Abstract: Radio frequency (RF) front end circuitry is disclosed that includes a filter circuit, a first switch device, and a second switch device. The filter circuit is coupled to present a filter capacitance to the first RF port and to the second RF port. The second switch device is configured to present a device capacitance to the second RF port when a common port of the second switch device is shunted to ground. The first switch device is configured to present approximately the filter capacitance and the device capacitance to its common port. The device capacitance from the second switch device can thus be used to tune a total capacitance presented to the common port of the first switch device. As such, the total capacitance presented to the common port of the first switch device can be maintained substantially unchanged without requiring a substantial increase in the number of switching components.

Abstract: A reconfigurable RF filter, which includes a first resonator, a second resonator, and a first coupling circuit, is disclosed. The first coupling circuit is coupled between the first resonator and the second resonator. The reconfigurable RF filter operates in one of a group of operating modes, which include a first operating mode and a second operating mode. During the first operating mode, the reconfigurable RF filter is a bandpass filter having a first bandwidth and a first insertion loss via the first resonator. During the second operating mode, the reconfigurable RF filter is a bandpass filter having a second bandwidth and a second insertion loss via the first resonator, such that the first bandwidth is greater than the second bandwidth and the first insertion loss is less than the second insertion loss.

Abstract: RF circuitry, which includes a first acoustic RF resonator (ARFR), a first compensating ARFR, and a second compensating ARFR, is disclosed. The first compensating ARFR is coupled between a first inductive element and a first end of the first ARFR. The second compensating ARFR is coupled between a second inductive element and a second end of the first ARFR. The first inductive element and the second inductive element are negatively coupled to one another. The first compensating ARFR, the second compensating ARFR, the first inductive element, and the second inductive element at least partially compensate for a parallel capacitance of the first ARFR.

Abstract: RF multiplexer circuitry includes a first signal path coupled between a first intermediate node and a common node, a second signal path coupled between a second intermediate node and the common node, first resonator circuitry coupled between the first signal path and ground, and second resonator circuitry coupled between the second signal path and ground. The first resonator circuitry is configured to allow signals within a first frequency pass band to pass between the first intermediate node and the common node, while attenuating signals outside of the first frequency pass band. The first resonator circuitry includes a first LC resonator. The second resonator circuitry is configured to allow signals within a second frequency pass band to pass between the second intermediate node and the common node, while attenuating signals outside of the second frequency pass band.

Abstract: Described are embodiments of stacked field effect transistor (FET) switch having a plurality of FET devices coupled in series to form an FET device stack. To prevent the FET device stack from being turned on during large signal conditions, one or more decoupling paths are provided and are configured to pass the time-variant input signal during the open state of the FET device stack. The first decoupling path may include a capacitor, a transistor, or the like, that passes the time-variant input signal by, for example, presenting a low impedance to the time-variant input signal during the open state. The decoupling paths may be connected so that the time-variant input signal bypasses a portion of the FET device stack during the open state.

Abstract: RF front end circuitry includes primary transceiver circuitry associated with a primary antenna and secondary receiver circuitry associated with a secondary antenna. Generally, the primary transceiver circuitry and the primary antenna are located on one end of a mobile communications device, while the secondary receiver circuitry and the secondary antenna are located at an opposite end of the device. Cross-coupling connection lines run between the antenna switching circuitry for the primary antenna and the secondary antenna, and are reused to send a portion of primary RF transmit signals from the primary transceiver circuitry to the secondary receiver circuitry so that primary RF transmit signals coupled into the secondary receiver path via antenna-to-antenna coupling can be reduced.

Abstract: Radio frequency (RF) circuitry is configured to separately route RF transmit signals in different RF frequency bands through one or more non-linear elements, such as switches, in order to avoid intermodulation of the RF transmit signals. One or more filters may be arranged to provide different switching paths in RF front end circuitry to ensure that RF transmit signals are not routed together through a non-linear element, thereby improving the performance of the circuitry.

