自制2.4GHz全向天线分步指南.pdf

自制自制 2.4GHz2.4GHz 全向天线分步指南全向天线分步指南 Easy Homemade 2.4 Ghz Omni Antenna 自制 2.4 Ghz 全向天线分步指南自制 2.4 Ghz 全向天线分步指南 An easy step-by-step guide go making a homemade wireless antenna,for a fraction of the cost of commercial antenna.Uses readily available parts,and requires no specialist tools or knowledge.Or in geek speak-a diy homebrew omnidirectional colinear dipole design suitable for 802.11 wifi compatible hardware with external antenna connector.一个简单的分步指南带我们自制无线天线，其成本只是商业天线的一小部分。使用现成的零件，而无需专门的工具和知识。或者如 geek 所说一个自制的全向的共线偶极子，设计与 802.11 兼容的无线外接天线。Introduction Getting The Parts Cutting The Pieces Build A Jig Testing Problems Disclaimer Introduction 介绍介绍 Most of the designs on the web for 2.4 GHz omni antenna seem to involve brass tubing and lmr-400 cable,none of which are readily available to me.I then found a coax only design for 444Mhz that was based on the same idea.The only reasonable cable I could get my hands on was RG-213 from Maplin.By scaling the 444Mhz design up to 2.4 Ghz and using RG-213 I thought Id have a go.In order to get about 6db gain from the antenna,it would need 8 sectors,with a 1/4 wave section at the top and a fly-lead with N-connector at the bottom.It should take about 2-3 hours to build an antenna using this design,but dont worry if it takes longer,you will get quicker,especially as you only need to make the jig once.大多数网络设计的 2.4 GHz的全向天线，似乎大部分涉及铜管材和LMR-400同轴电缆，对我都不适用。后来我发现了一个只使用同轴电缆的为 444Mhz设计的天线，而我手头正好就有从Maplin买的RG213 同轴电缆。就采用我已有的RG-213，把 444Mhz的设计扩大至 2.4 GHz。为了使天线获得大约 6dB的增益，上端需要有 1/4 波长的电缆 8 截，底部有一个带N型连接器的引线。采用该设计建造一个天线大约需要 2-3 小时，如果你不想花费太多的时间，你只需要制作一个模具，就会做的更快。1 自制自制 2.4GHz2.4GHz 全向天线分步指南全向天线分步指南 Most of the designs either had toroid magnets or a decoupler on the fly-lead of the antenna.However the location of the decoupler seems different in each design,and some designs quoted a decoupler length of 1/4 wavelength,others were!/4 wavelength times the velocity factor of the decoupler tube(brass tube quoted at 0.95).Ive tried most locations and can report that without proper testing kit I can see no difference in the Signal to Noise ratio between having a decoupler and not.I decided to not bother as it simplified the design.If anyone knows a good reason why you must have a decoupler then I would love to know(especially if you know where it should be exactly).If you want to add a decoupler,please do,I found using 15mm or 22mm copper tube and a 15mm or 22mm end stop made a good design,just needing to be soldered together to get the right length,and a hole drilled in the end of the end stop to fit the cable.在天线的引线部分，大部分的设计不是使用环形磁铁就是一个去耦电路。然而去耦器的位置似乎却每个设计都不同，有的设计用了一个长度为 1/4 波长的去耦器，其他的去耦管长度是 1/4 波长乘以速度因子（铜管是 0.95）。我已经试过大多数位置，并可以告诉你，如果你没有配套的测试设备，我认为，有没有去耦装置，对信号的信噪比没有什么差别。我决定不理会它，以简化设计。如果有人知道为什么必须有去耦器的充足理由的话，我很想知道（特别是你准确地知道它应该在哪个位置）。当然，如果你想添加一个去耦器，尽管做一个好了，我发现使用 15 毫米（或 22 毫米）的铜管和 15 毫米（或 22 毫米）的终端挡板，是一个很好的设计，只需要焊接在一起，得到正确的长度，并在终端挡板钻一个洞，用来安装电缆。