A Semi-Analytic Numerical Algorithm of Diamond Pillbox Windows for Terahertz Vacuum Electron Device Applications

A semi-analytic numerical algorithm for general pillbox windows, named the pillbox window mode-matching algorithm (PWMMA), is proposed in this letter. The PWMMA shows quite consistent calculation results with CST Microwave Studio (CST-MWS) within a remarkably reduced time than CST-MWS. Four pillbox windows, each consists of a double-side metalized diamond disk, were fabricated and tested at the frequency bands of 0.21 THz-0.25 THz and 0.32 THz-0.36 THz. The experimental results of the transmission characteristics are consistent well with the calculation results of the PWMMA.