阅读说明：本技术 一种l频段嵌入式宽带车载全向天线 (L-frequency-band embedded broadband vehicle-mounted omnidirectional antenna ) 是由 钟玲玲 李鹏 于 2021-09-28 设计创作，主要内容包括：本发明公开了一种L频段嵌入式宽带车载全向天线,其结构为：下层圆环介质垫片、下层方形金属辐射体、上层圆环介质垫片及上层方形金属辐射体由下至上依次叠置在方形金属腔体内,同轴馈电连接器安装在方形金属腔体底部,同轴馈电连接器的同轴连接器内芯依次贯穿连接方形金属腔体底部、下层圆环介质垫片、下层方形金属辐射体、上层圆环介质垫片及上层方形金属辐射体,天线罩盖设在方形金属腔体顶部。本发明天线可以完全嵌入到车辆内部安装,便于与车身共形,不易损坏,不额外增加设备尺寸；天线馈电方式简单,易获得阻抗匹配,无需加载,不需匹配电路或平衡转换器,不存在天线与射频电路之间的物理限制。(The invention discloses an L-frequency-band embedded broadband vehicle-mounted omnidirectional antenna, which has the following structure: lower floor's ring dielectric gasket, the square metal radiator of lower floor, upper ring dielectric gasket and the square metal radiator of upper strata superpose in proper order in square metal cavity by supreme down, coaxial feed connector installs in square metal cavity bottom, coaxial feed connector's coaxial connector inner core run through the square metal cavity bottom in proper order, lower floor's ring dielectric gasket, the square metal radiator of lower floor, upper ring dielectric gasket and the square metal radiator of upper strata, antenna shroud establishes at square metal cavity top. The antenna can be completely embedded into the vehicle for installation, is convenient to be conformal with the vehicle body, is not easy to damage, and does not increase the size of equipment additionally; the antenna has simple feed mode, is easy to obtain impedance matching, does not need loading, does not need a matching circuit or a balance converter, and does not have physical limitation between the antenna and a radio frequency circuit.)

1. An L-frequency-band embedded broadband vehicle-mounted omnidirectional antenna is characterized by comprising an upper-layer square metal radiating body (1), a lower-layer square metal radiating body (2), an upper-layer circular ring dielectric isolation gasket (3), a lower-layer circular ring dielectric isolation gasket (4), a square metal cavity (5), a coaxial feed connector (6) and an antenna cover (7); lower floor's ring dielectric spacer (4), lower floor's square metal radiator (2), upper ring dielectric spacer (3) and upper square metal radiator (1) superpose in proper order in square metal cavity (5) by supreme down, install in square metal cavity (5) bottom coaxial feed connector (6), the coaxial connector inner core (6.c) of coaxial feed connector (6) run through the connection square metal cavity (5) bottom in proper order, lower floor's ring dielectric spacer (4), lower floor's square metal radiator (2), upper ring dielectric spacer (3) and upper square metal radiator (1), establish at square metal cavity (5) top radome (7) lid.

2. The L-band embedded broadband vehicle-mounted omnidirectional antenna according to claim 1, wherein the upper square metal radiator (1) and the lower square metal radiator (2) are both square thin plates, and the side length of the upper square metal radiator (1) is smaller than that of the lower square metal radiator (2), and the upper square metal radiator (1) and the lower square metal radiator (2) are welded and connected with the inner core (6.c) of the coaxial connector.

3. The L-band embedded broadband vehicle-mounted omnidirectional antenna according to claim 2, wherein the upper square metal radiator (1) and the lower square metal radiator (2) are made of brass.

4. The L-band embedded broadband vehicle-mounted omnidirectional antenna according to claim 3, wherein the upper-layer annular dielectric isolation gasket (3) and the lower-layer annular dielectric isolation gasket (4) are made of polytetrafluoroethylene.

5. The L-band embedded broadband vehicle-mounted omnidirectional antenna according to claim 4, wherein a mounting plate (5.a) is provided at the top edge of the square metal cavity (5), and a through hole is provided in the mounting plate (5.a) for connecting with a vehicle body and an antenna cover (7) by screws.

