No abstract

This paper creatively proposes a new fractal iterative structure of a gradual defect patch and combines it with a rectangular array structure. Aiming at the performance requirements of the UAV system for multi-band compatible antennas, a gradual defect patch fractal array is designed. The radiation performance of the fractal array antenna was simulated by the method of moments, and antenna samples were made and the radiation performance was tested. Both simulation and actual measurement results show that this antenna has a working bandwidth of 5.5 GHz or more, a minimum return loss as low as -44 dB and excellent omnidirectional radiation capability. This antenna is compatible with the GPS system frequency band, Beidou system frequency band, all working frequency bands of the second to fifth generation mobile communication systems and the three working frequency bands of the RFID system, and is expected to be widely used as an unmanned aerial vehicle system antenna.

Aiming at the antenna performance requirements of Bluetooth and UWB indoor positioning system, an octagon monopole dual-frequency indoor positioning beacon antenna is made. The antenna can operate in both UWB and Bluetooth communication bands. The antenna performance is improved by grooving the antenna and adding metal strips. The use of curved and gradual structure feeders also makes the antenna get better bandwidth performance.

In this paper, the rectangular nested fractal and Cantor fractal slot are skillfully fused together, and the composite fractal embedded slot radiation structure is creatively designed. It combines the microstrip monopole antenna of high radiation intensity and excellent directional radiation capability with the microstrip Balun feed structure of wide frequency range and step-by-step impedance matching capability to design composite fractal embedded slot monopole antenna that can meet the performance requirements of BeiDou Navigation Satellite System. Actual test results show that the antenna has the advantages of both a high-performance redundant antenna and a directional radiation antenna and can completely cover the BeiDou Navigation Satellite System working for the frequency band. It is a high-performance satellite positioning antenna with strong application potential.

Compared with the performance index of UAV system antenna, a compatible trigeminal monopole array antenna is proposed. This antenna uses photosensitive resin as the substrate material, and can be made with UAV shell using 3D printing technology, realizing the integration of the antenna system and UAV. The antenna uses a trigeminal monopole antenna as the basic radiation unit, which is arranged in accordance with the Sierpinski fractal structure to form fractal radiation array. While enhancing the radiation through the array, it ensures that the antenna has a larger working bandwidth. In radiation performance test, the antenna is operating over a frequency spectrum of 1.038-11.916 GHz, and the minimum S11 is -37.92 dB. The proposed antenna has multi-band compatibility, better radiation performance, and greater performance redundancy.