CN103682651B - A kind of miniaturization broad beam microstrip antenna - Google Patents

Abstract

The invention discloses a miniaturized wide-beam circularly polarized antenna, which is characterized in that the circularly polarized antenna includes a microstrip patch antenna, a dielectric cone and a metal cylinder, and the dielectric cone is arranged on the microstrip On the upper surface of the patch antenna, the metal cylinder is embedded inside the dielectric cone. Compared with other wide-beam circularly polarized microstrip antennas, the antenna proposed by the invention has compact structure, low profile and excellent wide-beam radiation characteristics. The invention and its design principle can be directly used in the terminal user machine and miniaturization design of the satellite navigation system.

Description

A Miniaturized Wide Beam Microstrip Antenna

technical field

The invention relates to the technical field of antennas, in particular to a miniaturized, wide-beam high-performance navigation antenna design, which is mainly used for ground user equipment of satellite navigation systems and the like.

Background technique

The satellite navigation and positioning system has the advantages of being less affected by external conditions such as day and night, seasons, and weather conditions, and has the advantages of high navigation and positioning accuracy, fast positioning speed, and high reliability. Satellite navigation and positioning technology has basically replaced traditional radio navigation technology, and together with mobile communication and the Internet, it has become the three fastest-growing information industries in the world. At present, the main satellite navigation systems include the GPS system of the United States, the GLONASS system of Russia, the GALILEO system of Europe, and the Beidou system of China.

The antenna is one of the most critical components of the application equipment of the satellite navigation and positioning system. When the terminal navigation equipment is working, it needs to receive the navigation signals of multiple satellites through the antenna, and the positioning and navigation functions can be completed through software calculation. However, when the satellite signal reaches the ground, the signal is very weak. In order to receive more satellite signals and obtain a better signal-to-noise ratio, the terminal antenna beam is required to cover the entire upper half space and have a uniform amplitude for the satellite signal. response, i.e. its pattern has wide beam characteristics.

The common forms of wide-beam circularly polarized antennas mainly include microstrip antennas, cross-symmetric dipole antennas, dual-arm and quadruple-arm helical antennas, etc. The microstrip antenna is an antenna formed by attaching a conductive sheet to a dielectric substrate with a metal ground plane. Common microstrip antenna circular polarization methods are single-feed method, multi-feed method and multi-element method. Microstrip antenna has the characteristics of low profile, easy integration and conformal, light weight, easy to achieve circular polarization and bipolar, dual-frequency or multi-frequency operation, etc., and has been widely used in handheld, vehicle-mounted and other terminal equipment.

In order to further widen the beamwidth of the microstrip antenna, Ka Ming Mak, Kwai Man Luk et al. wrote in the document "A Circularly Polarized Antenna With Wide Axial Ratio Beam width" (IEEETRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL.57, NO.10, 2009, pp .3309-3312) designed a wide-beam circularly polarized antenna by using a symmetrical vibrator composed of two butterfly-shaped patches and combining Wilkinson power dividers with equal amplitude and 90° phase difference feed.

On the other hand, C.-W.Su, S.-K.Huang and C.-H.Lee etc. in the literature "CP microstrip antenna with wide beamwidth for GPS band application" (ELECTRONICS LETTERS, Vol.43, No.20 , 2007, pp.) added a metal wall structure to the edge of the microstrip antenna, and used the floor of the pyramid structure to realize a wide-beam circularly polarized antenna.

However, the proposed wide-beam circularly polarized microstrip antennas, crossed dipole antennas, and quadrifilar helical antennas and other wide-beam circularly polarized antennas have complex structures and large volumes, which are not conducive to the miniaturization of equipment.

Contents of the invention

In view of the deficiencies in the prior art, the purpose of the present invention is to solve the problem that the low-elevation angle circular polarization gain of typical circularly polarized microstrip antennas is low, and proposes a miniaturized, low-profile circularly polarized microstrip antenna, which improves the radiation characteristics At the same time, the structural volume of the antenna is reduced, thereby improving the performance of the terminal user equipment of the satellite navigation system, and helping to realize the miniaturization of the equipment.

It should be noted that the rectangular microstrip antenna is composed of a radiation patch on the dielectric substrate and a conductive ground plate on the back of the dielectric substrate. The radiation of the microstrip antenna is generated by the fringing field between the edge of the microstrip antenna conductor patch and the ground. Microstrip antennas have the advantages of low profile, small size, and easy processing. Microstrip antennas are used to achieve circular polarization and multi-band applications. The key to the circular polarization of the microstrip antenna is to generate two linearly polarized waves with orthogonal polarization directions, equal amplitude, and 90° phase difference. The circular polarization of the antenna can be realized by means of microstrip patch shape perturbation, slot loading, multi-feed combination and other technical means.