6. The L-band embedded broadband vehicle-mounted omnidirectional antenna according to claim 5, wherein the square metal cavity (5) is made of brass.

7. The L-band embedded broadband vehicle-mounted omnidirectional antenna according to claim 6, wherein the material selected for the radome (7) is glass fiber reinforced plastic.

8. The L-band embedded broadband vehicle-mounted omnidirectional antenna according to claim 7, characterized in that the coaxial connector (6) is fed by an N-type coaxial connector.

9. The L-band embedded broadband vehicle-mounted omnidirectional antenna according to claim 8, wherein the coaxial connector (6) further comprises a coaxial connector medium (6.b) formed outside the lower end of the inner core (6.c) of the coaxial connector, a coaxial connector outer conductor (6.a) formed outside the lower end of the coaxial connector medium (6.b), and a coaxial connector flange (6.d) located on the outer periphery of the upper end of the coaxial connector medium (6.b), the square metal cavity (5) and the inner core (6.c) of the coaxial connector are isolated by the coaxial connector medium (6.b), and the coaxial connector flange (6.d) is fixedly connected with the square metal cavity (5) through screws.

10. An application of an L-band embedded broadband vehicle-mounted omnidirectional antenna based on any one of claims 1-9 in the technical field of microwave antennas.

Technical Field

The invention belongs to the technical field of microwave antennas, and particularly relates to an L-band embedded broadband vehicle-mounted omnidirectional antenna which is stable and reliable in structure, can be completely embedded into the top of a vehicle, does not protrude out of the surface, and is good in performance, and the communication system of civil and military vehicles is mainly used.

Background

In a radio communication system, an antenna is an indispensable important component that converts between a free-space radio wave and a waveguide electromagnetic wave to each other, thereby realizing a transition between the free space and a waveguide device in a transmission system, and therefore, in any radio system, the antenna takes an important role and once leaving the antenna that takes charge of transmitting and receiving the electromagnetic wave, the radio communication system cannot continue to operate.

The vehicle-mounted communication system takes a vehicle as a carrier, and can transmit wireless signals along with the movement of the vehicle. As a key component for radiating and receiving energy in a vehicle-mounted communication system, the performance requirements of a vehicle-mounted antenna comprise multiple aspects of wide frequency band, small volume, low processing cost and the like; because the vehicle often runs on complex and severe landforms such as open fields, mountainous regions and the like, communication equipment such as an antenna and the like on the vehicle is frequently damaged by vibration, impact, collision and the like, and thus higher and higher requirements are provided for the reliability of the vehicle-mounted antenna; in addition, in order to satisfy the communication condition of "communication in motion", the vehicle-mounted antenna must have a characteristic of omnidirectional radiation to ensure that the vehicle-mounted communication system in motion can transmit and receive signals from various directions.

The current commonly used vehicle-mounted antenna mainly comprises a cross series feed antenna, a series feed sleeve antenna, a slot antenna, a symmetrical oscillator antenna, a printed oscillator antenna and the like. A coaxial collinear (COCO) antenna is taken as a representative of an early omnidirectional antenna and is widely applied to engineering practice, and theoretical analysis shows that a half-wavelength coaxial inner core and an outer skin are in cross connection in a cross feeding mode, and the omnidirectional high gain of the COCO antenna is realized by increasing the number of units, but due to the self resonance structure of the antenna, the bandwidth becomes a key parameter for limiting the performance of the antenna, the bandwidth can be widened in a top loading mode, but the gain of the antenna is influenced, and the size of the antenna is increased; the frequency band of the sleeve antenna is wider than that of the cross feed antenna, but the problems of strength and precision of a medium support of a coupling gap exist; the waveguide slot antenna works in a higher frequency band, and for an L frequency band, the antenna structure is complex and debugging is difficult; the length of the commonly used dipole whip antenna is longer (the L-frequency band antenna is 75 mm-150 mm). No matter the antenna is a cross series feed antenna, a series feed sleeve antenna, a slot antenna, a symmetrical dipole antenna or a printed dipole antenna, when the antenna is installed on a vehicle, the antenna needs to be completely protruded out of the surface of the vehicle body and can not be embedded into the vehicle body.

