Research On Reconfigurable Antenna With Frequency And Pattern

At present,communication technology and information science are developing rapidly,and both systems and wireless communication equipment need to be able to adapt to complex and changeable different scenarios.The transmitting and receiving antenna is very critical in the system.Its performance is closely related to the performance of the system,and its impact on the system cannot be ignored.Therefore,its size and basic characteristics are also required to be optimized.However,the spectrum resources of wireless communication are limited.How to achieve multiple switchable characteristics in a single antenna and meet the requirements of antenna miniaturization,broadbandization,low cost,and light weight has become a current research focus.The reconfigurable antenna can be reconfigured into a variety of working states,which is an economical and effective solution to the above problems.Therefore,this paper conducts research on antennas with reconfigurable single characteristics and two reconfigurable characteristics.The specific research contents are as follows:(1)Aiming at the current frequency reconfigurable antenna frequency that has insufficient frequency adjustable range,narrow bandwidth and difficulty in covering common frequency bands such as WIFI/Wi MAX/5G,a 5G-oriented hexagonal frequency reconfigurable antenna was designed.The antenna uses a microstrip line to feed power at the center of the edge of the patch.Two slots are cut on the upper hexagonal patch antenna.Among them,load two symmetrical varactor diodes on the gap close to the feeder and control their bias voltage to achieve continuous frequency adjustment.,and load a PIN diode on the center of the gap far away from the feeder and control its state can broaden frequency adjustment range on the original basis and realize a wide bandwidth.This frequency reconfigurable antenna completely covers the WIFI/Wi MAX/5G frequency band,and has the advantages of small size,large frequency adjustable range and wide bandwidth.(2)Aiming at the problems of small scanning range,large volume,and complex feeding structure of the current pattern reconfigurable antenna,a bent pattern reconfigurable antenna that can cover the WLAN 2.4GHz frequency band is designed.The antenna is composed of a middle hexagonal patch and six symmetrical bent monopole branches.It is coaxially fed to the middle hexagonal patch,which acts like a power splitter.When the state of the PIN diodes on the six bent branches is that three consecutive PIN diodes are on and the remaining PIN diodes are all off,the antenna can realize five different pattern states in the horizontal plane(XOY plane).The antenna has a simple structure and low profile,and can be used for indoor WLAN communication.(3)In view of the current frequency and pattern reconfigurable antennas,which have the problems of small scanning range,complex structure,and inability to continuously adjust the frequency,a frequency and pattern reconfigurable tapered slot antenna is studied.By changing the state of the PIN diode on the ground gradual gap,different gaps can be radiated,thereby achieving two different pattern states.At the same time,in order to reduce the complexity of the structure,a rectangular ring is loaded at the upper feeder.When the PIN diodes on the ring are all turned on and the varactor changes,the current at the feeder changes so that the frequency is continuously adjustable.The antenna structure and feed bias circuit are simple,and the frequency can be continuously adjusted.The bandwidth includes the GSM mobile communication frequency band(900MHz)and the broadcasting and television field frequency band(840MHz-845MHz),which can be applied to these scenarios.