A novel circularly polarized array designed for millimeter wave digital radar module was proposed and validated in this paper. The circularly polarized array was designed with single feeding point for easily integrating with front-end module. A new kind of medium filled circular cavity was employed as transition to connect the output of the T/R module and the feeding point of the array. TM010 mode was selected as the operating mode of the circular cavity based transition for its special field distribution. Good performance of flexibility, return-loss, axial ratio and radiation pattern were observed.
2. Li, E. S., J.-C. Cheng, and C. C. Lai, "Designs for broad-band microstrip vertical transitions using cavity couplers," IEEE Transactions on Microwave Theory and Techniques, Vol. 54, No. 1, 464-472, Jan. 2006.
doi:10.1109/TMTT.2005.860495
3. Chen, C., M.-J. Tsai, and N. G. Alexopoulos, "Optimization of aperture transitions for multiport microstrip circuits," IEEE Transactions on Microwave Theory and Techniques, Vol. 44, No. 12, 2457-2465, Part 2, Dec. 1996.
doi:10.1109/22.554578
4. Li, E. S. and C. C. Lai, "A comprehensive study on the bandwidth of broad-band slot-coupled and cavity-coupled vertical transitions," Antennas and Propagation International Symposium, 2007 IEEE, 3109-3112, Jun. 9--15, 2007.
5. Nedil, M., T. A. Denidni, and A. Djaiz, "Ultra-wideband microstrip to CB-CPW transition applied to broadband filter," Electronics Letters, Vol. 43, No. 8, 464-466, Apr. 12, 2007.
doi:10.1049/el:20070693
6. Lee, J.-H., Y.-T. Im, and S.-O. Park, "Doppler radar sensing system of respiration and heart rate," The 8th International Symposium on Antennas, Propagation and EM Theory, 976-978, 2008.
7. Wu, D. and K. Seo, "Waveguide to microstrip line transition and power divider," Electronics Letters, Vol. 43, 169-170, 2007.
doi:10.1049/el:20073694
8. Wu, Y., Y. Liu, and S. Li, "A new dual-frequency wilkinson power divider," Journal of Electromagnetic Waves and Applications, Vol. 23, No. 4, 483-492, 2009.
doi:10.1163/156939309787612400
9. Ruiz-Cruz, J. A., J. R. Montejo-Garai, J. M. Rebollar, and S. Sobrino, "Compact full Ku-band triplexer with improved E-plane power divide," Progress In Electromagnetics Research, Vol. 86, 39-51, 2008.
doi:10.2528/PIER08082803
10. Chen, H. and Y. Zhang, "A novel compact planar six-way power divide using folded and hybrid-expanded coupled lines," Progress In Electromagnetics Research, Vol. 76, 243-252, 2007.
doi:10.2528/PIER07070601