Design and protocol analysis for passive star topology of a WDM network

✍ Scribed by Ioannis E. Pountourakis

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 197 KB
• Volume: 25
• Category: Article
• ISSN: 0895-2477
• DOI: 10.1002/(sici)1098-2760(20000505)25:3<216::aid-mop16>3.0.co;2-5

✦ Synopsis

Figure 7 Patch radius versus normalized substrate thickness for a patch radius necessary to suppress the surface-wave excitation in a single-mode operation. MAR, solid lines; MCR model, dashed lines; hra s 0.05

VII. CONCLUSION

The method of analytical regularization combined with the Galerkin method has been proposed to determine the fundamental antenna effects in a circular-disk metallic patch antenna on a dielectric substrate backed by a PEC ground plane and coaxially excited by a vertical electrical dipole. Due to analytical inversion of the free-space static-part operator, the dual-integral equations in the transform domain proved able to be converted into the infinite matrix equation of the Fredholm second kind. This matrix equation has been solved by means of an efficient numerical procedure. Our solution is stable in the resonant region, unlike the conventional MoM ones. Further, this algorithm enables one to significantly reduce the machine time and memory resources.

Antenna characteristics, such as the surface-and spacewave powers and the radiation efficiency, have been obtained and analyzed for different values of the substrate thickness and permittivity, patch radius, and frequency. The resonance conditions have been established as those that maximize radiation power or efficiency. The criteria have been determined for the material properties and dimensions, for which the surface waves are nearly eliminated and the radiation efficiency approaches 100%. A comparison with the mag-Ž netic-ring model i.e., the cavity model applied to compute . the radiated field is given. This approximation has been shown to have a limited range of application: thin and highcontrast dielectric substrates.