All metal insert E-plane filter with integrated extracted pole resonator

Abstract

All-metal insert E-plane band-pass filter with asymmetric frequency response is presented. The extracted pole technique is used to introduce transmission zero. The proposed metal-insert E-plane extracted pole resonator is suitable for direct integration with straight waveguide section. An additional modification of the structure is offered which facilities the design process and makes practical implementation more feasible. The discussed structure provides solution for all-metal E-plane filters with two transmissions zeros of extracted pole variety and proves to be particularly useful in diplexer design. The concept was validated by designing and manufacturing a 4-order filter with a transmission zero located on the upper side of the pass-band.