An Improved TEM-TE11 Mode-Transducing Sectoral Antenna Using Dual Dielectric Window
Abstract
Most of microwave sources, such as electromagnetic tubes, generate circular TEM or circular TM01 mode. The best radiating mode of cylindrical waveguides is circular TE11 mode. Therefore, mode transducers are used to convert circular TEM or circular TM01 to circular TE11 mode. In this paper, designing and fabricating of a mode transducer that convert circular TEM to circular TE11 mode are investigated. The combination of this mode transducer with an open-ended waveguide antenna makes it sutible for compact usages. The mode transduser antenna is designed to handle high power and therefore its internal area is closed by the help of a dielectric window to become vacuum. Mode conversion is carried out by changing the phase velocity of each mode-transducing section. The maximum achieved gain of this antenna is 8.8 dB in 1.48 GHz frequency. An optimized dual dielectric window at the end of the waveguide improves the antenna matching. The measured results are in a good agreement with simulation results.
C. W. Yuan, Y. W. Fan, H. H. Zhong, Q. X. Liu, and B. L. Qian, “A novel mode-transducing antenna for high-power microwave application,” IEEE Transactions on Antennas and Propagations, Vol. 54,No. 10, pp. 3022-3025, 2006##
A. Chittora, J. Mukherjee, S. Singh, and A. Sharma, “Dielectric Loaded TM01 to TE11 Mode Converter for S-band Applications,” IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 22, No. 4, pp. 2057-2062, 2015##
Y. W. Fan, H. H. Zhong, C. W. Yuan, Z. Q. Li, T. Shu, H. W. Yang, Y. Wang, and L. Luo, “Investigation of a 1.2-GHz Magnetically Insulated Transmission Line Oscillator,” IEEE Transactions on Plasma Science, Vol. 39, No. 1, pp. 540-544, 2011##
L. G. Shen and Z. J. Juan, “Converters for the TE11 mode generation from TM01 vircator at 4GHz,” Chin.Phis.Lett, Vol. 18, NO. 9, pp. 1285-1287, 2001##
C. C. Courtney, T. M. Veety, J. Tate and D. E. Voss, “Design and measurement of COBRA lens antenna prototypes for HPM effects testing applications,” Sensor and Simulation Notes, Note 492, pp. 2-18, 2004##
S. H. Min, H. C. Jung, G. S. Park, J. Ahn, S. H. Lee, Y. J. Yoon, J. Kim, J. H. Choi, and J. So, “Mode Conversion of High-Power Electromagnetic Microwave Using Coaxial-Beam Rotating Antenna in Relativistic Backward-Wave Oscillator,” IEEE Transactions on Plasma Science, Vol. 36, No. 6, pp. 1391-1397, 2010##
S. J. Hosseini, R. A. Sadeghzadeh & H. Aliakbarian, “A TEM-TE11 mode-transducing sectoral antenna by using dual dielectric window,” International Journal of Electronics Letters, pp. 1-10, 2017##
M. Abrishamian, “Ch3. Circular cylinder,” in Advanced electromagnetic waves, Tehran, K. N. Toosi University of Technology, pp. 54-56, 2012##
C. W. Yuan, Q. X. Liu, H. H. Zhong, and B. L. Qian, “A novel TEM—TE11 mode converter,” IEEE Microwave and Wireless Components Letters, Vol. 15, No. 8, pp. 513-515, 2005##
David M. Pozar, "Microwave Engineering," Hoboken, John Wiley & Sons, fourth edition, pp. 54-132, 2012##
)
