2.4g平板天线的制作图
2.4G_各式各样WiFi天线的DIY试验
2.4G WiFi 天线的DIY试验初学者型奶粉罐天线一、选型先上网收集天线资料，看到很多国外的天线DIYER做出来的WIFI天线真是五花八门！有螺旋天线、有八木天线、有菱形天线、有栅网天线、还有罐头天线......让人看得眼花缭乱。
经过再三筛选，最终把制作目标锁定在罐头天线上。
选择它为DIY对象主要是因为这种天线取材方便、效率高！十分适合初学者制作。
二、制作圆筒天线之所以取材方便，是由于人人家里必定有铁罐、金属筒之类的东西。
笔者就是随便拿了一个奶粉罐制作的。
下面是参照外国WIFI网站的图片而画的制作图。
各数据如下：中心频点＝2.445G圆筒直径＝127mm圆筒长度＝111mm振子长度＝31mm振子距圆筒底部边距＝37mm从图片可以看出，馈线的屏蔽网连接金属圆筒，信号通过圆筒反射到振子上，当然振子就是馈线的芯线了，芯线与金属筒是绝缘的，这点必须注意！在参照外国爱好者制作WIFI天线的同时，笔者加入了自己的想法：很多爱好者都喜欢在圆筒加装N座或BNC座，然后在馈线的连接处做对应的N头或BNC头，用于连接。
但笔者觉得虽然该方法对使用十分方便，但同时也对信号造成了损耗（估计1－2DBI），尤其在2.4G 的频段更加明显！因此，mr7决定把屏蔽网直接焊在圆筒上（焊接前先把外壳打磨光滑），而作为振子的芯线则保留其原来的泡沫绝缘。
这样一来把损耗减到最低。
有点专线专用的味道了！建议大家最好在焊接前找根直径稍比馈线粗一点的小铜管和热缩套管，先把铜管套在馈线上，然后跟屏蔽网一起焊牢在金属圆筒的外壳上，然后用热风筒把热缩套管来回吹多次，把馈线固定在铜管上，这样一来可以很好的减低由于调节天线时给馈线和振子带来的影响！馈线笔者是选用双屏蔽的RG-58电缆，接头是SMA母头，用于接在WIFI的AP上面。
一般来说馈线直径越粗越好，而且长度要尽量短，不然馈线过长所造成的损耗比天线增益还大，失去DIY的意义！笔者使用的馈线直径由于比较小，所以长度取在1米这个数值。
2.4G天线设计完整指南设计(原理、设计、布局、性能、调试)
本文章使用简单的术语介绍了天线的设计情况，并推荐了两款经过测试的低成本PCB天线。
这些PCB天线能够与PRoC?和PSoC?系列中的低功耗蓝牙(BLE)解决方案配合使用。
为了使性能最佳，PRoC BLE和PSoC4 BLE2.4GHz射频必须与其天线正确匹配。
本应用笔记中最后部分介绍了如何在最终产品中调试天线。
1、简介天线是无线系统中的关键组件，它负责发送和接收来自空中的电磁辐射。
为低成本、消费广的应用设计天线，并将其集成到手提产品中是大多数原装设备制造商(OEM)正在面对的挑战。
终端客户从某个RF产品(如电量有限的硬币型电池)获得的无线射程主要取决于天线的设计、塑料外壳以及良好的PCB布局。
对于芯片和电源相同但布局和天线设计实践不同的系统，它们的RF(射频)范围变化超过50%也是正常的。
本应用笔记介绍了最佳实践、布局指南以及天线调试程序，并给出了使用给定电量所获取的最宽波段。
图1.典型的近距离无线系统设计优良的天线可以扩大无线产品的工作范围。
从无线模块发送的能量越大，在已给的数据包错误率(PER)以及接收器灵敏度固定的条件下，传输的距离也越大。
另外，天线还有其他不太明显的优点，例如：在某个给定的范围内，设计优良的天线能够发射更多的能量，从而可以提高错误容限化(由干扰或噪声引起的)。
同样，接收端良好的调试天线和Balun(平衡器)可以在极小的辐射条件下工作。
最佳天线可以降低PER，并提高通信质量。
PER越低，发生重新传输的次数也越少，从而可以节省电池电量。
2、天线原理天线一般指的是裸露在空间内的导体。
该导体的长度与信号波长成特定比例或整数倍时，它可作为天线使用。
因为提供给天线的电能被发射到空间内，所以该条件被称为“谐振”。
图2. 偶极天线基础如图2所示，导体的波长为λ/2，其中λ为电信号的波长。
信号发生器通过一根传输线(也称为天线馈电)在天线的中心点为其供电。
按照这个长度，将在整个导线上形成电压和电流驻波，如图2所示。
自制24gwifi天线
自制2.4G WIFI天线以前我总觉得DIY天线是一件十分困难的事情，受到BG7IOO的影响，我现在对天线也发烧了。
由于收到自身技术和器材限制，我一般只玩手持机的天线，平时也经常跟BG7IOO通长途聊天线，权当生活中的一种乐趣！最近我沉迷于2.4G频段的WIFI，WIFI让人着迷之处在于它是有线宽带网络的无线延伸！但由于技术规范的限制，WIFI设备的发射功率都非常低，一般都是mW级的功率。
这样一来，数据传输的距离就显得捉襟见肘。
有鉴于此，很多业余无线电爱好者都热衷于在WIFI天线上做文章。
为了让自己的WIFI设备也能插上翅膀，我下定决心DIY一根属于自己的WIFI ANT！第1步：选型先上网收集天线资料，看到很多国外的天线DIYER做出来的WIFI天线真是五花八门！有螺旋天线、有八木天线、有菱形天线、有栅网天线、还有罐头天线......让人看得眼花缭乱。
经过再三筛选，最终把制作目标锁定在罐头天线上。
选择它为DIY对象主要是因为这种天线取材方便、效率高！十分适合初学者制作。
同时在05年的《业余无线电家》会刊第4期也有介绍。
不过，我喜欢把它的名字称为“圆筒天线”！第2步：制作圆筒天线之所以取材方便，是由于人人家里必定有铁罐、金属筒之类的东西。
我就是随便拿了一个奶粉罐制作的。
下面是我参照外国网站的图片而画的制作图。
各数据如下：中心频点＝2.445G圆筒直径＝127mm圆筒长度＝111mm振子长度＝31mm振子距圆筒底部边距＝37mm从图片可以看出，馈线的屏蔽网连接金属圆筒，信号通过圆筒反射到振子上，当然振子就是馈线的芯线了，芯线与金属筒是绝缘的，这点必须注意！在参照外国爱好者制作WIFI天线的同时，我加入了自己的想法：很多爱好者都喜欢在圆筒加装N座或BNC座，然后在馈线的连接处做对应的N头或BNC头，用于连接。
但我觉得虽然该方法对使用十分方便，但同时也对信号造成了损耗（估计1－2DBI），尤其在2.4G 的频段更加明显！因此，我决定把屏蔽网直接焊在圆筒上（焊接前先把外壳打磨光滑），而作为振子的芯线则保留其原来的泡沫绝缘。
动手自制2.4G八木天线
2.4G的定向天线有很多种:罐头盒式，反射板式，八木天线，卫星天线，裂隙天线，螺旋天线，以及厨房用具的简单天线。
根据天线的制作难易程度以及取材方面考虑，罐头盒式和反射式太简单，厨房用具的那些玩玩倒可以不实用，螺旋天线还要分左旋和右旋，卫星天线和裂隙天线太专业，手工制作不现实。最后决定制作八木天线，虽然要求精度也很高，制作精度的。
第二步钻孔：给有机玻璃棒上钻15个孔，根据图纸用游标卡尺在有机玻璃棒上画好线，标注好孔位置，这一步很关键，孔的位置将直接影响到后续的工艺精度，钻孔时也要注意，要用台钻，一气呵成，保证所有孔在一条直线上，孔的间距要满足尺寸要求，并且孔的垂直度要保证，否则装上振子后就会发现振子不在一个平面上了。钻头用3.2MM的。
动手自制2.4G八木天线(2008-11-03 15:51:17)标签：it 分类：电脑/网络
好长时间没有上来更新了。一则单位事儿多，没空；二则，自己心情也不太好，没兴致。
上周查单子时突然发现家里的ADSL快到期了，想想邻居家里的AD是2M的，自己用不了怪可惜的，不如我跟他合用，但是距离太原，无法拉网线，从网上得知可以用无线路由器及无线网卡组件无线局域网，时间长距离的无线传输，于是在网上查找资料，研究可行性。
第一步选材；根据图纸计算材料，1根12MM的有机玻璃棒，市场上没有12.7MM的，这个尺寸没有问题。直径3.3的铜棒，宽4MM厚1MM的铜条，50欧--5的电缆，虽然比不上--7的电缆，但是只需要1米，效果还是能保证的。由于没有3.3的规格的铜棒，只好用3.2的铜焊条挂上一层焊锡，尺寸比较接近了。
天线无线DIY大全 2.4G
天线制作大全 本天线制作教程仅供无线ＤＩＹ交流群学习交流 图片教程收集于网络商业天线(24 dBi/27 dBi,覆盖范围4公里)这个反射面天线尺寸是：宽度： 87厘米长度： 91厘米反射面网格尺寸： 2.5厘米×1厘米反射面伸出到偶极子的方管长度是30厘米和面积是2.5厘米× 2.5厘米。
收集器的尺寸:天线FA20的设计. (18..22 dBi).尺寸图纸如下:天线成品图片:2.4Ghz Yagui天线(17dbi和60cm垂直极化) 设计图的尺寸:从左向右1,2 (21)铜线的直径2毫米序号长度(mm) 位置(mm)1 60.3 0.02 54.0 19.653 50.8 41.04 49.2 66.55 48.3 93.76 45.8 127.47 45.8 154.48 45.8 181.49 45.8 208.410 45.8 235.411 45.8 262.412 44.2 289.413 44.2 316.414 44.2 343.415 44.2 370.416 44.2 397.417 36.6 424.418 42.6 451.419 42.6 478.420 45.6 505.421 35.6 530.4环形八木天线 2.4GHz 14 dBi实际图:设计图:反射面R1的尺寸:(黄铜板直径123毫米x0.5毫米厚)使用的铜管直径为12毫米,圆环使用的铜线直径为1.5毫米. 1米的长度和22个圆环，使增益大约为14dbi50厘米长度和11个圆环的天线,使增益大约为11dbi序号周长位置反射面 1 123mm直径0 mm反射面 2 135mm 42mm 接驳器123mm 55mm 导向器 1 114mm 70mm 导向器 2 114mm 81mm 导向器 3 114mm 105mm 导向器 4 114mm 129mm 导向器 5 114mm 146mm 导向器 6 114mm 177mm 导向器 7 114mm 225mm 导向器 8 114mm 273mm 导向器 9 114mm 321mm 导向器 10 114mm 369mm 导向器 11 114mm 417mm 导向器 12 114mm 465mm 导向器 13 110mm 513mm 导向器 14 110mm 561mm 导向器 15 110mm 609mm 导向器 16 110mm 657mm 导向器 17 110mm 705mm 导向器 18 110mm 753mm 导向器 19 110mm 801mm 导向器 20 110mm 849mm 导向器 21 106mm 897mm直径4毫米x 长度60毫米的一根铜管。
自制2.4GHz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•DisclaimerIntroduction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 I'd 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 don't 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。
天线制作大全
商业天线(24 dBi/27 dBi,覆盖范围4公里)这个反射面天线尺寸是：宽度：87厘米长度：91厘米反射面网格尺寸： 2.5厘米×1厘米反射面伸出到偶极子的方管长度是30厘米和面积是2.5厘米× 2.5厘米。
