Abstract: An RF switch includes series-coupled RF switch cells coupled between an RF input and ground, each RF switch cell having an input, and a biasing network having outputs for individually biasing each of the RF switch cell inputs to a distinct bias voltage based upon a rank number of the RF switch cell

Abstract: An RF switch includes series-coupled RF switch cells coupled between an RF input and ground, a transistor including a first current node coupled to a first load resistor, a second current node coupled to ground, and a control node coupled to an internal switch node, and a filter having an input coupled to the first current node of the first transistor and an output for providing a DC voltage corresponding to the RF power present at the internal switch node.

Abstract: An RF switch includes series-coupled RF switch cells coupled between an RF input and ground, a transistor including a first current node coupled to a first load resistor, a second current node coupled to ground, and a control node coupled to an internal switch node, and a filter having an input coupled to the first current node of the first transistor and an output for providing a DC voltage corresponding to the RF power present at the internal switch node.

Abstract: A notch filter includes an inductor coupled between an input node and an output node, and a dual-resonator structure coupled between the input node, the output node, and ground.

Abstract: In accordance with an embodiment, a method of operating an RF system includes generating a first RF signal having a first frequency; filtering the generated first RF signal to form a first filtered transmitted signal; producing a first coupled signal and a first transmitted signal from the first filtered transmitted signal; transmitting the first transmitted signal; transmitting a second RF signal having a second frequency; bandpass filtering the first coupled signal to form a first tunable bandpass filtered signal; and measuring a parameter of the first tunable bandpass filtered signal.

Abstract: A notch filter includes a first inductor coupled between an input node and an output node, a dual-resonator structure coupled between the input node and the output node, and a second inductor coupled between the dual-resonator structure and ground, and a bandpass filter includes a capacitor coupled between an input node and an output node, and a dual-resonator structure coupled between the input node, the output node, and ground.

Abstract: In accordance with an embodiment, an RF system includes a transmit path having a first tunable transmit band stop filter, and a power amplifier coupled to an output of the first tunable transmit band stop filter, where the first tunable transmit band stop filter is configured reject a receive frequency and pass a transmit frequency; a receive path comprising an LNA; and a duplex filter having a transmit path port coupled to an output of the power amplifier, a receive path port coupled to an input of the LNA, and an antenna port, where the duplex filter is configured to pass the transmit frequency and reject the receive frequency between the antenna port and the transmit path port, pass the receive frequency and reject the transmit frequency between the antenna port and the receive path port.

Abstract: A resonator element for use in a filter is provided. The resonator element includes a first resonator acoustically coupled to a second or third resonator or both. The first resonator has terminals for incorporation in a filter structure. A tuning circuit is coupled to the second or third resonator or both to enable tuning of the resonator element. The tuning circuit includes a variable capacitor and an inductor.

Abstract: In accordance with an embodiment, a method of operating an RF system includes filtering a first wideband RF signal using a wideband filter bank. Filtering the first RF signal includes separating the first wideband RF signal into frequency cluster signals, where each frequency cluster signal of the frequency cluster signals includes different frequency ranges, the first wideband RF signal includes multiple RF bands, and each of the different frequency ranges comprises a plurality of RF bands of the multiple RF bands. The method further includes band stop filtering at least one of the frequency cluster signals to produce a band stopped frequency cluster signal.

Abstract: A resonator element for use in a filter is provided. The resonator element includes a first resonator acoustically coupled to a second or third resonator or both. The first resonator has terminals for incorporation in a filter structure. A tuning circuit is coupled to the second or third resonator or both to enable tuning of the resonator element. The tuning circuit includes a variable capacitor and an inductor.

Abstract: In accordance with an embodiment, an RF system includes a transmit path having a transmit RF filter and an adjustable transmit phase shifter/matching network coupled between the transmit RF filter and a transmit antenna port, where the adjustable transmit phase shifter/matching network is configured to transform an impedance of the transmit RF filter at a receive frequency from a first lower impedance to a first higher impedance at the transmit antenna port; and a receive path having a receive RF filter and an adjustable receive phase shifter/matching network coupled between the receive RF filter and a receive antenna port, where the adjustable receive phase shifter/matching network is configured to transform an impedance of the receive RF filter at a transmit frequency from a second lower impedance to a second higher impedance at the receive antenna port.

Abstract: A bandpass filter includes a capacitor coupled between an input node and an output node, and a dual-resonator structure coupled between the input node, the output node, and ground.

Abstract: In accordance with an embodiment, a method of operating an RF system includes filtering a wideband RF signal using an adjustable center frequency bandpass filter to produce a filtered RF signal; amplifying the filtered RF signal to produce an amplified RF signal; and band stop filtering the amplified RF signal to produce a band stopped RF signal.

Abstract: RF communications circuitry, which includes a first RF antenna element, a second RF antenna element, a third RF antenna element, and a fourth RF antenna element is disclosed. The first RF antenna element is proximal to the second RF antenna element. The third RF antenna element is proximal to the fourth RF antenna element. A primary axis of the first RF antenna element is about perpendicular to a primary axis of one of the third RF antenna element and the fourth RF antenna element.

Abstract: An RF switch includes series-coupled RF switch cells coupled between an RF input and ground, a transistor including a first current node coupled to a first load resistor, a second current node coupled to ground, and a control node coupled to an internal switch node, and a filter having an input coupled to the first current node of the first transistor and an output for providing a DC voltage corresponding to the RF power present at the internal switch node.

Abstract: A bus interface system is disclosed that includes a master bus controller and a slave bus controller that are coupled by a bus line. The slave bus controller includes a decoder that allows for data to be transmitted along just the bus line. The decoder includes an oscillator, a first counter, and a comparison circuit. The oscillator is configured to be enabled by data pulses defined by the input data signal and generate oscillation pulses while enabled. The first counts the oscillation pulses and indicates a number of the oscillation pulses generated during a time slot. The comparison circuit is configured to this number with a reference number and generate a data output that represents a first logical value in response to the number being greater than the reference parameter and represents a second logical value in response to the number being less than the reference parameter.

Abstract: According to one embodiment, a communication device is described comprising an antenna, a signal path for supplying a signal to the antenna, two directional couplers arranged within the signal path, wherein each directional coupler is coupled to an adjustable impedance defining the characteristic impedance of the directional coupler, a controller configured to set, for each of a plurality of impedances, the adjustable impedances of the directional couplers to the impedance, a return loss measurement circuit configured to determine, for each of the plurality of impedances, a return loss of the signal path when the adjustable impedances of the directional couplers are set to the impedance and a load impedance determination circuit configured to determine a load impedance of the signal path based on the determined return losses.

Abstract: Methods for manufacturing resonator structures and corresponding resonator structures are described. A first wafer including a first piezoelectric material is singulated and bonded to a second wafer.

Abstract: A resonator is described including a piezoelectric material with first and second electrodes provided on the piezoelectric material. An acoustic metamaterial at least partially surrounds an active region of the resonator.

Abstract: In accordance with an embodiment, a circuit includes a plurality of filter circuits having a first port, a second port and a third port, where a second port of a first of the plurality of filter circuits is coupled to a first port of a second of the plurality of filter circuits, and each of the plurality of filter circuits includes a first passive filter, a second passive filter, a first coupler and a combining network. The first coupler includes an input port coupled to the first port, an isolated port coupled to the second port, a first phase shifted port coupled to the first passive filter and a second phase shifted port coupled to the second passive filter, and the combining network includes a first input coupled to the first passive filter, a second input coupled to the second passive filter, and an output coupled to the third port.