Study On The Slotted Patch Antenna With Capacitive Loading Technology

With the development of mobile satellite communications, mobile Internet and IoT technology, the demands on the performance of the antenna miniaturization, broadband, multi-band, circular polarization are increasing. The microstrip antennas with the above performances are paid more attention. A variety of loading techniques can be used by patch antenna to match these requirements on antenna performance, in which slotting and capacitive loading technologies are adopted with the low manufacturing cost, simple structure, antenna’s strong controllability and other advantages. Capacitive loading technology can be used to change the resonance point, bandwidth of the antenna and optimize the antenna’s circular polarization performance flexibitly. Therefore, this thesis mainly focus on slotted patch antenna with capacitive loading technology to study the patch antenna’s miniaturization, broadband, multi-band and circular polarization properties.In this thesis, the performances of microstrip antenna with a rectangular slot and SMD capacitor loaded on the slot of microstrip antenna are studied. The research reveals that loading rectangular slot will shift resonance point of patch antenna under the effect of meandering principle. Loading capacitance technique can be used in further changing the resonance point of antenna, bringing a reduction in the size of microstrip antennas. The microstrip antenna can be minimizing by 19.4% when the capacitance is loaded. At the same time, loading capacitance technique can also makes the bandwidth broaden by 68.7% and the resonance range can be adjusted up to 1.35 GHz freely. This method is a very effective tool on tuning frequency and phase in microstrip antennas. The compact slotted patch antenna and capacitance loaded antenna have be processed and measured. It is found that the antenna’s test results are consistent with the simulation results.The loading capacitance technology demonstrates an effect on the far field magnitude and phase parameters of antenna. By using microstrip antenna’s tuning frequency and phase principle, three antennas have been designed: small double resonance antenna, single-slot compact circularly polarized microstrip and dual-slot compact circular polarized antenna. These antennas’ miniaturization are 27.7%, 11.43% and 25.97% respectively. The antennas of double resonance compact antenna, single-slot compact circularly polarized antenna and dual-slot compact circular polarized antenna are processed and measured. The antenna’s test results are consistent with the simulation results.