Abstract: Described are embodiments of stacked field effect transistor (FET) switch having a plurality of FET devices coupled in series to form an FET device stack. To prevent the FET device stack from being turned on during large signal conditions, one or more decoupling paths are provided and are configured to pass the time-variant input signal during the open state of the FET device stack. The first decoupling path may include a capacitor, a transistor, or the like, that passes the time-variant input signal by, for example, presenting a low impedance to the time-variant input signal during the open state. The decoupling paths may be connected so that the time-variant input signal bypasses a portion of the FET device stack during the open state.

Abstract: Radio frequency (RF) front end circuitry includes primary communications circuitry and secondary communications circuitry. The primary communications circuitry is configured to provide primary RF transmit signals and receive primary RF receive signals. The secondary communications circuitry is configured to provide primary RF transmit signals during certain uplink carrier aggregation configurations to provide antenna-to-antenna isolation between primary RF transmit signals and thus reduce intermodulation between signals in problematic operating band combinations.

Abstract: RF front end circuitry includes mid/high-band switching circuitry and a carrier-aggregation diplexer. The mid/high-band switching circuitry is configured to receive and selectively route mid-band and high-band signals between a mid/high-band output port and a number of mid/high-band transceiver ports. The carrier-aggregation diplexer is coupled to a first one of the mid/high-band transceiver ports. Further, the carrier-aggregation diplexer is configured to pass mid-band signals between a mid-band diplexer port and the first one of the mid/high-band transceiver ports while attenuating other signals, and pass high-band signals between a high-band diplexer port and the first one of the mid/high-band transceiver ports while attenuating other signals.

Abstract: RF coupling circuitry includes a first coupled signal output node, a second coupled signal output node, an RF coupler, RF filtering circuitry, and attenuator circuitry. The RF coupler is configured to couple RF signals from an RF transmission line to provide coupled RF signals. The RF filtering circuitry is coupled to the RF coupler and configured to separate RF signals within a first RF frequency band in the coupled RF signals from RF signals within a second RF frequency band in the coupled RF signals. The attenuator circuitry is coupled between the RF filtering circuitry, the first coupled signal output node, and the second coupled signal output node. The attenuator circuitry is configured to attenuate the RF signals within the first RF frequency band and the RF signals within the second RF frequency band.

Abstract: RF filtering circuitry includes a first input/output node, a second input/output node, a common node, first filtering circuitry, second filtering circuitry, and transmit signal cancellation circuitry. The first filtering circuitry is coupled between the first input/output node and the common node, and is configured to pass RF transmit signals within one or more transmit signal frequency bands while attenuating signals outside the one or more transmit signal frequency bands. The second filtering circuitry is coupled between the second input/output node and the common node, and is configured to pass RF receive signals within one or more receive signal frequency bands while attenuating signals outside the one or more receive signal frequency bands. The transmit signal cancellation circuitry is coupled between the common node and the second input/output node and is configured to generate a transmit cancellation signal from the RF transmit signals.

Abstract: Radio frequency (RF) front end circuitry is disclosed that includes a filter circuit, a first switch device, and a second switch device. The filter circuit is coupled to present a filter capacitance to the first RF port and to the second RF port. The second switch device is configured to present a device capacitance to the second RF port when a common port of the second switch device is shunted to ground. The first switch device is configured to present approximately the filter capacitance and the device capacitance to its common port. The device capacitance from the second switch device can thus be used to tune a total capacitance presented to the common port of the first switch device. As such, the total capacitance presented to the common port of the first switch device can be maintained substantially unchanged without requiring a substantial increase in the number of switching components.

