Analysis of Curved Boundaries by FDTD and FE Methods

Abstract

Curved waveguide surfaces have been dealt with by using modified finite difference time domain (FDTD), finite element method (FEM) and hybrid methods. The propagation characteristics and S-parameters of the circular waveguides have been determined, and results compared with the analytic results, thus determining the computational efficiency of each of the method. Both FDTD and FE techniques are extensively used in the analysis and design of microwave problems. For the analysis of curved boundary, however, the traditional FDTD method suffers from significant degradation in accuracy due to staircasing approximation. A novel approach is presented here which combines the efficiency of the Cartesian mesh with the accuracy of the conformal grid. Further, an efficient finite element method is presented in which a variational expression is formulated in terms of transverse electric and magnetic field components. The method can be applied to anisotropic media also. Finally a partially prism gridded FDTD method is proposed which hybridizes the prism based FEM to handle the curved boundaries and rectangular gridded FDTD for most of the regular region.

Indexing terms:

• Curved boundaris
• FDTD
• FE methods
• Hybrid method

Additional information

Notes on contributors

Anupma Marwaha

Anupma Marwaha born on April 1969 at Chandigarh. Presently she is Lecturer in the Department of Electronics and Comp Sc & Engg, BCET Gurdaspur. Did her BE (Electronics) from Punjab University in 1990 and M Tech (Electronics) from Kurukshetra University in 1992 and presently doing PhD from GNDU, Amritsar. She is life member of ISTE. She has twenty publications at national and International level in her credit. Her area of interest are Communication Systems, Microwave and Antennas.

Sanjay Marwaha

Sanjay Marwaha born on April 1966 at Nahan. Dr Marwaha is Assistant Professor in the Department of Electronics and Comp. Science and Engineering, BCET Gurdaspur. Completed his BE (Electrical) from Gorakhpur University in 1988, ME (Power Systems) from Punjab University in 1990 and PhD from GNDU, Amritsar in 2000. He is life member of ISTE. Having twenty eight publication in national and international standards. His area of interest are Design and Analysis of Electromagnetic Devices, Power Systems and HV Engg, Electrical and Electronic Measurements & Instrumentations, Industrial Electronics and Microwave Engineering.

I S Hudiara

I S Hudiara, obtained his MS (Microwave & Quantum Electronics) from university college London, University of London on British Council Fellowship. He was then offered university research fellowship by University of Bradford from where he joined his PhD. Dr Hudiara then joined university of Surrey (Guildford) England as a Post Doctoral Research Fellow. He worked on Injection Locking of high efficiency microwave oscillators.

Later he joined Marconi Company as Senior Design and Development Engineer where he worked on high frequency transistor oscillators. On returning to India, Dr Hudiara joined IIT Delhi, after having a short stint at IIT, he joined Department of Electronics Technology of Guru Nanak Dev University, Amritsar.

Dr Hudiara has several research publications in National and International journals. His biographical sketch has been included in the latest edition of Marquis WHO IS WHO in the world. His interests are in the field of Microwave and Optical Communication Systems and Microwave Ferrites.