Abstract: Disclosed are devices, systems, and methods for performing time-domain multiply-and-accumulate (MAC) computations. In some embodiments, an apparatus comprises first and second circuits. The first circuit is configured to (a) perform a first multiplication in response to a trigger signal, the first multiplication being a product of a first value and a second value, and (b) generate a completion signal, wherein the completion signal indicates completion of the first multiplication. The second circuit is coupled to the first circuit and is configured to (i) perform a second multiplication in response to the completion signal, the second multiplication being a product of a third value and a fourth value, and (ii) generate an output signal, wherein the output signal indicates completion of the second multiplication. An amount of elapsed time between the trigger signal and the generation of the output signal represents a sum of the first and second multiplications.

Abstract: A multi-port hybrid-based cancellation network may include a first and second hybrid coupler, and a first and second two-port network. The second hybrid coupler may be distinct from the first hybrid coupler. The first two-port network may include a first filter connected between the first and the second hybrid couplers. The second two-port network may include a second filter that is distinct from but essentially the same as the first filter connected between the first and the second hybrid couplers. Other circuitry components may be connected to one of the ports of multi-port hybrid-based cancellation network. These other circuitry components may have a configuration that increases or maximizes signal isolation between at least two of the ports of the multi-port hybrid-based cancellation network.

Abstract: A multi-port hybrid-based cancellation network may include a first and second hybrid coupler, and a first and second two-port network. The second hybrid coupler may be distinct from the first hybrid coupler. The first two-port network may include a first filter connected between the first and the second hybrid couplers. The second two-port network may include a second filter that is distinct from but essentially the same as the first filter connected between the first and the second hybrid couplers. Other circuitry components may be connected to one of the ports of multi-port hybrid-based cancellation network. These other circuitry components may have a configuration that increases or maximizes signal isolation between at least two of the ports of the multi-port hybrid-based cancellation network.

Abstract: A communication unit having a transmitter and method of harmonic distortion content reduction is described. The transmitter is configured to operate in a training mode of operation and a normal transmission mode of operation. The transmitter includes a signal generator; a digital predistortion, DPD, circuit; and a first frequency shift circuit to frequency shift a signal for transmission in a first frequency direction. A feedback path and a second frequency shift circuit frequency shifts a fed back power amplified predistorted signal portion in a second frequency direction opposite to the first frequency direction. A calibration engine, receives and compares a digital baseband signal representative of a signal for transmission with the fed back power amplified predistorted signal portion shifted in the second frequency direction to determine at least one DPD compensation value only during a training mode of operation.

Abstract: A cancellation-based filter may have at least one frequency pass band and at least one frequency stop band. The cancellation-based filter may include a first group of one or more band pass filters, each having at least one acoustic resonator, the first group providing at least one frequency pass band for the cancellation-based filter; at least one hybrid coupler; and a second group of one or more band pass filters, each having at least one acoustic resonator, the second group coupled to at least one of the at least one hybrid couplers, wherein the at least one hybrid coupler and the second group of one or more band pass filters interact to provide at least one frequency stop band for the cancellation-based filter.

Abstract: A two-port tunable or reconfigurable network having a filter transfer function may include: a network input port; a network output port; a hybrid coupler having a hybrid input port, a hybrid isolated port, a hybrid through port, and a hybrid coupled port; a first internal two-port network connected between the network input port and the hybrid input port; a second internal two-port network connected between the network output port and the hybrid isolated port; and a third internal two-port network connected between the hybrid through port and the hybrid coupled port. At least one of the first internal two-port network, the second internal two-port network, the third internal two-port network, and the hybrid coupler may be tunable or reconfigurable in response to an electrical signal or a user-operated control in a way that tunes or reconfigures the filter transfer function of the two-port tunable or reconfigurable network.

