Abstract: A switch mode power supply converter, a parallel amplifier, and a parallel amplifier output impedance compensation circuit are disclosed. The switch mode power supply converter provides a switching voltage and generates an estimated switching voltage output, which is indicative of the switching voltage. The parallel amplifier generates a power amplifier supply voltage at a power amplifier supply output based on a compensated VRAMP signal. The parallel amplifier output impedance compensation circuit provides the compensated VRAMP signal based on a combination of a VRAMP signal and a high frequency ripple compensation signal. The high frequency ripple compensation signal is based on a difference between the VRAMP signal and the estimated switching voltage output.

Abstract: A front end radio architecture is configured to provide a split band frequency arrangement that includes co-banding. The disclosed split band frequency arrangement combines a medium bandwidth filter with a small bandwidth filter to provide enough bandwidth to pass a relatively large communication band. The medium bandwidth filter has a bandwidth that is large enough to support co-banding of smaller communication bands, while also having a narrow enough bandwidth to realize a relatively steep roll-off that ensures coexistence with adjacent bands that are not co-banded. The bandwidths of the medium bandwidth filter and the small bandwidth filter overlap in bandwidth by an amount that is at least as large as the highest bandwidth signal expected to be received or transmitted. The split band frequency arrangement reduces the number of filters needed in the front end radio architecture by repurposing the small bandwidth filter, and by co-banding the smaller communication bands.

Abstract: This disclosure includes embodiments of a tunable hybrid coupler. The tunable hybrid coupler includes a first inductive element having a first inductance, a second inductive element having a second inductance and mutually coupled to the first inductive element, a first variable capacitive element having a first variable capacitance, and a second variable capacitance having a second variable capacitance. The first variable capacitive element is coupled between a first port and a second port. The second variable capacitive element is coupled between a third port and a fourth port. The first inductive element is coupled from the first port to the third port, while the second inductive element is coupled from the second port to the fourth port. Accordingly, the tunable hybrid coupler may form an impedance matching network that is tunable to different radio frequency (RF) communication bands. The tunable hybrid coupler can be used in a tunable RF duplexer.

Abstract: A digital log gain to digital linear gain multiplier is disclosed. The digital log gain to digital linear gain multiplier includes a log gain splitter adapted to split a log gain input into an integer log part and a remainder log part. A log scale-to-linear scale converter is adapted to output a linear gain value in response to the integer log part and the remainder log part. A gain multiply circuit is adapted to multiply a digital signal by the linear gain value to output a gain-enhanced digital signal.

Abstract: A communication device is disclosed that efficiently manages power. In one embodiment, this communication device includes a first (main) transmitter including a first low band amplifier and a first high band amplifier; a second (MIMO) transmitter including a second low band amplifier and a second high band amplifier; a first power manager in communication with the first low band amplifier and with the second high band amplifier; a second power manager in communication with the first high band amplifier and with the second low band amplifier; and a control system in communication with the first transmitter, the second transmitter, the first power manager, and the second power manager.

Abstract: This disclosure includes embodiments of a radio frequency (RF) transceiver having a distributed duplex filtering topology. The RF transceiver includes a power amplifier and a tunable RF duplexer. The tunable RF duplexer is configured to input an RF transmission input signal from the power amplifier, generate an RF transmission output signal that operates within an RF transmission band in response to the RF transmission input signal from the power amplifier, and simultaneously output the RF transmission output signal to an antenna and input an RF receive input signal that operates within an RF receive band from the antenna. The power amplifier includes a plurality of RF amplifier stages coupled in cascode and an RF filter coupled between a first one of the RF amplifier stages and a second one of the RF amplifier stages. Accordingly, the RF filter is configured to provide tuning within the RF receive band.

Abstract: An efficient power transfer power amplifier (PA) architecture is disclosed that includes a first PA, a first impedance transformation network (ITN) coupled to the first PA, a second PA, and a second ITN coupled to the second PA. A switching network having a plurality of load outputs along with a first switch input coupled to a first impedance output of the first ITN and a second switch input coupled to a second impedance output of the first ITN, a third switch input coupled to a third impedance output of the second ITN, and a fourth switch input coupled to a fourth impedance output of the second ITN. A control system is adapted to control the switching network to switch signals at the first, second, third, and fourth switch inputs such that select ones of the signals travel paths having matching impedances to loads coupled to the plurality of load outputs.

