CN102683827A - Bidirectional radiating antenna used in mine shafts and tunnels - Google Patents
Bidirectional radiating antenna used in mine shafts and tunnels Download PDFInfo
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- CN102683827A CN102683827A CN2012101859884A CN201210185988A CN102683827A CN 102683827 A CN102683827 A CN 102683827A CN 2012101859884 A CN2012101859884 A CN 2012101859884A CN 201210185988 A CN201210185988 A CN 201210185988A CN 102683827 A CN102683827 A CN 102683827A
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Abstract
The invention discloses a bidirectional radiating antenna used in mine shafts and tunnels, belonging to the field of antenna design in wireless communication. The bidirectional radiating antenna is characterized in that a rectangular metal frame is stimulated by a short metal post, wherein the metal frame works in a one-wavelength mode, two narrow sides of the metal frame are radiating main bodies, the distance between the two narrow sides is a little bit smaller than half wavelength, the radiating main bodies form an array and realize the bidirectional radiating with higher gain, the bidirectional radiating antenna can be matched better at a feed port by regulating the height and the diameter of the short metal bars, the long side length and the narrow side length of the metal frame and the width of the metal frame, and the bidirectional radiating property with higher gain is realized. The bidirectional radiating antenna has the advantages of being small in volume, small in windward area, low in cost, easy to process, high in gain and the like, is suitable for realizing wireless communication in the classical space-limited non-free space propagation channels, such as the mine shafts and the tunnels.
Description
Technical field
The present invention relates to a kind of bidirectional antenna, be applicable to and realize reliable radio communication in mine, the tunnel, belong to the Antenna Design field of wireless communication technology.
Background technology
In this year, China's mining manufacture safety accident takes place again and again, has caused social extensive concern, and safety in production becomes focus.Mine communication is as the scheduling overall situation, and command in the front, and the necessary means of security monitoring also more and more receives publicity.In mine communication system, be divided into wire communication and radio communication.The mine communication scheme of early stage comparative maturity all is to adopt wired communication mode, i.e. telephone line or leaky cable basically both at home and abroad.Yet in mine communication system, wire communication exists problems: at first, under mine, mine has several kilometers usually, even tens kilometers, the laying cost of cable is higher, safeguards also relatively difficulty; Secondly, the most mines of China are through the man-made recovery, and mining sequence is many, and operating location disperses, and flow of personnel property is big, and wire communication is difficult to satisfy so flexibly uses; Once more, in the wired communication system, the loss of cable is bigger, thereby needs the increase repeater to increase communication distance, has increased the complexity and the cost expense of system, and too much repeater makes background noise sharply increase, and can reduce communication quality on the contrary; In addition, the fault of any one relay station will cause follow-up communication paralysis.
Along with coal mining enterprise is information-based, development of modernization, the introducing of radio communication can make the operating personnel and the commander place of down-hole, and keeps in touch whenever and wherever possible between the operating personnel, improves organizational efficiency, operating efficiency.When breaking down, during dangerous situation, can find rapidly, and organize counter-measure, safeguard work personnel's personal safety.
When adopting communication, at first need consider the characteristics of radio channels of mine in the down-hole.Mine is a non-free space propagation channel that typical space is limited; When electromagnetic wave is propagated therein,, thereby produce significant multipath effect because the object of irregular distribution causes frequent reflection, diffraction, scattering in tunnel wall and the mine; Simultaneously; Electromagnetic wave receives the absorption and the reflection of rock, ore etc. in the mine, and it is very fast to decay, and transmission range shortens greatly.In order to ensure the reliability of radio communication, in mine, need a lot of radio nodes, cause system cost to increase, in order to reduce cost, we at first need increase the coverage of each radio node.From aerial angle, solution is to adopt the antenna of the bidirectional characteristic with higher gain, with the direction that main radiation direction is aimed at the mine internal channel, can resist the electromagnetic transmission loss like this, increases the area coverage of each relay base station.Secondly, need to reduce the cost of each radio node.The antenna implementation helps to reduce the cost of system cheaply.Therefore, research has low cost, and the antenna of the bidirectional of higher gain has great importance for radio communication under the mine.
