Study On Phased Microstrip Antenna Array Feed Network

Microstrip antenna are popular owing to its small size, light weight, flexible feed, low cost and easy to conformal with the target and easy to integrated with microwave integrated circuits. The new antenna has become mature today, and its applications are increasing. As an important part of microstrip antenna, feed network which determines the advantages and disadvantages of the whole system has become the research focus in industry.The parallel feed network was composed by several two power dividers in this paper, and its input and output ports were both matched with 50Ωload. Substrate that dielectric constant is 4.3, thickness is 0.8mm was used, and ADS software was applied to calculate the width of microstrip line. First of all, started from low frequency, two feed networks were designed, which composed by Wilkinson power divider and their center working frequency was 2.4GHz. Remained the impendence characteristics of ports and adjusted the length of transmission lines and the distance between the units to get the best of each performance. Secondly, the feeding network for satellite broadcast was studied based on the 2.4GHz ones, two kinds of four units feed network were designed. One consisted by Wilkinson power divider and the other was consisted by traditional T-type microstrip power divider. Simulation results showed that the performance of these two feed networks both met the design requirements. Finally, a phased array of two units at 2.45GHz was designed and fabricated through microstrip phase shifters. Test and simulation results were consistent. Then serial and parallel feed networks of microstrip phased antenna array were designed respectively, through simulation and optimization two feed networks met the performance indicators at the center frequency. As taking into account the feed network of phased array only, phase shifter was seen as a black box that replaced by 50Ωpure resistance during the simulation for the input and output ports impedance of phase shifter were both 50Ω. The best performance of whole network achieved by adjusting the distance between each unit and the length of feed lines. Simulation and optimization results showed that the return loss and the insertion loss of both feed networks were satisfied in the center frequency.