In summary, the conventional vehicle-mounted omnidirectional antenna mainly has the following technical problems:

(1) the antenna can not be embedded in the vehicle shell, and is large in size and easy to damage. Although the traditional vehicle-mounted antenna is simple and convenient to mount, the antenna needs to be completely protruded to the outside of a vehicle, the structure is very unstable, when the carrier speed is high or the ambient wind speed is high, the antenna resistance is high, the antenna is easy to break, the height limit requirement of the vehicle is influenced, a lot of inconvenience is caused in the aspects of antenna manufacturing, mounting, transporting, concealing and the like, the antenna is not suitable for special application occasions with complex environments, and for military antennas, the motor combat capability of the vehicle can be reduced due to an overhigh antenna structure.

(2) The antenna needs a matching circuit or a component to be loaded, so that the loss is large and the cost is high. In order to meet the broadband requirement of the vehicle-mounted omnidirectional antenna, the conventional antenna adopts ways of increasing a matching network, adding a load and the like to improve the narrow-band characteristic, and although the measures broaden the frequency band of the antenna, the measures complicate the structure of the antenna and bring more loss and overhigh cost.

Disclosure of Invention

Objects of the invention

The purpose of the invention is: an embedded omnidirectional antenna form is developed for an actual L-band vehicle-mounted communication platform, and more ideal electromagnetic characteristics and structural characteristics are provided compared with the existing antenna design.

(II) technical scheme

In order to solve the technical problem, the invention provides an L-band embedded broadband vehicle-mounted omnidirectional antenna which comprises a double-layer square metal radiator, a double-layer circular ring medium isolation gasket, a square metal cavity, a coaxial feed connector inserted into an antenna structure and an antenna cover; the double-layer square metal radiator is a square thin plate, the side length of the upper layer square metal radiator is small, the side length of the lower layer square metal radiator is long, through holes are formed in the middle of the upper layer square metal radiator, the diameter of each through hole is consistent with the diameter of the inner core of the connector, the double-layer square metal radiator is connected with the inner core of the coaxial connector in a welding mode, and the double-layer square metal radiator is made of brass; the middle of the double-layer circular ring dielectric gasket is provided with a through hole, the inner diameter of the circular ring is consistent with the diameter of the inner core of the connector, the circular ring dielectric gasket is used for supporting and isolating the square metal cavity and the double-layer square metal radiator, and the circular ring dielectric gasket is made of polytetrafluoroethylene; the square metal cavity is hollowed, a through hole is formed in the bottom of the square metal cavity, the diameter of the through hole is consistent with that of the connector inner core, a mounting plate is arranged on the edge of the square metal cavity, the lower-layer circular ring dielectric gasket, the lower-layer square metal radiator, the upper-layer circular ring dielectric gasket and the upper-layer square metal radiator are sequentially placed in the square metal cavity from bottom to top, the connector inner core penetrates and is connected with the bottom of the square metal cavity from bottom to top, the mounting plate on the edge of the square metal cavity is provided with the through hole for being connected with the vehicle body and the antenna housing through screws, and the square metal cavity is made of brass; the antenna housing is a square medium thin plate and is screwed on the mounting plate at the edge of the square metal cavity through screws, so that other structural components of the antenna and the antenna housing form a whole, the antenna housing is made of glass fiber reinforced plastic, and the antenna housing is firm, durable and good in wave transmission rate, and can ensure efficient receiving and transmitting of vehicle-mounted communication signals; the antenna adopts an N-type coaxial connector to connect feed, the connector adopts N-50KFD52 of Shaanxi Huada science and technology limited company, and is characterized in that the extended coaxial inner core is longer (28.2mm), the inner core can sequentially pass through the bottom of a square metal cavity, a lower layer circular ring dielectric gasket, a lower layer square metal radiator, an upper layer circular ring dielectric gasket and an upper layer square metal radiator, and a flange of the connector is connected with the square metal cavity through a screw; the energy output by the coaxial connector is fed from the feed end, so that the surface current of the double-layer square metal radiator is excited, and radiation is generated.