收集器的尺寸:尺寸图纸如下:天线成品图片:2.4Ghz Yagui天线(17dbi和60cm垂直极化) 设计图的尺寸:从左向右1,2 (21)铜线的直径2毫米环形八木天线 2.4GHz 14 dBi 实际图:设计图:反射面R1的尺寸:(黄铜板直径123毫米x0.5毫米厚)使用的铜管直径为12毫米,圆环使用的铜线直径为1.5毫米. 1米的长度和22个圆环，使增益大约为14dbi50厘米长度和11个圆环的天线,使增益大约为11dbi直径4毫米x 长度60毫米的一根铜管。
穿入RG - 316同轴电缆,与接驳器连接. 准备: 35毫米，34毫米，40毫米直径的任何材料的管子各一根. 直径35毫米的管子制作1-12的导向器圆环直径34毫米的管子制作13至22的导向器圆环,其中两个圆环切除4mm 长,作为导向器21,22. 直径40毫米的管子制作123毫米的接驳器和135毫米的反射面2.导向器22后留7.5厘米长结束,使的天线长度为102厘米.(从R1开始计算) 按照表上给出的位置把圆环焊接到12mm 直径的铜管上即可完成该天线的制作.Amos 天线增益为12 dBi天线成品图:天线设计图纸和尺寸:接线头和接线电缆详细介绍:1/2波长1:4巴伦的同轴电缆. RG-316 (v=0,697): 长度43mm RG-58 (v=0,66): 长度40,7mm CFD200 (v=0,83): 长度51mm实际图:设计图(尺寸):铜管制作图:2.4G定向天线,增益17 dBi一.成品图:二.设计图(尺寸):9dBi增益天线完成的天线图:使用直径1-2mm的铜线.设计图及尺寸:Moxon - 6 dBi天线效果图:结构和设计图(尺寸):Interline 平面定向天线,增益14dBi@2,4GHz结构图:设计图及尺寸:平板与反射面距离为5mm.ANTENA 16 dBi's ( 平板PCB ) 打印图:ANTENA 19dBi's ( 平板PCB ) 打印图:平板SMC天线11 dBi增益结构图:印刷图:12根元件的八木天线,增益16dBi 天线原图:设计图及尺寸:1. 需要直径2.5mm的电缆芯作为商用,家用只要1.6mm的铜线即可.2. 6x6mm 450mm长的小木棍3. RG174同轴电缆.用8mm的钻头来弯曲偏振子.I nterline双矩形8 dBi天线图中细线条的宽度1.5毫米.Cisco 平板天线6.5dBi 增益产品图:打印图纸:自制平板天线实物图:打印图纸:平板天线,增益6dBi 实物标识图:多偏振天线,增益17dBi4,6,8个矩形天线设计PCW-24-08012-01八木12,16,17和19 dBi增益天线12 dBi16 dBi17 dBi19 dBi2.425GHZ螺旋天线材料准备:一.1根55cm长内经40mm,外经42-43mm的PVC管子.二.1个内经40mm的端盖三.1个130mm直径的PVC端盖四.几米长的1mm直径的铜线打印图纸:Cλ= 0.75 到1.33 λ圆周长Sλ= 0.2126 Cλ到0.2867 Cλ管子的轴向长度G = 0.8 到1.1 λ圆板的直径/ 反射器Cλ= πDλ周长是π乘直径管子的直径是固定的, 即PVC管子直径42mm.中心频率(2.425GHz)的波长是l = 0.123711 metres.Cλ = π * 0.042m = 0.13195m= 1.066 λSλ = 0.3183 * 0.13195m = 0.042mG = 1.05 λ = 0.130mGain = 11.8 + 10log10(Cλ * Cλ * n * Sλ) n是缠绕的线圈数. Gain = 11.8 + 10log10(1.066 * 1.066 * 13 * 0.31830)= 18.5dBi第二种方法:G = 11.8 + 10 * log {(C/λ)^2 * N * d} dBi (1)Z = 140 * (C/λ) Ohm (2)λ = (0.3/2.43) = 0.1234567 m (12.34 cm) (3)线圈的直径= (λ/pi) = 39.3 mm (4)With D = 42 mm, C = 42*pi = 132 mm (值1.07 λ) (5)Now d = 0.25C = 0.25*132 = 33 mm (6)Z = 140 * (C/λ) = 140*{(42*pi)/123.4} = 150 Ohm (7)。
四大蓝牙天线设计方式
四大蓝牙天线设计方式
一直以来，无论是智能手机，还是笔记本电脑，亦或是平板电脑，蓝牙都是智能设备的标配。
随着移动互联网的发展，现在涌现出大量的智能可穿戴设备，而支撑这些应用的发展不仅需要移动软件支持，同样也需要无线传感技术的支持，蓝牙依然是无线连接的首选通信方式。
蓝牙技术，就是这中间最重要的一环。
不仅要求通讯灵敏度，还需要小型化，更需要低功耗，更重要的是要低成本。
Bluetooth 4.0版本的出现，解决了这些问题，它包含Bluetooth Smart（低功耗）功能，具有以下特点：
1）能耗低
2）成本低
3）标准纽扣电池能让设备运行数年
4）多供应商互操作性
5）增强射程
在硬件设计中，天线设计是比较有讲究，常用的低成本设计方式是PCB板载天线设计方式，但PCB板载天线在实际中应该如何设计，才能达到很好的收发效果呢？以下有四种蓝牙天线设计可供参考。
蓝牙天线设计之倒F型天线
倒F型天线的天线体可以为线状或者片状，当使用介电常数较高的绝缘材料时还可以缩小蓝牙天线尺寸。
作为板载天线的一种，倒F型天线设计成本低但增加了一定体积，在实际应用中是最常见的一种。
天线一般放置在PCB顶层，铺地一般放在顶层并位于天线附近，但天线周围务必不能放置地，周围应是净空区。
如下图：
图1：倒F型天线设计示意图
蓝牙天线设计之曲流型天线设计。
飞思卡尔2.4GPCB天线设计
Freescale Semiconductor Application Note AN2731Rev. 1.2, 11/20041Introduction Good antenna design is the most critical factor in obtaining good range and stable throughput in a wireless application. This is especially true in low power and compact designs, where antenna space is less than optimal. However, several compact, cost efficient, and very effective options exist for implementing integrated antennas.To obtain the desired performance, it is required thatusers have at least a basic knowledge about howantennas function, and the design parameters involved.These parameters include selecting the correct antenna,antenna tuning, matching, gain/loss, and knowing therequired radiation pattern.This note will help users understand antenna basics, andaid in selecting the right antenna solution for theirapplication.Compact Integrated Antennas Designs and Applications for the MC13191/92/93Contents1Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 12Antenna Terms . . . . . . . . . . . . . . . . . . . . . . . . 23Basic Antenna Theory . . . . . . . . . . . . . . . . . . 24Impedance Matching . . . . . . . . . . . . . . . . . . . 65Miniaturization Trade-offs . . . . . . . . . . . . . . 136Potential Issues . . . . . . . . . . . . . . . . . . . . . . 147Recommended Antenna Designs . . . . . . . . 148Design Examples . . . . . . . . . . . . . . . . . . . . . 16Antenna Terms2Antenna TermsAntenna Gain A measure of how well the antenna radiates the RF power in a given direction, compared to a reference antenna, such as a dipole or an isotropic radiator. The gainis usually measured in dB’s. A negative number means that the antenna in questionradiates less than the reference antenna, a positive number means that the antennaradiates more.Decibel (dB) A logarithmic scale used to represent power gain or loss in an RF circuit. 