CN114583439A

CN114583439A - Conical helical antenna

Info

Publication number: CN114583439A
Application number: CN202210231342.9A
Authority: CN
Inventors: 刘斌辉; 赵凯; 陈超英
Original assignee: China Electronic Product Reliability and Environmental Testing Research Institute
Current assignee: China Electronic Product Reliability and Environmental Testing Research Institute
Priority date: 2022-03-09
Filing date: 2022-03-09
Publication date: 2022-06-03

Abstract

The invention relates to a conical helical antenna, comprising: the spiral double arm, the balun, the feed piece and the connector. The spiral double-arm comprises a first spiral line section and a second spiral line section connected with the first spiral line section, and the cone angle of the first spiral line section is smaller than that of the second spiral line section. The balun is arranged in a surrounding area of the spiral double arms, the top end of the balun is connected with one end, far away from the second spiral line section, of the first spiral line section through the feeding piece, and the bottom end of the balun is connected with the connector. On one hand, the conical helical antenna has the advantages that the radiation arm adopts a structural form of a helical double arm, so that the bandwidth of the antenna can be ensured to be wider; on the other hand, because the cone angle of the first spiral line section is smaller than that of the second spiral line section, the antenna can be ensured to have good directional radiation performance in a frequency band, and has good circular polarization characteristic.

Description

Conical helical antenna

Technical Field

The invention relates to the technical field of antennas, in particular to a conical helical antenna.

Background

With the development of electronic information technology, the requirements for antenna characteristics such as small size, light weight, wide frequency band, wide beam, circular polarization and the like are increasingly urgent. At present, the circularly polarized wide beam antenna mainly adopts antenna forms such as a microstrip antenna, a conical helical antenna and the like. Microstrip antenna has the advantages of simple structure and low section, and usually uses high dielectric constant printed board to reduce the size of antenna and meet the requirement of wide beam, but this will also cause the loss of antenna to increase and the efficiency to decrease. When the conical helical antenna, also called a conical logarithmic helical antenna, is used as a wide-beam antenna, it usually adopts the form of a quadrifilar helical antenna or a bifilar helical antenna, and is widely applied in the fields of communication, electronic countermeasure, radar detection, electromagnetic compatibility measurement, and the like.

The radiation direction of the conical helical antenna mainly faces the top end direction of the cone, the effective radiation area of the conical helical antenna is basically in an area with the circumference of about one wavelength, when the frequency changes, the effective radiation area moves back and forth along the axial direction, when the frequency is high, the effective radiation area moves towards the cone top direction, and when the frequency is low, the effective radiation area moves towards the cone bottom direction, so that the working bandwidth of the antenna is mainly controlled by the diameters of the cone top and the cone bottom. The conical logarithmic spiral antenna is equivalent to winding a logarithmic spiral on a cone, and the gain and the directional diagram of the conical spiral antenna are mainly determined by the cone angle and the spiral wrap angle. However, the conventional conical helical antenna has a drawback of poor directional radiation performance when the bandwidth is wide.

Disclosure of Invention

In view of the foregoing, there is a need to overcome the drawbacks of the prior art and to provide a conical helical antenna that can maintain good directional radiation characteristics over a wide frequency band.

The technical scheme is as follows: a conical helical antenna, comprising:

the double-arm spiral comprises a first spiral line section and a second spiral line section connected with the first spiral line section, and the cone angle of the first spiral line section is smaller than that of the second spiral line section;

the balun is arranged in a surrounding area of the two spiral arms, the top end of the balun is connected with one end, far away from the second spiral line section, of the first spiral line section through the feeding piece, and the bottom end of the balun is connected with the connector.

On one hand, the conical helical antenna can ensure that the bandwidth of the antenna is wider because the radiation arm adopts a structural form of a helical double arm; on the other hand, because the cone angle of the first spiral line section is smaller than that of the second spiral line section, the antenna can be ensured to have good directional radiation performance in a frequency band, and has good circular polarization characteristic.

