CN109037917A - Helical antenna with coupled structure - Google Patents

Abstract

The invention discloses a helical antenna with a coupling structure, which includes a bottom plate, a support body is fixed on the bottom plate, a helical radiator and a coupling radiator are wound on the support body at an equal angle, and a support medium is arranged in the middle of the support body; The bottom end of the spiral radiator is connected to the feed port of the bottom plate; the coupling radiator is located between the helixes of the spiral radiator, and its bottom end is fixed on the surface of the support body; the invention has a simple structure and is easy to manufacture; without increasing On the basis of the extra feeding structure, the circular polarization axis ratio of the antenna is reduced and the gain of the helical antenna is improved by adding a coupling structure.

Description

Helical Antenna with Coupling Structure

technical field

The invention relates to a communication helical antenna, in particular to a helical antenna with a coupling structure.

technical background

As a classic circularly polarized antenna, the end-fired helical antenna is widely used in satellite communications due to its excellent circular polarization performance and wide beam bandwidth. Circular polarization axis ratio gain, gain drop and other issues.

Contents of the invention

Purpose of the invention: Aiming at the problems existing in the prior art, the purpose of the present invention is to provide an end-fire helical antenna that improves circular polarization performance based on a coupling structure.

Technical solution: a helical antenna with a coupling structure, including a base plate, a support body is fixed on the base plate, a helical radiator and a coupling radiator are wound on the support body at an equal angle, and a support medium is provided in the middle of the support body; The bottom end of the spiral radiator is connected to the feeding port of the bottom plate; the coupling radiator is located between the helixes of the spiral radiator, and the bottom end is fixed on the outer surface of the support body. The outer conductor of the feed port is connected to the metal layer of the bottom plate, and the inner conductor passes through the bottom plate to connect with the bottom end of the spiral radiator.

Preferably, the tops of the helical radiator and the coupling radiator are flush with the top of the supporting body.

Further preferably, the line radius of the coupling radiator is smaller than the line radius of the helical radiator.

The support body is preferably cylindrical.

Beneficial effects: Compared with the prior art, the present invention has the following improvements: 1. The structure is simple and easy to manufacture; 2. On the basis of not adding an additional feeding structure, the circular polarization axis of the antenna is reduced by adding a coupling structure Ratio, improving the helical antenna gain.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a structural representation (bottom side view) of the present invention;

Figure 3 shows the VSWR of the antenna with and without the coupled radiator;

Figure 4 shows the ratio of the circular polarization axis of the antenna with and without the coupled radiator;

Figure 5 shows the circular polarization gain of the antenna with and without the coupled radiator.

Detailed ways

The technical scheme of the invention will be further described below in conjunction with the accompanying drawings.

As shown in FIGS. 1-2 , the present invention includes a helical radiator 1 , a coupling radiator 2 , a cylindrical support 3 , a bottom plate 4 and a feed port 5 . The structural relationship is as follows: the support body 3 is fixedly installed on the bottom plate 4, the spiral radiator 1 is rotated and wound obliquely around the support body, its top end is flush with the top of the support body 3, and the bottom end is connected to the feed port 5 passing through the bottom plate 4 The inner conductors are connected; the coupling radiator 2 is located between the helixes of the spiral radiator 1, preferably at the center line, and is also rotated around the support body 3 at an equal angle, and its top is also flush with the top of the support body 3, and the bottom end Fixed on the support body 3, the specific position is determined by the electrical characteristics of the high-frequency end; the outer conductor of the feed port 5 is connected to the metal layer of the bottom plate 4, and the inner conductor passes through the bottom plate 4 to connect with the bottom of the spiral radiator 1. Wherein, the winding angles of the helical radiator 1 and the coupling radiator 2 depend on the result of designing the antenna according to the requirements of the system index, and usually an equiangular helix can meet the requirements.

In addition to the situation shown in Figure 1-2, multiple helical radiators can also be set. For example, in the case of a four-armed helical antenna, a total input terminal will be used to form four 90-degree-different in turn through the feed network. The output feeds the four arms of the antenna sequentially, and the coupling radiator can also be added theoretically.

Further preferably, the line radius of the coupling radiator 2 is thinner than the line radius of the helical radiator 1. Specifically, there is no special requirement for the line radius of the coupling radiator 2, as long as it is thinner than the helical radiator 1. In practical applications, Usually, ready-made wire body radius materials are selected.

Generally, the support body 3 can adopt shapes such as a cylinder, a truncated cone or a cone, but when a truncated cone or a cone is used, the radiation inclination angle of the helical antenna will change, and the bandwidth, etc. will also change, so the present invention preferably uses a cylindrical support body 3 . In addition, in practical applications, if the structure of the support body 3 is hollow, the antenna is prone to deformation, especially in the case of multiple helices, usually a support medium is used in the middle. Because of the existence of coupling radiators in the present invention, a supporting medium must be used. The selection of the supporting medium has a certain influence on the performance of the antenna, but it can be adjusted. Specifically, metal cannot be used, and there are no special requirements for others. It is preferred to be a conventional material with a low dielectric constant and a certain hardness.

Example:

S-band left-handed circularly polarized helical antenna, the bottom plate radius is 50mm, the support body radius is 21.6mm, the height is 34.6mm, the spiral radiator rotates 3.2 times, the line radius is 1.2mm, the coupling radiator rotates 1.9 times, the line radius is 0.9mm, two The pitches of all the radiators are 9.2 mm.

As shown in Figure 3, the abscissa represents the operating frequency, the ordinate represents the VSWR, the dotted line represents the VSWR of the helical antenna without a coupling structure, and the solid line represents the VSWR of the helical antenna with a coupling structure. Comparing the two curves, it can be seen that the coupling structure will not reduce or increase the VSWR of the helical antenna, but it will move the VSWR to the high frequency direction.

As shown in Figure 4, the abscissa indicates the operating frequency, the ordinate indicates the polarization axis ratio, the dotted line indicates the polarization axis ratio of the helical antenna without coupling structure, and the solid line indicates the polarization axis ratio of the helical antenna with coupling structure. Comparing the two curves, it can be seen that the polarization axis ratio of the helical antenna with the coupling structure is lower, and the circular polarization performance is better.

As shown in Figure 5, the abscissa represents the operating frequency, the ordinate represents the left-handed circular polarization gain, the dotted line represents the gain of the helical antenna without a coupling structure, and the solid line represents the gain of the helical antenna with a coupling structure. Comparing the two curves, it can be seen that the helical antenna with the coupling structure has higher gain and better performance.

Claims (5)

1. a kind of helical antenna with coupled structure, it is characterised in that: including bottom plate, a supporter is fixed on bottom plate, is supported Angle tilts are wound with spiral radiation body and coupling radiator on body etc., and the middle part of supporter is equipped with Supporting Media；The spiral The bottom end of radiator connects with the feed port of bottom plate；Coupling radiator is located between the helix of spiral radiation body, and bottom end is solid Due to support external surface.

2. the helical antenna according to claim 1 with coupled structure, it is characterised in that: the spiral radiation body and coupling Close radiator top with flushed at the top of supporter.

3. the helical antenna according to claim 1 with coupled structure, it is characterised in that: the line of the coupling radiator The line radius of radius ratio spiral radiation body is thin.

4. the helical antenna according to claim 1 with coupled structure, it is characterised in that: the outer of the feed port is led Body connects with the metal layer of bottom plate, and inner conductor passes through bottom plate and connects with the bottom end of spiral radiation body.

5. the helical antenna according to claim 1 with coupled structure, it is characterised in that: the supporter is cylinder Shape.