CN105186140B - A kind of small-sized broad beam double polarized micro strip antenna - Google Patents

Abstract

The invention discloses a small wide-beam dual-polarized microstrip antenna, which comprises a radiation substrate with four miniature radiation pieces attached and a feed network substrate embedded in a supporting frame, and the radiation substrate is located on the top of the feed network substrate ; There are two intersecting feeder wires on the feeder network substrate, and a metal base plate is attached to the bottom surface, and the crossing parts of the feeder wires are connected by a bridge element; a feeder probe is connected between each micro-radiating sheet and the feeder wires, and A short-circuit column is connected between each micro-radiating sheet and the metal base plate; in addition, a support column is located between the radiation base plate and the feed network base plate, and its two ends are respectively connected to the radiation base plate and the feed network base plate; one side of the bottom surface of the metal base plate There are radio frequency connectors, which are respectively connected to the feeders on the two cross feeders. The invention simultaneously realizes the miniaturization, wide beam and dual polarization characteristics of the microstrip antenna.

Description

A Small Wide Beam Dual Polarized Microstrip Antenna

technical field

The invention relates to a small-sized wide-beam dual-polarized microstrip antenna, in particular to a small-sized dual-polarized antenna terminal used as a mobile carrier.

Background technique

A dual-polarized antenna can transmit or receive two orthogonally polarized electromagnetic waves, so within the same frequency band, the antenna can simultaneously transmit or receive two signals. Therefore, one antenna can realize the function of two antennas, which can reduce the antenna cost and installation space; at the same time, the use of orthogonal polarization for the transceiver antenna can reduce the mutual coupling effect between the transceiver antennas and improve the communication quality; when the transceiver antennas work at the same time It can also expand the communication link and increase the communication capacity.

Commonly used dual-polarized antenna forms include orthogonal half-wave dipole antennas and dual-polarized microstrip antennas. The orthogonal half-wave oscillator adopts two half-wave oscillator antennas to be placed orthogonally, and the two antennas are respectively fed at the center. The antenna is bidirectional radiation with low gain. In order to obtain one-way radiation, 0.25λ on one side of the antenna is required. A reflector is placed at the position of -0.5λ, and the side length of the reflector is longer than the length of the half-wave dipole, so the size of the orthogonal half-wave dipole antenna is usually larger than 0.5λ×0.5λ×0.25λ. In the application of mobile carrier communication, the antenna is generally required to have a small size, especially the low profile characteristic of the antenna, which is especially obvious in the application of high-speed mobile carrier. The dual-polarized microstrip antenna has the characteristics of low profile of the microstrip antenna, but the lateral dimension of the microstrip antenna is large, and it is necessary to adopt miniaturization technology to reduce the lateral dimension of the antenna. But at the same time, it will bring problems such as narrowing of the frequency band.

In mobile communications, the antenna's wide-beam characteristics can provide better communication stability for the system and eliminate communication blind spots. Therefore, wide-beam microstrip antennas have always been a problem that needs to be solved urgently. While reducing the size of the dual-polarized microstrip antenna, the radiation proportion of surface waves will increase, and the beam width of the antenna will increase to 95°, but it still cannot meet the current requirements for wide beam performance. Therefore, under the condition of satisfying a certain working bandwidth, it is the main problem to be solved to realize the small size and wide beam of the dual-polarized microstrip antenna.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention aims to provide a small wide-beam dual-polarization microstrip antenna, which simultaneously realizes the small size, wide beam and dual-polarization characteristics of the microstrip antenna, and solves the problems of the traditional dual-polarization microstrip antenna. Performance flaws.

A small wide-beam dual-polarized microstrip antenna, including a feed network substrate embedded in a support frame and a radiation substrate connected to the top of the feed network substrate, the radiation substrate is provided with at least four discrete A microstrip radiation piece composed of a micro-radiation piece, and at least two cross-connected feed lines are arranged on the feed network substrate; in addition, at least one feed probe is connected between each micro-radiation piece and the feed line , wherein the top of the feeding probe is connected to the micro-radiating sheet, and the end is connected to the feeding line; the bottom of the feeding network substrate is attached with a metal base plate, and at least one is connected between each micro-radiating sheet and the metal base plate. A short-circuit column, the top of the short-circuit column is connected to the micro radiator, and the end is connected to the metal base plate through the feed network substrate; at least two radio frequency connectors are provided on the bottom side of the metal base plate, the top of which passes through the feed network substrate and the metal base plate. Feed line connection.

