| In recent years,the rapid development of society has increasingly diversified the demand for wireless communication,and the requirements for the application environment of the system are also becoming more and more complicated,which has prompted the development of antenna technology and other various communication devices towards the direction of high performance and multiple operating modes.The reconfigurable antenna has the advantage of switchable functions under various working states,which can reduce the cost of the antenna,and at the same time realize the miniaturization,integration,broadband and multi-function of the wireless communication system.Based on the transmission line impedance matching theory,this paper proposes a reconfigurable principle with constant amplitude and switchable phase,and designs a phase converter based on this theory.Using the PIN diode ESC control method and phase converter mechanism,a variety of feed networks are designed,and two pattern reconfigurable antenna arrays and a multi-polarization reconfigurable antenna array are implemented respectively.The main work and innovations of the paper are as follows:Firstly,a reconfigurable phase converter composed of two microstrip transmission lines is proposed.The mechanism of phase reconfiguration is to use PIN diodes to control multiple nodes in the circuit to work in the on or off state,so that the circuit can be operated in different states.In the working state,it can be equivalent to different quarter-wavelength microstrip line branches.Based on this mechanism,two phase converters of ±90° and ±45°are simulated and designed.The accuracy and feasibility of the proposed phase reconstruction scheme are verified by comparing the simulation results with the theoretical values.Then,a three-beam pattern reconfigurable antenna array operating at 2.45 GHz is designed.For the designed 1 × 4 microstrip antenna array,the feeding network that excites the antenna array has reconfigurable performance,and the PIN diode can be used to switch the phase difference between the excitations of each element of the antenna.The simulation results show that the reconfigurable array antenna can achieve beam scanning function at three angles of + 30°,0° and-30° after optimized phase adjustment control.Then,a four-beam pattern reconfigurable antenna array operating at 2.45 GHz is designed.In order to improve the anti-jamming capability of the proposed pattern reconfigurable antenna,the circular polarization performance is optimized for the elements of the 1×4microstrip antenna array.Using the diagonal cutting process of the metal microstrip antenna unit patch and the double feed point method using the L-shaped probe coupling feeding,the circular polarization performance of the pattern reconfigurable antenna is realized,and the multi-path interference of the microwave signal is reduced.The designed feed network can use the phase reconfigurable mechanism to control the phase difference between the excitation of each antenna element to switch between ±45° and ±135°,thus realizing the beam of the pattern reconfigurable antenna at four angles(+40°,+15°,-15° and-40°).Finally,a coupled-feed quad-polarized reconfigurable antenna is proposed.The feeding network and radiation part of the antenna are designed and optimized in layers,and the L-shaped probe coupling feeding method is adopted to reduce the influence of the feeding and improve the radiation performance of the antenna.The feeding network uses the phase reconfigurable mechanism,which can control the state of the PIN diode according to the requirements of different polarization modes,and reconfigure the phase of the network output,thereby changing the internal current distribution of the antenna,and realizing the antenna in two linear polarizations and two circular poles.chemical radiation state switching. |
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