A four-mode reconfigurable microstrip filter integrated with reflectionless and multi-zero responses

Abstract

The application discloses a four-mode reconfigurable microstrip line filter integrated with reflection-free and multi-zero-point response, which adopts a single microstrip circuit topology with left-right symmetry and is composed of an upper branch band-pass filter circuit, a T-shaped joint structure, a pair of cross-shaped absorption branches, a pair of coupled line absorption branches, five groups of switch pairs and input and output ports; the coupled lines at the two ends of the upper branch band-pass filter circuit are connected with the ground through the switch pair connection ports and the T-shaped joint structure, and the absorption branches are connected with the ports in parallel through the switches; the four-mode switching of double-band rejection, full-band reflection-free band-pass, full-band reflection-free band-stop and multi-transmission zero-point band-stop is realized in the same circuit through the on-off control of the switches; the integration degree is improved; the reflection-free characteristic of the band-stop energy dissipation is realized by relying on the resistance-loaded absorption branches; the frequency selectivity and the band-stop suppression capability are strengthened in combination with the multi-transmission zero points; and the problems of low resource reuse rate, lack of reflection-free characteristic and uneven multi-mode performance of the traditional structure are solved.

Images