A 77 GHz microstrip antenna array with a small surface providing high side and grating lobe suppression is presented. This may serve as a starting point for 77 GHz automotive radar applications. Multiple Wilkinson dividers guarantee both impedance matching at the input port (TX) as well as low return loss for the incoming (RX) signal. Phase shifting is done by adjusting the level of the Wilkinson dividers or by meandered sections of transmission line. The influence of the radiation caused by the feeding network is analyzed and the absolute degradation in side lobe suppression is derived in this paper.
2. Cui, B., C. Wang, and X.-W. Sun, "Microstrip array double-antenna (mada) technology applied in millimeter wave compact radar front-end," Progress In Electromagnetics Research, Vol. 66, 125-136, 2006.
3. Freese, J., R. Jakoby, H.-L. Blocher, and J. Wenger, "Synthesis of microstrip series-fed patch arrays for 77 GHz-sensor applications," Microwave Conference, 2000 Asia-Pacific, 29-33, 2000.
4. Jit Bahl, I. and P. Bhartia, Microstrip Antennas, UMI, Ann Arbor, Michigan, 1998.
5. Kumar, G., Broadband Microstrip Antennas, Artech House, Boston, Mass., 2003.
6. Zhang, R., X. Tang, L. Wang, and X. Zhang, "Study of microstrip-line inset-fed and two-layer electromagnetically coupled rectangular patch antennas," Microwave Conference Proceedings, 2005. APMC 2005. Asia-Pacific Conference Proceedings, Vol. 4, 4, 2005.
7. Porter, B. G., L. L. Rauth, J. R. Mura, and S. S. Gearhart, "Dual-polarized slot-coupled patch antennas on Duroid with teflon lenses for 76.5 GHz automotive radar systems," IEEE Transactions on Antennas and Propagation, Vol. 47, No. 12, 1836-1842, 1999.