Abstract
We present a triple-band microstrip passive device
using a quasi-hybrid-ring coupler feeding. The proposed hybridring
feeder is based on the rat-race coupling mechanism using a
balanced mode arrangement. The input excitation energy is split
into two superimposed excitation electromagnetic waves
travelling in opposite direction though with equal amplitude but
with 1800 phase difference. The proposed feeder caused excitation
resonance at modes TM11, TM02, and TM20 leading to triple
bands. The findings have been validated using available
numerical method and by measurement.