There is provided wireless transmitter that includes a poly phase filter (PPF) configured to receive an input differential intermediate frequency (IF) signal and to generate an in-phase differential IF signal and a quadrature differential IF signal. The wireless transmitter further includes a transformer-based circuit configured to receive an input differential local oscillator (LO) signal and to generate an in-phase differential LO signal and a quadrature differential LO signal based on the input differential LO signal. In addition, the wireless transmitter includes a mixer configured to multiplicatively mix the in-phase differential IF signal with the quadrature differential LO signal to produce a first RF signal component and to multiplicatively mix the quadrature differential IF signal with the in-phase differential LO signal to produce a second RF signal component, the mixer further configured to provide a differential RF signal comprising a (filtered or unfiltered) combination of the first RF signal component and the second RF signal component. Furthermore, the wireless transmitter includes an amplification stage configured to amplify the differential RF signal, the amplification stage comprising a driver stage and a power amplifier stage.

A quadrature phase clock generator includes a tunable polyphase filter and a phase detector. The tunable polyphase filter is configured to receive an input clock signal and generate four quadrature phase clock signals. The phase detector is coupled to receive at least two of the four quadrature phase clock signals and generate a control signal adapted to tune the polyphase filter based on the received quadrature phase clock signals. Further, the phase detector is configured to provide the control signal to the polyphase filter in a feedback loop. Based on the control signal from the phase detector, the tunable polyphase filter generates four tuned quadrature phase clock signals as output phase clock signals.

A quadrature phase clock generator includes a tunable polyphase filter and a phase detector. The tunable polyphase filter is configured to receive an input clock signal and generate four quadrature phase clock signals. The phase detector is coupled to receive at least two of the four quadrature phase clock signals and generate a control signal adapted to tune the polyphase filter based on the received quadrature phase clock signals. Further, the phase detector is configured to provide the control signal to the polyphase filter in a feedback loop. Based on the control signal from the phase detector, the tunable polyphase filter generates four tuned quadrature phase clock signals as output phase clock signals.

There is provided wireless transmitter that includes a poly phase filter (PPF) configured to receive an input differential intermediate frequency (IF) signal and to generate an in-phase differential IF signal and a quadrature differential IF signal. The wireless transmitter further includes a transformer-based circuit configured to receive an input differential local oscillator (LO) signal and to generate an in-phase differential LO signal and a quadrature differential LO signal based on the input differential LO signal. In addition, the wireless transmitter includes a mixer configured to multiplicatively mix the in-phase differential IF signal with the quadrature differential LO signal to produce a first RF signal component and to multiplicatively mix the quadrature differential IF signal with the in-phase differential LO signal to produce a second RF signal component, the mixer further configured to provide a differential RF signal comprising a (filtered or unfiltered) combination of the first RF signal component and the second RF signal component. Furthermore, the wireless transmitter includes an amplification stage configured to amplify the differential RF signal, the amplification stage comprising a driver stage and a power amplifier stage.

There is provided wireless transmitter that includes a poly phase filter (PPF) configured to receive an input differential intermediate frequency (IF) signal and to generate an in-phase differential IF signal and a quadrature differential IF signal. The wireless transmitter further includes a transformer-based circuit configured to receive an input differential local oscillator (LO) signal and to generate an in-phase differential LO signal and a quadrature differential LO signal based on the input differential LO signal. In addition, the wireless transmitter includes a mixer configured to multiplicatively mix the in-phase differential IF signal with the quadrature differential LO signal to produce a first RF signal component and to multiplicatively mix the quadrature differential IF signal with the in-phase differential LO signal to produce a second RF signal component, the mixer further configured to provide a differential RF signal comprising a (filtered or unfiltered) combination of the first RF signal component and the second RF signal component. Furthermore, the wireless transmitter includes an amplification stage configured to amplify the differential RF signal, the amplification stage comprising a driver stage and a power amplifier stage.

A first input terminal is connected to a point of connection of a drain terminal of a first transistor and a gate terminal of a fourth transistor. A second input terminal is connected to a point of connection of a drain terminal of a third transistor and a gate terminal of a second transistor. One of first through fourth output terminals to is connected to a source terminal of each of the first through fourth transistors to. A gate terminal of the first transistor and a drain terminal of the second transistor are connected, and a gate terminal of the third transistor and a drain terminal of the fourth transistor are connected.

A first input terminal is connected to a point of connection of a drain terminal of a first transistor and a gate terminal of a fourth transistor. A second input terminal is connected to a point of connection of a drain terminal of a third transistor and a gate terminal of a second transistor. One of first through fourth output terminals to is connected to a source terminal of each of the first through fourth transistors to. A gate terminal of the first transistor and a drain terminal of the second transistor are connected, and a gate terminal of the third transistor and a drain terminal of the fourth transistor are connected.

Apparatus and methods for quadrature combined Doherty amplifiers are provided herein. In certain embodiments, a separator is used to separate a radio frequency (RF) input signal into a plurality of input signal components that are amplified by a pair of Doherty amplifiers operating in quadrature. Additionally, a combiner is used to combine a plurality of output signal components generated by the pair of Doherty amplifiers, thereby generating an RF output signal exhibiting quadrature balancing.

A radio-frequency switching apparatus that can be used to turn a signal path on or off or to attenuate a radio-frequency signal. The switching apparatus comprises at least one radio-frequency input, at least one radio-frequency output, at least one transmission line providing a signal path between the at least one radio-frequency input and the at least one radio-frequency output, and at least one transition metal oxide portion. The radio-frequency switching apparatus also comprises direct current blocking means electrically coupled between the at least one transition metal portion and the at least one radio-frequency input. The radio-frequency switching apparatus also comprises biasing means for providing a bias across the at least one transition metal oxide portion such that power transferred between the radio-frequency input and the radio-frequency output is controlled by controlling the bias level across the at least one transition metal oxide portion.

A radio-frequency switching apparatus that can be used to turn a signal path on or off or to attenuate a radio-frequency signal. The switching apparatus comprises at least one radio-frequency input, at least one radio-frequency output, at least one transmission line providing a signal path between the at least one radio-frequency input and the at least one radio-frequency output, and at least one transition metal oxide portion. The radio-frequency switching apparatus also comprises direct current blocking means electrically coupled between the at least one transition metal portion and the at least one radio-frequency input. The radio-frequency switching apparatus also comprises biasing means for providing a bias across the at least one transition metal oxide portion such that power transferred between the radio-frequency input and the radio-frequency output is controlled by controlling the bias level across the at least one transition metal oxide portion.