Finite Element Method Analysis of the Cutoff Wavelength of Dominant Mode in Unilateral Finline
- PDF / 171,838 Bytes
- 6 Pages / 439.37 x 666.142 pts Page_size
- 46 Downloads / 156 Views
Finite Element Method Analysis of the Cutoff Wavelength of Dominant Mode in Unilateral Finline Hai Sun & Yujiang Wu
Received: 13 October 2010 / Accepted: 25 November 2010 / Published online: 14 December 2010 # Springer Science+Business Media, LLC 2010
Abstract The cutoff wavelength of dominant mode in unilateral finline is analyzed by finite element method. The cutoff wavelength can be changed by adjusting the thickness of metallic fins and dielectric constant of dielectric substrate. Numerical results provide in this paper have important values in practical applications. Keywords The dominant mode cutoff wavelength . Unilateral finline . Finite element method
1 Introduction In the past decades, finlines have received considerable attention. They have been increasingly used in millimeter-wave integrated circuits, such as directional couplers, phase shifters, filters, and so on. They are also easily compatible with semiconductor devices. Compared with the microstrip, finlines hold many better characteristics, such as large dominant cutoff wavelength, wide bandwidth for single mode operation, moderate attenuation and low dispersion in the frequency range of interest. Because of ignored metallic fin thickness, Saad and Begemann [1] assumed that finline structure is approximately equalized to a form of planar ridged waveguide, which is numerical efficiency at the expense of the accuracy. Hofmann [2] presented a relatively accurate solution of propagation in idealized finline, but it demands considerable analytical efforts. In order to have a design method which combines the flexibility of analytical expressions with the accuracy of numerical techniques, some empirical formulations were provided by Sharma and Hoefer [3]. Then, Beyer [4] and Vahldieck [5] employed the mode-matching method and the unified hybrid-mode approach to calculate transmission characteristics of H. Sun (*) : Y. Wu School of Mathematics and Statistics, Lanzhou University, Lanzhou 730000, China e-mail: [email protected] H. Sun School of Mathematics and Informational Sciences, East China Institute of Technology, Fuzhou 344000, China
J Infrared Milli Terahz Waves (2011) 32:34–39
35
Fig. 1 Cross section of the unilateral finline.
more general finline structures by considering the non-zero metallic fin thickness, mounting grooves, and anisotropic dielectric substrate, these transmission characteristics include characteristic impedance, bandwidth, and propagation constant and so on. Zheng and Song [6] analyzed the finlines by using multipole theory method. But the full wave analysis can provide more accuracy than any of the other methods in calculating transmission characteristics of inhomogeneous waveguide structure, so finite element method have enjoyed popularity nowadays, such as Lu, Leonard and Sun analyzed several different kinds of waveguide structures by finite element method [7–10]. Recently, Lu and Leonard [10] studied the field patterns of the dominant mode in unilateral finline, in their paper, they mentioned the cutoff wave number of
Data Loading...