In one embodiment, the distance between the two ends of the first spiral line segment along the central axis of the spiral double arm is defined as L1, and L1 is 40mm-70 mm; the distance between the two ends of the second spiral line segment along the central axis of the spiral double arm is defined as L2, and L2 is 330mm-360 mm. Therefore, the antenna has good directional radiation performance in a wide frequency band and good circular polarization characteristic.

In one embodiment, L1 is 45mm-55 mm; l2 is 345mm-355 mm. Therefore, the antenna has good directional radiation performance in a wide frequency band and good circular polarization characteristic.

In one embodiment, the maximum value of the operating wavelength of the conical helical antenna is defined as M, and the minimum value of the operating wavelength is defined as N; the diameter of the end of the first spiral segment remote from the second spiral segment is defined as D1, D1 is 0.2N-0.3N; the diameter of the end of the second spiral segment remote from the first spiral segment is defined as D2, D2 is 0.3M-0.45M. Thus, the antenna can have a wider operating bandwidth.

In one embodiment, D1 is 0.25N; d2 was 0.375M.

In one embodiment, the taper angle of the first helical segment is 12 ° to 16 °, and the taper angle of the second helical segment is 26 ° to 30 °.

In one embodiment, the balun is a plate, the width of the balun is defined as W, the width W gradually decreases along the direction from one end of the balun to the other end, the end with the larger width W of the balun is connected with the connector, and the end with the smaller diameter of the balun is connected with the feeding piece; or, the balun is in a conical shape, the end of the balun with the larger diameter is connected with the connector, and the end of the balun with the smaller diameter is connected with the feeding piece. Thus, the antenna is ensured to have good standing wave ratio in a frequency band range of 0.6GHz-11 GHz.

In one embodiment, the conical helical antenna further comprises a housing, and the helical arms are fixedly disposed on an outer surface of the housing. Thus, the shell plays a protective role, prevents the two spiral arms from being damaged, and can play a role in supporting and fixing the two spiral arms.

In one embodiment, a wire groove adapted to the spiral double arm is formed on the outer surface of the housing, and the spiral double arm is fixedly arranged in the wire groove. Therefore, the wire groove has a fixing effect on the two spiral arms, and the two spiral arms can be stably fixed on the outer surface of the shell, so that the two spiral arms are prevented from moving on the outer surface of the shell, the installation stability is good, and the reliability of the performance of the antenna is guaranteed.

In one embodiment, the housing is tapered and comprises a first shell and a second shell connected to each other, the first shell being adapted to the first helical wire section fixedly disposed on the first shell outer surface; the second shell is adapted with the second helical wire section, which is fixedly arranged on the outer surface of the second shell. Thus, the spiral double arm can be stably fixed on the outer surface of the shell, and the spiral double arm is prevented from moving on the outer surface of the shell.

In one embodiment, the conical helical antenna further comprises a fixing member fixedly disposed inside the housing, and the balun and/or the connector are fixedly disposed on the fixing member. Therefore, the balun is supported and fixed through the fixing piece, and the mounting stability of the balun is good.

In one embodiment, a clamping groove is formed in the fixing piece, and the end portion of the balun is clamped and fixed in the clamping groove. So, through fixing the balun joint ground and installing on the mounting, the installation effectiveness is higher.

In one embodiment, the fixing piece and the shell are of an integrated structure; the fixing piece and the shell are insulating pieces.

In one embodiment, the conical helical antenna further comprises a chassis, the housing is connected to the chassis, and the connector is fixedly disposed on the chassis.

In one embodiment, at least one fixing block is arranged at the end part of the shell, and the fixing block is fixedly connected with the chassis. Therefore, the fixing block is positioned at the end part of the shell, the wall thickness of the shell is increased, and the fixing block can be stably combined with the chassis when being connected with the chassis.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention.