Abstract: A reconfigurable RF filter, which includes a first resonator, a second resonator, and a first coupling circuit, is disclosed. The first coupling circuit is coupled between the first resonator and the second resonator. The reconfigurable RF filter operates in one of a group of operating modes, which include a first operating mode and a second operating mode. During the first operating mode, the reconfigurable RF filter is a bandpass filter having a first bandwidth and a first insertion loss via the first resonator. During the second operating mode, the reconfigurable RF filter is a bandpass filter having a second bandwidth and a second insertion loss via the first resonator, such that the first bandwidth is greater than the second bandwidth and the first insertion loss is less than the second insertion loss.

Abstract: Embodiments of radio frequency (RF) filtering circuitry are disclosed. In one embodiment, the RF filtering circuitry includes a first port, a second port, a first RF filter path, and a second RF filter path. The first RF filter path is connected between the first port and the second port and includes at least a pair of weakly coupled resonators. The weakly coupled resonators are configured such that a first transfer response between the first port and the second port defines a first passband. The second RF filter path is coupled to the first RF filter path and is configured such that the first transfer response between the first port and the second port defines a stopband adjacent to the first passband without substantially increasing ripple variation of the first passband defined by the first transfer response.

Abstract: Disclosed is an RF front-end with improved insertion loss having at least a first resonator with a first port and a second port and at least a second resonator having a third port and a fourth port, wherein the first resonator and the second resonator are magnetically coupled by no more than 5%. Also included is at least one coupling structure coupled between the second port of the first resonator and the third port of the second resonator, wherein the coupling structure has a coupling control input for varying a coupling coefficient between the first resonator and the second resonator such that an RF signal transfer between the first port of the first resonator and the fourth port of the second resonator is controllably variable between 5% and 95%.

Abstract: This disclosure relates to radio frequency (RF) front end circuitry used to route RF signals. In one embodiment, the RF front end circuitry has a filter circuit and a switch device. The switch device includes a common port, an RF port, and switchable path connected in series between the common port and the RF port. The switch device is configured to present approximately the filter capacitance of the filter circuit at the common port when the switchable path is closed. However, when the switchable path is open, the switch device is configured to present a device capacitance at the common port that is approximately equal to the filter capacitance of the filter circuit. In this manner, if the common port is connected to an antenna, the capacitance seen by the antenna from the common port remains substantially unchanged regardless of which of the switchable path is opened or closed.

Abstract: RF filtering circuitry includes a common node, a first input/output node, a second/input output node, a first filter coupled between the common node, the first input/output node, and the second input/output node, and a second filter coupled between the common node, the first input/output node, and the second input/output node. The first filter is configured to provide a first bandpass filter response between the common node and the first input/output node, where the first bandpass filter response is configured to pass RF signals within a first subset of the first frequency band while attenuating other signals. Further, the first filter is configured to provide a bandstop filter response between the common node and the second input/output node, where the bandstop filter response is configured to attenuate RF signals within the first subset of the first frequency band while passing other signals.

Abstract: Antenna swapping circuitry includes a first pole, a second pole, a first throw, a second throw, and a number of switching elements. A first switching element is coupled between the first pole and the first throw. A second switching element is coupled between the first pole and the second throw. A third switching element is coupled between the second pole and the first throw. A fourth switching element is coupled between the second pole and the second throw. A linearity of the first switching element and the fourth switching element is higher in a closed state of operation than in an open state of operation. A linearity of the second switching element and a third switching element is higher in an open state of operation than in a closed state of operation.

Abstract: RF front-end circuitry, which includes a first RF low noise amplifier (LNA) and a first reconfigurable RF filter, is disclosed. The RF front-end circuitry operates in one of a group of operating modes. The first reconfigurable RF filter, which has a first reconfigurable RF filter path, includes a first receive (RX) shunt switching element coupled between the first reconfigurable RF filter path and ground. The first reconfigurable RF filter path is coupled to an input of the first RF LNA. The group of operating modes includes a first operating mode and a second operating mode. During the first operating mode, the first RX shunt switching element is ON. During the second operating mode, the first RX shunt switching element is OFF and the first RF LNA receives and amplifies a first filtered RF receive signal from the first reconfigurable RF filter to provide a first receive signal.