system (204). The electromagnetic tuning element (112) controls the impedance between the resonator patch (110) and the portable antenna system (204) while the resonator patch transfers the RF energy between the portable radio antenna and the external antenna (124).

Abstract: First and second shielding portions (110, 112) formed of electroless plated plastic enclose a radio frequency (RF) board (108). Bosses (148) extend from inner surfaces (130, 142) of the first and second shielding portions (110, 112) to make contact with compressible ground clip members (126) located on the RF board (108).

Abstract: Battery (300) includes a first redundant limiting circuit (302) for limiting the voltage and current levels which are outputted by the first limited battery output (308). A second redundant limiting circuit (304) provides for a second limited battery output (310). Connected to both the first (308) and second (310) battery outputs is a fault monitoring circuit (306), which monitors for any faults such as electrical shorts, occurring at any of the two battery outputs (308 or 310). The fault monitoring circuit (306) interrupts the appropriate output, if a fault, or a current limiting condition occurs. Battery (300) allows for radios which would otherwise not be able to achieve intrinsic safe level approvals to attain such approvals.