CN114050410A

CN114050410A - Circularly polarized antenna and reference station

Info

Publication number: CN114050410A
Application number: CN202111637762.9A
Authority: CN
Inventors: 张伟伟; 冯维星; 王鹏; 朱良; 谢亚运; 陆超
Original assignee: Shaanxi Haiji Information Technology Co ltd
Current assignee: Shaanxi Haiji Information Technology Co ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2022-02-15

Abstract

The utility model relates to a circular polarization antenna and reference station, broadband merit divides the network to be connected with the feed network electricity, the feed network is connected with main radiation unit coupling electricity, main radiation unit and parasitic radiation unit have the interval of predetermineeing between them, and main radiation unit and parasitic radiation unit coupling electricity are connected, broadband merit divides the network can convert the radio frequency signal received into the four ways sub-signal that satisfies the circular polarization requirement, the feed network can feed in four ways sub-signal into main radiation unit and parasitic radiation unit, like this, main radiation unit produces first resonance point under the excitation of four ways sub-signal, parasitic radiation unit produces the second resonance point under the excitation of four ways sub-signal, the bandwidth that the frequency of this first resonance point and the frequency of second resonance point correspond is greater than or equal to the full frequency band bandwidth of navigation. The antenna can be used not only when receiving satellite signals, but also when transmitting the satellite signals, thereby enriching the use scene of the antenna on the basis of realizing the full-band coverage of satellite navigation.

Description

Circularly polarized antenna and reference station

Technical Field

The application relates to the technical field of antennas, in particular to a circularly polarized antenna and a reference station.

Background

Circular polarization is a main propagation method used in a satellite navigation system, and there is no limitation in the directions of transmission and reception of electromagnetic waves, compared to the linear polarization propagation method. In addition, when the circular polarization propagation method is used, the electromagnetic wave generates a faraday rotation effect in the ionosphere, so that the circular polarization has great importance in satellite navigation in recent years.

In the related art, most of circularly polarized antennas in Satellite Navigation use two microstrip arrays with different frequencies, and the two microstrip arrays with different frequencies are synthesized in an active link through an active combiner, so that the broadband of the antenna can be widened after synthesis, and the full coverage of a Global Navigation Satellite System (GNSS) Satellite Navigation frequency band (1.1-1.7 GHz) is realized.

However, in the related art, when the full-band coverage of satellite navigation is implemented, different frequencies are synthesized by the active combiner, but the active combiner is damaged when the signal power of the antenna is high, so that the antenna can only be used when receiving satellite signals, and the use scenario of the antenna is limited.

Disclosure of Invention

Therefore, it is necessary to provide a circular polarization antenna and a reference station for implementing full-band coverage of satellite navigation, which can be used not only for receiving satellite signals but also for transmitting satellite signals, thereby enriching the use scenarios of the antenna.

In a first aspect, the present application provides a circularly polarized antenna, including a parasitic radiation unit, a main radiation unit, a feed network, and a broadband power division network, which are arranged from top to bottom;

the broadband power distribution network is electrically connected with the feed network, the feed network is electrically connected with the main radiation unit in a coupling mode, a preset interval is formed between the main radiation unit and the parasitic radiation unit, and the main radiation unit is electrically connected with the parasitic radiation unit in a coupling mode;

the broadband power distribution network is used for converting the received radio frequency signals into four paths of sub-signals meeting the circular polarization requirement; the feed network is used for feeding the four paths of sub-signals into the main radiating unit and the parasitic radiating unit;

the main radiation unit is used for generating a first resonance point under the excitation of the four paths of sub-signals, the parasitic radiation unit is used for generating a second resonance point under the excitation of the four paths of sub-signals, and the bandwidth corresponding to the frequency of the first resonance point and the frequency of the second resonance point is larger than or equal to the navigation full-band bandwidth.

In one embodiment, the frequency of the second resonance point is less than the frequency of the first resonance point.

In one embodiment, the vertical height between the main radiating element and the parasitic radiating element is 4 mm.

In one embodiment, the parasitic radiation unit and the main radiation unit are planar structures laid on the printed circuit board.

In one embodiment, the parasitic radiation unit and the main radiation unit are both in a centrosymmetric shape, and the first printed circuit board where the parasitic radiation unit is located and the second printed circuit board where the main radiation unit is located are fixedly connected through a non-metal connector.

