Asymmetric Dual-Passband Coplanar Waveguide Filters Using Periodic Composite Right/Left-Handed and Quarter-Wavelength Stubs

Abstract

A novel dual-passband coplanar waveguide (CPW) filter periodically loaded with the composite right/left-handed (CRLH) short-circuited stubs and the quarter-wavelength open-circuited stubs in asymmetric configuration is presented. The unit-cell equivalent circuit of the periodic structure in conjunction with Floquet's theorem is employed to find the propagation characteristics of passband and stopband regions. Unlike the conventional quarter-wavelength transmission-line inverter suitable only for a narrow frequency range, the dual-band inverter is adopted in the dual-passband filter to achieve a better frequency response within two operating bands. The performance of the 2.4/5.8-GHz third-order CRLH CPW dual-passband filter with 52% and 23% bandwidths is measured and validated by full-wave simulation. Two arbitrary passband regions are presented and the stopband within the passbands can be controlled by varying the length of open-circuited stub, supporting the flexibility and compactness of the proposed dual-passband filter.Index Terms-Composite right/left-handed (CRLH) coplanar waveguide (CPW), dual-passband filter, periodic structure.

A New Approach to the Synthesis of Microwave Lossy Filters

“…Inverters are realized with the dual-band equivalent model described in [14] since they are critical components in the used architecture. The dual-band model allows one to impose the behavior of the equivalent component equal to the ideal one in two frequency points, and we have chosen the center frequencies of the passband and of the stopband.…”

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Design of Space-Filling Antennas for Passive UHF RFID Tags

“…These structures are usually printed on a single conducting plane with an ungrounded substrate. Some researchers have successfully applied metamaterial ideas to achieve much smaller CPW filters (Mao et al, 2007). It is anticipated, that these same principles could be extended to the use of planar antennas on passive UHF RFID tags.…”

Design of Passive UHF RFID Tag Antennas Using Metamaterial-Based Structures and Techniques

“…The second design involves using coplanar waveguide elements (CPW) to reduce the overall size of a meanderline antenna. In particular, series connected CPW inductors and capacitors found in CPW filters (Mao et al, 2007) are used to periodically load a meander-line antenna. The result is a much smaller meander-line antenna with a lower resonant frequency (Braaten et al, 2009b).…”

“…It is often desirable to have the tag antenna on a single conducting layer. Thus, a CPW structure is needed to introduce the series and (Mao et al, 2007). An image of the series connected CPW-LC is shown in Fig.…”