3 dB isa doubling of the power, -3 dB is half the power. -6 dB represents half the voltageor current, and quarter the power.Radiation Resistance The part of antenna’s impedance which produces radiated power. The measured impedance of an antenna is comprised of radiation resistance and loss.3Basic Antenna TheoryEvery structure carrying RF current generates an electromagnetic field and can radiate RF power to some extent and likewise an external RF field can introduce currents in the structure. This means that theoretically any metallic structure can be used as an antenna. However, some structures are more efficient in radiating and receiving RF power than others. The following set of examples explains this concept. Transmission lines (striplines, coaxial lines etc.) are designed to transport RF power with as little radiation loss as possible because these structures are designed to contain the electromagnetic fields. To obtain any appreciable radiation from such a structure, requires excessively high RF currents which causes low efficiency due to high losses. Likewise, the ability to introduce RF currents into the structure is of importance, described by the feed point impedance. If the feed point impedance is very high, low, and/or highly complex, it is difficult to introduce RF current with good efficiency.The antenna structure should be of reasonable size compared to the wavelength of the RF field. A natural size is half a wavelength, which corresponds to approximately 6 cm at the 2.4 GHz ISM band. This size is effective because when fed with RF power at the center point, the structure is resonant at the half wave frequency. Reducing the size below 6cm tends to make the antenna less visible to the RF field and not resonant which causes low efficiency. Not all structures make an efficient antenna.Numerous structures have been devised that provide good efficiency and impedance match, but most of these are derived from a few basic structures. A short description of these basic antennas, and some good advice on how to implement these with success is provided later in this note.This note does not include complicated formulas concerning antenna theory because it is beyond the scope of this note. The intention of this note is to provide basic information about how antennas work, which should allow users to achieve reasonable performance with a minimum number of attempts.If users are interested in performing complex calculations and antenna simulations, they should consult the abundant and widely available literature concerning antenna theory and design. Note that simply copying an existing design does not necessarily ensure reasonable performance. A lot of external factors affect antenna tuning, gain, radiation patterns, etc. An antenna tuned for one set of environmental factors may not perform at all if put into a new environment, and may require a lot of tuning to achieve even reasonable performance.Basic Antenna Theory 3.1Basic Antenna Variations3.1.1 3.1.1 Dipole AntennaThe dipole is one of the most basic antennas. The dipole is a straight piece of wire cut in the center and fed with a balanced generator or transmission line. As previously stated, this structure is resonant, ornon-reactive, at the frequency where the conductor length is 1/2 wavelength. For the ISM band, this length is approximately 6 cm or about 2 ½ inches. At this length, the dipole shows resonance, the feed impedance is resistive, and is close to 73 Ohms. This also holds true for a very thin wire in free space.Figure1. Basic DipoleA practical dipole of some thickness, loaded with different dielectric materials (PCB etc.), and perhaps relatively close to ground, shows resonance at a slightly shorter length than calculated, and the radiation resistance drops somewhat. For dipoles not too close to ground, the shorting factor is typically in the range of 5-20%, the shorter being more heavily dielectric loaded, and radiation resistance is in the range of 35-65 Ohms.This dipole setup exhibits a relatively good match to a 50 Ohm generator, but the feed is differential. A small ceramic balun can be used for single-ended feed. The bandwidth is typically 2-5%, depending on the return loss required. The radiation pattern in free space is doughnut-shaped, with pronounced dips along the direction of the wires.To fill out these dips, the outer ends of the antenna can be bent at a 45 degree angle. Several configurations are possible, including the “broken arrow” shape. Any materials close to the antenna can distort the radiation pattern.Basic Antenna TheoryFigureTo reduce the size of the dipole, several options exist: •Replacing some of the wire length with loading coils •Bending the dipole ends back on the dipole•Folding the dipole into a meander pattern•Hairpin or coil loading of the center•Capacitive loading of the dipole endsBasic Antenna TheoryFigure3. Dipole Loading ExamplesIn general, the smaller the antenna, the lower the radiation resistance and the lower the efficiency. The antenna should also be removed somewhat from the ground plane, preferably at least ¼ wavelength (3 cm) but not less than 1 cm. Sometimes a loading technique is employed where the dipole ends are bent