In one embodiment, the parasitic radiation unit and the main radiation unit are both in a circular radiation structure, and the diameter of the radiation surface of the parasitic radiation unit is 60 mm; the diameter of the radiating surface of the main radiating element is 70 mm.

In one embodiment, the main radiation unit is a circular radiation structure with at least one hollow structure in the middle.

In one embodiment, the broadband power distribution network comprises 4 feeding points; the feed network has 4 feed components;

the feed network is connected with 4 feed points through 4 feed components and is accessed into the broadband power distribution network.

In one embodiment, the broadband power distribution network is disposed on a third printed circuit board, and the third printed circuit board is disposed below and parallel to the second printed circuit board.

In one embodiment, a feed network is disposed between the third printed circuit board and the second printed circuit board, the feed network including 4 symmetrically disposed feed sub-networks, each feed sub-network including two dielectric support posts and a feed element and a feed assembly disposed between the two dielectric support posts.

In one embodiment, the power feeding unit is a linear structure laid on the fourth printed circuit board;

the vertical height between the fourth printed circuit board and the second printed circuit board is 5 mm.

In one embodiment, the radiating area of the feed element is 18mm in length and 4mm in width.

In one embodiment, the circularly polarized antenna further includes a choke coil disposed on a fifth printed circuit board, the fifth printed circuit board being disposed below the third printed circuit board and being disposed in parallel with the third printed circuit board.

In one embodiment, the circularly polarized antenna further comprises a first antenna cover and a first cylindrical non-metallic side wall, wherein the bottom of the first antenna cover is connected with the top end of the first cylindrical non-metallic side wall to form a first antenna cavity;

the parasitic radiation unit, the main radiation unit, the feed network and the broadband power distribution network are all located in the first antenna cavity.

In one embodiment, the circularly polarized antenna further comprises a second antenna housing and a second cylindrical nonmetal side wall, the second cylindrical nonmetal side wall is sleeved on the periphery of the first cylindrical nonmetal side wall, and the bottom of the second antenna housing is connected with the top end of the second cylindrical nonmetal side wall to form a second antenna cavity.

In a second aspect, the present application also provides a reference station comprising a circularly polarized antenna as provided in any of the embodiments of the first aspect.

According to the circularly polarized antenna and the reference station provided by the embodiment of the application, the broadband power dividing network is electrically connected with the feed network, the feed network is electrically coupled with the main radiation unit, a preset interval is formed between the main radiation unit and the parasitic radiation unit, and the main radiation unit is electrically coupled with the parasitic radiation unit; based on the structure, the broadband power division network can convert the received radio-frequency signals into four paths of sub-signals meeting the circular polarization requirement, the feed network can feed the four paths of sub-signals into the main radiation unit and the parasitic radiation unit, in this way, the main radiation unit generates a first resonance point under the excitation of the four paths of sub-signals, the parasitic radiation unit generates a second resonance point under the excitation of the four paths of sub-signals, the bandwidth corresponding to the frequency of the first resonance point and the frequency of the second resonance point is larger than or equal to the navigation full-band bandwidth, equivalently, the coupling feed realized by the feed network, the main radiation unit and the parasitic radiation unit can increase the bandwidth of the antenna, and the circular polarization antenna can cover the navigation full-band because the bandwidth is larger than or equal to the navigation full-band bandwidth, so that the circular polarization antenna can cover the navigation full-band. In addition, in the structure of the whole circularly polarized antenna, an active combiner is not needed, and the antenna can be used for scenes with large signal power, so that the antenna can be used for receiving satellite signals and transmitting the satellite signals, and the use scenes of the antenna are enriched on the basis of realizing full-band coverage of satellite navigation.

