Mesh truncation by perfectly matched anisotropic absorbers in the finite-element method

✍ Scribed by Mustafa Kuzuoglu; Raj Mittra

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 526 KB
• Volume: 12
• Category: Article
• ISSN: 0895-2477
• DOI: 10.1002/(sici)1098-2760(19960620)12:3<136::aid-mop5>3.0.co;2-i

✦ Synopsis

Figure shows the percentage discrepancies between the measured resonant frequencies and those obtained from, respectively, (91, (15), and ( ) as functions of substrate electrical thicknesses of all antenna elements given in Table . The average discrepancies of expressions (9), (13, and (16) are, respectively, 0.9%, 0.6%, and 1%. These small discrepancies can be due to a variety of factors, for example, the tolerances associates with the thickness and permittivity of the substrate material, the error in the fabrication process, the actual patch dimensions not being the same as the designed dimensions, and the tolerance of the network analyzer system. Even the best calibration process cannot provide accurate results when transitions and connectors are badly mismatched or lossy.

5. CONCLUSION

Three new closed-form expressions for calculating the resonant frequency of rectangular microstrip antenna elements with substrates satisfying the criterion h 2 0.0815A, and 3.3 mm 5 h I 12.81 mm for E, = 2.55 have been proposed. They are derived by modifying the TLM and the CM, and by the curve-fitting method. The correction factors were derived by means of a curve-fitting method. The accuracy of the proposed expressions has been established by comparing calculated results with measurements for all antenna elements listed in Table .