Each sector of the antenna needs to be a 1/2 wavelength long multiplied by the velocity factor of the cable.The velocity factor of RG-213 is 0.66.If you decide to use different cable(such as LMR-400)then you need to get the velocity factor of that cable(which will be different),and recalculate all the dimensions.天线的每一截的长度，必须是 1/2 波长长度乘以电缆的速度因子。RG213 的速度因子是 0.66。如果您决定使用不同的电缆（如 LMR-400），那么您需要获取该电缆的速度因子（这将会有所不同），并重新计算所有尺寸。V*C 0.66*299792458 1/2 wavelength=-=-=0.0405m=40.5mm 2*F 2*2441000000 2 自制自制 2.4GHz2.4GHz 全向天线分步指南全向天线分步指南 V=Velocity Factor of RG213=0.66 V=RG213 的速度因子=0.66 C=speed of light=299792458 C=光速=299792458 F=Frequency of Signal=2441000000(middle of 2.4ghz range)F=信号的频率=2441000000(2.4ghz 频段的中间频率)The 1/4 wave element is not adjusted by the Velocity factor,as it is in the open,so works out at just 31mm long giving a total antenna length of 355mm+fly-lead.(Thanks to Oscar for correcting me of this.)1/4 波长的振子不用速度因子调整，因为它是开放的，因此计算出正好是 31mm长，天线全长 366mm引线。（感谢 Oscar 纠正我此问题。）Getting the parts 获取零件获取零件 All of the parts are available cheaply from either Maplin and any diy shop.所有的零件都是从 Maplin 和任何 DIY 商店买的便宜货。1m RG-213U cable(available by the meter from Maplin).This is enough for 2 antenna.Buy more for whatever flylead length you want.1 米的 RG-213U 电缆（可从 Maplin 买）。这足够 2 个天线。再买些你想要的长度的引线。N connectors,Depending on what you want to connect to,use either male or female connectors,and inline or bulkhead.Remember inline connectors need to fit 10mm diameter RG-213 cable N 型连接器，根据你准备连接的方式，可使用公头或者母头，内芯或连接器。记住连接器内芯需要配合直径 10mm 的 RG-213 电缆。20mm pvc conduit(available from any diy store)Has a 20mm inside diameter,and 22mm outside.20 毫米聚氯乙烯导管（从任何自助商店可得到），内径 20 毫米，外径 22毫米。22mm pipe clips(depending on how you want to mount the antenna),pipe clips make it easy to mount and unmount,or use the proper conduit brackets(but they seem a little expensive).22 毫米管卡（视你如何安装天线而定），管卡使天线很容易地安装和卸载，或使用合适的导管壁架（但他们似乎有点贵）。You dont need any special tools 你不需要任何特殊的工具 mm rule for measuring!毫米尺用于测量！3 自制自制 2.4GHz2.4GHz 全向天线分步指南全向天线分步指南 junior hacksaw 简易的钢锯 stanley knife 斯坦利刀 pliers 老虎钳 standard soldering iron(dont need a heavy duty one)and solder 标准电烙铁（不需要重型的）和焊锡 off cuts of wood to make a jig to aid soldering 木制夹具帮助焊接 bench or vice to hold cable while you cut it 长凳或老虎钳，在你切割电缆时夹住它 Cut the pieces 切割成段切割成段 After much trial and error,I found that the neatest way to cut the cable is actually with a junior hacksaw.It gives a much cleaner finish than wirecutters.Each sector consists of a short length of RG-213 cable,with the central core sticking out each end.经过多次反复试验，我发现最简单的方法实际上是用一个简易钢锯切断电缆。它比钢丝钳更干净利索。每一节由一段 RG-213 电缆组成，中心芯线突出每个末端一截。When building the antenna,the exact length of each piece of RG-213 is not that important,it is the overall length of each sector that counts.I found that cutting the cable to 37mm with 6mm of core sticking out each end,gets enough overlap to easily solder the segments together.If you allow 1mm for the width of the hacksaw when cutting the sectors apart,it means you need 37+6+6+1=50mm of cable for each sector making 8sectors+1/4wave section come to 420 mm of cable for the antenna+cable for the fly lead.