(III) advantageous effects

The L-band embedded broadband vehicle-mounted omnidirectional antenna provided by the technical scheme has the following advantages:

(1) the antenna can be completely embedded into the vehicle for installation, is convenient to conform to the vehicle body, is not easy to damage, and does not increase the size of equipment additionally;

(2) the antenna feed mode is simple, the impedance matching is easy to obtain, the loading is not needed, a matching circuit or a balance converter is not needed, and the physical limitation between the antenna and the radio frequency circuit is avoided;

(3) the antenna has wide bandwidth and relatively high gain and efficiency, and can keep the vehicle-mounted communication equipment to operate efficiently.

Drawings

Fig. 1 is a cross-sectional view of an antenna of the present invention.

Fig. 2 is a top view of the antenna of the present invention.

Fig. 3 is a bottom view of the antenna of the present invention.

Fig. 4 is a standing wave ratio versus frequency for the antenna of the present invention.

Fig. 5 is a horizontal plane pattern of the antenna of the present invention.

In the figure:

1. upper square metal radiator 2, lower square metal radiator

3. Upper layer ring medium isolation spacer 4, lower layer ring medium isolation spacer

5. Mounting plate for square metal cavity 5.a square metal cavity edge

6. Coaxial connector 6.a. coaxial connector outer conductor

Coaxial connector medium 6.c. coaxial connector inner core

6, d. coaxial connector flange 7. antenna housing

8-11, 12-15 screws

16-19. screw

Detailed Description

In order to make the objects, contents and advantages of the present invention clearer, the following detailed description of the embodiments of the present invention will be made in conjunction with the accompanying drawings and examples.

An embedded antenna is a special form of antenna, which refers to an antenna whose shape is completely embedded inside the carrier and can conform to the outer surface of the carrier, i.e. the surface shape of the antenna is determined by the aerodynamic shape or functional shape of the carrier, and not by the electromagnetic shape of the antenna. A typical communication antenna is a vertically polarized antenna, requiring a horizontal plane with an omni-directional pattern. Because the vehicle-mounted communication equipment has a severe transportation environment, the vehicle-mounted antenna adopts an embedded design, and the reliability of the equipment in a complex mechanical environment for vehicle running can be ensured.

The L-band embedded broadband vehicle-mounted omnidirectional antenna provided by the embodiment solves the problems that the traditional vehicle-mounted communication antenna cannot be embedded into a vehicle shell, is large in size and easy to damage, needs a matching circuit or elements for loading, is large in loss, high in cost and the like. The invention is used for transmitting and receiving vertical polarization electromagnetic waves, has simple structure, and the whole antenna only consists of metal brass, polytetrafluoroethylene medium and glass fiber reinforced plastic, and has easy processing and manufacturing, light weight and low cost; the antenna is of a square full-embedded structure, can be completely embedded into the vehicle for installation, is convenient to conform to the vehicle body, is not easy to damage, and does not increase the size of equipment additionally; the antenna connects the double-layer radiator with the connector through welding spots, and the connector and the cavity are screwed through screws, so that the overall structure is stable; the antenna is easy to match, can be directly fed by a coaxial line of 50 omega, and can meet the requirements of a vehicle-mounted communication system of an L waveband; the whole antenna has a simple structure, and no matching circuit or component is loaded, so that the antenna has good consistency and is convenient for batch production; the radiation field of the antenna is uniformly distributed in the range of 360 degrees in the horizontal plane, and good omnidirectional characteristic can be realized.

Specifically, referring to fig. 1, 2 and 3, the invention is an embedded L-band broadband vehicle-mounted omnidirectional antenna, which includes an upper square metal radiator 1, a lower square metal radiator 2, an upper annular dielectric isolation gasket 3, a lower annular dielectric isolation gasket 4, a square metal cavity 5, a coaxial feed connector 6 and an antenna housing 7; lower floor's ring dielectric spacer 4, lower floor's square metal radiator 2, upper ring dielectric spacer 3 and upper square metal radiator 1 superpose in proper order in square metal cavity 5 by supreme down, coaxial feed connector 6 is installed in square metal cavity 5 bottom, coaxial feed connector 6's coaxial connector inner core 6.c run through the square metal cavity 5 bottom of connection in proper order, lower floor's ring dielectric spacer 4, lower floor's square metal radiator 2, upper ring dielectric spacer 3 and upper square metal radiator 1, 7 lids of antenna house are established at square metal cavity 5 tops.

