Investigation of a High-Efficiency Multistage Depressed Collector for Dual-Mode mmWave Communication TWTs

Due to the existence of peak-to-average operating states in communication traveling wave tubes (TWTs), a design method for a high-efficiency multistage depressed collector (MDC) in dual-mode operation has been introduced to improve TWT performance. The primary concept combines a multistage depressed collection of saturated electrons with a deeply depressed collection of linear electrons. Additionally, the optimization of the electrode potential and shape is crucial. To validate this concept, a high-efficiency, low back-streaming five-stage depressed collector for a 71–76-GHz TWT was simulated and developed. The measured saturated and linear collector efficiencies exceed 93.4% and 95.3%, respectively, with back-streaming below 0.5%, consistent with the simulated results. Consequently, the saturated and linear TWT efficiencies surpass 32% and 21%, respectively. These enhancements are significant for advancing the practicality of communication TWT.