A travelling wave mixer (TWM) is provided that includes an input artificial transmission line configured to transmit an input signal, an output artificial transmission line configured to transmit an output signal, a local oscillator (LO) artificial transmission line configured to transmit an LO signal, and a plurality of mixer stages connected in parallel between the output artificial transmission and the input artificial transmission line. Each of the mixer stages includes an input amplifier, a mixer and an output amplifier connected in series between the input artificial transmission line and the output artificial transmission line, where an input of the mixer receives an output of the input amplifier, and an output of the mixer is applied to an input of the output amplifier. Further, each of the mixer stages includes a phase-adjustable LO amplifier circuit connected between the LO artificial transmission line and an LO input of the mixer, where the phase-adjustable LO amplifier is configured to adjust an LO signal phase applied to the LO input of each mixer to null out a phase error in each mixer stage independently.

A travelling wave mixer (TWM) is provided that includes an input artificial transmission line configured to transmit an input signal, an output artificial transmission line configured to transmit an output signal, a local oscillator (LO) artificial transmission line configured to transmit an LO signal, and a plurality of mixer stages connected in parallel between the output artificial transmission and the input artificial transmission line. Each of the mixer stages includes an input amplifier, a mixer and an output amplifier connected in series between the input artificial transmission line and the output artificial transmission line, where an input of the mixer receives an output of the input amplifier, and an output of the mixer is applied to an input of the output amplifier. Further, each of the mixer stages includes a phase-adjustable LO amplifier circuit connected between the LO artificial transmission line and an LO input of the mixer, where the phase-adjustable LO amplifier is configured to adjust an LO signal phase applied to the LO input of each mixer to null out a phase error in each mixer stage independently.

Traveling-wave tube amplifiers and methods for making slow-wave structures for the amplifiers are provided. The SWSs include helical conductors that are self-assembled via the release of stressed electrically conductive strips from a sacrificial material. The helical conductors can be electroplated post-self-assembly to fortify the helix, reduce losses, and tailor the dimensions and operating parameters of the helix.

Traveling-wave tube amplifiers and methods for making slow-wave structures for the amplifiers are provided. The SWSs include helical conductors that are self-assembled via the release of stressed electrically conductive strips from a sacrificial material. The helical conductors can be electroplated post-self-assembly to fortify the helix, reduce losses, and tailor the dimensions and operating parameters of the helix.

In one aspect, a power amplifier apparatus comprising a power amplifier (PA) and an adaptive controller is provided. The PA comprises at least one transistor and the adaptive controller is configured to control a bias voltage of the transistor based on a measured power efficiency of the PA and a measure output signal quality of the PA. In another aspect, a method of optimizing PA performance is provided. The PA comprises at least one transistor and the method includes initializing a bias voltage of the transistor, receiving measurements indicating a power efficiency and an output signal quality of the PA, evaluating the received measurements, calculating a new bias voltage for the transistor based on the evaluation, and applying the calculated new bias voltage to the transistor.

In one aspect, a power amplifier apparatus comprising a power amplifier (PA) and an adaptive controller is provided. The PA comprises at least one transistor and the adaptive controller is configured to control a bias voltage of the transistor based on a measured power efficiency of the PA and a measure output signal quality of the PA. In another aspect, a method of optimizing PA performance is provided. The PA comprises at least one transistor and the method includes initializing a bias voltage of the transistor, receiving measurements indicating a power efficiency and an output signal quality of the PA, evaluating the received measurements, calculating a new bias voltage for the transistor based on the evaluation, and applying the calculated new bias voltage to the transistor.

A signal transmitter is provided. The signal transmitter includes a signal splitting module, including M output interfaces, where the signal splitting module is configured to split a signal into N sub-signals, and output the N sub-signals through N of the M output interfaces, where M and N are integers, M≥2, N≥1, and M≥N, an integrated array traveling-wave tube amplifier, including M radio frequency channels, where the M channels one-to-one correspond to the M output interfaces, each channel is configured to perform power amplification on a sub-signal that is output from a corresponding output interface, and each channel is openable and closeable, a power supply module, configured to supply power to the integrated array traveling-wave tube amplifier, and at least one transmit antenna, configured to send a signal obtained through power amplification.

The objective of the invention is to provide a microwave tube, or the like, wherein gas adsorption action of a getter may be satisfactorily performed independently from a microwave amplification operation. In order to solve this problem, this microwave electron tube comprises: a helix wherein a microwave may progress oriented from an input section to an output section within a helical tube; an electron gun emitting an electron flow oriented toward the helix; a focusing device causing the electron flow to traverse the vicinity of the helix in the direction of a collector; the collector absorbing the electron flow; and a getter having a heater insulated from the cathode provided in the electron gun.

The objective of the invention is to provide a microwave tube, or the like, wherein gas adsorption action of a getter may be satisfactorily performed independently from a microwave amplification operation. In order to solve this problem, this microwave electron tube comprises: a helix wherein a microwave may progress oriented from an input section to an output section within a helical tube; an electron gun emitting an electron flow oriented toward the helix; a focusing device causing the electron flow to traverse the vicinity of the helix in the direction of a collector; the collector absorbing the electron flow; and a getter having a heater insulated from the cathode provided in the electron gun.

Traveling-wave tube amplifiers for high-frequency signals, including terahertz signals, and methods for making a slow-wave structure for the traveling-wave tube amplifiers are provided. The slow-wave structures include helical conductors that are self-assembled via the release and relaxation of strained films from a sacrificial growth substrate.