The upper square metal radiator 1 and the lower square metal radiator 2 are square thin plates, the side length of the upper square metal radiator 1 is small, the side length of the lower square metal radiator 2 is large, a through hole is formed in the middle of the upper square metal radiator, the diameter of the through hole is consistent with that of the inner core 6.c of the coaxial connector, the upper square metal radiator 1, the lower square metal radiator 2 and the inner core 6.c of the coaxial connector are in welded connection, and the upper square metal radiator 1 and the lower square metal radiator 2 are made of brass.

There is the through-hole in the middle of upper ring medium spacer 3, the ring medium spacer 4 of lower floor, and the through-hole diameter is unanimous with coaxial connector inner core 6.c diameter, and its effect is that support keeps apart square metal cavity 5 and upper square metal irradiator 1, the square metal irradiator 2 of lower floor, and upper ring medium spacer 3, the ring medium spacer 4 of lower floor select the material to be polytetrafluoroethylene.

The square metal cavity 5 is hollowed, a through hole is formed in the bottom of the square metal cavity, the diameter of the through hole is consistent with that of the coaxial connector inner core 6.c, an installation plate 5.a is arranged on the edge of the top of the square metal cavity 5, a through hole is formed in the installation plate 5.a and used for being connected with a vehicle body and an antenna housing 7 through screws 8-15, and the square metal cavity 5 is made of brass.

The antenna housing 7 is a square medium thin plate and is screwed on the mounting plate 5.a at the edge of the square metal cavity 5 through screws, so that the upper square metal radiator 1, the lower square metal radiator 2, the upper ring medium isolation gasket 3, the lower ring medium isolation gasket 4, the square metal cavity 5, the coaxial feed connector 6 and the antenna housing 7 form a whole, the antenna housing 7 is made of glass fiber reinforced plastics, the antenna housing is firm and durable, the wave transmission rate is good, and the efficient receiving and sending of vehicle-mounted communication signals can be guaranteed.

The coaxial connector 6 adopts an N-type coaxial connector for connecting and feeding, adopts N-50KFD52 of Shaanxi Huada science and technology Limited company, and is characterized in that the extended inner core 6.c of the coaxial connector is longer and about 28.2 mm.

The coaxial connector 6 further comprises a coaxial connector medium 6.b formed outside the lower end of the inner core 6.c of the coaxial connector, a coaxial connector outer conductor 6.a formed outside the lower end of the coaxial connector medium 6.b, and a coaxial connector flange 6.d located on the periphery of the upper end of the coaxial connector medium 6.b, the square metal cavity 5 and the inner core 6.c of the coaxial connector are isolated by the coaxial connector medium 6.b, and the coaxial connector flange 6.d is fixedly connected with the square metal cavity 5 through screws 16-19.

In the invention, the upper layer square metal radiator 1 and the lower layer square metal radiator piece 2 are the most main components playing a role of radiation and are used for radiating electromagnetic waves to space, when a signal is transmitted, the coaxial connector 6 inputs a transmission signal of an external transmitter through a connected coaxial cable, and the energy output by the coaxial connector excites the surface currents of the upper layer square metal radiator 1 and the lower layer square metal radiator piece 2, so as to generate radiation; the antenna is completely embedded into the vehicle for installation, is convenient to conform to the vehicle body and is not easy to damage; due to the adoption of the basic structure of the upper square metal radiator 1, the lower square metal radiator piece 2 and the square metal cavity 5, the antenna can receive or transmit vertical polarization electromagnetic waves and has a wide bandwidth, and the polarization and bandwidth requirements of the antenna in an L frequency band are met; due to the introduction of the upper-layer circular ring dielectric isolation gasket 3 and the lower-layer circular ring dielectric isolation gasket 4, the upper-layer square metal radiator 1, the lower-layer square metal radiator piece 2 and the floor of the square metal cavity 5 of the antenna are separated under the condition that the size of the antenna is not increased, so that the cable connected with the coaxial connector 6 can effectively excite the antenna current; due to the axisymmetric characteristic of the whole antenna structure, the radiation field of the antenna can be uniformly distributed within 360 degrees of the horizontal plane; because the whole antenna is only provided with two welding spots (the upper square metal radiator 1 and the lower square metal radiator piece 2 are welded and connected with the inner core 6.c of the coaxial connector) in the vertical and symmetrical directions, no other adhesion devices are arranged, the antenna is good in consistency, and the mass production of the antenna is convenient.

