Circular polarization spiral antenna with high low elevation gain

Abstract

The invention discloses a circular polarization spiral antenna with high low elevation gain, which comprises a cylindrical spiral antenna radiator, a cross-shaped cross vibrator parasitic unit and a power division phase shift broadband microstrip feed network. The power division phase shift broadband microstrip feed network is positioned below the cylindrical spiral antenna radiator and is connected with the bottom of the cylindrical spiral antenna radiator; and the cross-shaped cross vibrator parasitic unit is positioned above the cylindrical spiral antenna radiator, and comprises two vertical vibrators, wherein when the vibrators are used as antenna directors, the length of the vibrators is less than half wavelength; and when the vibrators are used as antenna reflectors, the length of the vibrators is greater than the half wavelength. The antenna has the advantages of wide frequency band, excellent directional diagram performance, high low elevation gain, compact structure and light weight.

Description

technical field [0001] The invention relates to a circularly polarized helical antenna, in particular to a circularly polarized helical antenna with high and low elevation angle gain. Background technique [0002] At present, the application of global positioning and navigation systems is becoming more and more extensive. China's Beidou second-generation system has basically covered the Asia-Pacific region and is expected to cover the whole world in the next ten years. Circularly polarized antennas play a vital role in this system. effect. According to the positioning principle, the low elevation signal close to the ground contributes the most to the positioning accuracy, while the zenith signal is easy to accept but does not contribute much to the positioning accuracy. With the improvement of positioning accuracy requirements, the antenna is generally required to have a higher low-elevation gain, especially for the Beidou system, which has relatively few satellites, and pu...

AI Technical Summary

Problems solved by technology

The microstrip antenna has a low profile, simple manufacture, and low cost. However, the performance of the pattern and axial ratio is slightly inferior to that of the helical antenna, and its lobe width is narrow, which is difficult to meet the higher index requirements in actual use.

[0004] The traditional helical antenna has a good upper hemispherical pattern and a wide lobe width, but the gain at low elevation angles is generally not high enough to meet relatively high index requirements

and direction Figure 1 Generally, it is adjusted through the spiral parameters, and these parameters will affect other performances of the antenna at the same time, sometimes it is difficult to balance and take into account, and the design process is cumbersome and time-consuming

[0005] In order to improve the low elevation gain, the easiest way is to change the shape and size of the floor, but the effect of this method is very limited, and it will bring the disadvantage of increased volume and weight

[0006] In addition, the use of conical helical antennas can increase the beam width and increase the gain at low elevation angles, but the range of improvement is also very limited, and there are disadvantages of large volume and complex structure

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