Design And Measurement Of High Gain Omnidirectional And Directional Antenna In C Band

Microstrip antenna is widely used in modern telecommunication like satellite communications, missile monitoring and wireless communication systems for its advantages such as small size, light weight, low profile and easy mass production. There are also various application demands such as high-gain, low sidelobes,wide coverage and beam scanning.Therefore, phased-array antenna or antenna array is used to meet these requirements.This thesis first introduces the principle of microstrip patch antennasand microstrip antennas, then discusses several types of band broadening technology and its characteristics, at last, presents the design of an omnidirectional antenna and a directional antenna according to the requirement of the subject.One part of this thesis is the design of a high-gain parallel feed patch antenna. Considering the disadvantage of the serial feed antennas, such as that the angle of the antenna is easy to downtilt,a parallel feed antenna array scheme is put forward and the design is completed. The antenna consists of three parallel feed patch antenna arrays which are arranged in triangular configuration. By changing the loading resistors of the parasitic elements, the fluctuation of the composite pattern can be suppressed in horizontal plane. The experiments show that this antenna has good performance, Practical tests show that the antenna has a high gain, gain of12dBi, good omni-directional and the roundness is2dB, achieve the design requirement.Another part of the work in this thesis is to use microstrip antenna design a high-gain directional antenna, using Dolph-Chebyshev distribution, through design, produce amplitude and phase values, simulation and optimization of experimental measurements, the actual making of the antenna.the directional antenna gain is tested19dBi, sidelobe suppression is measured15dB, meet the design requirements.The whole wide band high gain antennas and directional antennas based on the design is applied to the actual communication system, the omnidirectional antenna used in the central node, the user node is a directional antenna,the distance increases greatly in the communication network system, and greatly improving the system noise immunity.