Optimization of an Air Filled Compact Re-Entrant Coaxial Resonator for a C-Band Bandpass Filter

Abstract

This paper proposes an enhanced model for a re-entrant coaxial resonator and analyzes the capacitance behavior between its different sections and the Q-factor, for which mathematical expressions are derived. This model makes it possible to carry out a geometric optimization to minimize the volume of a compact coaxial resonator. Theoretical conclusions are compared with electromagnetic simulations and an optimized symmetrical six-pole re-entrant coaxial resonator bandpass filter prototype is designed and fabricated to illustrate the optimization.

Keywords

• re-entrant coaxial resonator
• SIR
• C-band filter
• frequency model
• Q-factor model%22%2C%22default_operator%22%3A%22AND%22%7D%7D%7D"> <italic xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">Q</italic>-factor model
• optimization