Design Of Matching Structure For Microstrip Antennas Using Real Frequency Technique

Real frequency technique is an efficient method for the optimization design of broadband matching networks. This method has such features that there is no need to express the load impedance or source impedance by a model or analytic function, there is no need to assume the topology of equalizer, there is no need to assume the analytic form of the system transducer function, and the optimization progress is performed directly by computer. Combined the classical real frequency technique and simplified real frequency technique with the design of broadband and multi-band microstrip antennas, the realization method of distributed parameter matching networks is researched. Some progresses on the design of broadband and multiband microstrip antennas and their matching structures and the optimization design of a microstrip antenna array are achieved.(1) Several usual methods for the optimization design of broadband matching networks are comparatively analyzed. Thereafter, their advantages and disadvantages are concluded.(2) Based on the classical real frequency technique, a realization program for the distributed parameter matching structures of broadband microstrip antennas is given. Utilizing the program, the matching structures of a broadband microstrip monopole and a broadband E-shaped microstrip antenna are designed, respectively. The simulated results show that their impedance bandwidth are increased by 80% and 35%, respectively.(3) Based on the simplified real frequency technique, a realization program for the distributed parameter matching structures of multi-band microstrip antennas is given. Utilizing the program, the matching structures of a compact dual-band planar inverted-F antenna (PIFA) and a compact tri-band PIFA are designed, respectively. The simulated results show that their matching situation in the operating band is improved obviously.(4) A Ku-band planar microstrip antenna array is comprehensively optimized by using the broadband matching optimization method and suspending microstrip method. Through those methods, matching situation and antenna gain of the array are both improved effectively.