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic cross-sectional view of a conical helical antenna according to an embodiment of the present invention with a housing hidden;

fig. 2 is a schematic structural diagram of a conical helical antenna according to an embodiment of the present invention;

FIG. 3 is a schematic top view of the housing shown in FIG. 2 with the housing hidden;

FIG. 4 is a schematic structural diagram of the bottom of the housing according to an embodiment of the present invention;

FIG. 5 is a diagram illustrating simulation results of standing-wave ratio of a conical helical antenna according to an embodiment of the present invention;

FIG. 6 is a directional diagram of a conical helical antenna at 1.5GHz according to an embodiment of the invention;

FIG. 7 is a directional diagram of a 4.5GHz conical helical antenna according to an embodiment of the invention;

FIG. 8 is a directional diagram of a conical helical antenna at 8.5GHz according to an embodiment of the present invention;

fig. 9 shows a 10.5GHz pattern of a conical helical antenna according to an embodiment of the present invention.

10. A spiral double arm; 11. a first helical line segment; 12. a second spiral line segment; 13. an enclosed area; 20. a balun; 30. a feeding member; 40. a connector; 50. a housing; 51. a first shell; 52. a second shell; 53. a fixed block; 60. a fixing member; 61. a card slot; 70. a chassis.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Referring to fig. 1 to 3, fig. 1 is a schematic cross-sectional view illustrating a conical helical antenna according to an embodiment of the present invention with a housing hidden, fig. 2 is a schematic structural view illustrating a conical helical antenna according to an embodiment of the present invention, and fig. 3 is a schematic top-view structural view illustrating a housing 50 hidden in the structure shown in fig. 2. An embodiment of the present invention provides a conical helical antenna, including: double spiral arm 10, balun 20, feed 30 and connector 40. The spiral double arm 10 comprises a first spiral segment 11 and a second spiral segment 12 connected to the first spiral segment 11. The taper angle of the first helical segment 11 is smaller than the taper angle of the second helical segment 12. The balun 20 is disposed in the enclosing region 13 of the dual-spiral arm 10, the top end of the balun 20 is connected to the end of the first spiral segment 11 away from the second spiral segment 12 through the feeding element 30, and the bottom end of the balun 20 is connected to the connector 40.

On one hand, the conical helical antenna adopts the structural form of the helical double-arm 10 as the radiation arm, so that the bandwidth of the antenna can be ensured to be wider; on the other hand, because the cone angle of the first spiral line segment 11 is smaller than that of the second spiral line segment 12, the antenna can be ensured to have good directional radiation performance in a frequency band and better circular polarization characteristics.

It should be noted that the spiral double arms 10 in the present embodiment are conical logarithmic spirals, and not only the pitches are different from each other, but also the wrap angles of the spiral lines at the first spiral line segment 11 and the second spiral line segment 12 are also different.

It should be noted that the "first spiral segment 11" may be a part of the "second spiral segment 12", that is, the "first spiral segment 11" and the "other part of the second spiral segment 12" are integrally formed; or a separate member that is separable from the "other part of the second spiral segment 12", i.e., the "first spiral segment 11" may be manufactured separately and then combined with the "other part of the second spiral segment 12" into a single body.

Referring to fig. 1, in one embodiment, the distance between the two ends of the first spiral line segment 11 along the central axis (indicated by the arrow S in the figure) of the spiral double arm 10 is defined as L1, and L1 is 40mm-70 mm. The distance between the two ends of the second spiral segment 12 along the central axis of the spiral double arm 10 is defined as L2, and L2 is 330mm-360 mm. Therefore, the antenna has good directional radiation performance in a wide frequency band and good circular polarization characteristic.

Referring to fig. 1, in one embodiment, the maximum value of the operating wavelength of the conical helical antenna is defined as M, and the minimum value of the operating wavelength is defined as N; the diameter of the end of the first spiral segment 11 remote from the second spiral segment 12 is defined as D1, D1 is 0.2N-0.3N; the diameter of the end of the second spiral segment 12 remote from the first spiral segment 11 is defined as D2, D2 is 0.3M-0.45M. Thus, the antenna can have a wider operating bandwidth.

In one embodiment, D1 is 0.25N; d2 was 0.375M.

Specifically, D1 is 7mm, 7.2mm, 7.4mm, 7.5mm, 7.6mm, 7.8 mm; d2 is 182mm, 185mm, 188mm, 190mm, 195mm, 200 mm. In this way, the antenna can be guaranteed to operate in a frequency band of, for example, 0.6GHz-11 GHz.