It should be noted that all the micro radiation sheets are arranged in a square shape.

It should be noted that the supporting frame is made of metal or insulating dielectric material, and the supporting frame is provided with flange holes for antenna installation. The supporting frame is used to support the feed network substrate and the radiation substrate.

It should be noted that both the radiation substrate and the feed network substrate are printed circuit boards.

It should be noted that corner holes are provided at one corner of each micro-radiating sheet, and each corner hole corresponds to the end of a feeder line, and the top of the corresponding feeding probe is inserted into the corner hole, while the end is Insert it at the end of the feeder line corresponding to the position of the corner hole.

It should be noted that the intersections of the feeder lines are connected by a bridge element of a sheet metal structure.

It should be noted that the micro radiating sheet is provided with a through hole, and the top of the corresponding short-circuit column is plugged into the through hole.

It should be noted that there is also a support column made of metal or insulating medium, and the top and end of the support column are respectively connected to the radiation substrate and the feed network substrate.

It should be noted that, a power feeding part is provided on the feeding line at a position corresponding to the radio frequency connector, and the top end of the radio frequency connector is specifically connected to the power feeding part.

It should be further noted that the radio frequency joint includes an inner core and an outer skin wrapping the inner core, the top of the inner core is connected to the feeder part of the feeder, and the top of the outer skin is welded to the bottom side of the metal base plate .

The beneficial effects of the present invention are:

1. The microstrip radiation piece of the present invention is composed of four discrete micro-radiation pieces, and is fed separately by a feed network. A pair of radiating sheets in the diagonal direction of the radiating substrate constitutes a linearly polarized working state, and the other pair of radiating sheets constitutes an orthogonal linearly polarized working state. Each miniature radiator works in omnidirectional radiation. When a pair of radiators are excited by equal-amplitude and anti-phase currents, a pattern with wide beam characteristics can be obtained right above the antenna. Due to the small size and compact structure of the four miniature radiators, the overall size of the antenna can be significantly smaller than that of the traditional microstrip antenna, and the beam width of the antenna can be significantly increased, which can reach 110°;

2. The four micro-radiators need to be fed separately through the feed network, and a pair of micro-radiators need to be excited with equal amplitude and opposite phase. The traditional feed network often adopts T-junction or power divider structure, but these structures are more complicated and difficult to realize in the small space of the present invention, so a double cross linear feed network structure is proposed: a pair of radiators pass through a The first bent feeder line is directly connected to feed power at a suitable position on the line, and the other pair of radiators is also connected and fed through a similar bent line. The intersection of the two feeder lines is isolated by a bridge element. The feeding network designed by the present invention has simple structure and superior performance, and can provide good feeding for four miniature radiators, and at the same time, the dual polarization state of the antenna also achieves good isolation;

3. The present invention also adopts a supporting frame structure, which is not available in traditional microstrip antennas. The supporting frame plays a role in supporting and shielding the antenna. When the supporting frame is made of metal, it can reduce the impact of the installation environment on the performance of the small antenna. The impact of the support frame is equipped with flange holes, which is convenient for the direct installation of the antenna.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the present invention;

Figure 2 is a schematic diagram of the layered structure of Figure 1;

Fig. 3 is a schematic structural diagram of the feed network substrate in Fig. 1;

Fig. 4 is a side view structural schematic diagram of Fig. 1;

Fig. 5 is the voltage standing wave ratio curve figure of two ports of antenna of the present invention;

Fig. 6 is the _S21 curve diagram of the antenna of the present invention;

Fig. 7 is the E plane gain pattern of antenna of the present invention;

Fig. 8 is an H-plane gain pattern of the antenna of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings. It should be noted that this embodiment is based on the technical solution and provides detailed implementation and specific operation instructions, but the scope of protection of the present invention is not limited to the present invention. Example.