However, for the navigation antenna used in the ground application equipment of the Beidou satellite navigation system, the classic microstrip antenna not only has a narrow frequency band, but the beam width still cannot meet the requirements, and the beam width needs to be further widened.

Therefore, the antenna proposed in the present invention uses a classic circularly polarized microstrip antenna to generate circularly polarized waves, and covers a dielectric cone frustum on the antenna, and uses a special dielectric structure to widen the beam width of the antenna. Moreover, in order to further widen the beam width of the antenna, several metal cylinders are embedded inside the dielectric cone on this basis.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A miniaturized wide-beam circularly polarized antenna, the circularly polarized antenna includes a microstrip patch antenna, a dielectric cone and a metal cylinder, and the dielectric cone is arranged on the upper surface of the microstrip patch antenna.

It should be noted that the microstrip patch antenna includes a dielectric substrate, a radiation patch, a floor and a coaxial radio frequency connector, the floor is arranged on the lower surface of the dielectric substrate; the radiation patch is arranged on the dielectric substantially on the surface, and located within the dielectric frustum; the core wire of the coaxial radio frequency connector passes through the dielectric substrate and is welded to the radiation patch, and the outer skin of the coaxial radio frequency connector is welded to the The floor is welded.

It should be further explained that the center of the bottom of the dielectric frustum is coincident with the center of the radiation patch.

It should be further explained that several metal cylinders are arranged in the medium frustum.

It should be further explained that the plurality of metal cylinders are uniformly arranged in a circular symmetry and their centers are coaxial with the center of the medium frustum.

As a preferred solution, the shape of the radiation patch is a regular geometric shape such as a rectangular patch, a circular patch, or a triangular patch.

As a preferred solution, the cross-sections of the top and bottom of the medium frustum are circular.

The invention has the beneficial effects that, compared with the existing wide-beam antenna, the structure is simple and compact, and the section is low, and the wide-beam characteristic of the antenna is realized by using a dielectric cone and a metal cylinder to load, and the engineering application prospect is broad.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Fig. 2 is a schematic structural diagram of the microstrip patch antenna in Fig. 1, wherein a is a top view, and b is a bottom view;

Fig. 3 is a schematic diagram of the structure of the medium frustum in Fig. 1, wherein a is a top view, and b is a bottom view;

Fig. 4 is a schematic diagram of antenna gain directions proposed by the present invention.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings. It should be noted that this embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

As shown in FIG. 1 , the present invention is a miniaturized wide-beam microstrip antenna, including the microstrip patch antenna 1 , a dielectric frustum 2 and a metal cylinder 3 . The dielectric frustum 2 is arranged on the surface of the microstrip patch antenna 1; the radiation patch 12 is also provided on the surface of the microstrip patch antenna 1, and the center of the radiation patch 12 is connected to the The centers of the bottoms of the media frustum 2 coincide. As a preferred solution, the microstrip patch antenna 1 and the dielectric frustum 2 can be bonded by screws or glue.

It should be noted that, when the dielectric frustum 2 does not exist, the electromagnetic wave radiated by the microstrip patch antenna 1 will propagate in a straight line, forming a typical radiation pattern.

In the present invention, the electromagnetic wave radiated by the microstrip patch antenna 1 will pass through the dielectric frustum 2, so the electromagnetic wave propagation direction changes, and further, change the structural parameters in the dielectric frustum 2, such as the frustum of the dielectric Volume, slope, etc., can make the antenna pattern change. By properly adjusting the structural parameters, the beam width of the pattern can be broadened. In order to further widen the beam width of the antenna, the metal cylinder 3 can be embedded inside the dielectric frustum 2 .

It should be further explained that, the metal cylinders 3 are circularly symmetrical and evenly distributed based on the center of the radiation patch 12 . The metal cylinder 3 is a metal wire with a certain thickness. The thickness and length of the metal wire will affect the beam width of the antenna. The structural parameters of the metal cylinder 3 can be appropriately selected according to the working frequency. During actual assembly, an upper circular section in the medium frustum 2 can be uniformly drilled with symmetry to the central circle, the diameter of the hole is the same as the thickness of the metal cylinder 3, and then the metal cylinder 3 is inserted Corresponding hole, so as to achieve fixation. Further, in order to prevent the metal cylinder 3 from shaking, while ensuring the accuracy of the hole drilled on the medium frustum 2, glue is applied before the metal cylinder 3 is inserted into the corresponding hole.

