Metamaterial-inspired waveguide filters with compact size and sharp skirt selectivity

• In this paper, a metamaterial-inspired miniaturization method for waveguide filter design is proposed. The transmission response and effective medium parameters of I-shaped resonator in metallic rectangular waveguide are first discussed. By embedding such an I-shaped resonator, a novel g/2-type inverter is then proposed ( g: the guided wavelength). The large effective refraction index with low loss which appears below the resonant frequency of the I-shaped resonator is skillfully exploited, and then the size of g/2-type inverter is greatly reduced with acceptable low insertion loss. The most negative permittivity of the I-shaped resonator at its resonant frequency produces an additional transmission zero which leads to sharp skirt selectivity in the upper side band. Using the novel g/2-type inverter, two improved waveguide filters are further designed with good performances. One has an extremely compact size. The other has further improved selectivity. Two such filters are finally fabricated and the measured results agree well with the simulated ones.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Keyword

band bandpass filter

shaped resonators

broad-band

dual-band

design

enhancement

lens

Publication and Content Type

ref (subject category)

art (subject category)