Drawings

FIG. 1 is a schematic diagram of a circularly polarized antenna according to an embodiment;

FIG. 2 is a schematic structural diagram of a parasitic radiating element and a main radiating element in one embodiment;

fig. 3 is a schematic diagram of an implementation of a broadband power distribution network in an embodiment;

fig. 4 is a schematic structural diagram of a broadband power distribution network in another embodiment;

fig. 5 is a schematic diagram of an embodiment of a broadband power distribution network on a printed circuit board;

FIG. 6 is a schematic representation of a simulation result of a standing wave of the broadband power distribution network in one embodiment;

FIG. 7 is a schematic diagram of the structure of a feed network in one embodiment;

FIG. 8 is a schematic diagram of a section of an antenna according to an embodiment;

FIG. 9 is a schematic cross-sectional view of an antenna according to an embodiment;

FIG. 10 is a graph illustrating simulation results of antenna vertex gain in one embodiment;

FIG. 11 is a simulation result of low elevation gain of an antenna according to an embodiment;

FIG. 12 is a graph illustrating antenna axial ratio simulation results in one embodiment;

description of reference numerals:

10: a parasitic radiation element; 20: a main radiation unit;

30: a feed network; 40: a broadband power distribution network;

50: a first printed circuit board; 60: a second printed circuit board;

70: a third printed circuit board; 80: a fourth printed circuit board;

90: a first antenna cover; 100: a first cylindrical non-metallic sidewall;

110: a second radome; 120: a second cylindrical non-metallic sidewall;

301: a feeder sub-network; 3011: a dielectric support post;

3012: a power feeding unit; 3013: a feeding assembly.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and that modifications may be made by one skilled in the art without departing from the spirit and scope of the application and it is therefore not intended to be limited to the specific embodiments disclosed below.

In the description of the present application, it is to be understood that the terms "center," "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 present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present application.

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 application, "plurality" means at least two, e.g., two, three, etc., unless explicitly specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, 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 intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate 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. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

The circularly polarized antenna provided by the embodiment of the application can cover the full frequency band of navigation on the basis of no need of the active combiner through a single-array sub-technology, and can be used as an integrated antenna for receiving and transmitting navigation signals.

Specifically, referring to fig. 1, fig. 1 shows a main schematic diagram of a circularly polarized antenna in an embodiment of the present application, where the circularly polarized antenna includes a parasitic radiation unit 10, a main radiation unit 20, a feed network 30, and a broadband power division network 40, which are arranged from top to bottom; the broadband power distribution network 40 is electrically connected with the feed network 30, the feed network 30 is electrically coupled with the main radiation unit 20, a preset interval is formed between the main radiation unit 20 and the parasitic radiation unit 10, and the main radiation unit 20 is electrically coupled with the parasitic radiation unit 10; the broadband power distribution network 40 is configured to convert the received radio frequency signal into four sub-signals meeting a circular polarization requirement; the feed network 30 is used for feeding four paths of sub-signals into the main radiating element 20 and the parasitic radiating element 10; the main radiating element 20 is used for generating a first resonance point under the excitation of the four paths of sub-signals, the parasitic radiating element 10 is used for generating a second resonance point under the excitation of the four paths of sub-signals, and the bandwidth corresponding to the frequency of the first resonance point and the frequency of the second resonance point is greater than or equal to the navigation full-band bandwidth.

In the embodiment of the present application, the parasitic radiation unit 10, the main radiation unit 20, the feed network 30, and the broadband power distribution network 40 are arranged from top to bottom; optionally, when the parasitic radiation element 10, the main radiation element 20, the feeding network 30 and the broadband power dividing network 40 are disposed from top to bottom, the respective geometric centers are located on the same straight line.

With continued reference to fig. 1, the broadband power distribution network 40 is electrically connected to the feeding network 30, the feeding network 30 is electrically coupled to the main radiating element 20, and the main radiating element 20 is electrically coupled to the parasitic radiating element 10.

A preset interval exists between the main radiating element 20 and the parasitic radiating element 10, and a preset interval also exists between the feeding network 30 and the main radiating element 20, and specific values of the two preset intervals are not limited in the embodiments of the present application and can be determined according to actual situations.

Based on the above connection structure, the feeding network 30 performs coupling feeding with the parasitic radiation element 10 and the main radiation element 20. Therefore, after the broadband power dividing network 40 converts the received radio frequency signal into four sub-signals meeting the circular polarization requirement, and the four sub-signals enter the feeding network 30, the feeding network 30 can feed the four sub-signals into the main radiating element 20 and the parasitic radiating element 10 for coupling feeding, so as to convert the signal into an electromagnetic wave signal and transmit the electromagnetic wave signal to the space. Or, the process of receiving the electromagnetic wave signal is a completely reverse process, and is not described herein again.

