Monopulse Antenna In Millimeter-wave Planar Structure

MMW monopulse radar has wide application prospect in the fields of detecting and tracking, whose key technologies are the sum-difference network and the transmit/receive antennas. Taking the MMW detection as the application background, the planar structure MMW sum-difference network and transmit/receive antenna are studied in this paper. The detailed work includes:1. Based on analyzing the principle of the MMW microstrip branch coupler using odd-even mode theory, a microstrip directional coupler has been designed using ADS, and a cross shaped sum-difference network has been built by 4 couplers, which is compact in structure. Parameters of the system such as S parameters and the minimum zero depth are gained and analyzed, which supply academic reference to the feasibility and validity of this kind of sum-difference network using at MMW band.2. A 4X4 antenna array of microstrip has been designed using HFSS. The important parameters such as the gain and bandwidth achieve the designing request, which supplies efficient antenna model and parameters to the systemic analyze of the foreside subsystem.3. Placing 4 antenna arrays and the sum-difference network on the same plane to buildup the monopulse antenna, the whole antenna is simulated to get parameters such as pattern of sum channel and two difference channels and the VSWR of the input ports, which establishes the foundation for the investigation on the MMW monopulse radar and the forward subsystem.The MMW monopulse antenna designed in this paper has the advantages of smaller volume, less weight, compact structure and being convenient to be integrated with MMW forward components, which is especially suitable for Missile - Borne purpose.