Abstract: In electronic devices used in radio-frequency communications, impedance matching may result in desirable operating conditions. However, impedance of the antenna may change over time (e.g., due to frequency of signals being transmitted or received, due to ambient conditions, due to age of antenna or related components). Accordingly, it may be desirable to employ antenna tracking circuitry that may operate as an impedance matching network to dynamically match the antenna impedance. To dynamically match the antenna impedance, the matching network may include tunable components. To provide fast, dynamic, and effective impedance matching, antenna tracking circuitry having an architecture with analytically determinable impedance (e.g., determinable via one or more equations) may be implemented. The antenna tracking circuitry may include a variable resistor and three variable impedances.

Abstract: A differential double balanced duplexer (dDBD) includes a transmitter and a first balun are coupled to a first impedance tuner that produces a first impedance that blocks received signals at a first frequency range from travelling across the first balun and into the transmitter, and a second impedance that passes transmitted signals at a second frequency range to travel across the first balun to the antenna. The dDBD also includes a receiver and a second balun coupled to a second impedance tuner that produces a first impedance that allows the received signals at the first frequency range to travel across the second balun and into the receiver, and a second impedance that blocks the transmitted signals at the second frequency range from travelling across the second balun and into the receiver. As such, the dDBD allows for increased isolation and decreased insertion loss.

Abstract: An electronic device may include isolation circuitry coupled between a transmitter, a receiver, and one or more antennas. The isolation circuitry may include a 90 degree hybrid coupler configured receive a transmission (TX) signal from the transmitter, split the TX signal into a first portion and a second portion, and phase-shift a portion such that the portions are +90 degrees out-of-phase. The isolation circuitry may include phase shifters that phase-shift the portions such that the portions are in-phase prior to propagating to the antenna. The phase shifters may receive a first portion and a second portion of a receiver (RX) signal from splitter circuitry. The phase shifters may phase-shift the portions such that the portions are out-of-phase by ?90 degrees. The 90 degree hybrid coupler may phase-shift the first portion and/or the second portion such that the portions are in-phase and constructively combine prior to propagating to the receiver.

Abstract: A communication device includes a duplexer differentially coupled to a receiver and a transmitter. The duplexer may include phase shifters on the differential lines to provide differential received signals to the receiver and receive differential transmission signals from the transmitter for transmission. For example, the phase shifter are positioned such that single-ended received signals may be converted to differential received signals and convert the differential transmission signals to single-ended transmission signals for transmission. Moreover, the phase shifters may provide the single-ended transmission signals to antennas for transmission and to the differential lines of the receiver for cancellation/isolation. Furthermore, the phase shifters may provide the differential received signals to the receiver for reception and provide the single-ended received signals to the differential lines of the transmitter for cancellation/isolation.

Abstract: An electronic device may include wireless circuitry with a processor, a transceiver circuit, a front-end module, and an antenna. The front-end module may include amplifier circuitry such as a low noise amplifier for amplifying received radio-frequency signals. The amplifier circuitry may operation in different modes based on its operating environment. Accordingly, the amplifier circuitry may include multiple amplifying cascode stages coupled in parallel, some of which may be selectively enabled. The amplifier circuitry may include an intermodulation distortion suppression circuit coupled to an amplifying cascode stage and an n-path filter coupled to another amplifying cascode stage. One or more of these amplifier circuitry portions may be active depending on its operating mode.

Abstract: Systems and methods combine a test signal with a wanted (downlink or uplink) signal at an input of a duplexer of a communication device, and receive the test signal at an output of the duplexer. The test signal may include a radio frequency signal having less power than the wanted signal to avoid interference, or a digital signal that is added to or extracted from the wanted signal when the wanted signal does not have a radio frequency. A processor of the communication device causes the duplexer to operate in a tuning state (e.g., to transmit signals having a transmission frequency and receive signals having a receive frequency). The measurement system determines a difference or ratio in power between the test signal at the duplexer output and the duplexer input, and adjusts the tuning state based on the difference or ratio (e.g., to decrease or minimize the difference or ratio).

Abstract: Systems and methods combine a test signal with a wanted (downlink or uplink) signal at an input of a duplexer of a communication device, and receive the test signal at an output of the duplexer. The test signal may include a radio frequency signal having less power than the wanted signal to avoid interference, or a digital signal that is added to or extracted from the wanted signal when the wanted signal does not have a radio frequency. A processor of the communication device causes the duplexer to operate in a tuning state (e.g., to transmit signals having a transmission frequency and receive signals having a receive frequency). The measurement system determines a difference or ratio in power between the test signal at the duplexer output and the duplexer input, and adjusts the tuning state based on the difference or ratio (e.g., to decrease or minimize the difference or ratio).

Abstract: A waste-heat recovery system for a waste-heat source, made up of an ORC (Organic-Rankine Cycle) postconnected thereto. The waste-heat source is connected with the heating device of the ORC as well as an expansion machine, coupled to a generator, for steam expansion in the ORC, which has magnetic bearings with an associated control device and a power supply via a direct current intermediate circuit of a generator frequency converter. The design and safe operating behavior of a waste-heat recovery system made up of an ORC post-connected to a waste-heat source are optimized. In a power supply failure, the electric energy that a down-running generator continues to generate is used to supply the magnetic bearings with the associated control device in order to ensure a safe operation in the event of a power supply failure.

Abstract: A waste recovery system for a waste-heat source made up of an ORC (Organic-Rankine Cycle) postconnected thereto is described. The waste-heat source is in connection with the heating device of the ORC as well as with an expansion machine for steam expansion in the ORC coupled to a generator. The design and operating behavior of a force-heat coupling system is optimized, a waste-heat recovery system made up of an ORC post-connected to a waste-heat source. The expansion machine for steam expansion in the ORC is therefore started up by the generator which is operating in motor mode, and brought to a minimum starting engine speed able to be specified in a control device.

Abstract: A waste-heat recovery system for a waste-heat source includes an ORC (Organic-Rankine Cycle) postconnected thereto, the waste-heat source being in connection with the heating device of the ORC, as well as with an expansion machine, coupled to a generator, for steam expansion in the ORC, which has magnetic bearings with an associated control device and a power supply via a direct current intermediate circuit of a generator frequency converter. The unit made up of the expansion machine, the generator and the frequency converter is cooled by the coolant from the ORC circuit.

Abstract: A convertible wind protection device which is arranged behind a row of seats projects upward over the row of seats and extends along the entire width of the vehicle interior. The wind protection device can be displaced from an inoperative into an operative position. In order to provide a wind protection device with easy operability and in a space-saving housing in its inoperative position when the top is closed, it is provided that the swivellable wind protection device is disposed on the folding top of the convertible.