制作天线时，RG-213 每段的准确长度并不重要，总长度是每一节加起来。我发现，切割 37 毫米的电缆留出 6 毫米的芯线铜线，足够很容易地把每段电缆重叠地焊在一起的。如果您切割时留出 1 毫米的钢锯宽度，这意味着你需要 37+6+6+1=50 毫米的每节电缆，制作 8 节+1/4 波长总计 420 毫米的电缆做为天线+用作引线的电缆。4 自制自制 2.4GHz2.4GHz 全向天线分步指南全向天线分步指南 The best way to cut each sector is to make the cuts where each end of the sheathed section of the sector will be,before making the cut between each sector.The picture below shows the top 3 sections of the antenna,and the 1/4 wave section,showing the order that the cuts should be made.切割每一节的最好的办法是，在切断每一节之前，要先把每一节的末端区域切割好。下图显示天线的前 3 节和 1/4 波长的一截，显示了切割的次序。The best way to make the cuts is to mark them out on the cable first.When sawing the cable it has a tendancy（tendency？）to deform and bend,so lightly sawing round the outside sheath first,but not cutting through,helps give a guide to the cutting for real.I use the junior hacksaw to gently saw round the cable sheath to make the mark for each section.切割之前最好先在电缆上做出标记。在锯电缆时，电缆有变形和弯曲的趋势，先轻轻地绕着外包装锯，但不要锯穿，为真正的切割提供一个引导。我使用简易钢锯轻轻地围绕电缆护套锯一圈，给每一节做好标记。The first mark will be at 31mm from the end,which is for the 1/4 wave section at the top.Once you have made the mark,it is time to cut round the cable.You want to cut through the sheath,shielding,and just into the central insulation,but not into the central copper wires.You may need to practice a bit first,but you should be able to feel as you cut through the shielding into the central insulation.By leaving plenty of sheathed section either side of the cuts,the shielding stays in place when being cut.第一个标记在离末端 31 毫米处，它是顶部的 1/4 波长的部分。一旦你做出标记，就是你围绕电缆切割的时候了。你想切透外部覆盖物，屏蔽层，刚刚到达5 自制自制 2.4GHz2.4GHz 全向天线分步指南全向天线分步指南 中间的绝缘材料，但没有到达中间的铜线。您可能需要先练习一下，但你应该能够感觉到你切透屏蔽层到达中间绝缘层。每一端都切割掉大量的护套和屏蔽层。Now with pliers,gently twist off the end 31mm of sheath&shielding 用老虎钳轻轻扭断 31mm 末端的外包物和屏蔽层。This should leave the cenral（central？）insulator exposed.Using the stanley knife score round through the central insulator,but not too hard,or you will cut the central cable.Now twist off the insulation.You should be able to see the twist in the central cable through the insulation,which will show you which way to twist off the insulation,resulting in the central core twisting more tightly.这时应该分离暴露出来的中间绝缘体。使用斯坦利刀围绕绝缘体切割，但不要太重，否则将切断电缆芯线。然后，拧断绝缘层。您应该可以看到缠绕的电缆芯线穿过绝缘层，这将提示你该朝那个方向拧断绝缘层，拧掉绝缘层之后，中间的芯线应该缠绕的更加紧密。The next mark is 37mm down(68mm from end of the cable)and is the cut for other end of the sheathed section of the top sector.The next mark is 13mm down(consists of 6mm core from each sector and 1mm for cut between sectors)(81mm from end)and is the top of the sheathed section of the second sector.The next mark is 37mm down,then 13mm,then 37mm,and so on and so forth until you have each of the sheathed sections marked out.6 自制自制 2.4GHz2.4GHz 全向天线分步指南全向天线分步指南 下一个标记是往下的 37 毫米（距电缆的末端 68 毫米），是切断顶部一节的另一端的外包物。下一个标记是 13 毫米（是每一节的 6 毫米芯线和各节之间的1 毫米的切割口的长度）（从末端算 81 毫米），是第二节护套部分的顶部。下一个标记是 37 毫米，然后 13 毫米，然后 37 毫米，依此类推，直到每一节都做好标记。