Abstract: Multi-port hybrid-based cancellation networks may be used to enable simultaneous transmit and receive in one or more co-existent communication systems. A multi-port hybrid-based cancellation network may include a first and second quadrature hybrid, a first and second two-port network, and other circuitry components. The second quadrature hybrid may be distinct from the first quadrature hybrid. The first two-port network may include a first filter or a first amplifier connected between the first and the second quadrature hybrids. The second two-port network may include a second filter or a second amplifier that is distinct from but essentially the same as the first filter or the first amplifier connected between the first and the second quadrature hybrids. The other circuitry components may be connected between or connected to a connection between one of the quadrature hybrids and one of the two-port networks.

Abstract: A passive cancellation network may include a transmit input having a configuration that passively receives a transmit signal from a transmitter that is to be wirelessly transmitted; a transmit output having a configuration that passively delivers the transmit signal after processing by the passive cancellation network; a receive input having a configuration that passively receives a receive signal that includes undesirable leakage from the transmit signal; a receive output having a configuration that passively delivers the receive signal after processing by the passive cancellation network; and a passive feed forward cancellation circuit that passively cancels at least a portion of the undesired leakage from the transmit signal in the receive signal in a feed forward manner.

Abstract: One mixer circuit includes mixer elements having 3N pairs of differential inputs. There are non-overlapping clock signals provided to the mixer elements which have a duty cycle equal to or less than 33? percent, and N is a positive integer. Output differential signals of the mixer elements do not contain third order harmonic content of the non-overlapping clock signals. Another mixer circuit includes a first mixer element and a signal combining device. The first mixer element has 3N pairs of differential inputs, wherein there are non-overlapping clock signals provided to the first mixer element which have a duty cycle equal to or less than 33? percent, and N is a positive integer. The signal combining device combines outputs from the first mixer element wherein an output signal of the signal combining device do not contain third order harmonic content of the non-overlapping clock signals.

Abstract: A cancellation-based filter may have at least one frequency pass band and at least one frequency stop band. The cancellation-based filter may include a first group of one or more band pass filters, each having at least one acoustic resonator, the first group providing at least one frequency pass band for the cancellation-based filter; at least one hybrid coupler; and a second group of one or more band pass filters, each having at least one acoustic resonator, the second group coupled to at least one of the at least one hybrid couplers, wherein the at least one hybrid coupler and the second group of one or more band pass filters interact to provide at least one frequency stop band for the cancellation-based filter.

Abstract: A two-port tunable or reconfigurable network having a filter transfer function may include: a network input port; a network output port; a hybrid coupler having a hybrid input port, a hybrid isolated port, a hybrid through port, and a hybrid coupled port; a first internal two-port network connected between the network input port and the hybrid input port; a second internal two-port network connected between the network output port and the hybrid isolated port; and a third internal two-port network connected between the hybrid through port and the hybrid coupled port. At least one of the first internal two-port network, the second internal two-port network, the third internal two-port network, and the hybrid coupler may be tunable or reconfigurable in response to an electrical signal or a user-operated control in a way that tunes or reconfigures the filter transfer function of the two-port tunable or reconfigurable network.

Abstract: A multi-port hybrid-based cancellation network may include a first and second hybrid coupler, and a first and second two-port network. The second hybrid coupler may be distinct from the first hybrid coupler. The first two-port network may include a first filter connected between the first and the second hybrid couplers. The second two-port network may include a second filter that is distinct from but essentially the same as the first filter connected between the first and the second hybrid couplers. Other circuitry components may be connected to one of the ports of multi-port hybrid-based cancellation network. These other circuitry components may have a configuration that increases or maximizes signal isolation between at least two of the ports of the multi-port hybrid-based cancellation network.

Abstract: Multi-port hybrid-based cancellation networks may be used to enable simultaneous transmit and receive in one or more co-existent communication systems. A multi-port hybrid-based cancellation network may include a first and second quadrature hybrid, a first and second two-port network, and other circuitry components. The second quadrature hybrid may be distinct from the first quadrature hybrid. The first two-port network may include a first filter or a first amplifier connected between the first and the second quadrature hybrids. The second two-port network may include a second filter or a second amplifier that is distinct from but essentially the same as the first filter or the first amplifier connected between the first and the second quadrature hybrids. The other circuitry components may be connected between or connected to a connection between one of the quadrature hybrids and one of the two-port networks.

