Design of High Power THz TWT Amplifier for 6G Wireless-Communication System

High power, ultra-wideband, high linear gain, planar 0.22THz, 100W TWT amplifier is investigated for a 6G wireless communication system. The planar 0.22THz TWT is designed with a planar slow wave structure (SWS) with a planar sheet beam of voltage 20kV and current 100mA. For the 0.22THz planar TWT, the slow-wave structure is a rectangular waveguide loaded with staggered double vanes (SDV-SWS). It is used because it has high circuit impedance and wide circuit bandwidth. Sheet beams can inherently be used with this planar structure. Also, the planar structure can easily be fabricated with solid-state device technology (MEMS technology) with a good surface finish as well as high mechanical accuracy. The nine design parameters of the structure are determined for the highest possible circuit impedance and maximum possible cold circuit bandwidth. The phase variation characteristic for wide bandwidth and the circuit field characteristic for high gain and efficiency of the structure are determined for the desired mode with these initial design parameters using suitable analytical expressions. 0.22THz TWT designed for 100W output power and 30dB gain is analyzed using the modified SUNRAY large signal model. The results on output power and gain as achieved using SUNRAY code are compared with the RF performance as simulated by CST code for desired THz frequency band.