Reentrant wideband quasi-elliptic bandpass filter

ABSTRACT

The novel microwave wideband quasi-elliptic bandpass filter, in which the initially uncoupled strip transmission lines are used is considered in the present study. The proposed filter is based on the reentrant structure in which the metallic body with a floating potential is asymmetrical. Generally speaking, the internal and external dielectric fillings must be of unequal relative permittivity. As a result, the additional symmetrical transmission zeros are reached at the lower and upper stop bands of the pass band leading to the quasi-elliptic response function that improves the bandpass filter selectivity. The general TEM circuit model for the proposed filter, in terms of the multi-port series connection, is presented and then used to predict the initial electrical and geometrical quantities. A printed circuit prototype has been manufactured using a common printed circuit board implementation. The measured results are in an acceptable agreement with the simulation-derived ones, and that improves the degree of freedom in the frequency selective unit design.

KEYWORDS:

• Bandpass filter
• reentrant structure
• multilayer implementation

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

V. V. Atuchin http://orcid.org/0000-0002-7424-5604

Additional information

Funding

This study was supported by the Ministry of Education and Science of the Russian Federation (8.6847.2017/BCh) and by project C-13, the research issue: “Design of dual-band dipole antennas with an essential working frequency diversity” with the financial support of the Novosibirsk State Technical University internal grant for young scientists. Also, this work was supported by the Russian Foundation for Basic Research (16-52-48010, 17-52-53031).