CN102769183B - Quadruple spiral distribution loading oscillator microstrip antenna applied to Beidou system - Google Patents

Abstract

The invention discloses a four-helix distributed loading vibrator microstrip antenna applied to the Beidou system, and relates to a microstrip patch antenna. Provide a four-helix distributed-loaded vibrator microstrip antenna mainly used in the Beidou system, which not only has low return loss, low interference, high gain, symmetry and integration, miniaturization, but also has directional radiation characteristics and is applied to the Beidou system A four-helix distributed-loaded dipole microstrip antenna. There is a substrate, copper is covered on both sides of the substrate, and the upper surface of the substrate is provided with a four-helical vibrator arm structure. The electric hole, the four-helical vibrator arm structure wraps around 720° to the center of each side; the lower surface of the substrate is a grounding plate, the grounding plate is connected to the outer core of the feeding copper axis, and the loading hole is connected to the inner core of the feeding copper axis .

Description

Four-helix distributed-loaded oscillator microstrip antenna applied to Beidou system

technical field

The invention relates to a microstrip patch antenna, in particular to a microstrip antenna with four helical distributed loading dipoles applied to the Beidou system.

Background technique

Since 2000, China has successfully launched 4 Beidou-1 navigation and positioning satellites and 10 Beidou-2 navigation and positioning satellites. As an indispensable part of the satellite communication system, the antenna directly determines the performance of the satellite communication system. my country's Beidou-2 satellite communication system works in the B1 and B3 frequency bands, the uplink (transmission frequency) L frequency band and the downlink (reception frequency) S frequency band. Dual-frequency or multi-frequency is usually used to compensate the delay caused by ionospheric propagation, which requires the antenna to have good working performance on each frequency. In addition, since satellite communication signals are circularly polarized waves, the antenna should exhibit circular polarization. With the rapid development of information technology today, with the wide application of satellite communication systems, research on receiving antennas for satellite communication systems emerges in an endless stream, such as monopole, dipole, helical, quadrilateral helical and microstrip antenna structures, all of which are It can be used in various antennas of satellite communication systems. The traditional microstrip antenna has the advantages of low profile, small size, light weight, conformal, easy integration, flexible feeding mode, and easy to obtain linear polarization and circular polarization. It has been used in mobile communication, satellite communication, and missile telemetry. , Doppler radar and many other fields have been widely used, but the limited gain has always been a defect of the microstrip antenna. With the continuous development of digital communication technology, wireless network is no longer just a means for computers to connect to the Internet. Its advantages of wireless mobility bring people a more comprehensive, novel, fast and cheap way of communication.

Microstrip antenna is a new type of antenna gradually developed in the past 30 years. It has been widely used because of its inherent advantages, but it also has disadvantages such as small gain, poor directivity, existence of surface waves, and insufficient bandwidth. So in-depth research on microstrip antennas has very important engineering value and theoretical significance. Loading coupling cavity technology in microstrip antenna design is a commonly used method to realize miniaturization in antenna engineering. By loading resistance, reactance or conductor at the appropriate position of the antenna to improve the current distribution in the antenna, so as to change the resonant frequency of the antenna, Or reduce the height of the antenna and change the radiation pattern of the antenna under the same operating frequency. The loaded components can be passive devices or active networks, linear components or nonlinear, the most commonly used in practical engineering is passive loading, such as top loading, medium loading, series distributed loading, concentrated loading, etc. . Concentrated loading is often used when the working frequency is not high, and distributed loading is used when the working frequency is high, so the loading technology is the most effective way to realize the miniaturization of the antenna. The invention has an array of holes in the appropriate position of the antenna radiation sheet to form a distributed loading structure, which effectively improves the distribution of the feeding current, thereby obtaining a good radiation pattern of the antenna. And a novel and improved four-helix structure is used, which actually constitutes an array antenna, which increases its gain and optimizes its directivity.

Contents of the invention

The purpose of the present invention is to provide a four-helix distributed-loaded vibrator microstrip antenna mainly used in the Beidou system, which not only has low return loss, low interference, high gain, symmetry and integration, miniaturization, but also has directional radiation characteristics A four-helix distributed-loaded oscillator microstrip antenna applied to the Beidou system.

The present invention is provided with a substrate, copper is covered on both sides of the substrate, and the upper surface of the substrate is provided with a four-helical vibrator arm structure, and each side of the four-helical vibrator arm structure is wound to form a helical vibrator, and a loading hole is provided in the helical vibrator and the feed hole, the four-helical vibrator arm structure wraps around 720° to the center of each side; the lower surface of the substrate is a ground plate, the ground plate is connected to the outer core of the feed copper axis, and the loading hole is connected to the inner core of the feed copper axis The cores are connected.