As shown in Figures 1-4, a small wide-beam dual-polarized microstrip antenna includes a radiation substrate 1 and a feed network substrate 3 embedded in a supporting frame 2, and the radiation substrate 1 is located on the feed network substrate 3 the top of.

The base material of the radiating substrate 1 is a dielectric substrate, which is manufactured by printed circuit technology. The radiating substrate 1 is attached with four discrete micro-radiating sheets 101 and a number of soldering sheets 102. Specifically, a micro-radiating sheet 102 with a side length of 0.1λ-0.12λ can be used. The radiation sheet, the welding sheet 102 is used to connect the radiation substrate 1 to the top of the supporting frame 2 .

The support frame 2 is used to support the radiation substrate 1 and the feed network substrate 3. The support frame 2 is made of metal or insulating material; the support frame 2 plays the role of support and shielding. When it is made of metal, it can reduce the impact of the installation environment on the antenna. In addition, flange holes are provided on the support frame 2, which facilitates the direct installation of the antenna.

The feed network substrate 3 is embedded in the supporting frame 2. The base material of the feed network substrate 3 is also a dielectric substrate, which is manufactured by printed circuit technology. Two cross feed lines 301 are attached to the feed network substrate 3. There is a power feeder 302 with a metal bottom plate 303 attached to the bottom surface; the intersection of two feeder lines 301 is connected by a bridge element 4 with a metal sheet structure.

The small-sized wide-beam dual-polarized microstrip antenna also includes four feeding probes 5, and the ends of the feeding probes 5 are plugged into the end of a feeding line 301, specifically at the end of each feeding line Holes are provided such that the ends of the feeding probes 5 are inserted into the holes and soldered. And the top of the feeding probe is inserted into the corner hole of a micro radiation sheet 101 and welded.

The small wide-beam dual-polarized microstrip antenna also includes four short-circuit posts 6, the ends of the short-circuit posts 6 pass through the feed network substrate 3 and are welded to the metal base plate 303 attached to the bottom of the feed network substrate, and the top ends are inserted into the The through hole 103 of the radiation sheet 101 is soldered.

The small wide-beam dual-polarized microstrip antenna also includes a support column 7 made of insulating dielectric material, the top and end of which are respectively connected to the center of the radiation substrate 1 and the center of the feed network substrate 3 .

In addition, two radio frequency connectors 8 are provided on one side of the bottom surface of the metal bottom plate 303. The radio frequency connector 8 includes an inner core and an outer skin wrapping the inner core. The electrical part 302 is connected, and the top of the sheath is connected to the metal bottom plate 303 .

The microstrip radiation sheet of the radiation substrate 1 is composed of four discrete micro-radiation sheets 101 arranged in a square shape. Each micro-radiating sheet 101 is fed by a probe and grounded by a short-circuit column, so that each micro-radiating sheet can obtain an omnidirectional radiation pattern. When a pair of micro-radiating pieces in a diagonal position are fed with currents of equal amplitude and anti-phase, a wide beam pattern can be obtained in the upper half space of the antenna. At the same time, because the size of the four miniature radiators is small and the structure is compact, the antenna can realize the characteristic of miniaturization.

The feeder network adopts a double cross feeder structure, and the network structure is simple. A feeding line is connected to a pair of micro-radiating pieces through two feeding probes, and a suitable feeding position is determined on the feeding line through optimization. When the RF connector feeds high-frequency current, equal-amplitude and anti-phase currents can be obtained at both ends of the feeder line, and are fed into the micro-radiation sheet through the feeder probe. The same process is used for the other feeder line, where the two feeder lines intersect with a bridge element. The feed network designed by this method can improve the isolation of the dual polarization state of the antenna.

The thickness of the antenna of the present invention can be realized to be less than 0.07λ, and the lateral dimension can be realized to be less than 0.25λ, and the antenna also has the characteristics of wide beam and high isolation.

The following will illustrate the performance of the present invention through simulation experiments.

1. Simulation content

The voltage standing wave ratio, isolation, and gain pattern of the antenna of the above embodiment are simulated by using electromagnetic simulation software, as shown in FIGS. 5-8 .