Specifically, in the process that the feeding network 30 feeds the four sub-signals into the main radiating element 20 and the parasitic radiating element 10, the main radiating element 20 generates a first resonance point under the excitation of the four sub-signals, and the parasitic radiating element 10 generates a second resonance point under the excitation of the four sub-signals.

Wherein the first resonance point and the second resonance point are different resonance points.

Optionally, the frequency of the second resonance point is less than the frequency of the first resonance point. And the bandwidth corresponding to the frequency of the first resonance point and the frequency of the second resonance point is larger than or equal to the navigation full-frequency band bandwidth.

The navigation full-band bandwidth in the embodiment of the application, namely the satellite navigation full-band bandwidth, is 1.1-1.7 GHz. The bandwidth corresponding to the frequency of the first resonance point and the frequency of the second resonance point is greater than or equal to the navigation full-band bandwidth, so that the signals of the circularly polarized antenna, which are coupled and fed through the feed network 30, the parasitic radiation unit 10 and the main radiation unit 20, can cover the satellite navigation full-band bandwidth.

In practical applications, it can be ensured that the bandwidth corresponding to the frequency of the first resonance point and the frequency of the second resonance point together is greater than or equal to the navigation full-band bandwidth by adjusting the radiation areas of the parasitic radiation unit 10, the main radiation unit 20, and the feed network 30, and the intervals between the parasitic radiation unit 10 and the main radiation unit.

In the circularly polarized antenna provided in the embodiment of the present application, the broadband power dividing network 40 is electrically connected to the feeding network 30, the feeding network 30 is electrically coupled to the main radiation unit 20, a preset interval is provided between the main radiation unit 20 and the parasitic radiation unit 10, and the main radiation unit 20 is electrically coupled to the parasitic radiation unit 10; based on this structure, the broadband power dividing network 40 may convert the received radio frequency signal into four sub-signals meeting the circular polarization requirement, and the feeding network 30 may feed the four sub-signals into the main radiating element 20 and the parasitic radiating element 10, so that the main radiating element 20 generates a first resonance point under excitation of the four sub-signals, the parasitic radiating element 10 generates a second resonance point under excitation of the four sub-signals, and a bandwidth corresponding to a frequency of the first resonance point and a frequency of the second resonance point is greater than or equal to a navigation full-band bandwidth, which is equivalent to that, a coupling feed implemented by the feeding network 30, the main radiating element 20 and the parasitic radiating element 10 may increase a bandwidth of the antenna, and because the bandwidth is greater than or equal to the navigation full-band bandwidth, coverage of the circular polarization antenna to the navigation full-band is achieved. In addition, in the structure of the whole circularly polarized antenna, an active combiner is not needed, and the antenna can be used for scenes with large signal power, so that the antenna can be used for receiving satellite signals and transmitting the satellite signals, and the use scenes of the antenna are enriched on the basis of realizing full-band coverage of satellite navigation.

The connection mode between the components in the circular polarization antenna and the implementation structure of each component are described below with specific embodiments.

In one embodiment, the parasitic radiating element 10 and the main radiating element 20 are planar structures laid on a printed circuit board. For example, the flat-shaped structure may be a metal sheet laid on a printed circuit board.

As shown in fig. 2, the parasitic radiation element 10 is laid on the first printed circuit board 50 and the main radiation element 20 is laid on the second printed circuit board 60, taking a metal sheet as an example. Fig. 2 is a cross-sectional view of the design structure of the parasitic radiation element 10 and the main radiation element 20, and the parasitic radiation element 10 and the main radiation element 20 are illustrated with black background.

Wherein the first printed circuit board 50 and the second printed circuit board 60 are fixedly connected by non-metallic connectors (illustrated by screws in fig. 2). For example, the non-metal connecting member may be a screw, a rivet, or the like, and the specific type of the non-metal connecting member is not limited in the embodiments of the present application. In this way, the first printed circuit board 50 where the parasitic radiation unit 10 is located and the second printed circuit board 60 where the main radiation unit 20 is located are connected by using the non-metal connector, so that the influence of the connector on the antenna radiation can be reduced, and the radiation effect can be enhanced.

