Research On Reconfigurable Slot Antenna Based On Varactor Diode And PIN Tube

With the rapid development of modern radio communication technology,the research field of wireless communication is constantly striding forward to the direction of multi-frequency and reconfigurable.The demand from single-frequency reconfigurable to multi-frequency reconfigurable is increasing.Many,many actual communication equipment and application systems need to use multiple frequency points.At this time,a single frequency point can not meet the requirements of the application,so it is necessary to use equipment that realizes multiple frequency points to meet the actual needs;At the same time,the size of the antenna is required to be as small as possible to meet the needs of the application scenario,which increases the difficulty of antenna design.In addition,the application of reconfigurable pattern is also more extensive.Reconfigurable pattern is the basis for stabilizing the antenna resonance frequency.Change the antenna beam to radiate in a fixed spatial direction,which can not only improve the electromagnetic anti-interference ability of the antenna device,but also increase the signal-to-noise ratio in the passband signal,and further improve the safety and reliability of the antenna.In communication design and application systems,both frequency reconfigurable and pattern reconfigurable play a vital role.In this paper,we will focus on these two antennas:First,a PIN tube-based frequency reconfigurable antenna is designed.The antenna achieves the effect of dual frequency adjustment.The antenna adopts an asymmetrical T-shaped radiating element and uses 3 PIN tubes to make the antenna work in three modes.Each mode corresponds to a different resonance frequency band.The return loss coefficient S11 and radiation pattern of the antenna in each mode are simulated and tested,and the influence of structural parameters on the S11 curve of the antenna is studied.Next,a PIN tube-based frequency reconfigurable antenna is designed.The antenna adopts an asymmetric T-shaped radiating element,and 3 PIN tubes are used to make the antenna work in three modes,each mode corresponding to a different resonance frequency band.The antenna is simulated and tested.In the return loss coefficient S11 and radiation pattern in each mode,the influence of the structural parameters on the S11 curve of the antenna is studied.Then a frequency reconfigurable slot antenna based on the combination of PIN tube and varactor diode was designed.This antenna realizes dual-band reconfiguration at 2.45 GHz,5.5GHz,3.8GHz,and 5.25 GHz.Its characteristic is that it can be realized.It is continuously adjustable within the specified frequency range.The antenna is composed of a rectangular feeder line with the front and a symmetrical C-shaped slot on the grounding plate.This symmetrical structure makes the antenna look neat and organized as a whole,which is convenient for analyzing the slot.The influence of structure on antenna performance;There are 5 states in the design,and the test results are basically consistent with the simulation results.This paper has designed three slot antennas.The first antenna is based on the PIN tube frequency band.The frequency of the antenna can be switched between different frequency bands.The second antenna realizes the frequency by changing the equivalent capacitance of the slot.The PIN tube is used to change the adjustable frequency band of the antenna.The third antenna changes the size of the gap and the direction of the surface current through the turn-on and cut-off of the PIN tube to realize the reconfiguration of the pattern.Voltage drive to change the working mode of the antenna.