Abstract: A passive cancellation network may include a transmit input having a configuration that passively receives a transmit signal from a transmitter that is to be wirelessly transmitted; a transmit output having a configuration that passively delivers the transmit signal after processing by the passive cancellation network; a receive input having a configuration that passively receives a receive signal that includes undesirable leakage from the transmit signal; a receive output having a configuration that passively delivers the receive signal after processing by the passive cancellation network; and a passive feed forward cancellation circuit that passively cancels at least a portion of the undesired leakage from the transmit signal in the receive signal in a feed forward manner.

Abstract: A design for an oscillator, and a PLL incorporating such an oscillator, which takes up little physical area but maintains a large tuning range and low phase noise. Two LC-tanks are nested and switched. Through tuning the inactive tank, the range of the active tank may be increased and finer tuning becomes possible.

Abstract: One mixer circuit includes mixer elements having 3N pairs of differential inputs. There are non-overlapping clock signals provided to the mixer elements which have a duty cycle equal to or less than 33? percent, and N is a positive integer. Output differential signals of the mixer elements do not contain third order harmonic content of the non-overlapping clock signals. Another mixer circuit includes a first mixer element and a signal combining device. The first mixer element has 3N pairs of differential inputs, wherein there are non-overlapping clock signals provided to the first mixer element which have a duty cycle equal to or less than 33? percent, and N is a positive integer. The signal combining device combines outputs from the first mixer element wherein an output signal of the signal combining device do not contain third order harmonic content of the non-overlapping clock signals.

Abstract: A mixer circuit is disclosed. The mixer circuit comprises a plurality of mixer elements, wherein there are non-overlapping clock signals provided to the plurality of mixer elements which have a duty cycle of 33? percent. Outputs signals of the mixer elements do not contain third order harmonic content of the non-overlapping clock signals. The third-order harmonic of the mixer is eliminated by using mixer which uses voltage sampling on non-overlapping clocks and thereby achieves high linearity. The mixer circuit is further expanded to remove the I-Q image and even order harmonics.

Abstract: A mixer circuit is disclosed. The mixer circuit comprises a plurality of mixer elements, wherein there are non-overlapping clock signals provided to the plurality of mixer elements which have a duty cycle of 33 ? percent. Outputs signals of the mixer elements do not contain third order harmonic content of the non-overlapping clock signals. The third-order harmonic of the mixer is eliminated by using mixer which uses voltage sampling on non-overlapping clocks and thereby achieves high linearity. The mixer circuit is further expanded to remove the 1-0 image and even order harmonics.

Abstract: Systems, methods, and apparatus are described that provide for low phase-noise, spectrally-pure, and low-jitter signals from electrical oscillators. An aspect of the present disclosure includes utilization of an open-loop feed-forward phase-noise cancellation scheme to cancel phase noise, or jitter, of an electrical oscillator. Phase noise can be measured and then subtracted, with the phase noise measurement and subtraction being performed at a speed faster than phase noise variations of the oscillator. Another aspect of the present disclosure includes use of a feedback scheme for phase noise reduction. A feedback scheme can be used alone or in conjunction with a feed-forward scheme. Related phase-noise cancellation and/or reduction methods are described. Notch filter and RF amplifier circuits are also described.

Abstract: Systems, methods, and apparatus are described that provide for low phase-noise, spectrally-pure, and low-jitter signals from electrical oscillators. An aspect of the present disclosure includes utilization of an open-loop feed-forward phase-noise cancellation scheme to cancel phase noise, or jitter, of an electrical oscillator. Phase noise can be measured and then subtracted, with the phase noise measurement and subtraction being performed at a speed faster than phase noise variations of the oscillator. Another aspect of the present disclosure includes use of a feedback scheme for phase noise reduction. A feedback scheme can be used alone or in conjunction with a feed-forward scheme. Related phase-noise cancellation and/or reduction methods are described. Notch filter and RF amplifier circuits are also described.