Figure 4 is a plot of standing wave ratio VSWR versus frequency for an antenna of the present invention. The standing wave ratio is an important performance parameter of the antenna, reflects the impedance characteristic of the antenna to be tested and also determines the impedance bandwidth of the antenna. Referring to fig. 4, the working frequency band of the antenna of the present invention is in the L band, the standing wave ratio of the antenna is less than 2 in the wide frequency range of 1.03GHz to 1.46GHz, and the standing wave of the antenna is significantly reduced compared with the antenna with only one layer of square metal radiator, which indicates that the antenna can be well matched with a 50 Ω coaxial cable in the frequency band, the relative bandwidth is about 34.5%, while the relative bandwidth of the conventional dipole antenna is less than 10%, and the present invention ensures that the antenna has a wider impedance bandwidth.

Fig. 5 is a horizontal plane radiation pattern of the antenna of the present invention. The directional diagram is a graph representing the relationship between the radiation characteristic of the antenna and the spatial angle. Referring to fig. 5, the radiation field of the antenna is uniformly distributed in an omnidirectional manner within 360 degrees of the horizontal plane, the out-of-roundness is less than 0.6dB, and good omnidirectional radiation characteristics can be maintained.

The antenna structure designed by the invention can adopt the upper layer square metal radiator 1, the lower layer square metal radiator piece 2 and the square metal cavity 5, and can also properly adjust the shapes of the metal radiator and the metal cavity according to the actual appearance requirement of the vehicle, and the performance of the antenna is basically not influenced; the antenna designed by the invention can work in an L frequency band, and can shorten the sizes of the upper layer square metal radiator 1, the lower layer square metal radiator piece 2 and the square metal cavity 5 in an equal ratio according to requirements, so that the antenna can work in a frequency band (more than 2GHz) above the L frequency band.

According to the technical scheme, the invention has the following remarkable characteristics:

due to the adoption of the embedded structure, the antenna can be completely embedded into the vehicle for installation, is convenient to conform to the vehicle body and is not easy to damage; due to the adoption of the basic structure of the double-layer radiator and the square cavity, the antenna can receive or transmit vertical polarization electromagnetic waves and has wider bandwidth, and the polarization and bandwidth requirements of the antenna in an L frequency band are met; due to the introduction of the double-layer non-metal medium, the double-layer radiator of the antenna and the square cavity floor are separated under the condition that the size of the antenna is not increased, so that the coaxial cable can effectively excite the current of the antenna; due to the axisymmetric characteristic of the whole antenna structure, the radiation field of the antenna can be uniformly distributed within 360 degrees of the horizontal plane; the whole antenna is only provided with two welding spots in the vertical symmetrical direction, and no other adhesion devices are arranged, so that the antenna is good in consistency and convenient for batch production; in addition, the shape of the antenna cavity and the radiator can be round and square, the size of the antenna cavity and the radiator can be properly adjusted according to the actual vehicle appearance and application requirements, the use frequency of the antenna can also be changed in an equal proportion by adjusting the size of the antenna, and the whole antenna structure and application occasions are flexible.

The antenna has the advantages of lower voltage standing wave ratio, higher gain and wider bandwidth, can be completely embedded into the top of a vehicle for installation, does not damage the mechanical structure and strength of the surface of vehicle-mounted equipment, has good omnidirectional radiation characteristic, light weight, simple structure, easy processing and vehicle-mounted installation, and has important significance for the application in the field of vehicle-mounted communication.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.