In one embodiment, the taper angle of the first helical segment is 12-16 and the taper angle of the second helical segment is 26-30. Therefore, the antenna can be ensured to have good directional radiation performance and good circular polarization characteristic in a frequency band of 0.6GHz-11 GHz.

Referring to fig. 1, in an embodiment, the balun 20 is a plate, a width of the balun 20 is defined as W, the width W gradually decreases along a direction from one end of the balun 20 to the other end, the end of the balun 20 with the larger width W is connected to the connector 40, and the end of the balun 20 with the smaller diameter is connected to the feeding member 30. Thus, the antenna is ensured to have good standing wave ratio in a frequency band range of 0.6GHz-11 GHz.

As an alternative, the balun 20 may have a tapered shape, the larger diameter end of the balun 20 is connected to the connector 40, and the smaller diameter end of the balun 20 is connected to the feeding element 30.

Referring to fig. 1 and 2, in one embodiment, the conical helical antenna further includes a housing 50. Spiral arms 10 are fixedly disposed on the outer surface of housing 50. In this way, housing 50 serves as a shield to prevent double helix 10 from being damaged, and also serves to support and secure double helix 10.

In one embodiment, a slot (not shown) is formed on the outer surface of the housing 50 to accommodate the spiral double arm 10, and the spiral double arm 10 is fixedly disposed in the slot. Thus, the wire groove has a fixing effect on the spiral double-arm 10, and can stably fix the spiral double-arm 10 on the outer surface of the shell 50, so that the spiral double-arm 10 is prevented from moving on the outer surface of the shell 50, the installation stability is good, and the performance reliability of the antenna is ensured. Specifically, the double-arm 10 can be fixed in the slot in various ways, such as by being snapped into the slot, or by being pressed and positioned in the slot by the self-elasticity of the double-arm 10, or by being fixed in the slot by adhesive, etc.

As an alternative, the spiral double arm 10 may be directly and fixedly installed on the outer surface of the housing 50 in other ways without providing a wire groove on the outer surface of the housing 50, and the specific way is not limited herein, and the arrangement is flexible according to actual requirements.

Referring to fig. 1 and 2, in one embodiment, the housing 50 has a conical shape and includes a first shell 51 and a second shell 52 connected to each other. The first shell 51 is fitted with a first spiral line segment 11, and the first spiral line segment 11 is fixedly provided on the outer surface of the first shell 51. The second shell 52 conforms to the second helical segment 12, with the second helical segment 12 fixedly disposed on the outer surface of the second shell 52. In this way, double-arm 10 can be stably fixed to the outer surface of casing 50, and movement of double-arm 10 on the outer surface of casing 50 can be prevented.

The first shell 51 is fitted to the first spiral line segment 11, which means that the taper angle of the first shell 51 is the same as the taper angle of the first spiral line segment 11, and the length of the first shell 51 in the direction of the central axis thereof is equal to L1 of the first spiral line segment 11, so that the first spiral line segment 11 can be stably attached to and fixed to the outer surface of the first shell 51 when mounted on the outer surface of the first shell 51.

Similarly, the second shell 52 is fitted to the second spiral segment 12, which means that the taper angle of the second shell 52 is the same as the taper angle of the second spiral segment 12, and the length of the second shell 52 in the direction of the central axis thereof is the same as L2 of the second spiral segment 12, so that the second spiral segment 12 can be stably attached to and fixed to the outer surface of the second shell 52 when mounted on the outer surface of the second shell 52.

It should be noted that the "first shell 51" may be a part of the "second shell 52", that is, the "first shell 51" and the "other part of the second shell 52" are integrally formed; or may be a separate member that is separable from the "other portion of the second case 52", i.e., the "first case 51" may be manufactured separately and then integrated with the "other portion of the second case 52".

Referring to fig. 1 and 4 again, fig. 4 is a schematic structural diagram of a bottom portion of a housing 50 according to an embodiment of the invention. In one embodiment, the conical helical antenna further comprises a fixture 60 fixedly disposed inside the housing 50. The balun 20 and/or the connector 40 are fixedly arranged on the fixing member 60. Thus, the balun 20 is supported and fixed by the fixing member 60, and the mounting stability of the balun 20 is good.