close to the ground plane, or even loaded with small capacitors to ground. This technique shorts the dipole considerably but causes heavy RF currents to flow in the ground plane, resulting in low efficiency. Often some of the other loading techniques result in better performance.Impedance Matching4Impedance MatchingFor heavily loaded antennas and antennas close to ground, the radiation resistance may deviate considerably from 50 Ohms which causes a poor match. An Inductive/Capacitive (LC) matching network may be employed, but better efficiency is possible by raising the feed impedance.These techniques may also be employed if an impedance higher than 50 Ohm is required.The current and voltage distribution on a dipole is such that the impedance is low in the center and raises towards the ends. By tapering the dipole at some distance from the center, an appropriate match can be found. The tapering may take the form of Gamma, Delta or Capacitive tapping as shown in Figure 4. This allows for matching impedances from 2 up to 300 Ohms. Some loading may be required to take out the reactance introduced by the tapering, or the antenna could be slightly offset tuned to compensate for the added reactive component.Another approach is using the folded dipole. This is where two parallel wires are placed closely together. Due to the tight coupling, the current distribution is approximately proportional to the surface area of each wire. This means that in two equal wires, the current in the feeding wire is approximately half the value of the wires together. Half the current at the same power means twice the voltage, or four times the impedance of 73 Ohms (292 Ohms). In practice, the impedance is somewhat lower, as in the normal dipole case. however, by changing the relative wire diameter, or even introducing several wires, it is possible to tune the impedance from less than 100 Ohms to several hundred Ohms.Impedance MatchingFigure5. The Folded DipoleAll the different dipole types, loading techniques, and feeding networks total up to an enormous amount of possible combinations, each with its own advantages and disadvantages. Selection of the correct design for your application is best found using case-by-case assessment.4.1Monopole AntennasIf one part of a dipole antenna is removed and replaced by an infinite ground plane, the remaining half of the dipole “mirrors” itself in the ground plane, much in the same way that one sees their own reflection in water.For all practical purposes, the monopole behaves as a “half” dipole. That is, it has the same doughnut shaped radiation pattern, the radiation resistance is half that of the dipole (37 Ohm), it can be bend and be folded like the dipole, and the same loading and feeding techniques can be applied.However, one very important difference remains in that the antenna feed point is not balanced, but single ended. Because of this and because most RF circuits are of the unbalanced type, this antenna type has been immensely popular and a lot of variations of the monopole theme exist, most designed to match 50 Ohms.FigureIt is important to note that the “whip” is only half the antenna and that the remainder is made up of the ground plane, or counter weight, as it is sometimes called. In a practical application, the ground plane is often made up of the remainder of the PCB (ground and supply planes, traces, and components).Impedance MatchingThe ground plane should be a reasonably sized area compared to the antenna, and should be reasonably continuous. If a monopole is used on a very small PCB, perhaps even with only a small area of copper, efficiency suffers, and the antenna is difficult to tune. Components and tracks introduce additional losses and affect the feed point impedance.As for the dipole, resonance is obtained at a length slightly shorter than one quarter wavelength, typically 5-15% shorter. Typical lengths are slightly more than an inch or two or 3 to 5 cm. The radiation resistance is caused by bending the antenna, and like the dipole, the marked dip in the radiation pattern can be eliminated. By bending the antenna closer to ground, the radiation resistance and efficiency drops, so the antenna should not be placed too close to ground. Like the dipole, the monopole can also be folded and bent around corners, if board space requires this, or it can be loaded with series coils.Of the many variations that exist, the following sections highlight the most common.4.1.1PCB Whip, Quarter Wave Monopole, or Quarter WaveIf board space allows, a full-size quarter wave antenna is quite efficient and often provides a reasonable match to a 50 Ohm system. Slight folding or bending of the ends has negligible impact on performance.4.1.2Open Stub, Tilted WhipIf the monopole is bent and traced