Research On UWB Tightly Coupled Array Antenna With Parasitic Loading

In the field of modern civil communication represented by wireless communication,since the operating frequency bands of different generations of mobile communication are different,the design of base station antennas needs to take into account mobile communication signals of different frequency bands,which makes ultra-wideband an important design requirement for base station antennas.In addition,in the modern military field represented by radar detection,ultra-wideband array antennas have also been widely used.Compared with the traditional broadband array antenna,the ultra-wideband phased array antenna adopting tight coupling technology not only retains good bandwidth and scanning performance,but also has the advantages of small size and low profile that traditional broadband array antennas cannot match.Broad prospects for development.In this thesis,two methods of resistive loop loading and AMC loading are used to improve the broadband performance of tightly coupled array antennas.The specific research contents are as follows:1.The basic principles of infinite-period tight-coupled array antennas to realize ultra-wideband and the basic working principle of artificial magnetic conductors are studied,and the equivalent circuit of infinite-period tight-coupled array elements is given.Using the equivalent circuit simulation analysis of ADS software and HFSS full-wave simulation software for joint simulation,the equivalent circuit analysis model of the infinite period tightly coupled array is improved,and the infinite period array loaded with resistive loop and loaded artificial magnetic conductor are respectively given The equivalent circuit of the unit,and the simulation analysis results verify the correctness of the equivalent circuit.2.Combined with the equivalent circuit analysis method,the full-wave simulation analysis of the infinite-period tight-coupled array antenna is carried out,and the bandwidth is broadened through the resistive loop loading method,and a 14:1 double frequency bandwidth ultra-wideband array antenna is designed(working The frequency band is 0.47~6.74GHz,and its standing wave ratio is less than 3.0.The equivalent circuit model loaded with Marchand balun is designed,and the simulation results show that the array antenna can be less than 3.5 in the ultra-wideband of 0.36~6.84GHz.14:1 impedance bandwidth.For the ultra-wideband tightly coupled array loaded with double-layer resistive loops,a 4×4 finite-element array antenna was simulated and designed,and the reasons for its limited bandwidth at the low-frequency end were analyzed.The antenna can achieve The voltage standing wave ratio is less than 3.0 in the frequency band of 1.53~5.8GHz.3.Combined with the equivalent circuit analysis method,the artificial magnetic conductor structure was simulated and analyzed,and an artificial magnetic conductor with a 0° reflection phase frequency point of 3.82 GHz was designed.An equivalent circuit model of an infinite period tightly coupled array antenna loaded with an artificial magnetic conductor structure is proposed.Based on the simulation analysis of the ADS equivalent circuit and the full-wave simulation of the full-wave electromagnetic simulation software HFSS,a 7:1 frequency doubling is designed The bandwidth of the ultra-wideband array antenna has an impedance bandwidth of 0.59~4.23GHz,and its voltage standing wave ratio is less than 3.0.