Optionally, the vertical height between the main radiating element 20 and the parasitic radiating element 10 is 4mm, i.e. the preset interval between the main radiating element 20 and the parasitic radiating element 10 is 4 mm. Then, it is naturally understood that the vertical height here means a height of 4mm between the first printed circuit board 50 and the second printed circuit board 60.

The height between the parasitic radiating element 10 and the main radiating element 20 affects one of the parameters of the radiation effect of the circular polarization antenna, so the specific height value provided above is an example, and in practical applications, the height value can be adjusted according to practical situations as long as the required radiation effect is met.

Optionally, the parasitic radiating element 10 and the main radiating element 20 are both centrosymmetric in shape.

For example, the parasitic radiating element 10 and the main radiating element 20 may be circular, square, or the like in shape. In fig. 1 and 2, the parasitic radiation element 10 and the main radiation element 20 are illustrated as circular radiation structures.

Optionally, on the basis that the parasitic radiation unit 10 and the main radiation unit 20 are both circular radiation structures, the diameter of the radiation surface of the parasitic radiation unit 10 is 60 mm; the diameter of the radiating surface of the main radiating element 20 is 70 mm. Also, the specific diameter is an example, and can be adjusted according to the actual situation as long as the required radiation effect is met.

For the specific implementation pattern of the circular radiation structures on the parasitic radiation unit 10 and the main radiation unit 20 on the printed circuit board, the embodiment of the present application is not limited, for example, the parasitic radiation unit 10 may be a whole circular metal sheet attached to the printed circuit board, and the main radiation unit 20 may be a circular metal sheet with at least one hollow structure in the middle attached to the printed circuit board.

For example, as shown in fig. 2, the layout of the planar structure of the main radiation unit 20 on the printed circuit board is a hollow structure. The hollow structure shown in fig. 2 does not reduce the effect of signal radiation, and can prolong the current length to achieve the frequency reduction effect.

The implementation structures of the parasitic radiation element 10 and the main radiation element 20 listed above are only an example and are not limiting.

Based on the implementation manners of the parasitic radiation unit 10 and the main radiation unit 20, the feeding network 30 is coupled to the main radiation unit 20, and the broadband power dividing network 40 is electrically connected to the feeding network 30.

In one embodiment, the broadband power distribution network 40 includes 4 feeding points; the feed network 30 has 4 feed components 3013; the feeding network 30 is connected to 4 feeding points through 4 feeding components 3013 to access the broadband power dividing network 40.

Alternatively, the power feeding component 3013 may be a power feeding pin, which may be implemented as a metal rod.

Alternatively, the feed pin may be 19mm in height and 1mm in diameter.

Generally, two linear polarized waves orthogonal to each other, having equal amplitudes and 90 ° phase difference can be synthesized into a circular polarized wave, so to implement circular polarization of the satellite navigation antenna, it is necessary to make the currents of 4 feeding points connected to the four feeding pins on the broadband power distribution network 40 equal, and the phases differ by 90 ° in pairs.

Optionally, the feeding phases of the 4 feeding points may be sequentially lagged by 90 ° in a clockwise direction or a counterclockwise direction, and when the feeding phases of the 4 feeding points are sequentially lagged by 90 ° in the clockwise direction, left-handed circular polarization of the satellite navigation antenna is implemented; and when the feeding phases of the 4 feeding points sequentially lag behind by 90 degrees in the anticlockwise direction, the right-hand circular polarization of the satellite navigation antenna is realized. Specifically, the phases of the 4 feeding points may be set according to whether the antenna is to implement left-hand circular polarization or right-hand circular polarization.

Taking right-handed circular polarization as an example, the phases of 4 feeding points must realize phase changes of 0 °, 90 °, 180 °, and 270 °.

As shown in fig. 3, a schematic diagram of an implementation of the broadband power distribution network 40 is illustrated. Taking a wilkinson power divider implementation as an example, the broadband power dividing network 40 includes one Input port Input and four output ports. When transmitting signals, radio frequency signals received by the broadband power divider network 40 enter from an Input port Input, are divided into two paths after passing through the wilkinson power divider, and then each path is divided into different phases after passing through the wilkinson power divider: 0 °, 90 °, 180 °, 270 ° ports.

Therefore, the high-precision and circular polarization characteristics of the antenna can be guaranteed by adopting the design of the 4 feed phases, the axial ratio of the satellite navigation antenna is smaller due to the highly symmetrical structure, the satellite navigation antenna has higher circular polarization performance, and the precision of the satellite navigation antenna is improved.