You can now start making the cuts,remembering to only cut through the sheath,shielding and just into the central insulation.First make the cut at 37mm down,then the next cut a further 13mm down.You may find that some of the shielding pulls out when you make this cut,as the 13mm length of sheath cannot hold the shielding tight enough.Dont worry,it doesnt matter.您现在可以开始切割，记住只切透外层覆盖和屏蔽层，刚刚到达绝缘层。首先，切割 37 毫米，然后再切 13 毫米。您可能会发现，当你切割时，一些屏蔽层散开了，因为 13 毫米长度的外层覆盖，不能足够紧的包裹住屏蔽层。不要担心，没关系。Now you are ready to cut off the top sector from the cable.You want to cut through the whole cable at the mid point of the two cuts you have just made,that is about 43.5 mm from the end of the sheath,or 74.5 mm from the end of the cable.See position 4 in the diagram above.Just saw carefully the whole way through the cable.现在您可以从电缆切下顶部的一节了。在你刚刚完成的两个切口的中间点切断整个电缆，即距末端外层覆盖物大约 43.5 毫米处，或距电缆末端 74.5 毫米处。见上面的图表中 4 的位置。轻轻的从电缆锯下来。Now you can pull off the sheath and shielding from the each end.现在，您可以从每一端拉掉外层覆盖物和屏蔽层。7 自制自制 2.4GHz2.4GHz 全向天线分步指南全向天线分步指南 8 Now score round the insulation as you did before,being careful not to cut the central cable 现在沿绝缘层切割一周，像你以前那样，小心不要切到中央芯线 Now carry on making cuts 37mm down from the end of the sheath,and then 13mm further down(50mm from the end of the sheath),and then cut through the cable in the middle of the two cuts.Another sector made.You will need eight sectors in total.Make the same cuts as usual for the eighth sector as it will make top of the flylead as well.Now you have all eight sectors you need to check round the end of each sector to make sure that none of the shielding is touching the central cable,as odd strands can get left.现在，继续从外层覆盖的末端切下 37 毫米下来，然后下一步是 13 毫米（距外层覆盖物末端 50 毫米），然后在两个切口中间将电缆切断。又一节做成了。您总共需要做 8 节。第 8 节要像往常一样切割，因为它要和引线的顶端焊接在一起。现在，你有了所有的 8 节，您需要检查每节的末端，确信没有一个屏蔽层接触到中心电缆，把零星的屏蔽线清除干净。Now you need to make a gentle V shaped cut with the stanley knife,at each end of the sectors,to expose the shielding,which is where the central core of the next sector will be soldered.现在你需要用斯坦利刀在每节的末端切出一个 V 形的切口，使屏蔽层暴露出来，这里就是焊接下一节的中心芯线的地方。自制自制 2.4GHz2.4GHz 全向天线分步指南全向天线分步指南 Make sure that the V cuts at each end of the sector line up,othwise（otherwise？）,when you come to solder the antenna together,the whole thing will be twisted all around.Once you have all eight sectors finished,its time to put them together.确信每一节的末端的 V 形切口排成一行，否则，当你把天线焊在一起时，整个天线将被曲解。一旦你把所有 8 节都完成了，就是把它们组成整体的时候了。Build a Jig 制作一个夹具制作一个夹具 If you do not have a handy helper to hold the sectors together,then you will find it easier to make a small jig from offcuts of wood,to hold the sectors together as you solder them.The clamps on the right hand side of the picture need to be no more than 30mm long.The base board of the jig,needs to extend out to the right long enough to take the whole length of the completed antenna,as it will need to support it during the soldering,as the antenna is not rigid enough to support itself.如果你没有一个得心应手的助手把所有各节都组合在一起，这里教你不费力地用木材的边角料做一个小夹具，在焊接的时候把各节组合到一起。在图片右侧的夹具要不超过 30 毫米长。该夹具基板，需要扩展到整个天线的长度，因为在焊接过程中需要支撑电缆，由于天线不是刚性的，不足以支撑它自己。