along the ground plane, it will be more compact and the null in the radiation pattern is partly eliminated. The antenna should not bee too close to ground, preferably not closer than 1/10 wavelength (1 cm), or efficiency suffers too much. At this close spacing, the radiation resistance is so low (in the order of 10 Ohms) that a matching network is usually needed. If the monopole is very close to ground, it resembles a transmission line, with little or no radiation at all.4.1.3The F-AntennaThe F-antenna can be thought of as a tilted whip, where impedance matching is done by tapping the antenna at the appropriate impedance point. Because this antenna is reasonably compact, has an omnidirectional radiation pattern, good efficiency, and is very simple, it is used extensively in applications, including the mobile communications business. It should be noted that the currents in the ground leg are high, and that a good sized ground plane is necessary to provide good efficiency.Impedance Matching 4.1.4The HelixIf a quarter wavelength is coiled up, a very compact antenna can be made which still has reasonable efficiency. Some experimentation may be required to find resonance, because the length of the wire is not exactly related to a quarter wavelength. This type of antenna is very popular at lower frequencies.4.1.5The SpiralA spiral antenna, with the windings in one plane like a pancake, is well suited to be implemented on a PCB. Performance is similar to the helix.4.1.6The Meander AntennaThe meander antenna or meander pattern, is an antenna with the wire folded back and forth where resonance is found in a much more compact structure than can otherwise be obtained.The meander, spiral, and helix antennas are similar in that resonance is obtained in a compact space by compressing the wire in different ways. In all three cases, the radiation resistance, bandwidth, and efficiency drops off as size is decreased, and tuning becomes increasingly critical. Impedance matching can be implemented by tapping, as in the F-antenna. The meander and helix antenna, or a combination of these two, are easily implemented in a PCB, and many chip antennas are based on these types of antenna.Figure8. Meander Pattern (Tapped for Impedance Match)Impedance Matching4.2Loop AntennasLoop antennas can be divided in two groups:1.Half-wave antennas2.Full-wave antennasThe term wave refers to the approximate circumference of the loop.4.2.1Half-wave LoopThe half wave loop consists of a loop approximately half a wavelength in circumference, with a gap cut in the ring. It is very similar to a half-wave dipole that has been folded into a ring and much of the statements about the dipole apply to the half-wave loop. Because the ends are very close together, there exists some capacitive loading, and resonance is obtained at a somewhat smaller circumference than expected. The feedpoint impedance is also somewhat lower than the usual dipole, but all the usual feeding techniques can be applied to the half-wave loop. By increasing the capacitive loading across the gap, the loop can be made much smaller than a half wavelength. At heavy loading, the loop closely resembles a single winding LC tuned circuit. The actual shape of the loop is not critical. It can be shown that the efficiency is determined by the area enclosed by the loop. The half-wave loop is popular at lower frequencies. However, at higher frequencies, the tuning capacitance across the gap becomes very small and critical.4.2.2Full-wave LoopAs the name implies, the full wave loop is approximately one wavelength in circumference. Resonance is obtained when the loop is slightly longer than one wavelength, typically 10-15% longer. The full wave loop can be thought of as two end-connected dipoles. As is with the half-wave loop, the shape of the full wave loop is not critical, but efficiency is determined mainly by the enclosed area. The feed impedance is somewhat higher than the half-wave loop, typically around 120 Ohms.Loading can be done by inserting small coils or hairpins in the loop, thereby reducing the size. As is with the dipole and half-wave loop, there exists numerous ways for impedance matching, including gamma match and tapering across a loading coil or hairpin. The main advantage of the full-wave loop is that it does not have the air gap in the loop, which is very sensitive to load and PCB capacitance spread.Impedance Matching4.2.3Slot AntennasSlot antennas are used extensively in aircraft and radar applications. The basic slot antenna is a half wave slot cut in a conducting sheet of metal. The feed point is across the center of the slot and balanced. The feed impedance is high, typically several hundred Ohms. Because the slot antenna is the opposite of a dipole, that is, a non-conducting slot in a sheet of metal, as opposed to a conducting rod in free air, the slot antenna shows similarities to a dipole but also exhibits interesting differences as well.