A new approach to designing a compact size helical loaded cavity backed antenna from helical resonator filter is proposed. The 3-D modeling and simulation is done for three models by using the SINGULA simulation software by Integrated Engineering Software. The fabrication is done in aluminum cavity and copper helix. The measurements were done for return loss, directivity and gain using RF vector network analyzer, Agilent N9923A mode. The helix is enclosed in a highly conductive shield of Cylindrical Cavity. It provides wide bandwidth and circular polarization. Its volume is 10 times smaller than conventional helical antenna in axial mode operation. According to the classical design data for axial mode operation, the ratio of helix circumference to wavelength is 0.8 to 1.2. In this paper the ratio is reduced to 0.2. The same size helical antenna radiate in normal mode without cavity.

1. Sanjoy Kumar Saha, Amit K. Das, B. Chanda, “CBIR using Perception based Texture and Color Measures”, In : 17th Int. Conf. on Pattern Recognition(ICPR’04), Vol. 2, (Aug 2004).
2. Yong Rui, Thomas S. Huang, “Image Retrieval: Current Techniques, Promising Directions, and Open Issues”, Journal of Visual Communication and Image Representation vol. 10, pp.: 39–62, 1999.
3. J. Weszka, C. Dyer, and A. Rosenfeld, “A comparative study of texture measures for terrain classification”, IEEE Trans. on Sys., Man. and Cyb. SMC-6(4), 1976.
4. P. P. Ohanian and R. C. Dubes, “Performance evaluation for four classes of texture features”, Pattern Recognition 25(8), 1992, 819–833.
5. H.B.Kekre, Tanuja K. Sarode, Sudeep D. Thepade, Vaishali S., “Improved Texture Feature Based Image Retrieval using Kekre’s Fast Codebook Generation Algorithm”, In: Springer-Int. Conf. on Contours of Computing Tech. (Thinkquest-2010), 13-14 March, BGIT, Mumbai (2010).
6. H.B.Kekre, Sudeep D. Thepade, A.Athawale, A.Shah, P.Verlekar, S.Shirke, “Walsh Transform over Row Mean and Column Mean using Image Fragmentation and Energy Compaction for Image Retrieval”, In.: Int. Journal on Comp. Science and Engg. (IJCSE),Vol 2S, Issue 1, (Jan. 2010).
7. H.B.Kekre, Sudeep D. Thepade, “Creating the Color Panoramic View using Medley of Grayscale and Color Partial Images”, In: WASET Int. Journal of Electrical, Computer and System Engineering (IJECSE), Vol. 2, No. 3, Summer 2008. Available online at www.waset.org/ijecse/v2/v2-3-26.pdf (2008).
8. H.B.Kekre, Sudeep D. Thepade, “Rotation Invariant Fusion of Partial Images in Vista Creation”, WASET International Journal of Electrical, Computer and System Engineering (IJECSE), Volume 2, No. 2, Spring 2008. Available online at www.waset.org/ijecse/v2/v2-2-13.pdf (2008)
9. H.B.Kekre, Sudeep D. Thepade, “Scaling Invariant Fusion of Image Pieces in Panorama Making and Novel Image Blending Technique”, Int. Journal on Imaging (IJI), Autumn 2008, Volume 1, No. A08, Available online at www.ceser.res.in/iji.html (2008).
10. H.B.Kekre, Tanuja K. Sarode, Sudeep D. Thepade, “Image Retrieval by Kekre’s Transform Applied on Each Row of Walsh Transformed VQ Codebook”, In.: Invited at ACM-Int. Conf. & Workshop on Emerging Trends in Tech. (ICWET ),TCET, Mumbai, 26-27 Feb 2010, uploaded on ACM Portal. (2010)
11. H.B.Kekre, Sudeep D. Thepade, A. Athawale, A. Shah, P. Verlekar, S. Shirke, “Energy Compaction and Image Splitting for Image Retrieval using Kekre Transform over Row and Column Feature Vector”, In.: Int. Journal of Comp. Science &Network Security,Vol.10, No.1, Jan2010,www.IJCSNS.org. (2010).
12. H.B.Kekre, Sudeep D. Thepade, “Image Retrieval using Color-Texture Features Extracted from Walshlet Pyramid., In: ICGST Int. Journal on Graphics, Vision & Image Processing (GVIP), Vol. 10, Issue I, pp.9-18, (Feb. 2010)
13. H.B.Kekre, Sudeep D. Thepade, “Using YUV Color Space to Hoist the Performance of Block Truncation Coding for Image Retrieval”, In.: Proc. of IEEE Int. Advanced Computing Conference 2009 (IACC’09), 6-7 March 2009 Thapar University, Patiala, INDIA,(2009).