As shown in FIGS. 2 a and 2 b , the microstrip patch antenna 1 includes a dielectric substrate 11 , a radiation patch 12 , a floor 13 and a coaxial radio frequency connector 14 . The dielectric substrate 11 has a certain thickness, and an appropriate size can be selected according to the bandwidth and physical size requirements of the antenna. The radiation patch 12 is a square patch with cut corners, and the radiation patch 12 can adopt different shapes according to different circularly polarized microstrip antenna schemes, such as: rectangle, circle, triangle and so on. The power feeding of the present invention is realized through the coaxial radio frequency connector 14, the core wire of the coaxial radio frequency connector 14 passes through the dielectric substrate 11 and is welded on the radiation patch 12, and the coaxial radio frequency The outer skin of the connector 14 is welded together with the floor 13 .

As shown in Figures 3a and 3b, the medium frustum 2 presents a structure with a thin top and a thick bottom, and the upper and lower sections are circular. Based on the center of the upper circular section, on a circle with a certain radius (variable according to the antenna operating frequency and wave velocity width requirements), drill circularly symmetrical and evenly distributed holes, and insert the metal cylinder 3 into the corresponding hole Inside, the size and depth of the holes can vary with the size of the metal cylinder 3 . The structural size of the dielectric frustum 2, such as the size and height of the upper and lower sections, can be changed according to the operating frequency and beam width requirements of the antenna.

As shown in Fig. 4a and Fig. 4b, the measured antennas of the 0° and 90° cut planes (the line formed by the center of the radiation patch and the coaxial RF connector in Fig. 2a as the starting point and rotated counterclockwise) are given respectively. Circular polarization gain pattern, the solid line on the figure is the circular polarization gain pattern of the present invention, and the dotted line is the circular polarization gain pattern of the classic circularly polarized microstrip antenna, as can be seen from Fig. 4a, the 0 ° cut plane of the present invention The 3dB beamwidth is about 143°, the 3dB beamwidth of the classic circularly polarized microstrip antenna is about 72°, and the 3dB beamwidth of the present invention is about 142° for the 90° cut plane as seen in Fig. The beam width is about 72°, and the beam width of the invention is much larger than that of the classic circularly polarized microstrip antenna.

The above examples are only to illustrate the technical concept and characteristics of the present invention, and are only used to describe the present invention in detail, so that those familiar with the technology can understand the content of the present invention and implement it accordingly, and cannot limit the protection of the present invention. scope. All equivalent changes or modifications made according to the contents of the present invention shall fall within the protection scope of the present invention.

Claims (4)

1. A kind of miniaturization wide-beam circularly polarized antenna, described circularly polarized antenna comprises microstrip patch antenna and dielectric cone frustum, and described dielectric cone frustum is arranged on the surface of described microstrip patch antenna, and described dielectric cone A plurality of metal cylinders are arranged in the platform, and it is characterized in that holes are uniformly arranged with an upper circular section in the medium frustum as the center circle, and the diameter of the holes is the same as the thickness of the metal cylinder, and the metal The cylinder is inserted into the corresponding hole; The microstrip patch antenna includes a dielectric substrate, a radiation patch, a floor and a coaxial radio frequency connector, the floor is arranged on the lower surface of the dielectric substrate; the radiation patch is arranged on the upper surface of the dielectric substrate, and Located within the dielectric cone; the core wire of the coaxial radio frequency connector passes through the dielectric substrate and is welded to the radiation patch, and the outer skin of the coaxial radio frequency connector is welded to the floor; The center of the bottom of the dielectric frustum coincides with the center of the radiation patch. 2 . The miniaturized wide-beam circularly polarized antenna according to claim 1 , wherein the plurality of metal cylinders are uniformly arranged in a circular symmetry and their centers are coaxial with the center of the dielectric frustum. 3 . 3. The miniaturized wide-beam circularly polarized antenna according to claim 1, wherein the shape of the radiation patch can be a rectangular patch, a circular patch, or a regular geometric shape of a triangular patch. 4. The miniaturized wide-beam circularly polarized antenna according to claim 2, wherein the top and bottom sections of the dielectric frustum are circular.