Abstract: Embodiments disclosed in the detailed description relate to a pseudo-envelope follower power management system used to manage the power delivered to a linear RF power amplifier.

Abstract: A tunable radio frequency (RF) duplexer and duplexing methods are disclosed. The tunable RF duplexer includes a first hybrid coupler, a second hybrid coupler, and an RF filter circuit. The first hybrid coupler is operable to split the RF transmission input signal into first and second RF quadrature hybrid transmission signals (QHTSs). The second hybrid coupler is operable to split the RF receive input signal into first and second RF quadrature hybrid receive signals (QHRSs). The RF filter circuit is operable to pass the first and second RF QHTSs to the second hybrid coupler and to reflect the first and second RF QHRSs back to the second hybrid coupler. Additionally, the second hybrid coupler is configured to combine the first and second RF QHTSs into an RF transmission output signal and to combine the first and second RF QHRSs into an RF receive output signal.

Abstract: A tunable radio frequency (RF) duplexer is disclosed. The tunable RF duplexer includes a first hybrid coupler, a second hybrid coupler, and an RF filter circuit. The first hybrid coupler is operable to split an RF receive input signal into first and second RF quadrature hybrid receive signals (QHRSs). The first hybrid coupler is also operable to split an RF transmission input signal into first and second RF quadrature hybrid transmission signals (QHTSs). The RF filter circuit is operable to pass the first and second RF QHRSs to the second hybrid coupler and to reflect the first and second RF QHTSs back to the first hybrid coupler. Additionally, the second hybrid coupler is configured to combine the first and second RF QHRSs into an RF receive output signal, while the first hybrid coupler is configured to combine the first and second RF QHTSs into an RF transmission output signal.

Abstract: This disclosure relates to radio frequency (RF) power converters and methods of operating the same. In one embodiment, an RF power converter includes an RF switching converter, a low-drop out (LDO) regulation circuit, and an RF filter. The RF filter is coupled to receive a pulsed output voltage from the RF switching converter and a supply voltage from the LDO regulation circuit. The RF filter is operable to alternate between a first RF filter topology and a second RF filter topology. In the first RF filter topology, the RF filter is configured to convert the pulsed output voltage from a switching circuit into the supply voltage. The RF filter in the second RF filter topology is configured to filter the supply voltage from the LDO regulation circuit to reduce a ripple variation in a supply voltage level of the supply voltage. As such, the RF filter provides greater versatility.

Abstract: This disclosure relates to radio frequency (RF) power converters and methods of operating the same. In one embodiment, an RF power converter includes an RF switching converter, a low-drop out (LDO) regulation circuit, and an RF filter. The RF filter is coupled to receive a pulsed output voltage from the RF switching converter and a supply voltage from the LDO regulation circuit. The RF filter is operable to alternate between a first RF filter topology and a second RF filter topology. In the first RF filter topology, the RF filter is configured to convert the pulsed output voltage from a switching circuit into the supply voltage. The RF filter in the second RF filter topology is configured to filter the supply voltage from the LDO regulation circuit to reduce a ripple variation in a supply voltage level of the supply voltage. As such, the RF filter provides greater versatility.

Abstract: A baseband PA predistortion module, which includes a baseband combiner, a baseband PA correction circuit, and a baseband filter, is disclosed. The baseband PA correction circuit replicates behavior of an RF PA by processing a modulation data signal to provide a predistortion data signal. The behavior of the RF PA includes distortion. The modulation data signal is representative of an RF input signal to an RF PA and the predistortion data signal is representative of a correction needed at an output of the RF PA. The baseband filter receives and filters the predistortion data signal to provide a reduced predistortion data signal, such that a low frequency content of the reduced predistortion data signal is less than a low frequency content of the predistortion data signal. The baseband combiner receives and combines the modulation data signal and the reduced predistortion data signal to provide a baseband transmit signal.

