Desigh Of Tightly Coupled Arrays And Low Side Lobe Analysis

Phased array antenna is widely used in modern communication and radar system and it requires that phased array antenna has a wide band and a wide field scan angle. The traditional way of designing a phased array antenna is designing a broadband antenna unit before array analysis, it also requires that phased antenna unit has a wide beam so that the array has a wider scan field. It is hard to meet the purpose of wideband phased array antenna because of mutual coupling effect and the limit of spacing units. In recent years, there is a idea that expanding band of antenna using the coupling between units, called tight coupling effect. This paper works on wideband phased array antenna based on tight coupling effect.First, wideband phased array antenna is simply introduced, including the research significance, background and research status all around the world. Second, it shows the scanning principle of phased array antenna and the radiation characteristics with unequal amplitude feed by calculating. Making the broadband effect analysis combined tight coupling antenna equivalent circuit diagram. Third, a tight coupling antenna unit of a four octave is designed, a one-dimensional linear array 1*16 and a two-dimensional surface array are composed with the unit. The VSWR and radiation characteristics of the one-dimensional linear array and the scanning characteristics and low side lobe characteristics are presented. In E plane, the scan angle reaches ±45o and the maximum side lobe level is below-20 d B.Finally, for the one-dimensional array design of 1*16, a divided into 16 splitters is presented. And the line array is processing, assembly and testing. Experimental test results show that the VSWR of the array antenna in simulation band is less than 3.