PIER M
 
Progress In Electromagnetics Research M
ISSN: 1937-8726
Home | Search | Notification | Authors | Submission | PIERS Home | EM Academy
Home > Vol. 63 > pp. 23-31

WIDEBAND MATCHED FEED DESIGN EMPLOYING CONJUGATE FIELD RADIATED FROM A SQUARE CHOKE EXCITED BY TWO SLOTS ON A DIAGONAL WAVEGUIDE

By R. Jana and R. Bhattacharjee

Full Article PDF (914 KB)

Abstract:
A simple and compact diagonal matched feed structure is proposed for offset reflector antenna, which includes a square choke to radiate the desired conjugate mode (TE4: a higher order rectangular coaxial cable mode) for suppressing the cross-polar power of an offset reflector antenna when the reflector is illuminated by the dominant diagonal mode (TEVD: a linear combination of rectangular TE01 and TE10 modes) radiated from the aperture of a central diagonal waveguide. Square choke is excited by two identical slots on the central diagonal waveguide using the longitudinal magnetic field of main operating mode TEVD. Wideband conjugate matching as well as impedance matching for broadband operation can be achieved by such radiating main mode and conjugate mode from apertures which are spatially separated. Based on the above configuration, a J-band matched feed structure is designed using HFSS software for a given offset reflector geometry. The proposed matched feed structure is fabricated and measured. The measured results are compared with simulated ones, and close agreements are found.

Citation:
R. Jana and R. Bhattacharjee, "Wideband Matched Feed Design Employing Conjugate Field Radiated from a Square Choke Excited by Two Slots on a Diagonal Waveguide," Progress In Electromagnetics Research M, Vol. 63, 23-31, 2018.
doi:10.2528/PIERM17090402

References:
1. Rudge, A. W. and N. A. Adaita, "Offset-parabolic-reflector antennas: A review," IEEE Proceedings, Vol. 66, No. 12, 1592-1618, Dec. 1978.
doi:10.1109/PROC.1978.11170

2. Pour, Z. and L. Shafai, "A novel dual-mode dual-polarized circular waveguide feed excited by concentrically shorted ring patches," IEEE Transactions on Antennas and Propagation, Vol. 61, No. 10, 4917-4925, Oct. 2013.
doi:10.1109/TAP.2013.2274207

3. Jana, R. and R. Bhattacharjee, "A novel matched feed structure for achieving wide crosspolar bandwidth for an offset parabolic reflector antenna system," IEEE Antennas and Wireless Propagation Letters, Vol. 14, 1590-1593, 2015.
doi:10.1109/LAWP.2015.2413837

4. Dey, R. and S. B. Chakrabarty, "Broadband conjugate matched feed horn a novel concept," IEEE Antennas and Wireless Propagation Letters, Vol. 15, 164-169, 2016.

5. Koch, G. F., "Coaxial feeds for high aperture efficiency and low spillover of paraboloidal reflector antennas," IEEE Transactions on Antennas and Propagation, Vol. 21, No. 2, 4917-4925, Mar. 1973.
doi:10.1109/TAP.1973.1140437

6. Pour, Z. and L. Shafai, "A ring choke excited compact dual-mode circular waveguide feed for offset reflector antennas," IEEE Transactions on Antennas and Propagation, Vol. 60, No. 6, 3011-3015, Jun. 2012.
doi:10.1109/TAP.2012.2194662

7. Gruner, L., "Higher order modes in rectangular coaxial waveguides," IEEE Transactions on Microwave Theory and Techniques, Vol. 15, No. 8, 483-485, Aug. 1967.
doi:10.1109/TMTT.1967.1126510

8. Cruzan, O. and R. Garver, "Characteristic impedance of rectangular coaxial transmission lines," IEEE Transactions on Microwave Theory and Techniques, Vol. 12, No. 5, 488-495, Sep. 1964.
doi:10.1109/TMTT.1964.1125864

9. Silver, S., Microwave Antenna Theory and Design, 3rd Ed., McGraw Hill, New York, 1949.


© Copyright 2010 EMW Publishing. All Rights Reserved