Secondly, carry out radio communication in the down-hole, also will consider the particular surroundings of down-hole.As high-risk workplace, contain a large amount of gas (CH in the mine usually
4, CO), any Mars all possibly cause serious blast.In order to guarantee underground work personnel's personal safety, any equipment that is applied to the down-hole all must satisfy the requirement that national security is produced through through explosion-proof test.Any parts that possibly produce spark in the wireless communication system when using in the down-hole, all must apply certain blast resistance construction.Simply, can system be placed special armored cassette.But this also is not suitable for the explosion-proof of antenna.As radio-frequency front-end, antenna need also need receive electromagnetic wave to the free space radiated electromagnetic wave from free space, thereby antenna must contact with free space, that is to say that antenna part must be exposed in the air.The feed circuit of antenna must be positioned in the armored cassette, and antenna structure places among the air again, and just to the structure of entire antenna, the feeding classification design has proposed great challenge for this.Fully, reasonable use armored cassette structure, with antenna, feed, explosion-proof combining together cleverly is another requirement to Antenna Design under the mine.
In addition, well-known, the space, down-hole is narrow and small, and in order not hinder normal exploitation work, the volume of communication system can not be too big; Consider under the down-hole, particularly coal mine CH in addition
4, gas contents such as CO substantially exceed ground surface, in order to prevent blast and to suffocate, guarantee oxygen content, in the down-hole wind station must be arranged, and require wind speed to maintain 2-6m/s, thereby the communication system branch should not hinder ventilation.Consider that from aerial angle miniaturization Design is necessary.In the time of also will guaranteeing the antenna operate as normal simultaneously, can not hinder ventilation, promptly those have the antenna of high surface area not to be suitable for underground communica tion.Thereby little windage face need be considered in also designing.
Also have some other factor to take all factors into consideration,, be suspended in airborne ore particles (possibly conduct electricity) in a large number and be deposited on the influence of system surfaces system like the influence of high humility for feed circuit.Generally speaking, the abominable natural environment under the mine has proposed all challenges to underground radio communication, as the antenna foremost of wireless communication system, because its particularity has been born more complicated requirement.Have low cost, simple in structure and easy and explosion protection system combines, and volume is little, and the windage face is little, and the antenna of the bidirectional of higher gain will have good prospects for application in underground communica tion.
Research or design about the down-hole application antenna that meets above requirement still are fewer.Most researchs are energy to be concentrated on how to realize on the bidirectional; Being described below. two traditional secondary back-to-back Yagi antennas can be realized two-way end-fire radiation; It is all identical that yet feed need be divided into the two-way width of cloth through the 3dB power splitter; Phase place on the contrary to signal feed respectively, the Yagi antenna length of being made up of Unit 12 is 2.2 λ
0(λ
0Be the pairing free space wavelength of operating frequency), gaining is 12.25dB.When group battle array realized bidirectional back-to-back, the antenna array overall size was approximately 4.4 λ
0* 0.5 λ
0, and maximum gain has only 9.25dB.Back-to-back patch antenna array also can be realized the bidirectional characteristic.When encouraging back-to-back paster through coplanar waveguide structure, its antenna pattern is an omnidirectional, through the group battle array, can realize bidirectional.The common issue with of these two kinds of antennas is antenna structure, the feed structure more complicated, and antenna size is bigger, and cost is relatively also higher.Slot antenna is a kind of antenna of fairly simple realization bidirectional.Through cutting on a metallic plate, can realize the bidirectional about 5dBi.Yet, need be during slot antenna work with metallic plate perpendicular to the mine direction, the metallic plate required owing to slot antenna is bigger, is positioned over the circulation that can hinder air in the mine, and also there is this problem in back-to-back patch array above-mentioned.Notch antenna also can be a bidirectional.It digs defective paster through above the floor, placing two ends, through reverse probe excitation, has realized the bidirectional of double frequency; Lower frequency is by defective paster mode producing, and upper frequency is produced by feed probes (being similar to the antenna of falling L), but its gain has only 0.83dBi; Through respectively increase by three parasitic elements that play the director effect at two ends after; Its gain can reach 5.71dBi, in order to reduce the cross-polarization levels of H face, on the basis of above-mentioned antenna, revises; Formed crank type antenna, cross-polarization levels has obtained the improvement of 17.6dB.Under mine, floating dust is many especially, particularly in the colliery; Coal particles has conductive characteristic, be accumulated in antenna surface easily, and notch antenna just in time is a horizontal positioned; Be very easy on the big metallic plate of level pile up floating dust, these floating dust will have a strong impact on the operate as normal of antenna.Helical antenna is known with broadband circle polarized characteristic behaviour.This radiation pattern also is two-way.But it is lower to gain, and has only about 2dBi.Paster antenna also can be realized bidirectional when the size the same with top paster of following floor, but when antenna is very thin, and its radiation gain very low has only-2dBi, must promote gain with director.
