L-resonator bandstop filters

Abstract

A design procedure is presented for narrow bandstop filters using TEM transmission line L resonators, which are intermediate of the gap-and parallel-coupled resonators typically used. In this configuration, parallel coupling occurs over a portion of the resonator length, with the remaining resonator length forming a stub. The grounded end of the resonator may be in either the coupled or stub portion of the resonator. Uncoupled Through Lines Coupled-line Pair Shunt Stub sh deg* z o 7 L-2 6, deg* z , , z , f2 b, deg*

Compact highly selective passive notch filter for 3.1–5 GHz UWB receiver system

“…Indeed, by coupling a half-wavelength line or a grounded quarter-wavelength one to a main transmission line, a notch filter response occurs [4]. Although this approach is simple, it suffers from a major drawback which is related to its rejection capability.…”

A Compact Ultra-Wideband Microstrip Antenna With Multiple Notches

“…Since the L-type band-stop filter has been reported exactly [25][26][27], and the resonance frequency of the SRR can be postulated as (1), so we only to discuss the structure that the L branches on the radiation disk. In the numerical simulation, only one absolute parameter was varied every time, whereas the others were kept constant.…”

“…The first notch at 2.4 GHz was produced by the L-type band-stop filter, which was proposed in [27]. Figure 3 shows the typical configuration of the L-resonator.…”

“…We used a L-type band-stop filter, which was proposed in [27] and used in [25,26], to produce the first notch at 2.4 GHz. Then a split ring resonator (SRR), first proposed by Pendry to construct the left-hand materials [28], was used to bring the second notch at 3.5 GHz.…”

“…[24] proposed an inverted-T structure. An L-type band-stop filter was first proposed in [27], and was used in [25,26] to produce the bandnotched characteristic in their ultra-wideband antennas. But most of the antennas can generate no more than two notched bands.…”