The substrate can be a double-sided copper-plated ceramic dielectric substrate, the length of the substrate can be 40mm, the width can be 40mm, and the height can be 3mm.

The loading hole may be a loading round hole, the diameter of the round hole may be 1.5mm±0.05mm, and the distance between the round holes may be 2mm±0.05mm.

The feeding hole may be a hollow cylinder, the radius of the hollow cylinder may be 1mm±0.05mm, the height of the hollow cylinder may be 3mm±0.05mm, and the hollow cylinder passes through the substrate.

Compared with conventional microstrip antennas, the present invention has the following advantages:

The invention uses a high-performance new helical vibrator with a four-helix structure, and uses distributed loading technology on the radiation element. Through the comprehensive optimization of a series of technologies, the further miniaturization of the antenna is realized, which can well meet the requirements of the Beidou satellite communication system .

Due to the adoption of the above structure, the control of the radiation pattern of the antenna is realized, so that the present invention has the characteristic of directional radiation and obtains higher gain.

Due to the feeding in the form of copper axis offset feeding, this feeding form makes the S11 of the antenna lower and the gain increased.

Since the grounding plate is arranged under the high dielectric constant substrate, the mirror image oscillator of the novel quadruple helical oscillator of the present invention can be generated to enhance radiation, and the coupling electromagnetic parameters of distributed loading can be adjusted, which has a coupling parameter multiplication effect.

Due to the adoption of the above structure, the size of the circular loading coupling cavity and the position of the feeding point on the radiation surface of the good conductor can be rationally optimized, and the frequency band of the Beidou satellite communication system can be covered as needed to achieve excellent electromagnetic characteristics.

In summary, the present invention has excellent comprehensive characteristics such as high symmetry, high integration, miniaturization, good radiation characteristics, and high gain, and is low in cost and easy to integrate, which can meet the basic requirements of the Beidou satellite communication system for antennas.

Utilizing the comprehensive optimization of the structure of the present invention, segmented helical folding and coupling are beneficial to triggering multiple frequency points. At the same time, combined with the distributed loading technology, different frequencies of Beidou can be covered under the premise of miniaturization, and it can be flexibly and conveniently locked to the Beidou series according to requirements. In the satellite positioning system and GPS system, it is also expected to be compatible with other communication frequency bands.

Description of drawings

FIG. 1 is a schematic structural diagram of a four-helix distributed-loaded dipole microstrip antenna applied to the BeiDou system according to an embodiment of the present invention.

Fig. 2 is a return loss (S11) performance diagram of an embodiment of the present invention. The abscissa represents the frequency Frequency (GHz), and the ordinate represents the return loss strength The return loss of the antenna (dB). The coordinates in the figure are rectangular coordinates.

FIG. 3 is an E-plane pattern at a frequency point of 2.495 GHz according to an embodiment of the present invention. The coordinates in the figure are polar coordinates.

FIG. 4 is an H-plane pattern at a frequency point of 2.495 GHz according to an embodiment of the present invention. The coordinates in the figure are polar coordinates.

FIG. 5 is a 3D radiation pattern at a frequency point of 2.495 GHz according to an embodiment of the present invention. The coordinates in the figure are polar coordinates.

Detailed ways

The present invention will be further described below in conjunction with embodiment and accompanying drawing.

Referring to Fig. 1, the embodiment of the present invention is provided with a substrate 1, and copper is coated on both sides of the substrate 1. The upper surface of the substrate 1 is provided with a four-helical vibrator arm structure, and each side of the four-helical vibrator arm structure is wound to form a helical vibrator. , a loading hole 2 and a feeding hole 3 are provided in the helical vibrator, and the four-helical vibrator arm structure is wound around the center of each side by 720°; the lower surface of the substrate 1 is a grounding plate, and the outer surface of the grounding plate and the feeding copper axis The core is connected, and the loading hole 2 is connected with the inner core of the feed copper axis.

The substrate 1 is a double-sided copper-plated ceramic dielectric substrate, and the length of the substrate is 40mm, the width is 40mm, and the height is 3mm.

The loading hole 2 is a loading round hole, the diameter of the round hole is 1.5mm±0.05mm, and the distance between the round holes is 2mm±0.05mm.

The feed hole 3 is a hollow cylinder with a radius of 1 mm±0.05 mm and a height of 3 mm±0.05 mm, and the hollow cylinder passes through the substrate 1 .