•The feed point is across the center, instead of in series, so the feed point impedance is high instead of low• E and H fields are switched, so that the polarity is opposite• A horizontal slot is equivalent to a vertical dipole•The slot antenna may be of interest, if the RF unit has to be placed in a metal enclosure, where the slot antenna could be made in the enclosure itself•If the slot antenna is cut in the center, a quarter wave slot antenna is created, which is equivalent to the monopole•Impedance matching can be done by tapping across the slot close to the shorted endThe slot antenna could be used if a metal enclosure is required, or if considerable board area is available. If the slot antennas are implemented in FR4 PCB, considerable dielectric loading occurs which causes the physical length to be shorter than expected.Impedance MatchingFigure10. Half-wave and Quarter-wave Slot Antennas4.2.4Patch AntennasPatch antennas are a group of antennas with a very low profile and are capable of working very close to a ground plane. However, they require a fair amount of board space. The radiation pattern may be omnidirectional or unidirectional. A few examples are shown, but design and tuning is not straightforward and is best left to an experienced antenna engineer. Some types of chip antennas that show unidirectional characteristics are of this design.4.2.5Chip AntennasMany different chip antennas are available commercially. To many, these antennas seem to work for no apparent reason, but careful investigation reveals that most of these antennas are based on a helix, meander, or patch design. To ensure proper operation it is very important to follow the manufacturer’s recommendations regarding footprint, ground areas, and mounting of the chip antenna. The “keep out” area around the antenna is especially important. Even following the recommendations does not always guarantee good performance due to de-tuning by nearby objects. It is to be expected that fine tuning of the antenna and/or a matching network is required to ensure satisfactory performance. Because chip antennas normally, but not always, use a ceramic material with higher dielectric constant and lower loss than the usual FR4, it is possible to make smaller antennas with reasonable efficiency.The efficiency is not exceptionally high, typically in the range of 10-50%, which corresponds to 3-10 dB loss (-3 to –10 dBi). The lower number being inferior products with high inherent losses. As already stated, buying a chip antenna does not guarantee good performance. However, they do provide the smallest antenna solution possible but the size reduction comes at a cost both in performance and pricing.If a slightly larger PCB area is available than is required by the chip antenna, and the “keep out” area can be allocated to a PCB antenna, it is possible to implement a PCB antenna with the same or better performance than a chip antenna but at a much reduced cost.4.2.6BalunsMany of the above antennas mentioned are single-ended and designed to have a feed point impedance close to 50 Ohms. To interface these antennas to a balanced output/input, a device called a balun is required. The balun converts a single ended input to a balanced output together with an optional impedance transformation. The output is differential. That is, the output voltage on each pin is of equal magnitude, but off opposite phase. The output impedance is normally stated differential. That is, measured betweenMiniaturization Trade-offs the two output pins. Because the balun is a discrete device, it is bidirectional. The balanced port can be both input or output.Several discrete circuits are available that perform as baluns. Most of them are sensitive to input and output loading and PCB layout which requires cumbersome fine tuning. And all of these require at least two chip inductors. In the 2.4 GHz band, small ceramic baluns exist which are easy to use and are less sensitive to the PCB layout. Standard output impedances are 50, 100 and 200 Ohms.The cost of a discrete balun is comparable to, or higher than, the ceramic balun, and the ceramic balun requires less board space. Therefore, the ceramic balun is recommended for most designs.To interface with the MC13192/92/93, the standard component 50–200 Ohm balun is recommended. A 50–400 Ohm device provides slightly better performance, but it is not an off-the-shelf device.5Miniaturization Trade-offsAs previously stated, reducing antenna size results in reduced performance. Some of the parameters that suffer are:•Reduced efficiency (or gain)•Shorter range•Smaller useful bandwidth•More