14. H. B. Kekre, Tanuja K. Sarode, Sudeep D. Thepade, “Image Retrieval using Color-Texture Features from DCT on VQ Codevectors obtained by Kekre’s Fast Codebook Generation”, In.: ICGST-Int. Journal GVIP, Vol. 9, Issue 5, pp. 1-8, (Sept 2009).
15. H.B.Kekre, Sudeep D. Thepade, “Color Based Image Retrieval using Amendment Block Truncation Coding with YCbCr Color Space.”, In.: Int. Journal on Imaging (IJI), Vol. 2, No. A09, Autumn 2009, pp. 2-14. Available online at www.ceser.res.in/iji.html (2009)
16. Wang Xiaoling, “A Novel Cicular Ring Histogram for Content-based Image Retrieval”, In.: First International Workshop on Education Technology and Computer Science.(2009).
17. Jing Zhang, Gui-li Li, Seok-wum He, “Texture-Based Image Retrieval By Edge Detection Matching GLCM”, In.: 10th Int. conf. on High Perf. Computing and Comm., (Sept. 2008)
18. Xiaoyi Song, Yongjie Li, Wufan Chen, “A Textural Feature Based Image Retrieval Algorithm”, In.: Proc. of 4th Int. Conf. on Natural Computation. (Oct. 2008).
19. H.B.Kekre, Sudeep D. Thepade, “Image Retrieval using Non-Involutional Orthogonal Kekre’s Transform”, In.: Int. Journal of Multidisciplinary Research & Advances in Engg. (IJMRAE), Vol.1, No. I, www.ascent-journals.com (209).
20. R. M. Gray, “Vector quantization”, In.: IEEE ASSP Mag., pp.: 4-29, (Apr. 1984).
21. Y. Linde, A. Buzo, and R. M. Gray, “An algorithm for vector quantizer design”, In.: IEEE Trans. Commun., vol. COM-28, no. 1, pp.: 84-95. (1980).
22. H. B. Kekre, Tanuja K. Sarode, “An Efficient Fast Algorithm to Generate Codebook for Vector Quantization”, In.: 1st Int. Conf. on Emerging Trends in Engg. and Technology, ICETET-2008, Raisoni COE, Nagpur, India, pp.: 62- 67, 16-18 July 2008. (2008).
23. H. B. Kekre, Tanuja Sarode, “Fast Codebook Generation Algorithm for Color Images using Vector Quantization”, In.: Int. Journal of Comp. Sci. & IT, Vol.1, No.1,(Jan 2009).
24. H. B. Kekre, Tanuja K. Sarode, “Fast Codevector Search Algorithm for 3-D Vector Quantized Codebook”, In.: WASET Int. Journal of cal Comp.Info. Science & Engg. (IJCISE), Vol. 2, No. 4, pp. 235-239, Available: http://www.waset.org/ijcise.(Fall 2008)
25. H. B. Kekre, Tanuja K. Sarode, “Fast Codebook Search Algorithm for Vector Quantization using Sorting Technique”, In.: ACM Int. Conf. on Advances in Computing, Comm. and Control (ICAC3-2009), pp: 317-325, 23-24 Jan 2009, FCRCE, Mumbai. (2009).
26. H. Liao, D. Chen, C. Su, H. Tyan, “Real-time event detection and its applications to surveillance systems”, In.: IEEE Int. Symp. Circuits & Systems, Kos, Greece, pp.: 509–512, (May 2006).
27. H. B. Kekre, Tanuja K. Sarode, “New Clustering Algorithm for Vector Quantization using Rotation of Error Vector”, In.: Int. Journal of Computer Science & Information Security, Vol. 7, No. 03. (2010).
28. http://wang.ist.psu.edu/docs/related/Image.orig (Last referred on 23 Sept 2008).
29. H.B.Kekre, Sudeep D. Thepade, “Boosting Block Truncation Coding with Kekre’s LUV Color Space for Image Retrieval” WASET International Journal of Electrical Computer and Systems Engineering (IJECSE), Volume 2, Number 3, pp. 172-180, Spring 2008. http://www.waset.org/ijecse.
30. H.B.Kekre, Sudeep D. Thepade, “Improving ‘Color to Grey and Back’ using Kekre’s LUV Color Space”, In Proc. of IEEE International Advanced Computing Conference 2009 (IACC’09), Thapar University, Patiala, INDIA, 6-7 March 2009. Is uploaded and available online at IEEE Xplore
31. H.B.Kekre, Sudeep D. Thepade, Adib Parkar, “A Comparison of Kekre’s Fast Search and Exhaustive Search for various Grid Sizes used for Colouring a Greyscale Image”, In Proc. of 2nd IEEE International Conference on Signal Acquisition and Processing (ICSAP 2010), IACSIT, Bangalore, pp. 53-57, 9-10 Feb 2010.

Helical antenna normal mode axial mode helical resonator quarter-wave transformer