Referring to Fig. 2, it can be seen from Fig. 2 that the working frequency band of the present invention is 2.481-2.510 GHz. The return loss (S11) of the antenna in this working frequency band is below 10dB, and the minimum return loss at 2.495GHz is 29.2dB, indicating that the return loss performance of the antenna in the entire passband can meet the required indicators. The absolute bandwidth and relative bandwidth of the present invention at 2.495GHz are 0.029G and 1.16% respectively, and the bandwidth is relatively narrow, but the performance is stable and can directional radiation, so it can be well applied in the Beidou satellite communication system.

Referring to Figures 3 to 5, Figure 3 is the E-plane pattern of the 2.495GHz frequency point, Figure 4 is the H-plane pattern of the 2.495GHz frequency point, and Figure 5 is the 3D pattern of the 2.495GHz frequency point. It can be seen from the figure that the invention has directional radiation characteristics and can meet the requirements of the Beidou satellite and WIFI system. The gain of the antenna at the 2.495GHz frequency point is 5.697dB, and the radiation performance is superior.

See Table 1 for the influence of manufacturing processing errors on antenna characteristics in the embodiments of the present invention.

Table 1

Note: The data in the table has certain redundancy, and there is a certain correlation between the parameters, and the balance characteristics are given.

Can be specially designed according to requirements.

The manufacturing and processing errors of the present invention have a great influence on the parameters of the antenna, requiring a very fine manufacturing process. For example, when the size of the patch, the width of the gap, the distance between the gap and each side, the size of the ceramic dielectric substrate, the thickness of the metal-coated good conductor layer of the dielectric plate, and the position of the feed point are controlled within 0.01%, and the ceramic dielectric substrate When the relative permittivity error of the antenna is controlled within 0.1%, the parameters of the antenna do not change much.

The embodiment of the present invention provides a microstrip antenna with four helical distributed loading dipoles applied to the Beidou system. The embodiment of the present invention provides an antenna whose application frequency band is 2.495 GHz Beidou system. Embodiments The high-performance dielectric substrate material can use high-quality materials with a high dielectric constant of 6 to 30 as the substrate, and a typical value can be a composite ceramic with a relative dielectric constant of 10. The side length of the ceramic dielectric board is 30 to 50 mm, and the thickness is 2 to 30 mm. 4mm, the typical value is a cuboid of 40mm×40mm×3mm.

In the present invention, metal good conductors, such as copper or silver, are coated on both surfaces of the ceramic dielectric substrate. The good conductor on its upper surface is processed into an improved four-helix distribution structure, and each side of the structure is wound in a helical form to extend the effective radiation side, and the typical value is 720° to the center of each side. There are loading circular holes evenly distributed on the radiation patch, the radius of the circular small holes is 0.80~1.60mm, and the distance between the circular holes is 1.8~2.2mm. The feeding point is located on a certain radial outer arm, the horizontal distance relative to the center point is 6.5~7.0mm, and the vertical distance relative to the center point is 6.9~7.1mm; the distance between the wide side and the boundary of the rectangular dielectric substrate is 1.5mm ~3mm. The frequency position and gain can be flexibly controlled directly by adjusting the position of the feed point and the size of each circular hole. The ground plane under the high-performance high-permittivity substrate generates image radiation and image coupling of the new structured antenna, thereby optimally controlling the radiation characteristics.

Claims (5)

1. four Spiral distributions being applied to dipper system load oscillator microstrip antenna, it is characterized in that being provided with substrate, copper is covered with on the two sides of substrate, the upper surface of substrate is provided with four helicon arm configurations, each limit form of unrolling of described four helicon arm configurations forms helicon, in helicon, be provided with loading hole and power feed hole, described four helicon arm configurations unroll 720 ° to the center on each limit; The lower surface of substrate is ground plate, and ground plate is connected with the outer core of feedback copper axis, and the radiation arm with loading hole is connected with the inner core of feeding coaxial lines by power feed hole.

2. four Spiral distributions being applied to dipper system as claimed in claim 1 load oscillator microstrip antenna, it is characterized in that described substrate adopts two-sided copper facing ceramic dielectric substrate.

3. four Spiral distributions being applied to dipper system as claimed in claim 1 or 2 load oscillator microstrip antenna, and it is characterized in that the length of described substrate is 40mm, wide is 40mm, and height is 3mm.

4. four Spiral distributions being applied to dipper system as claimed in claim 1 load oscillator microstrip antenna, and it is characterized in that described loading hole adopts and load circular hole, the diameter of circular hole is 1.5mm ± 0.05mm, and circular hole distance is each other 2mm ± 0.05mm.

5. four Spiral distributions being applied to dipper system as claimed in claim 1 load oscillator microstrip antenna, it is characterized in that described power feed hole adopts hollow cylinder, the radius of hollow cylinder is 1mm ± 0.05mm, and the height of hollow cylinder is 3mm ± 0.05mm, and described hollow cylinder is through substrate.