Split-Ring Slot in the Broad-Wall of a Rectangular Waveguide

Recently the Slotted Waveguide Antenna Stiffened Structure (SWASS) was introduced, where an antenna array is incorporated as an integrated part of a load bearing structure. The array element spacing and individual radiating element sizes play a critical role in the overall mechanical strength of the structure. These parameters are constrained by Slotted Waveguide Antenna (SWA) array design, and the coupling of the waveguide electromagnetic fields to the radiating apertures. In this letter, the radiation characteristics of a split-ring slot in the broad-wall of a rectangular waveguide are investigated for the first time. The simulated and measured results show that the split-ring slot radiates a linearly polarized wave with a total efficiency and realized gain close to those of conventional rectangular slots. The proposed split-ring slot has an outer diameter of 0.186 λ0, a significant size reduction compared to a traditional 0.5 λ0 rectangular slot and the previous limit of 0.25 λ0 for metamaterial loaded rectangular slots. The reduced aperture size of the split-ring slot alleviates the impact of the radiating elements on the mechanical strength of the structure.

[1]  K. Ghorbani,et al.  Split-Ring Resonator Loading for the Slotted Waveguide Antenna Stiffened Structure , 2011, IEEE Antennas and Wireless Propagation Letters.

[2]  Paul J. Callus,et al.  Small slot design for slotted waveguide antenna stiffened structure , 2012 .

[3]  Sembiam R. Rengarajan,et al.  Waveguide-Fed Slot Antennas and Arrays: A Review , 1999 .

[4]  F. Martín,et al.  LEFT-HANDED METAMATERIAL BASED ON DUAL SPLIT RING RESONATORS IN MICROSTRIP TECHNOLOGY , 2004 .

[5]  F. Martín,et al.  Effective negative-/spl epsiv/ stopband microstrip lines based on complementary split ring resonators , 2004, IEEE Microwave and Wireless Components Letters.

[6]  Ferran Martin,et al.  Metamaterial filters: A review , 2008 .

[7]  J. Bonache,et al.  Babinet principle applied to the design of metasurfaces and metamaterials. , 2004, Physical review letters.

[8]  H. Bethe.  Theory of Diffraction by Small Holes , 1944 .

[9]  Paul J Callus,et al.  Novel Concepts for Conformal Load-Bearing Antenna Structure , 2008 .

[10]  Norman A. Fleck,et al.  Hole-hole interaction in carbon fibre/epoxy laminates under uniaxial compression , 1991 .

[11]  Tatsuo Itoh,et al.  Metamaterial-Based Antennas , 2012, Proceedings of the IEEE.

[12]  T. Ebbesen,et al.  Light in tiny holes , 2007, Nature.

[13]  J. Bonache,et al.  Equivalent-circuit models for split-ring resonators and complementary split-ring resonators coupled to planar transmission lines , 2005, IEEE Transactions on Microwave Theory and Techniques.