Referring to fig. 1 again, in one embodiment, the fixing member 60 is provided with a locking groove 61, and an end portion of the balun 20 is locked and fixed in the locking groove 61. Thus, the balun 20 is fixedly clamped on the fixing member 60, so that the mounting efficiency is high. Of course, the balun 20 may be fixedly mounted on the fixing member 60 by other means, for example, by welding, riveting, or by mounting members such as screws and pins, and the mounting and fixing manner of the balun 20 on the fixing member 60 is not limited herein, and may be flexibly set according to actual requirements.

In one embodiment, the fixture 60 is a unitary structure with the housing 50; the fixing member 60 and the housing 50 are insulating members.

It should be noted that the "fixing member 60" may be a part of the "housing 50", that is, the "fixing member 60" and the other part of the "fixing member 60" are integrally formed; the "fixing member 60" may be made separately from the "other part of the housing 50" and may be integrated with the "other part of the housing 50" as a single body.

Referring back to fig. 1 and 2, in one embodiment, the conical helical antenna further includes a chassis 70. The housing 50 is connected to the chassis 70, and the connector 40 is fixedly provided on the chassis 70.

Referring to fig. 1 and 2 again, in one embodiment, at least one fixing block 53 is disposed on an end of the housing 50, and the fixing block 53 is fixedly connected to the chassis 70. Thus, the fixing block 53 is located at the end of the housing 50, which corresponds to the increase of the wall thickness of the housing 50, and can be stably combined with the chassis 70 when being connected with the chassis 70.

It should be noted that the "fixing block 53" may be a part of the "housing 50", that is, the "fixing block 53" and the "other part of the housing 50" are integrally formed; the "fixing block 53" may be made separately from the "other part of the housing 50" and may be combined with the "other part of the housing 50" as a single body.

It should be noted that the "bottom plate 70" may be a part of the "housing 50", that is, the "bottom plate 70" and the "other part of the" housing 50 "are integrally formed; or a separate member separable from the rest of the housing 50, i.e., the chassis 70 may be manufactured separately and then integrated with the rest of the housing 50.

In one embodiment, the chassis 70, the fixing member 60, the fixing block 53 and the housing 50 are integrally formed, including but not limited to, by means of 3D printing.

In one embodiment, the insulating member includes, but is not limited to, resin, rubber, plastic, wood.

In one embodiment, the spiral double arm 10 includes but is not limited to metal wire and metal sheet, and is flexibly arranged according to actual requirements. When the metal wire is used for the spiral double arm 10, the wire with a relatively small diameter can be selected to meet the requirement, and the diameter can be flexibly set according to the actual requirement without limitation. Similarly, when the spiral double arm 10 is made of metal sheet, it is sufficient to select a thin plate, and the thickness can be flexibly set according to actual requirements, which is not limited herein.

In one embodiment, the metal material used for spiral arms 10 includes, but is not limited to, copper, brass, aluminum foil, steel wire.

In one embodiment, connector 40 includes, but is not limited to, a SAM connector through which electrical signals are transmitted.

In one embodiment, the power feed 30 includes, but is not limited to, a sector plate. Thus, since the width of the top end of the spiral double arm 10 is not equal to the width of the top end of the balun 20, the top end of the balun 20 is transited to the top end of the spiral double arm 10 through the sector plate, so that the impedance matching can be improved. In addition, the number of the feeding elements 30 is two, for example, the number of the baluns 20 is two, one feeding element 30 connects the top end of one of the baluns 20 and the top end of one of the radiating arms of the dual-spiral arm 10, and the other feeding element 30 connects the top end of the other balun 20 and the top end of the other radiating arm of the dual-spiral arm 10.

