Compact UWB Bandpass Filter as Cascaded Center-Tapped CRLH Transmission-Line ZORs for Improved Stopband

Abstract

-The design of a new compact UWB bandpass filter is proposed, which has cascaded center-tapped microstrip composite right/left-handed transmission-line zeroth-order resonators (CRLH-TL ZORs). In an attempt to reduce the size, instead of the conventional half-wavelength resonators or periodic and multiple CRLH-TL cells, only one cell ZOR geometry is adopted as each resonator in the filter. Additionally, two center-tapped ZORs are coupled to increase the slope of the skirt. Besides, stepped impedance matching parts are placed in the paths to the input and output ports to enhance passband and stopband performances. The proposed filter is shown to have the overall size of 0.69 g λ × 0.70 g λ , the insertion loss much less than 1 dB, and an acceptable return loss performance in the predicted and measured results.

Design of the miniaturized ultra-wide band (UWB) filter using the metamaterial characteristic

“…In order to solve the problem above, we propose a method to design ultra-wideband Bandpass Filter using the basic concept of the CRLH-TL [4][5] Unlike the periodic CRLH-TL structure having a large number of cells, we design one cell of the -type CRLH-TL resonator in order to reduce the size of the filter showing an ultra-wide band.…”

Compact UHF 9th-Order Bandpass Filter with Sharp Skirt by Cascaded-Triplet CRLH-ZOR

“…For this, the sum of the admittance from the CCP and sequential path should become zero at a target TZ in terms of phase cancellation. So, the admittance of the sequential path Y 21,seq should equal -Y 21,ccp at the TZ frequencies for CCP 13 , CCP 46 and CCP 79 from the three CTs, as shown in Fig. 3(b).…”

“…1(b) that are coupled through the inductive connection IRC i,j as the way of [8][9][10]. CCP 13 bridges resonators 1 and 3. CCP 46 and CCP 79 couple across resonators 4 and 6, and 7 and 9, respectively.…”

“…While the filter performance gets improved, it is expected that the growth of its physical size needs to be suppressed. As the effective means to design compact RF components, the CRLH lines and ZOR of lumped elements were suggested by Caloz et al in [7], the no-phase variation phenomenon as β=0 and non-linear dispersion relation have been used to design sub-wavelength resonators and compact filters [8][9][10][11][12][13]. The CRLH ZOR filters in [8,10] and ENZ filter [9] show improvement in reducing the sizes as well as insertion loss.…”

A Metamaterial-Based Handset Antenna with the SAR Reduction

“…The antenna is a metamaterial [7][8][9]-inspired geometry which comprises a split-ring-resonator(SRR) and a meandered line. Its size is 0.09λg much smaller than the quarter-guided wavelength.…”