critical tuning•Increased sensitivity to component and PCB spread•Increased sensitivity to external factorsAs stated, several performance factors deteriorate with miniaturization, but some antenna types tolerate miniaturization better than others. How much a given antenna can be reduced in size depends on the actual requirements for range, bandwidth, and repeatability. In general, an antenna can be reduced to half its natural size without much impact on performance. However, after a one half reduction, performance gets progressively worse as the radiation resistance drops off rapidly. As a rule, one half the antenna size equals one quarter the radiation resistance. As loading and antenna losses often increase with reduced size, it is clear that efficiency drops off quite rapidly.The amount of loss that can be tolerated depends on the range requirements. Bandwidth also decreases, which causes additional mismatch losses at the band ends. The bandwidth can be increased by resistive loading, but this often introduces even more loss than the mismatch loss. The low bandwidth combined with heavy loading requires a spread analysis to ensure adequate performance with variations in component values and PCB parameters. As shown by these facts, it is often better not to reduce antenna size too much, if board space allows. Even if range requirements do not require optimum antenna performance, production problems and spread are minimized. It is also best to keep some clearance between the antenna and nearby objects. Although the antenna may be retuned to compensate for the loading introduced by the surroundings, tuning becomes more critical, and the radiation pattern can be heavily distorted.Potential Issues6Potential IssuesNumerous things can go wrong with an antenna design. The following list provides a few do’s and don’t’s which may server as a good checklist in a final design. Many of these items seem obvious to the experienced antenna designer, but many of these issues are routinely encountered in practice. This is obviously not a complete list.•Never place ground plane or tracks underneath the antenna•Never place the antenna very close to metallic objects•Be careful about the wiring in the finalized product, not too close to the antenna• A monopole antenna should have a reasonable ground plane to be efficient•Do the final tuning in the end product, not in free air•Never install a chip antenna in a vastly different layout than the reference design, and expect it to work without tuning•Do not use a metallic enclosure or metallized plastic for the antenna•Test the plastic casing for high RF losses, preferably before production•Never do a cut and paste antenna design and expect it to work without testing•Never use low-Q loading components, or change manufacturer without retesting•Do not use very thin PCB tracks, the tracks should be fairly wide7Recommended Antenna DesignsTwo antenna designs are employed for the MC13192/93 hardware.1.Dipole (lowest cost implementation)2.F-antennaHowever, most antenna designs are intended to interface with the usual 50 Ohm industrial standard. This is certainly true for all chip antennas. For interfacing the MC13191/92/93 to a single-ended 50 Ohm antenna, it has been shown that the smallest and most cost-effective solution are two ceramic baluns and an RX/TX switch.The MC13192-EVB, which is included in the MC13193EVK-A00, provides an example of this setup. Users can omit the RX/TX switch and add two chip antennas, but in most cases the switch is less costly than another antenna. Any other 50 Ohm, single ended antenna design can be added if required. This includes among others the F-antenna, monopole, helical, and the usual commercially available chip antennas. The single-port, 50 Ohm solution has the added advantage that by adding a ceramic bandpass filter for improved performance is easy. For a very low cost, low bill of materials (BOM) count solution, users should consider interfacing the antenna(s) directly to MC13191/92/93, and integrate both antennas and matching components into the PCB.This setup does have some unique requirements, due to the input/output requirements of theMC13191/92/93. To achieve a good match to the MC13192/92/93, the antenna should include the following properties:•Balanced designRecommended Antenna Designs•Feedpoint impedance of 2-300 Ohm•Easily loaded to smaller size, with PCB or lumped loading•Provide a DC feed to the TX port•Easy to implement in FR-4 PCBOf the different antenna types, the following are especially suited to interface with the MC13191/MC13192:•Dipoles with gamma match, or folded dipoles•Half or quarter wave loops•The slot antenna may also prove useful in some casesBecause the MC13192/92/93 has separate RX and TX ports, two antennas will eliminate RX/TX switching. The two antennas should ideally be placed at least ¼ wavelength apart to reduce coupling, but due to the low power requirements, closer spacing can be allowed. The following list shows the results from testing with dipole antennas and shows the typical isolation. The values are empirical, and depend somewhat on the surrounding layout etc., but they should provide a reasonable indication of the isolation obtainable.