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Electromagnetically coupled notch filters and effect of resonator geometries
Author(s) -
Harikrishna J. V. S.,
Karekar R. N.,
Aiyer R. C.
Publication year - 2008
Publication title -
microwave and optical technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 76
eISSN - 1098-2760
pISSN - 0895-2477
DOI - 10.1002/mop.23002
Subject(s) - ground plane , resonator , microstrip , microwave , square (algebra) , band stop filter , plane (geometry) , physics , engineering , optics , optoelectronics , filter (signal processing) , electronic engineering , electrical engineering , telecommunications , geometry , mathematics , low pass filter , antenna (radio)
Electromagnetically coupled notch filters is a relatively recent innovation. Resonators with three ring geometries (square, triangular, and circular) and L (half wave) are fabricated (all 2.4 GHz) on TMM4 (ε r = 4.5, h = 0.762 mm) substrates (without ground plane) and coupled electromagnetically to a 50‐Ω microstrip feed line (on separate TMM4 substrate with ground plane) under it. The comparisons show that square is found to give best notch effect (−37.2 dB) followed by triangular, L, and circular. These notch filters not only offer improved matching performance over their in‐plane coupled counterparts but also provide other flexibilities like easy resonator replacement, multi frequency operation. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 48–51, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23002