Alternatively, as shown in fig. 4, the broadband power distribution network 40 is disposed on a third printed circuit board 70; the third printed circuit board 70 is positioned below the second printed circuit board 60 and is disposed in parallel with the second printed circuit board 60. Optionally, the feeding network 30 is arranged between the third printed circuit board 70 and the second printed circuit board 60. In fig. 4, the broadband power dividing network 40 on the third printed circuit board 70 and the feeding network 30 disposed in the middle are not shown in specific structures, and are only shown in simple text and lines.

Taking the schematic diagram of the broadband power distribution network 40 shown in fig. 3 as an example, when the broadband power distribution network 40 is implemented on a printed circuit board, the implementation layout is as shown in fig. 5, where A, B, C, D in fig. 5 corresponds to four phase feeding points of 0 °, 90 °, 180 °, and 270 °.

For different phases of the four feeding points, isolation is performed by isolation resistors R1, R2, and R3. Optionally, R1= R2= R3=100 Ω.

In addition, in the foregoing embodiment, it has been described that the feeding network 30 increases the antenna bandwidth by performing coupling feeding with the main radiating element 20 and the parasitic radiating element 10, and the four sub-signals of the feeding network 30 are fed from the broadband power dividing network 40, so in order to ensure that the bandwidth of the broadband power dividing network 40 is expanded, in fig. 5, a two-stage matching section is adopted for a line segment of the broadband power dividing network 40, that is, a thick line and a thin line in fig. 5 represent different-stage matching sections, so as to implement a wider bandwidth of the broadband power dividing network 40.

For the implementation layout of the broadband power distribution network 40 shown in fig. 5, data after network simulation is shown in fig. 6, which can be seen from a dotted line frame shown in fig. 6, and standing waves in a frequency band of 1.1 to 1.7GHz (full navigation band) are all less than 1.3, so that the data meet design indexes.

The feed network 30 of fig. 4 is disposed between the third printed circuit board 70 and the second printed circuit board 60. That is, one end of the feeding network 30 is coupled to the main radiating element 20, and the other end is electrically connected to the broadband power dividing network 40 disposed on the third printed circuit board 70.

For the implementation structure of the feeding network 30, as shown in fig. 7, in one embodiment, the feeding network 30 includes 4 symmetrically disposed feeding sub-networks 301, and each feeding sub-network 301 includes two dielectric support posts 3011, and a feeding unit 3012 and a feeding component 3013 disposed between the two dielectric support posts 3011.

In particular, 4 symmetrically arranged feeder sub-networks 301 are arranged centrally symmetrically, i.e. at an angle of 90 ° to each other. Correspondingly, each feed sub-network 301 includes one feed unit 3012, one feed component 3013, and two dielectric support posts 3011.

Taking the feed component 3013 as an example of a feed pin, each feed unit 3012 is horizontally disposed, and a feed pin is vertically connected below the feed unit 3012, that is, one end of the feed pin is connected to the feed unit 3012, and the other end is connected to a feed point on the broadband power distribution network 40 below, so that when signal transmission is ensured, transmission between the feed unit 3012 and the broadband power distribution network 40 can be achieved through the feed pin.

Since the feed network 30 where the feed unit 3012 is located is coupled to the upper main radiating unit 20, and there is no connecting component between the two, in order to ensure the stability of the feed unit, two dielectric support posts 3011 are respectively disposed at two ends of each feed unit 3012 for support.

In one embodiment, the power feeding unit 3012 is a linear structure laid on the fourth printed circuit board 80. For example, the power feeding unit 3012 may be a metal tape laid on the fourth printed circuit board 80. The metal strip is a radiation patch for coupling feeding of the feeding unit 3012. Alternatively, the radiating area of the feed unit 3012 has a length of 18mm and a width of 4 mm. Also, the specific diameter is an example, and can be adjusted according to the actual situation as long as the required radiation effect is met.

Each feed unit 3012 is supported by a dielectric support post 3011, and the feed unit 3012 is laid on the fourth printed circuit board 80, so that the dielectric support post 3011 is connected to the fourth printed circuit board 80 at one end and connected to the third printed circuit board 70 where the lower broadband power dividing network 40 is located at the other end, so as to improve the stability of the whole antenna.

