As a part of the plan to deploy a wideband high-power module (HPM) to very high-throughput satellite (VHTS) network systems, Communications and Power Industries LLC (CPI) has been developing a ${V}$ -band high-power traveling-wave tube (TWT) amplifier. The power amplifier is designed with a staggered-vane TWT (SVTWT) circuit and a circular beam, operating at beam voltage ( ${E}_{k}{)} =18$ –20 kV and beam current ( ${I}_{k}{)} =400$ –500 mA with the perveance of $0.168 \mu \text{P}$ . Within the development program, three prototypes have been built and tested so far—the first two prototypes only include simple features in their circuit configuration, excluding servers and complex tuning elements. The signal amplification process in the novel beam–wave scheme was demonstrated with the first prototype, showing 35 dBm of output power ( ${P}_{\text {out}}{)}$ with 10–15 dB of small-signal gain and 4 GHz of 1-dB bandwidth (47.2–51.2 GHz). ${P}_{\text {out}} =57$ dBm (500 W) and 24 dB of small-signal gain (SSG) were demonstrated over 4.2 GHz (47.2–51.4 GHz) of 1-dB bandwidth with the second prototype. During the RF test, the tube operated at the continuous wave (CW) mode (100% of duty cycle) with extra external cooling fans. The third prototype is designed with more complex features, including servers, mode anode, and multistage depressed collector (MDC). Its test results showed ${P}_{\text {out}} =54$ dBm (250 W) and 24 dB of SSG over 5.2 GHz (47.2–52.4 GHz) of 1-dB bandwidth, running at CW mode with extra external cooling fans.

As a part of plan to deploy a wideband high-power module (HPM) to very high-throughput satellite (VHTS) network systems, CPI has been developing a V-band high-power TWT amplifier. The first two prototypes designed for 500 W and 250 W levels of saturated output power were fully tested, showing 24 dB gain and more than 5 GHz bandwidth with 50 - 100 % of duty factor. Currently, a 3 rd prototype is being developed with the plan to release its version compatible with market-demands. This paper will summarize their fabrication processes and test results.

A multi-beam inductive output tube (MB-IOT) is being developed that will produce over 1.2 MW peak power at 704 MHz with over 65% efficiency. This is a collaborative effort between Thales Electron Devices (TED) and Communications & Power Industries (CPI) to design and fabricate a new RF source for the European Spallation Source (ESS). Design features and test results will be presented.

Design of a beam energy recovery system for application to the CPI VKS-8262S S-band klystron is presented. The multi stage pulsed depressed collector optics, mechanical and thermal design, energy recovery modulator, and experimental program will be highlighted.

Worldwide demand for high-power amplifiers for digital satellite communication at Ka-band frequencies between 27 and 31 GHz is steadily increasing (2003). Communication and Power Industries (CPI) has developed a 500-W periodic permanent magnet focused coupled-cavity traveling wave tube (TWT) for conduction-cooled amplifier systems, which is being introduced into the commercial satellite communication market. The TWT is capable of greater than 500-MHz instantaneous bandwidth and is cathode voltage tunable from 28.3 to 30 GHz. The TWT may be operated saturated at the 500-W output power level or backed off from saturation in the linear mode. CPI's Satcom Division has integrated the TWT into a conduction-cooled transmitter box suitable for antenna hub-mount applications. The amplifier uses predistortion networks to provide a high degree. of linear response when operated in output power back-off mode.

Last year CPI reported the development of a 500 W PPM focused coupled-cavity TWT for conduction cooled amplifier systems which is to be introduced into the commercial satellite communication market. This paper is to update the community on technical progress regarding performance of the TWT in communication systems. Basically, the TWT is capable of greater than 500 MHz instantaneous bandwidth and is cathode voltage tunable from 28.3 to 30 GHz. The TWT may be operated saturated at the 500 W output power level or backed off from saturation in the linear mode. CPI's Satcom Division has integrated the TWT into a conduction cooled transmitter box suitable for antenna hub-mount applications. The amplifier uses pre-distortion networks to provide a high degree of linear response when operated in output power back-off mode.

Summary form only given. This paper explores the current state of vacuum technology, specifically in the millimeter wavelength regime. A view of the market priorities and technology development is described. Current applications utilizing millimeter devices are characterized. Areas of interest are industrial microwave heating, satellite communications, and radar. Finally, new applications and research in the areas of millimeter wavelengths are discussed.

The authors are developing Ka-band coupled cavity TWT technology for airborne radar and SAR applications. The general requirement is for a small, lightweight, high efficiency, conduction cooled TWT which produces approximately I kilowatt peak output power over 1 GHz bandwidth.

The radar, electronic warfare and communications industries will benefit from the recent development of a new family of coupled-cavity traveling wave tubes. The new tubes, given the generic name of MILLITRONS can now provide these industries with affordable and available devices for high power millimeter wave transmitters. Conventional techniques for manufacturing coupled-cavity traveling wave tubes become impractical for millimeter wave frequencies because of extremely tight tolerances. The ladder is a new circuit which eliminates cumulative errors of stacked tubes by a method of simultaneously machining cavities of a circuit. The MILLITRON uniquely incorporates ladder technology in the development of millimeter wave devices. A recent accomplishment is a 100 W CW coupled-cavity traveling wave tube operating from 80 to 100 GHz.