Bandpass filter with improved spurious performance using modified ring dielectric resonator in MIC environment

Abstract

A C‐band bandpass filter is designed using modified ring dielectric resonator in microwave integrated circuit (MIC) environment for improved spurious response. The dielectric resonator (DR) filters are generally made in cavity environment because of its good spurious response in cavity environment, but its spurious performance degrades as the filter is designed in MIC environment. In MIC environment, the smaller substrate thickness makes DR closer to ground plane and affects its resonance mode spectrum which, in turn, affects closely spaced resonant frequencies. The dense resonant mode spectrum of DR in MIC environment limits its application for filter designing. This article introduces a comparative study on filter realization with modified ring DR and conventional ring DR to show the improvement of spurious response in MIC environment. The simulated and measured results of these filters are presented to demonstrate the validity of the design procedure and improvement of spurious response. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1426–1431, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23391

Bandpass filter using dielectric resonator with transmission zeros

“…However, the new architecture in Ref. [12] can be only applied in single-polarization applications and the design in Ref. [13] is much more complex than the general design.…”

“…In MIC environment DR is placed on the substrate makes its mode separation week and its resonant frequency will be highly influenced by the ground plane. In recent literatures, some research articles are available on DR filter in MIC environment, having a smaller size, compatible with MIC and better in band/out band performance [11,12].…”

Multilayer multipermittivity ring dielectric resonator antenna filter

“…Various researches have been carried out in past with partial success for improving the spurious free response of DR. It was found that spurious response can be improved using a ring in a DR .For further improvement in spurious response, ring DR with different shapes were investigated which had better spurious performance than a ring DR in MIC environment. Multilayer multipermittivity (MLMP) ring DR is also a modified version of ring DR. Stacking of layers with different permittivity is done accordingly as to affect the fields and consequently the frequency of the higher order modes.Generally, DRs are placed on a dielectric substrate in MIC environment.…”

“…This asymmetry reduces the mode separation which consequently leads to inferior spurious response of the system. The effect of this asymmetry can be compensated using appropriate stacking of layers of different permittivity (MLMP) . The mode separation of a DR has a direct correlation with its resonant mode fields.…”

“…Adding MLMP feature to a conventional ring DR significantly improves its spurious response. This MLMP ring DR was fabricated in Microwave laboratory of IIT, Kanpur .…”