How it should be noted that the above Antenna Design of mentioning is not all considered combines with explosion protection system.Thereby we can say really can be few at the antenna of down-hole application.
Therefore, research, design are a kind of simple in structure, and easily with the explosion protection system combination, with low cost, the bidirectional antenna of little front face area, higher gain plays crucial effects to radio communication under the mine.
Summary of the invention
The purpose of this invention is to provide a kind of simple in structure, easy and explosion protection system combination, low cost, front face area is little, the design of the bidirectional antenna of higher gain.This bidirectional antenna works in 909-923MHz.Through short metal column excitation rectangular metal frame, produce bidirectional.Radiating principal is the in-phase current on the narrow limit of rectangular metal frame.The total length of metal frame is approximately 1 λ
0If regard metal frame as one section very short rectangular waveguide, the length of long sides of metal frame is less than 0.5 λ
0, so as the basic mode TE of waveguide
10Pattern is ended.The short metal column height of feed has only 0.045 λ
0So the overall structure height is very low.Because overall structure symmetry, need not power distributing network, energy is through short metal column, and to metal frame, the formation bidirectional makes feed structure succinct naturally.This bidirectional antenna feed only needs a half steel coaxial feeder.The inner wire of said half steel coaxial feeder is connected on the short metal column, and outer conductor is connected to metal frame.The antenna overall structure is simple, and feeding classification is succinct, and processing is simple, and this makes said bidirectional antenna be easy to be integrated together with armored cassette.Metal frame can be accomplished through folding rectangular metal sheet, and when said bidirectional antenna was worked, windage was very little, and this bidirectional antenna actual measurement bi-directional gain 5.8dBi has good bidirectional ability.
The invention is characterized in, contain rectangular metal frame 1, do the short metal column 2 that short probe is used, half steel coaxial feeder 3, wherein:
Rectangular metal frame 1 is a rectangular metal ring as antenna body, and said rectangular metal frame is to form by the strip sheet metal is folding; The short brink sealing; Long side opens wide, and the upper surface center position has one because of the folding slit that produces, and the center position place has an aperture in the lower surface; Hole diameter is equal to or slightly less than the diameter of said half steel coaxial feeder 3, and the girth of said rectangular metal ring is about 1 λ
0, length of long sides is 0.45 λ
0, be slightly less than 0.5 λ
0, length of short sides is 0.06 λ
0, short metal column height is 0.045 λ
0, λ
0Be the pairing free space wavelength of operating frequency, this bidirectional antenna working frequency range is 909MHz-923MHz,
Half steel coaxial feeder 3 is made up of outer conductor and inner wire; Described outer conductor is welded on the said center position place in the outside, said rectangular metal frame 1 lower surface; Coaxial with said aperture; Inner wire is incorporated in the said rectangular metal frame 1, links to each other with an outside, lower surface of sealing that use as probe and short metal column 2 that be positioned at said rectangular metal frame 1 all around.
2. the bidirectional antenna that is applied to mine, tunnel according to claim 1 is characterized in that: the diameter of said half steel coaxial feeder 3 is 3.5mm, and characteristic impedance is 50 Ω.
The present invention has compact conformation, miniaturization, little, the flexible design of windage area, and cost is low, and the advantage of higher bidirectional gain is applicable to and realizes reliable radio communication in mine, the tunnel.
Description of drawings
Fig. 1 is a bidirectional antenna graphics provided by the invention, and solid line is the actual profile of seeing, dotted line is the profile that is blocked.
Fig. 2 be the A of Fig. 1 to view, dotted line is the profile that is blocked.
Fig. 3 be the B of Fig. 1 to view, dotted line is the profile that is blocked.
Fig. 4 is the embodiment dimensional drawing of the A of Fig. 1 to view structure, and unit is millimeter (mm).
Fig. 5 is the embodiment dimensional drawing of the B of Fig. 2 to view structure, and unit is millimeter (mm).
Fig. 6 is the return loss plot (S11) that is used for the bidirectional antenna under the mine of Fig. 6-Fig. 7 embodiment :-▲-.
Power gain directional diagram when Fig. 7 works in 916MHz for the bidirectional antenna of the embodiment of Fig. 4-Fig. 5: (■-: cross polar component power gain directional diagram;-▲-: co-polarization component power gain directional diagram): (a): X-Y plane power gain directional diagram; (b): X-Z planar power gain pattern.