Referring to fig. 5 to 9 again, fig. 5 is a schematic diagram illustrating simulation results of standing-wave ratio of the conical helical antenna according to an embodiment of the present invention; FIG. 6 shows a 1.5GHz directional pattern for a conical helical antenna in accordance with an embodiment of the invention; FIG. 7 shows a 4.5GHz pattern for a conical helical antenna according to an embodiment of the invention; FIG. 8 shows a pattern of a conical helical antenna at 8.5GHz in accordance with an embodiment of the invention; fig. 9 shows a 10.5GHz pattern for a conical helical antenna according to an embodiment of the invention. It can be concluded from fig. 5 that the antenna of this embodiment has a good standing-wave ratio in the frequency band range of, for example, 0.6GHz-11 GHz. It can be seen from fig. 5 that the standing wave ratios in the frequency range of 0.6-11GHz are all less than 2; the directional pattern forward gain shown in FIG. 6 is 6.5 dBi; FIG. 7 directional diagram forward gain is 8 dBi; the directional pattern forward gain shown in FIG. 8 is 4.7 dBi; the pattern forward gain shown in fig. 9 is 3.2 dBi. It can be concluded from fig. 6 to 9 that the antenna of the present embodiment has satisfactory directivity patterns in the frequency band range of, for example, 0.6GHz to 11 GHz.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is specific and detailed, but not to be understood as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent should be subject to the appended claims.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be interconnected within two elements or in a relationship where two elements interact with each other unless otherwise specifically limited. The specific meanings of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "above," and "over" a second feature may be directly on or obliquely above the second feature, or simply mean that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. As used herein, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are for purposes of illustration only and do not denote a single embodiment.

Claims

1. A conical helical antenna, comprising:

2. A conical helical antenna as claimed in claim 1 wherein the distance between the ends of the first helical segment along the central axis of the helical arms is defined as L1, L1 is 40mm-70 mm; the distance between the two ends of the second spiral line segment along the central axis of the spiral double arm is defined as L2, and L2 is 330mm-360 mm.

3. The conical helical antenna of claim 2, wherein L1 is 45mm-55 mm; l2 is 345mm-355 mm.

4. A conical helical antenna as claimed in claim 1, wherein a maximum value of the operating wavelength of the conical helical antenna is defined as M and a minimum value of the operating wavelength is defined as N; the diameter of the end of the first spiral segment remote from the second spiral segment is defined as D1, D1 is 0.2N-0.3N; the diameter of the end of the second spiral segment remote from the first spiral segment is defined as D2, D2 is 0.3M-0.45M.

5. The conical helical antenna of claim 4, wherein D1 is 0.25N; d2 was 0.375M.

6. A conical helical antenna as in claim 1, wherein the cone angle of the first helical line segment is between 12 ° and 16 ° and the cone angle of the second helical line segment is between 26 ° and 30 °.

7. The conical helical antenna of claim 1, wherein said balun is a plate, a width of said balun is defined as W, the width W gradually decreases from one end of said balun to the other end, the end of said balun with the larger width W is connected to said connector, and the end of said balun with the smaller diameter is connected to said feed; or, the balun is in a conical shape, one end of the balun with the larger diameter is connected with the connector, and one end of the balun with the smaller diameter is connected with the feeding piece.

8. The conical helical antenna of claim 1 further comprising a housing, said helical arms fixedly disposed within said housing.

9. The conical helix antenna of claim 8, wherein the housing has a slot on an outer surface thereof that accommodates the helical arms, and wherein the helical arms are fixedly disposed within the slot.

10. A conical helical antenna as claimed in claim 8, wherein said housing is conical in shape and comprises first and second interconnected shells, said first shell conforming to said first helical wire segment fixedly disposed on said first shell outer surface; the second shell is adapted with the second helical wire section, which is fixedly arranged on the outer surface of the second shell.

11. The conical helical antenna of claim 8, further comprising a fixture fixedly disposed within said housing, said balun and/or said connector being fixedly disposed on said fixture.

12. The conical helical antenna of claim 11, wherein the fixing member is provided with a slot, and an end of the balun is fixed in the slot in a snap fit manner.

13. The conical helical antenna of claim 11, wherein said fixture is a unitary structure with said housing; the fixing piece and the shell are insulating pieces.

14. The conical helical antenna of claim 11 further comprising a chassis, said housing being attached to said chassis, said connector being fixedly disposed on said chassis.

15. The conical helical antenna of claim 14, wherein at least one anchor block is disposed on an end of said housing, said anchor block being fixedly attached to said chassis.