Abstract: A direct current (DC)-DC converter, which includes switching circuitry, a first parallel amplifier, and a second parallel amplifier, is disclosed. The switching circuitry has a switching circuitry output. The first parallel amplifier has a first feedback input and a first parallel amplifier output. The second parallel amplifier has a second feedback input and a second parallel amplifier output. A first inductive element is coupled between the switching circuitry output and the first feedback input. A second inductive element is coupled between the first feedback input and the second feedback input.

Abstract: Embodiments of a tunable radio frequency (RF) diplexer and methods of operating the same are disclosed. In one embodiment, the RF diplexer includes a first hybrid coupler, a second hybrid coupler, an RF filter circuit, and a phase inversion component. Both the RF filter circuit and the phase inversion component are connected between the first hybrid coupler and the second hybrid coupler. The phase inversion component is configured to provide approximately a differential phase. The RF filter circuit is configured to provide a passband and a notch. The RF filter circuit is tunable to provide the notch on both a high-frequency side of the passband and a low frequency side of the passband. Accordingly, the tunable RF diplexer provides lower insertion losses and higher isolation regardless of whether the one of the diplexed frequency bands is set at higher frequencies or lower frequencies than the other diplexed frequency band.

Abstract: Embodiments of a tunable radio frequency (RF) diplexer and methods of duplexing transmission and receive signals are disclosed. In one embodiment, the RF diplexer includes a first hybrid coupler, a second hybrid coupler, and an RF filter circuit, and a phase inversion component. Both the RF filter circuit and the phase inversion component are connected between the first hybrid coupler and the second hybrid coupler. In some embodiments, the phase inversion component is provided by the RF filter circuit, while in other embodiments, the phase inversion component is provided separately. The phase inversion component is configured to provide a differential phase shift. The benefit of introducing the differential phase shift is that it provides increased isolation and broadband isolation between the different frequency bands being diplexed by the RF diplexer.

Abstract: A transmit and receive RF multiplexer, which includes a first hybrid RF transmit coupler, a first hybrid RF receive coupler, a hybrid RF antenna coupler, and RF bandpass filter and inversion circuitry, is disclosed. The first hybrid RF transmit coupler has a first main transmit port and a pair of transmit ports having a first in-phase transmit port and a first quadrature-phase transmit port. The first hybrid RF receive coupler has a first main receive port and a pair of receive ports having a first in-phase receive port and a first quadrature-phase receive port. The hybrid RF antenna coupler has a main coupler port and a pair of coupler ports having an in-phase coupler port and a quadrature-phase coupler port, such that the main coupler port is coupled to a primary RF antenna.

Abstract: A parallel amplifier, a switching supply, and a radio frequency (RF) notch filter are disclosed. The parallel amplifier has a parallel amplifier output, such that the switching supply is coupled to the parallel amplifier output. Further, the RF notch filter is coupled between the parallel amplifier output and a ground. The RF notch filter has a selectable notch frequency, which is based on an RF duplex frequency.

Abstract: A transceiver may include an antenna tuning control system operably associated with an antenna tuner to control the current power levels of the transmission signal and the receive signal. The antenna tuner control system may receive transmit power control (TPC) information, which was transmitted to the transceiver from a base station on the receive signal. The TPC information may be utilized to change the current power level of the transmission signal to a desired transmission power level. In addition, the antenna tuner control system may generate receive power control (RPC) information. The RPC information may be utilized to change the current power level of the receive signal to a desired receive power level. The antenna tuner control system is operable to adjust the pass band in accordance with the TPC information and the RPC information.

Abstract: A method for power amplifier (PA) calibration for an envelope tracking system of a wireless device is disclosed. The method involves measuring an output power of a PA that is a part under test (PUT) at a predetermined input power. Another step includes calculating a gain equal to the output power of the PA divided by the predetermined input power. A next step involves calculating a gain correction by subtracting the calculated gain from a desired gain. Other steps include determining an expected supply voltage for the PA at the desired gain using the gain correction applied to a nominal curve of gain versus PA supply voltage, and then storing the expected supply voltage for the PA versus input power in memory.