Embodiment
The present invention provides a kind of bidirectional antenna that is applied to mine, tunnel, and specific embodiments comprises:
Rectangular metal frame 1 is to form by the sheet metal of strip is folding as antenna body, and its upper surface 11 is not closed.Its lower surface 12 center positions are made a call to one aperture 15, and the diameter of aperture is equal to or slightly less than the diameter of half steel coaxial feeder 3.The outer conductor 31 of half steel coaxial feeder is welded on the lower surface 12 of rectangular metal frame, and inner wire 32 reaches the inside of metal frame 1, welds together with short metal column 2.
Like Fig. 1-shown in Figure 3, antenna system comprises rectangular metal frame 1, short metal column 2 and half steel coaxial feeder 3.The diameter of half steel coaxial cable 3 is 3.5mm, and characteristic impedance is 50 ohm.When by half steel coaxial cable 3 feeds, signal path is: half steel coaxial cable 3-metal column 2-becket 1-free space.
Technical scheme of the present invention is achieved in that through the coaxial feeder feed, has encouraged the basic mode of metal frame, for this energisation mode, the electric current self feeding point of metal frame basic mode up to becket upper surface midpoint direction not to, i.e. phase invariant.The girth of whole metal frame is approximately an operation wavelength.On two narrow limits of metal frame, stronger same-phase electric current is arranged like this, become radiating principal, and last (descending) surface current of metal frame is reverse, its space radiation will have and offset to a great extent, thereby very little to the whole radiation contributions of antenna.Metal frame is just simplified the radiation that becomes two narrow limits like this.So just can instruct Antenna Design with the viewpoint of array.Regard two narrow limits two unit of array as, in order to improve gain and to guarantee that current-mode is constant, need broadside be broadened, draw back the spacing on two radiating principals (narrow limit) as far as possible, this is equivalent to the spacing that increases array element.When two array element spacings increases, it is big that antenna array gain also becomes thereupon.Because about 1 λ of length of whole metal frame
0, there is certain altitude to carry out radiation for guaranteeing two narrow limits, the long edge lengths of becket is chosen as 0.45 λ
0, slightly be shorter than 0.5 λ
0Through adjusting the height of short metal column, diameter, the length of long sides of metal frame, and the width of fine setting metal frame matees in required frequency range to realize said bidirectional antenna.For making said bidirectional antenna structure more solid; Metal frame has certain width, but width can not be excessive, otherwise said bidirectional antenna just can not be understood with the angle of current-mode again; But will understand through the angle of waveguide, promptly bidirectional is because two actinal surfaces of waveguide are realized.From the angle of making,, at first need a sheet metal with certain thickness strip for easy making process; Its width equals the width of antenna metal frame; Its length equals the girth of metal frame, and the strip sheet metal is bent, and just can be processed into the required becket of antenna.Obviously the metal frame that processes so is not closed, thereby, at the beginning of designing antenna, just this point is taken into account, promptly design an inc metal frame.The electric current of noting said bidirectional antenna is in the upper surface midpoint, and promptly not closed place is exactly current zero originally, needs only opening much smaller than wavelength, and such design can not influence said bidirectional antenna operate as normal.Said bidirectional antenna belongs to all-metal construction, and feed structure is succinct, and in practical application, said bidirectional antenna can combine with armored cassette, and feeder cable can be hidden in the armored cassette, makes the entire antenna design satisfy requirement of explosion.
This structure specifies as follows:
Realize the requirement of operating frequency at first as requested, design the wide and high of metal frame, wide and high requirement has 2 points to metal frame: the girth of at first whole frame should be about a wavelength; The spacing on next two narrow limit; The long edge lengths that is metal frame should be slightly less than half-wavelength, and the reason of adjustment is following like this: be in order to obtain enough big array factor, two narrow limits (main radiant body) should be apart about half-wavelength; Promptly work as the height of the height of short metal column (probe) a little less than metal frame; The long limit of fine setting metal frame, narrow limit makes the directivity of metal frame reach near the operating frequency about 6dBi; Can further adjust the height of short metal column then, diameter, the width of becket is so that entire antenna is in required working frequency range coupling.Each part size such as Fig. 4-shown in Figure 5, unit is millimeter (mm).
S11 test result with the bidirectional antenna of Fig. 4-sized shown in Figure 5 is as shown in Figure 6, and the resonance frequency of this bidirectional antenna is 916MHz, and <bandwidth of 10dB is 909-923MHz to return loss S11.
Power gain direction when working in 916MHz with the bidirectional antenna of Fig. 4-sized shown in Figure 5 is shown in Figure 7.E face (X-Z plane) and H face (X-Y plane) directional diagram are similar to down 8 types; Can know that said bidirectional antenna has been realized bidirectional.Bidirectional antenna overall structure is simple simultaneously, and feeding classification is succinct, very easily processing, and cost of manufacture is low, owing to adopt sheet metal to process, during this antenna work, does not almost have windage.The present invention is that Antenna Design provides solution in the radio communication in mine, tunnel.
