Cheng Jin

Quarter-Mode Substrate Integrated Waveguide and Its Application to Antennas Design

A quarter-mode substrate integrated waveguide (QMSIW) which is the quadrant sector of a square waveguide resonator is proposed and investigated in this paper. The QMSIW is realized by bisecting the half-mode substrate integrated waveguide (HMSIW) into two parts along the fictitious quasi-magnetic wall when it operates with TE101 and TE202 modes as the way bisecting the substrate integrated waveguide (SIW) to HMSIW. The QMSIW can almost preserve the field distribution of original SIW and leaky wave is achieved from the dielectric aperture of the QMSIW. When the feeding port is placed at one corner of the QMSIW, a linearly polarized radiation is obtained when the QMSIW resonates in TE101QM mode, and when the QMSIW resonates in TE202QM mode, a circularly polarized (CP) wave is achieved. An antenna is designed, fabricated, and measured based on the proposed QMSIW. The measurement results match with the simulation results very well.

Compact Triple-Mode Filter Based on Quarter-Mode Substrate Integrated Waveguide

An isosceles right triangular waveguide with one electric wall and two magnetic walls is proposed to design a triple-mode filter implemented in a substrate integrated waveguide. The complete closed-form modal solutions are presented for both transverse electric and transverse magnetic modes in the isosceles right triangular waveguide. The resonant frequencies of a resonator made of a short isosceles right triangular waveguide can then be calculated. A structure called a quarter-mode substrate integrated waveguide (QMSIW) is introduced to realize the proposed triangular waveguide resonator in a compact and planar form. Simulated electric field distributions of modes excited in the QMSIW are in good agreement with theoretical predictions for the solid waveguide structure, demonstrating the feasibility of QMSIW resonators. Finally, a compact triple-mode filter is designed and fabricated based on the discussed QMSIW. The frequency responses and group delay of the filter are tested, and measured results agree very well with simulated ones. This demonstrates that the proposed QMSIW structure is an excellent candidate for compact triple-mode filters.

Compact Circularly Polarized Antenna Based on Quarter-Mode Substrate Integrated Waveguide Sub-Array

A compact and circularly polarized planar antenna is presented in this communication based on a quarter-mode substrate integrated waveguide sub-array. The operating principle and design guidelines of the proposed antenna are discussed with the aid of an isosceles right triangular cavity with two magnetic side walls and one electric side wall. The mode solutions are determined and the resonant frequencies of the triangular cavity are calculated. The designed antenna is fabricated and its radiation characteristics are measured. Measured results are in good agreement with predicted ones. It is demonstrated that the proposed structure is a simple and compact candidate of high-performance circularly polarized antenna.

CONICAL BEAM WINDMILL-SHAPED ARRAY ANTENNA DESIGN BASED ON QUARTER-MODE SUBSTRATE INTEGRATED WAVEGUIDE

This paper presents a compact conical beam antenna based on quarter-mode substrate integrated waveguide (QMSIW). The antenna array is consisted of six isosceles right-angled triangle metallic patch printed on the upper side of the substrate in a windmill-shape and diagonal periodic metallic via holes drilled along the hypotenuse of the triangle patch. The planer structure exhibits conical beam radiation. The typical radiation is obtained at 5.2GHz with conical beam radiation pattern. The measured gain is about 5.36dBi and the radiation e-ciency is around 50%.

Capped Dielectric Inserted Perforated Metallic Plate Bandpass Frequency Selective Surface

A capped dielectric inserted perforated metallic plate is proposed to design wide-bandpass frequency selective surface (FSS). The proposed structure is using the conventional perforated metallic plate with certain thickness inserted by a series of capped circular dielectric resonators, which satisfies tight mechanical requirements of applications such as huge dichroic mirror. Comparing with the conventional perforated metallic plate, it exhibits much more stable frequency response under oblique incidence of wide angles. An equivalent circuit modal is presented using the even–odd mode method, and the calculated frequency responses are discussed with variation of different parameters and they are in good agreement with the full-wave simulated results. Finally, an FSS is designed based on the discussed structure. The FSS is tested, and the measured frequency responses agree well with simulated ones. Measurements show that the minimum insertion loss is 0.31 dB at the two transmission poles under normal incidence, and insertion loss is 0.5 dB at the center frequency of the passband. The fractional 3 dB bandwidth is 20% under the normal incidence. In addition, the wideband filtering performance for both TE and TM polarizations can be obtained under various oblique incidence angles up to 40°.

TM mode analysis in a metamaterial based dielectric waveguide

A TM mode analysis in a metamaterial based dielectric waveguide is proposed and introduced. Rigorously derived from Maxwell’s equations, the dispersion properties are focussed on the fundamental properties of bound, surface and leaky modes of metamaterial based dielectric waveguide. Comparing with the conventional right handed material based waveguide, typical backward wave characteristic of volume and surface wave modes are found from the distribution of Poynting power to the transverse direction of waveguide.