On the new prospects of high power wideband TWT creation

A new design of a slow - wave structure of a “crossed staircase” type for a powerful broadband multi-beam X-band TWT has been considered. The use of dense packing of beams and diaphragms with bushings allows to increase the interaction impedance to 4-7 Ohm and the dispersion correction makes it possible to expand the band up to 18% using a special form of coupling slots. The calculation of electronics demonstrates a possibility of obtaining the power of 24 kW, gain of 17 dB and efficiency of 28% in the TWT with such a slow-wave structure. The design of the permanent magnet system with an interpole gap of 119 mm was developed which provides 100% transportation of the electron beam to the collector.

Feedback linearization for decoupled position/stiffness control of bidirectional antagonistic drives

To ensure safe human-robot interaction impedance robot control has arisen as one of the key challenges in robotics. This paper elaborates control of bidirectional antagonistic drives - qbmove maker pro. Due to its mechanical structure, both position and stiffness of bidirectional antagonistic drives could be controlled independently. To that end, we applied feedback linearization. Feedback linearization based approach initially decouples systems in two linear single-input-single-output subsystems: position subsystem and stiffness subsystem. The paper elaborates preconditions for feedback linearization and its implementation. The paper presents simulation results that prove the concept but points out application issues due to the complex mechanical structure of the bidirectional antagonistic drives.

U-shaped meander-line slow-wave structure with stub-loading

In this paper, a U-shaped meander-line slow-wave structure (SWS) with stub-loading is proposed for applications in Ka-band traveling-wave tube (TWT). This new slow-wave structure, loaded with a stub at the center of the U-turn section, has higher interaction impedance and lower phase velocity compared with conventional U-shaped meander-line SWSs, indicating that the devices based on this structure may have a lower operating voltage and higher output power. The dispersion characteristic, interaction impedance, transmission characteristics, and beam-wave interaction are simulated by utilizing simulation tool. The simulation result predicts that the millimeter-wave traveling-wave tube design based on this slow-wave structure is capable of delivering over 200 W with a gain of 33 dB and interaction efficiency 14.5% at the center frequency 34 GHz. This design, more compact and powerful in comparison with those based on more conventional vacuum electronic mechanisms, is demonstrated as a prospective option for integrated millimeter-wave power modules (MMPMs) empowering a broad spectrum of fields, from target detection, to imaging and telecommunications, among others.