As shown in fig. 8, a schematic cross-sectional view of a circularly polarized antenna array is provided by combining the implementation structures of the feeding unit 3012, the feeding pin, the parasitic radiating element 10, the main radiating element 20, and the dielectric supporting post 3011 in the above embodiments.

In fig. 8, since it is a sectional view, only 3 feeding elements 3012 and 4 feeding pins are illustrated. And a dielectric support post 3011 is disposed on the main radiating element 20 at an end extending from the feed unit 3012, and the bottom end of the dielectric support post 3011 is connected to a printed circuit board (not shown in fig. 8) on which the broadband power distribution network 40 is located, so as to support the main radiating element 20.

Specifically, the signal enters the feed pin through the feed point of the broadband power distribution network 40, and then enters the corresponding feed unit 3012 through the feed pin, and the 4 feed units 3012 perform coupling feed with the main radiation unit 20 and the parasitic radiation unit 10 above, so as to radiate the generated electromagnetic wave signal to the space.

Further, in order to secure an electromagnetic wave radiation effect of coupling feeding of the antenna, a vertical height between the fourth printed circuit board 80 and the second printed circuit board 60 where the feeding unit 3012 is located is 5 mm. The specific diameter value is also an example, and can be adjusted according to actual conditions as long as the required radiation effect is met.

The multipath effect is a significant error source of the satellite navigation system, and can be suppressed by providing the choke coil, and based on this, in one embodiment, the circularly polarized antenna provided in the embodiment of the present application further includes the choke coil provided on the fifth printed circuit board, which is located below the third printed circuit board 70 and is arranged in parallel with the third printed circuit board 70. Thus, the electromagnetic wave transmission multipath effect is improved, the radiation efficiency is improved, the important structure of the radiation uniformity is improved, and the low elevation gain can also be improved.

In an embodiment, with reference to the above embodiments, as shown in fig. 9, an overall sectional view of the circularly polarized antenna provided in the embodiment of the present application is illustrated.

In fig. 9, considering that the metal in the structures in the above embodiments is exposed to air for a long time and rusts, thereby affecting the radiation effect of the antenna, the circular polarization antenna provided in the embodiment of the present invention further includes a first antenna cover 90 and a first cylindrical non-metal sidewall 100. Wherein the bottom of the first antenna cover 90 is connected to the top of the first cylindrical non-metallic sidewall 100 to form a first antenna cavity. The parasitic radiating element 10, the main radiating element 20, the feed network 30 and the broadband power dividing network 40 in the above embodiments are all located in the first antenna cavity.

Optionally, the circularly polarized antenna further includes a second radome 110 and a second cylindrical non-metal sidewall 120, the second cylindrical non-metal sidewall 120 is sleeved on the periphery of the first cylindrical non-metal sidewall 100, and the bottom of the second radome 110 is connected to the top end of the second cylindrical non-metal sidewall 120 to form a second antenna cavity. A choke is located in the second antenna cavity.

In the above embodiments, the radome is made of a non-metal material, for example, FR4 composite material. The non-metallic material used for the columnar side wall can also be FR4 composite material. The embodiments of the present application do not limit this.

Alternatively, the shapes of the first antenna cover 90 and the second antenna cover 110 may be circular arcs, or square or irregular shapes. First antenna housing 90 and second antenna housing 110 can be transparent, also can be non-transparent, and this application embodiment does not do all to the shape, colour, material, the characteristic of antenna house do not do the restriction, as long as it can make the radiation signal of antenna pass, do not influence the radiation effect can.

Based on the above structural design, the circularly polarized antenna provided in the embodiment of the present application obtains simulation results of the vertex gain in fig. 10, the low elevation gain in fig. 11, and the axial ratio in fig. 12, and it can be seen from the simulation results that all gain bands of the antenna are greater than 8dBi, the minimum gain of 20 ° at low elevation angle is-2.8 dBi, out-of-roundness is less than 0.5, the axial ratio is within 80 ° and less than 3.6dB, and the circularly polarized characteristic is good. Therefore, the antenna directional diagram indexes obtained after electromagnetic simulation all meet the design requirements, and the top gain, the low elevation gain, the out-of-roundness and the axial ratio all have better indexes, so that the antenna in the application can realize ultra-wideband coverage through the design idea of 4-feed coupling feed, and simultaneously has the good characteristics of high gain, low elevation gain, out-of-roundness and axial ratio, and the antenna array all adopts a printed board, so that compared with the conventional microstrip composite material in the industry, the cost of the product is greatly reduced.