Bidirectional antenna of the present invention can the corresponding size of adjusting said antenna according to the vocational work frequency.The present invention is highly suitable for the radio communication of strips such as mine, tunnel.
Claims (2)
1. be applied to the bidirectional antenna in mine, tunnel, it is characterized in that, contain: rectangular metal frame (1), do short metal column (2) and half steel coaxial feeder (3) that short probe is used, wherein:
Rectangular metal frame (1) is a rectangular metal ring as antenna body, and said rectangular metal frame is to form by the strip sheet metal is folding; The short brink sealing; Long side opens wide, and the upper surface center position has one because of the folding slit that produces, and the center position place has an aperture in the lower surface; Hole diameter is equal to or slightly less than the diameter of said half steel coaxial feeder (3), and the girth of said rectangular metal ring is about 1 λ
0, length of long sides is 0.45 λ
0, be slightly less than 0.5 λ
0, length of short sides is 0.06 λ
0, short metal column height is 0.045 λ
0, λ
0Be the pairing free space wavelength of operating frequency, this bidirectional antenna working frequency range is 909MHz-923MHz,
Half steel coaxial feeder (3) is made up of outer conductor and inner wire; Described outer conductor is welded on the said center position place in the outside, said rectangular metal frame (1) lower surface; Coaxial with said aperture; Inner wire is incorporated in the said rectangular metal frame (1), links to each other with an outside, lower surface of sealing that use as probe and short metal column (2) that be positioned at said rectangular metal frame (1) all around.
2. the bidirectional antenna that is applied to mine, tunnel according to claim 1 is characterized in that: the diameter of said half steel coaxial feeder (3) is 3.5mm, and characteristic impedance is 50 Ω.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012101859884A CN102683827A (en) | 2012-06-07 | 2012-06-07 | Bidirectional radiating antenna used in mine shafts and tunnels |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012101859884A CN102683827A (en) | 2012-06-07 | 2012-06-07 | Bidirectional radiating antenna used in mine shafts and tunnels |
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|---|---|
| CN102683827A true CN102683827A (en) | 2012-09-19 |
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|---|---|---|---|
| CN2012101859884A Pending CN102683827A (en) | 2012-06-07 | 2012-06-07 | Bidirectional radiating antenna used in mine shafts and tunnels |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102938501A (en) * | 2012-12-10 | 2013-02-20 | 厦门大学 | Broadband bidirectional microstrip antenna |
| CN105655716A (en) * | 2014-11-13 | 2016-06-08 | 航天信息股份有限公司 | Microstrip antenna apparatus |
| CN107591612A (en) * | 2017-09-18 | 2018-01-16 | 苏州厚立智能科技有限公司 | A kind of two-way wave beam constrains formula car antenna |
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| CN2561107Y (en) * | 2002-08-12 | 2003-07-16 | 西安海天天线科技股份有限公司 | Broadband bilateral antenna and bilateral antenna array |
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|---|---|---|---|---|
| CN2561107Y (en) * | 2002-08-12 | 2003-07-16 | 西安海天天线科技股份有限公司 | Broadband bilateral antenna and bilateral antenna array |
| CN102231455A (en) * | 2010-07-27 | 2011-11-02 | 京信通信系统（中国）有限公司 | Gallery mobile communication coverage and distribution system and ultra broadband bidirectional radiating antenna |
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| S.LAMULTREE: "Full-wave investigations of a probe-excited rectangular ring antenna by method of moments with rwg basis functions", 《PROGRESS IN ELECTROMAGNETICS RESEARCH C 》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102938501A (en) * | 2012-12-10 | 2013-02-20 | 厦门大学 | Broadband bidirectional microstrip antenna |
| CN102938501B (en) * | 2012-12-10 | 2014-09-03 | 厦门大学 | Broadband bidirectional microstrip antenna |
| CN105655716A (en) * | 2014-11-13 | 2016-06-08 | 航天信息股份有限公司 | Microstrip antenna apparatus |
| CN105655716B (en) * | 2014-11-13 | 2020-06-12 | 航天信息股份有限公司 | Microstrip antenna device |
| CN107591612A (en) * | 2017-09-18 | 2018-01-16 | 苏州厚立智能科技有限公司 | A kind of two-way wave beam constrains formula car antenna |
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Application publication date: 20120919 |