Investigation Of Composite Right/Left-handed Transmission Line As Filters In Microwave Communication

In recent years, the composite right/left-handed (CRLH) transmission line (TL) hasdrawn particular attention in scientific and engineering communities. It isimplemented by periodically loading a conventional TL with lumped element seriescapacitors and shunt inductors. The novel properties of CRLH-TL have led to manyapplications and the developments of several novel microwave devices.Based on the analogy of the conventional TL resonant mode numbering, a conventionalresonator resonates in only positive-order mode, while the CRLH resonator can resonate innegative, zero and positive-order mode. The zeroth-order resonance (ZOR) will appear when aβof zero can be achieved at a non-zero frequency in CRLH transmission line. in this paper, anovel band-pass filter based on the zeroth-order resonance is demonstrated. As the zeroth-ordercentral frequency is independent of the physical length of the ZOR, the filter can be arbitrarilysmall in theory. Comparing with the traditional filter, it has the advantage of small volume andrelative low loss.