In addition, based on the same inventive concept, the embodiment of the application also provides a reference station. The reference station comprises a circularly polarized antenna as provided in any of the embodiments above. The implementation scheme for solving the problem provided by the reference station is similar to the implementation scheme described in the circularly polarized antenna, so the specific definition in the reference station can be referred to the definition of the circularly polarized antenna in the above, and is not described herein again.

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 application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A circularly polarized antenna is characterized by comprising a parasitic radiation unit, a main radiation unit, a feed network and a broadband power division network which are arranged from top to bottom;

the broadband power distribution network is electrically connected with the feed network, the feed network is electrically coupled with the main radiation unit, a preset interval is formed between the main radiation unit and the parasitic radiation unit, and the main radiation unit is electrically coupled with the parasitic radiation unit;

the broadband power distribution network is used for converting the received radio frequency signals into four paths of sub signals meeting the circular polarization requirement; the feed network is used for feeding the four paths of sub signals into the main radiation unit and the parasitic radiation unit;

2. The circularly polarized antenna of claim 1, wherein the frequency of the second resonance point is less than the frequency of the first resonance point.

3. The circularly polarized antenna of claim 2, wherein the vertical height between the main radiating element and the parasitic radiating element is 4 mm.

4. The circularly polarized antenna of claim 2, wherein the parasitic radiating element and the main radiating element are planar structures laid on a printed circuit board.

5. The circularly polarized antenna of claim 4, wherein the parasitic radiation element and the main radiation element are both in a centrosymmetric shape, and the first printed circuit board on which the parasitic radiation element is located and the second printed circuit board on which the main radiation element is located are fixedly connected through a non-metallic connector.

6. The circularly polarized antenna of claim 5, wherein the parasitic radiation element and the main radiation element are both circular radiation structures, and the diameter of the radiation surface of the parasitic radiation element is 60 mm; the diameter of the radiation surface of the main radiation unit is 70 mm.

7. The circularly polarized antenna of claim 6, wherein the main radiating element is a circular radiating structure having at least one hollow structure in the middle.

8. The circularly polarized antenna of claim 5, wherein the broadband power distribution network comprises 4 feed points; the feed network has 4 feed components;

the feed network is connected with the 4 feed points through the 4 feed components and is accessed to the broadband power distribution network.

9. The circularly polarized antenna of claim 8, wherein the broadband power distribution network is disposed on a third printed circuit board, the third printed circuit board being disposed below and parallel to the second printed circuit board.

10. The circularly polarized antenna of claim 9, wherein the feed network is disposed between the third printed circuit board and the second printed circuit board, the feed network comprising 4 symmetrically disposed feed sub-networks, each of the feed sub-networks comprising two dielectric support posts and a feed element and a feed assembly disposed between the two dielectric support posts.

11. The circularly polarized antenna of claim 10, wherein the feeding unit is a wire structure laid on a fourth printed circuit board;

12. The circularly polarized antenna of claim 11, wherein the radiating area of the feed element has a length of 18mm and a width of 4 mm.

13. The circularly polarized antenna of claim 9, further comprising a choke coil disposed on a fifth printed circuit board, the fifth printed circuit board being disposed below the third printed circuit board and in parallel with the third printed circuit board.

14. The circularly polarized antenna of any one of claims 1 to 13, further comprising a first antenna cover and a first cylindrical non-metallic sidewall, wherein a bottom of the first antenna cover is connected to a top end of the first cylindrical non-metallic sidewall to form a first antenna cavity;

15. The circularly polarized antenna of claim 14, further comprising a second radome and a second cylindrical non-metallic sidewall, wherein the second cylindrical non-metallic sidewall is sleeved on the periphery of the first cylindrical non-metallic sidewall, and the bottom of the second radome is connected with the top end of the second cylindrical non-metallic sidewall to form a second antenna cavity.

16. A reference station, characterized in that it comprises a circularly polarized antenna according to any of the preceding claims 1-15.