9 自制自制 2.4GHz2.4GHz 全向天线分步指南全向天线分步指南 Dont make the clamps too tight,as you need to be able to easily lift the cable out after it has been soldered.不要夹得太紧了，因为你需要能够轻松地取下已焊接的电缆。When you are readly to solder the sectors together,you need to take care,that each sector is correctly spaced.The overall length of each sector needs to be 40.5mm,measure from one end of the shielding of the sector you are adding,to the same end on the next sector,and slide the sectors together/apart until the distance is 40.5 mm.Try to get it as accurate as you can,as it affects the direction the antenna transmits in if you get it wrong.There should be a small 3mm gap between the sheaths of each sector.当您准备把每节焊接到一起，你需要当心每节正确的间距。每节的总长度必须是 40.5 毫米，从每节一端的屏蔽层开始测量，到下一节的同一末端。努力达到你能够达到的精度，因为如果你弄错了的话，它影响到天线的辐射方向。每一节的外覆盖层应该有一个 3mm 的小间距。Once you have soldered each sector together,lift it up,turn it over,and move it down the clamp ready for the next sector.This results in a nice straight antenna.When soldering,remember to heat both the shielding and core so that the solder runs smoothly and fixes them together.当你把每一节焊接在一起，就掀起它，转过来，把它移开夹具准备焊接下一10 自制自制 2.4GHz2.4GHz 全向天线分步指南全向天线分步指南 节。结果你会得到一个很直的天线。焊接时，请记住加热屏蔽层和芯线，这样就顺利地把它们焊接在一起。Once complete,test the cable with either a bulb and battery or a multimeter.The center of the fly lead should form a circuit to the 1/4 wave section,and the shield of the flylead to the shield of the top section.Now test that there are no crossed connections,by ensuring there is no circuit between the center of the flylead and the shielding of the top sector,and no circuit between the 1/4 wave section and the shielding of the flylead.焊完之后，用一个灯泡和电池或万用表测试电缆。引线的中点应该形成一个1/4 波长的回路，引线的屏蔽层到顶部的屏蔽层。测试这些不存在交叉连接，确保引线芯线和顶部屏蔽层中间不存在短路，1/4 波长和引线屏蔽之间没有短路。Now fix the N connector of your choice onto the end of the fly lead.The type of connector you use depends on what you want to connect to.I use inline connectors,but you could use any connector you like.Slide the antenna into a length of conduiting.It should be a snug fit,you may need to gently ease it in.Now find an old soft drink bottle top,and pop it on the top end of the antenna.Voila one complete antenna!Securing the antenna in the conduit is best left until you are ready to mount it somewhere.You can cut 5cm slots in the bottom if the conduit,and use a jubilee clamp to grip the flylead,or drill a hole through the conduit and use a cable tie to hold the fly lead,or use a bulkhead mount connector on a botle cap,and glue it to the bottom of the conduit,or glue the flylead in place.Its up to you.现在，引线末端安装您所选择的 N 连接器。连接器类型取决于你要连接什么。我使用内接连接器，但你可以使用你喜欢的任何连接器。天线从另一侧插进一段导管。导管应该合适，您可以轻轻地放进去。再找一个旧饮料瓶子的顶盖，盖在天线顶端。哇，一个完整的天线！您可以在导管底部切割一个 5cm 的槽，使用jubilee 夹具夹住引线，或在导管上钻一个洞，用电缆拴住引线，或使用连接座安装在瓶盖上，或粘在管道底部，或粘在任何合适的位置。这取决于你自己。Testing 测试测试 I will assume you are connecting the antenna to a wireless card in a laptop,and connecting to an accesspoint somewhere.You will need to a signal to noise meter to examine the signal strength.Most