A circuit arrangement for compensating for an attenuation occurring in an antenna signal link between a mobile radio terminal and an antenna has at least one antenna signal amplifier in the antenna signal link and a control unit for adjusting a gain factor. The antenna signal conducted through an associated antenna signal amplifier is amplified or attenuated. The circuit arrangement has a detection unit for detecting an antenna signal power (P.sub.M, P.sub.A) of the antenna signal in the signal path of the antenna signal link. The control unit is configured for changing the gain factor, detecting a change, changing the transmit power (P.sub.M) of the mobile radio terminal, and adapting the gain factor to the coupling attenuation of the antenna signal link in dependence on a detected response of the mobile radio terminal.

A front-end module (FEM) is disclosed that includes an integrous signal combiner. The integrous signal combiner can process received signals and use a set of resonant circuits to filter signal noise prior to recombination of a plurality of signal bands that form an aggregate carrier signal. These resonant circuits may be placed after a set of low noise amplifiers and can be used to more efficiently reduce noise and parasitic loading within each of a set of signal paths. Each resonant circuit may be configured to filter noise relating to a bandwidth for a signal that is to be combined with the signal of the signal path that includes the resonant circuit. In some implementations, the integrous signal combiner can be a tunable integrous signal combiner with resonant circuits that may be reconfigurable or dynamically configurable.

A front-end module (FEM) is disclosed that includes an integrous signal combiner. The integrous signal combiner can process received signals and use a set of resonant circuits to filter signal noise prior to recombination of a plurality of signal bands that form an aggregate carrier signal. These resonant circuits may be placed after a set of low noise amplifiers and can be used to more efficiently reduce noise and parasitic loading within each of a set of signal paths. Each resonant circuit may be configured to filter noise relating to a bandwidth for a signal that is to be combined with the signal of the signal path that includes the resonant circuit. The signals may be combined using a dynamic impedance matching circuit. In some implementations, the integrous signal combiner can be a tunable integrous signal combiner with resonant circuits that may be reconfigurable or dynamically configurable.

A radio frequency switch apparatus includes switching circuits connected between respective signal terminals and an antenna terminal. Each of the switching circuits includes a series switching circuit and a shunt switching circuit configured to switch a signal band on and off. An inductor circuit includes an inductor device connected between at least one shunt switching circuit of the switching circuits and a ground. The inductor device suppresses noise and passes the signal band by being resonant with a capacitance present upon the shunt switching circuit being turned off.

Circuits and methods that provide fine-resolution measurements of RF signal power within a communication system band, thereby more accurately measuring RF interference or the potential of RF interference. One aspect of embodiments of the present invention is a narrow-band tunable filter that includes two elements coupled in series, a periodic passband filter and a tunable filter. The purpose of the periodic passband filter is to generate multiple periodic passbands for an applied RF signal. The purpose of the tunable filter is to generate a single passband, generally with a tunable center frequency. By serially coupling the two filter types in either order, the single passband of the tunable filter is superimposed over one of the periodic passbands of the periodic passband filter, synergistically resulting in an extremely narrow passband.

A correction method for a super-regenerative receiver being configured to resonate at at least one oscillator resonant frequency reference value and comprising at least one control stage, at least one varactor, at least one reference system and, at least one oscillator. The method includes at least one setup of at least one reference signal value by the at least one reference system, at least one comparison of at least one oscillator frequency actual value of the at least one oscillator with the at least one reference signal value by the at least one reference system and at least one adjustment of at least one gain of the at least one control stage.

Aspects and embodiments provide a transceiver comprising: a transmit signal path; a receive signal path; bidirectional amplification circuitry reconfigurable for use in both the transmit signal path or receive signal path. The amplification circuitry includes at least one resonant tunnelling diode; and the control circuitry is configured to selectively couple the amplification circuitry into the transmit or receive path of the transceiver in dependence upon whether the transceiver is to operate to transmit or receive a signal. The compact and energy efficient transceiver system in accordance with aspects and embodiments recognises that the physical properties of resonant tunnelling diodes provide a mechanism for simplification of transceiver circuitry and may enable transceiver arrangements which can operate in the high mm-wave and terahertz frequency ranges.

A multiplexer includes first, second, and third filters. The first filter has a first pass band including a first band to send a signal. The second filter has a second pass band including a second band to send a signal. The third filter has a third pass band including a third band. An unwanted frequency of a second-order or fourth-order distortion mode, generated when a first transmitted signal of the first band and a second transmitted signal of the second band are simultaneously transmitted, is included in at least one of the first, second, and third pass bands. An unwanted frequency of a third-order distortion mode, generated when the first transmitted signal and the second transmitted signal are simultaneously transmitted, is included in at least one of the first, second, and third pass bands. The first filter is a BAW filter. The second filter is a SAW filter.

According to one or more of the embodiments herein, systems and techniques are provided for demodulating a received signal which has rapidly varying frequency offset such as due to being transmitted or received with a system whose oscillator is rapidly varying or due to Doppler shift variation caused by change of relative motion between the transmitter and receiver, or due to frequency variations caused by a relaying device such as a communications satellite. The techniques herein establish a model for the carrier frequency and use it to compensate for the variations in frequency due to any source.