Loop antenna

[0020] In order to better illustrate the technical characteristics and structure of the present invention, the following describes in detail the preferred embodiments of the present invention and the accompanying drawings.

[0021] Refer to figure 1 with figure 2 The loop antenna provided by the present invention includes a feeder 100 and an antenna body 200. The feeder 110 is provided with a feeder anode 110 and a feeder cathode 120. The feeder anode 110 and the feeder cathode 120 are coaxial. The feeder anode 110 is located inside the feeder 100. The negative electrode 120 is a circle of medium surrounding the positive electrode 110 of the feeder line and forms the feeder line 100 with the positive electrode 110 of the feeder line. The antenna body 200 includes a plurality of antenna elements 210 in a loop structure, and the plurality of antenna elements 210 are symmetrically distributed around the feed line 100 around the feed line 100, wherein each antenna element 210 is connected to the positive pole 110 of the feed line and the feed line respectively. The negative pole 120 is connected, and all the antenna units 210 are located at the same level.

[0022] Specifically, considering that the size of the antenna unit 210 differs in response to frequency points, as the number of loops (the number of antenna units 210) increases, the frequency will increase. In this embodiment, three antenna units 210 are selected. , Where the angle θ between each antenna element 210 is 120 degrees, the total length of each antenna element 210 is about a quarter of a wavelength, the circular vertical array is on the antenna body, so that the radiation surface of the overall antenna is no longer Is a one-way axial plane, and the entire horizontal plane, such as figure 2 In the yz plane. In other embodiments, the number of antenna units 210 may be selected to be more, for example, 4, and the angle θ between each antenna unit 210 is 90 degrees.

[0023] Wherein, each antenna unit 210 has a ring structure, which includes at least a first arm 211, a second arm 212, and at least one third arm connecting the first arm 211 and the second arm 212. Arm 213, the first arm 211 is connected to the feeder anode 110, and the second arm 212 is connected to the feeder cathode 120. In this embodiment, as figure 1 As shown, the antenna unit 210 of the loop structure includes a first arm 211, a second arm 212, and a third arm 213 connecting the first arm 211 and the second arm 212, and the third arm 213 is It is arc-shaped, and the ring structure formed by surrounding the first arm 211 and the second arm 212 is fan-shaped. The angle ɑ between the first arm 211 and the second arm 212 is 80 degrees. In some other embodiments , The included angle ɑ can be selected between 75 degrees and 85 degrees. In other embodiments, the third arm 213 can have other shapes, and the number can be set to be more. For example, the third arm 213 is linear and the number is one. The ring structure surrounded by the arm 211 and the second arm 212 is a triangle; or, the third arm 213 is linear, and the number is two. At this time, the two third arm 213 and the first arm 211 , The ring structure surrounded by the second arm 212 is rhombus or square. The above-mentioned examples are only for the optimization of the structural form, and should not be regarded as a limitation of the specific structural form.

[0024] Among them, the first arm 211 of the antenna unit 210 connected to the positive electrode 110 of the feeder, the first arm 211 between each antenna unit 210 cannot overlap or interfere with each other, that is, the first arm 211 of each antenna unit 210 There needs to be a gap between them, and the included angle β between the first arm and the feeder axis is between 15 degrees and 21 degrees. In this embodiment, the included angle β is preferably 18 degrees. The second straight line 212 of the antenna unit 210 is connected to the negative electrode 120 of the feeder line, and the negative electrode 120 of the feeder line is used for grounding.

[0025] The loop antenna provided by the above embodiments inherits the frequency characteristics and directional characteristics of the small loop antenna; at the same time, the antenna elements are arranged and combined at a certain angle on a solid surface, and the array characteristics are used to change the impedance, thereby improving the directivity and directional characteristics of the small loop antenna. The impedance gain achieves the omnidirectional effect of reducing impedance and ensuring directivity, making it difficult to reduce the gain drastically, overcoming the impedance problem of the small loop antenna, and greatly improving the efficiency.

[0026] image 3 It is an illustration of the numerical verification of the loop antenna provided in the above embodiment using the method of simulation calculation. When the frequency of the loop antenna is 1.5GHz, the gain can reach -6dBi and the half power angle can reach more than 100°. The directivity is kept omnidirectional, which overcomes the impedance problem of the small loop antenna and greatly improves the efficiency.

[0027] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity from another, and do not necessarily require or imply any actual relationship between these entities. Or order.

[0028] The foregoing embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those of ordinary skill in the art, other changes or modifications in different forms can be made on the basis of the above description. There is no need and cannot give an exhaustive list of all implementation methods. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.