2. Simulation results

Fig. 5 is a curve of VSWR varying with operating frequency obtained by simulating the antenna of the embodiment. The solid and dashed lines represent the VSWR of the two ports, respectively. It can be seen that the range of the solid line VSWR is less than 2 is 1.99-2.11GHz, the resonant frequency is 2.05GHz, and the bandwidth is 120MHz; the range of the dotted line VSWR is less than 2 is 2.17-2.33MHz, the resonant frequency is 2.25GHz, and the bandwidth is 160MHz . Calculation results show that the antenna of the invention can be well matched within the relative bandwidth of 5%-7%, which is an excellent characteristic among small resonant antennas and can meet the requirements of most narrow-band work. In this example, the two ports have different resonant frequencies. By adjusting the antenna parameters, the two resonant frequencies can be independently controlled in position, which increases the flexibility of the antenna design.

Fig. 6 is a curve of the _S21 parameter changing with the working frequency obtained by simulating the antenna of the embodiment. It can be seen from Fig. 6 that the antenna isolation of the present invention has a very wide range of greater than 20dB, and the antenna isolation is greater than 23dB in the range of 2GHz-2.3GHz. Such a good isolation can ensure the stability of the dual-polarization operation of the antenna and reduce the mutual influence of the dual-polarization states of the antenna.

Fig. 7 and Fig. 8 are the E-plane gain pattern and the H-plane gain pattern obtained by simulating the antenna of the embodiment. As can be seen from the figure, the maximum gain of the antenna of the present invention is 5.3dB, and the 3dB beamwidth of the E plane pattern reaches 110°, which is far greater than the 85° beamwidth of the traditional microstrip antenna, and the 3dB beamwidth of the H plane pattern The beam width has also reached 95°, which is also larger than that of traditional microstrip antennas. In mobile carrier communications, especially for high-speed mobile carriers, the attitude of the antenna changes rapidly. The wide beam pattern can ensure that the antenna has a high gain in a large angle range, which is conducive to improving the performance of the communication system.

For those skilled in the art, various corresponding changes and modifications can be made according to the above technical solutions and ideas, and all these changes and modifications should be included in the protection scope of the claims of the present invention.

Claims (1)

1. A small-sized wide-beam dual-polarization microstrip antenna is characterized in that, comprising a feed network substrate embedded in a support frame and a radiation substrate connected to the top of the feed network substrate, the radiation substrate is provided with A microstrip radiation sheet mainly composed of at least four discrete micro-radiation sheets, and at least two cross-connected feed lines are arranged on the feed network substrate; in addition, each micro-radiation sheet and the feed line are connected At least one feeding probe, wherein the top of the feeding probe is connected to the micro-radiating sheet, and the end is connected to the feeding line; the bottom of the feeding network substrate is attached with a metal base plate, and each micro-radiating sheet and the metal base plate At least one short-circuit column is connected between them, the top of the short-circuit column is connected to the micro-radiation piece, and the end passes through the feed network substrate to connect with the metal bottom plate; there are at least two radio frequency connectors on one side of the bottom surface of the metal bottom plate, and the top end of the short-circuit column passes through the The overfeed network substrate is connected to the feeder; All micro-radiating sheets are arranged in a square shape; The supporting frame is made of metal or insulating material, and the supporting frame is equipped with flange holes for antenna installation; Both the radiation substrate and the feed network substrate are printed circuit boards; One corner of each micro-radiating sheet is provided with a corner hole, and each corner hole corresponds to the end of a feeding line, the top of the corresponding feeding probe is plugged into the corner hole, and the end is plugged into the corner hole. The end of the feeder corresponding to the position of the corner hole; The intersections of the feeders are connected by bridge elements of sheet metal structure; A through hole is provided on the miniature radiator, and the top of the corresponding short-circuit column is plugged into the through hole; There is also a support column made of metal or insulating medium material, and the top and end of the support column are respectively connected to the radiation substrate and the feed network substrate; A feeder is provided on the feeder at a position corresponding to the radio frequency connector, and the top end of the radio frequency connector is specifically connected to the feeder; The radio frequency connector includes an inner core and an outer skin wrapping the inner core. The top end of the inner core is connected to the feeder portion of the feeder line, and the top end of the outer skin is welded to the bottom side of the metal base plate.