An impedance matching device includes: a variable capacitor in which a plurality of first capacitance elements or a plurality of second capacitance elements are connected in parallel; a calculation unit that calculates an impedance or a reflection coefficient on the load side using information regarding the impedance acquired from the outside; and a control unit that determines an ON/OFF state to be taken by each of semiconductor switches included in the variable capacitor using the impedance or the reflection coefficient calculated by the calculation unit and turns on or off the semiconductor switches included in the first or second capacitance element based on the determined state. The control unit cyclically switches semiconductor switches to be turned on or off in a predetermined order.

A filter assembly is disclosed that includes a monolithic filter having a surface and a heat sink coupled to the surface of the monolithic filter. The heat sink includes a layer of thermally conductive material that can have a thickness greater than about 0.02 mm. The heat sink may provide electrical shielding for the monolithic filter. In some embodiments, the filter assembly may include an organic dielectric material, such as liquid crystalline polymer or polyphenyl ether. In some embodiments, the filter assembly may include an additional monolithic filter.

Certain aspects of the disclosure are directed to in-phase/quadrature (IQ) mismatch detection and correction in radio frequency receivers. According to a specific example, a method of manufacture or use comprises, in a quadrature radio-frequency receiver configured to process signals using I and Q components, providing parameters indicative of IQ mismatches associated with circuitry of the quadrature radio-frequency receiver due to changes in signal gain. The method further includes, while using the quadrature radio-frequency receiver to receive and process a received radio signal, correcting for the IQ mismatches by using the parameters in response to actual signal gain change.

Certain aspects of the disclosure are directed to in-phase/quadrature (IQ) mismatch detection and correction in radio frequency receivers. According to a specific example, a method of manufacture or use comprises, in a quadrature radio-frequency receiver configured to process signals using I and Q components, providing parameters indicative of IQ mismatches associated with circuitry of the quadrature radio-frequency receiver due to changes in signal gain. The method further includes, while using the quadrature radio-frequency receiver to receive and process a received radio signal, correcting for the IQ mismatches by using the parameters in response to actual signal gain change.

In accordance with a first aspect of the present disclosure, a tunable attenuator is provided, comprising: one or more transformer windings configured to facilitate attenuating a signal; one or more conductive loops provided underneath the transforming windings; a controller configured to control an amount of current flowing through the conductive loops, thereby providing a tunable attenuation of said signal. In accordance with a second aspect of the present disclosure, a corresponding method of producing a tunable attenuator is conceived.

A system for filter enhancement, preferably including one or more analog taps and a controller, and optionally including one or more couplers. The system is preferably configured to integrate with a filter, such as a passband filter or other frequency-based filter. The system can be configured to integrate with an RF communication system, an RF front end, or any other suitable RF circuitry. A method for filter enhancement, preferably including configuring one or more analog taps, and optionally including calibrating a system for filter enhancement and/or receiving temperature information.

Aspects of this disclosure relate to a filter that includes an acoustic wave device with a multi-layer substrate with heat dissipation. The multi-layer substrate includes a support substrate (e.g., a quartz substrate), a piezoelectric layer, an interdigital transducer electrode on the piezoelectric layer, and a thermally conductive layer configured to dissipate heat associated with the acoustic wave device. The thermally conductive layer is disposed between the support substrate and the piezoelectric layer. The thermally conductive layer has a thickness that is greater than 10 nanometers and less than a thickness of the piezoelectric layer.

Aspects of this disclosure relate to a filter that includes an acoustic wave device with a multi-layer substrate with heat dissipation. The multi-layer substrate includes a support substrate (e.g., a quartz substrate), a piezoelectric layer, an interdigital transducer electrode on the piezoelectric layer, and a thermally conductive layer configured to dissipate heat associated with the acoustic wave device. The thermally conductive layer is disposed between the support substrate and the piezoelectric layer. The thermally conductive layer has a thickness that is greater than 10 nanometers and less than a thickness of the piezoelectric layer.

A filter with three phases comprising for each phase an input terminal, an output terminal and a capacitor, wherein for each of the three phases the input terminal is electrically connected via a connection point to the output terminal, wherein the connection points of the three phases are electrically connected via the three capacitors in star and/or delta form, wherein the filter comprises a housing containing two coil blocks, wherein the housing comprises a first side and a second side opposite the first side, wherein the two coil blocks are arranged along a line between the first side and the second side, wherein a fan for cooling the two coil blocks is arranged on the first side of the housing, wherein the larger of the two coil blocks is arranged between the fan and the smaller of the two coil blocks.

A filter with three phases comprising for each phase an input terminal, an output terminal and a capacitor, wherein for each of the three phases the input terminal is electrically connected via a connection point to the output terminal, wherein the connection points of the three phases are electrically connected via the three capacitors in star and/or delta form, wherein the filter comprises a housing containing two coil blocks, wherein the housing comprises a first side and a second side opposite the first side, wherein the two coil blocks are arranged along a line between the first side and the second side, wherein a fan for cooling the two coil blocks is arranged on the first side of the housing, wherein the larger of the two coil blocks is arranged between the fan and the smaller of the two coil blocks.