Dual-polarized Single Pulse Microstrip Antenna

Antennas with dual polarization are required for the limitation of spectrum resource in modern communication. According to the advantages of microstrip antenna, like lightweight, thin profile and low cost, people focus on the realization of dual-polarized microstrip array. With the development of application in microstrip antenna, new requirement and ideas have been presented, such as low-side-lobe antenna and monopulse antenna.In this paper, low-side-lobe antenna and monopulse antenna have been designed to meet the application of the new case and requirement on the basis of dual-polarized microstrip antenna element.The main work includes:1. A dual-polarized microstrip antenna is presented, feeding with two vertical "H" slots, which resulting in high isolation, meanwhile, the structure with multi-layers has wide band.2. A low-side-lobe, dual-polarized monopulse microstrip antenna array is designed. The 6x8 array is series fed with Dolph-Chebyshev current distribution, using quarter-wave length transformer to reduce the side lobe level, and using a 180°hybrid ring to realize the sum and difference pattern.3. A low-side-lobe, dual-polarized monopulse microstrip antenna array is designed. The 8×8 array is parallel fed with Taylor current distribution, using unequal power divider network to reduce the side lobe level. The monopulse comparator comprises directional couplers and several 90°delay lines, which realizes the sum and difference pattern.The method proposed can be used in the monopulse radar systems. It is also the foundation for the later research of millimeter microwave antenna array.