•On each side of a PCB, on top of each other: – 3 to – 4 dB•Very close, on the same side of the PCB: – 6 dB•15 mm apart: – 10 dB•25 mm apart: – 13 dBFor the MC13192/92/93 to show optimum performance, at least 6 dB of TX to RX isolation is required or the ESD protection diodes in the RX input cause some TX power loss and perhaps also increased 3rd harmonic output. However, placing the RX and TX dipoles on top of each other, with only 3 dB of isolation results in the smallest design possible, and only reduces TX power a few dB, which is entirely acceptable in most cases. The RX side works well with any isolation available. When the antennas are very close, the coupling results in some interaction in the tuning of the two antennas. With just a few attempts, users should be able to optimize performance.。
平板增益天线的评测及制作方法大全
崴海尼可测试大赛 11、12、1416、19、20、21平板天线测试测试器材:测试用天线11db圆盘 12db19db 16db21db 12db双菱14db本次测试的主角：崴海尼可20db平板包装非常精美全家福崴海尼可20db平板正面崴海尼可20db平板反面不锈钢的抱杆夹具做工非常好、用料足有保修卡、测试报告跟自制21db的对比简单改制成台式再来一张正面照反面夹具的安装夹具可调整角度不锈钢的夹具厚度有2.5mm测试用网卡：（白色卡王、瑞银、GA800BT）测试天线用到的软件：BT3WiFiHopperNetwork StumblerWirelessMon世纪网络测速/gb/broadmeter/SpeedAuto/测试内容：信号测试：用WiFiHopper测试，全部的图片太多，就选21db、16db的跟20db测试。
16db以下的在我这里常用的2个信号，开始没有信号了，就不上图了，有兴趣的可以问我索要。
GA800BT＋20dbGA800BT＋21dbGA800BT＋16db─────────────────────瑞银＋20db瑞银＋21db瑞银＋16db─────────────────────────白色卡王＋20db白色卡王＋21db白色卡王＋16db用WirelessMon测试：GA800BT＋20dbGA800BT＋21dbGA800BT＋16db───────────────────────瑞银＋20db瑞银＋21db瑞银＋16db─────────────────────────白色卡王＋20db白色卡王＋21db白色卡王＋16db──────────────────────────BT3下测试：20db＋白色卡王＋BT321db＋白色卡王＋BT316db＋白色卡王＋BT3测试数据汇总八种PCB天线Network Stumbler测试：网卡用的是白色卡王。
世纪网络测速：（虽然这个测试不是很准确，但在短时间测试同一个服务器，用来横向比较还是可以的。
2.4G RF天线的设计情况
本文章使用简单的术语介绍了天线的设计情况，并推荐了两款经过赛普拉斯测试的低成本PCB天线。
这些PCB天线能够与赛普拉斯PRoC™和PSoC®系列中的低功耗蓝牙(BLE)解决方案配合使用。
为了使性能最佳，PRoC BLE和PSoC4BLE2.4GHz射频必须与其天线正确匹配。
本应用笔记中最后部分介绍了如何在最终产品中调试天线。
1.简介天线是无线系统中的关键组件，它负责发送和接收来自空中的电磁辐射。
为低成本、消费广的应用设计天线，并将其集成到手提产品中是大多数原装设备制造商(OEM)正在面对的挑战。
终端客户从某个RF产品(如电量有限的硬币型电池)获得的无线射程主要取决于天线的设计、塑料外壳以及良好的PCB布局。
对于芯片和电源相同但布局和天线设计实践不同的系统，它们的RF(射频)范围变化超过50%也是正常的。
本应用笔记介绍了最佳实践、布局指南以及天线调试程序，并给出了使用给定电量所获取的最宽波段。
设计优良的天线可以扩大无线产品的工作范围。
从无线模块发送的能量越大，在已给的数据包错误率(PER)以及接收器灵敏度固定的条件下，传输的距离也越大。
另外，天线还有其他不太明显的优点，例如：在某个给定的范围内，设计优良的天线能够发射更多的能量，从而可以提高错误容限化(由干扰或噪声引起的)。
同样，接收端良好的调试天线和Balun(平衡器)可以在极小的辐射条件下工作。
最佳天线可以降低PER，并提高通信质量。
PER越低，发生重新传输的次数也越少，从而可以节省电池电量。
2.天线原理天线一般指的是裸露在空间内的导体。
该导体的长度与信号波长成特定比例或整数倍时，它可作为天线使用。
因为提供给天线的电能被发射到空间内，所以该条件被称为“谐振”。
如图2所示，导体的波长为λ/2，其中λ为电信号的波长。
信号发生器通过一根传输线(也称为天线馈电)在天线的中心点为其供电。
按照这个长度，将在整个导线上形成电压和电流驻波，如图2所示。
2.4G 无线路由 天线制作大全
天线制作大全Neity制作2008年7月转载请注明原创作者及出处。
商业天线(24 dBi/27 dBi,覆盖范围4公里)这个反射面天线尺寸是：宽度： 87厘米长度： 91厘米反射面网格尺寸： 2.5厘米×1厘米反射面伸出到偶极子的方管长度是30厘米和面积是2.5厘米× 2.5厘米。
收集器的尺寸:天线FA20的设计. (18..22 dBi).尺寸图纸如下:天线成品图片:2.4Ghz Yagui天线(17dbi和60cm垂直极化) 设计图的尺寸:从左向右1,2 (21)铜线的直径2毫米序号长度(mm) 位置(mm)1 60.3 0.02 54.0 19.653 50.8 41.04 49.2 66.55 48.3 93.76 45.8 127.47 45.8 154.48 45.8 181.49 45.8 208.410 45.8 235.411 45.8 262.412 44.2 289.413 44.2 316.414 44.2 343.415 44.2 370.416 44.2 397.417 36.6 424.418 42.6 451.419 42.6 478.420 45.6 505.421 35.6 530.4环形八木天线 2.4GHz 14 dBi实际图:设计图:反射面R1的尺寸:(黄铜板直径123毫米x0.5毫米厚)使用的铜管直径为12毫米,圆环使用的铜线直径为1.5毫米. 1米的长度和22个圆环，使增益大约为14dbi50厘米长度和11个圆环的天线,使增益大约为11dbi序号周长位置反射面 1 123mm直径0 mm反射面 2 135mm 42mm 接驳器123mm 55mm 导向器 1 114mm 70mm 导向器 2 114mm 81mm 导向器 3 114mm 105mm 导向器 4 114mm 129mm 导向器 5 114mm 146mm 导向器 6 114mm 177mm 导向器 7 114mm 225mm 导向器 8 114mm 273mm 导向器 9 114mm 321mm 导向器 10 114mm 369mm 导向器 11 114mm 417mm 导向器 12 114mm 465mm 导向器 13 110mm 513mm 导向器 14 110mm 561mm 导向器 15 110mm 609mm 导向器 16 110mm 657mm 导向器 17 110mm 705mm 导向器 18 110mm 753mm 导向器 19 110mm 801mm 导向器 20 110mm 849mm 导向器 21 106mm 897mm直径4毫米x 长度60毫米的一根铜管。
低功耗蓝牙模块四大板载天线PCB设计方式
图 2：曲流型天线设计示意图 1
图 3：曲流型天线设计示意图 2
注：天线长度计算公式： 天线的长度（米）=（300/f）*0.25*0.96 其中 f 表示频率（MHz），0.96 为波长缩短率 蓝牙天线长度约为 300/2.4G*0.25*0.96 大约为 31mm
蓝牙天线设计之陶瓷天线设计： 陶瓷天线是另外一种适合于蓝牙装置使用的小型化天线。陶瓷天线的种类分为块状陶瓷天线和多层陶瓷天 线。由于陶瓷本身介电常数较 PCB 电路板高，所以使用陶瓷天线能有效缩小天线尺寸，在介电损耗方面， 陶瓷介质也比 PCB 电路板的介电损失小，所以非常适合低耗电率的的蓝牙模块中使用。在 PCB 设计时，天 线周围要净空就可以了，特别注意不能敷铜。如下图：
图 4：陶瓷天线设计示意图
蓝牙天线设计之 2.4G 棒状天线设计： 2.4G 棒状蓝牙天线体积大，但传输距离要强于其他天线。在 PCB 设计时，天线周围也和上述的三种天线设 计一样意图
关于蓝牙天线设计的其它相关注意点： 1）天线的信号（频率大于 400MHz 以上）容易受到衰减，因此天线与附近的地的距离至少要大于三倍的线 宽。 2）对于微带线与带状线来说，特征阻抗与板层的厚度、线宽、过孔以及板材的介电常数相关。 3）过孔会产生寄生电感，高频信号对此会产生非常大的衰减，所以走射频线的时候尽量不要有过孔。
Bluetooth 4.0 版本的出现，解决了这些问题，它包含 Bluetooth Smart（低功耗）功能，具有以下特点： 1）能耗低 2）成本低 3）标准纽扣电池能让设备运行数年 4）多供应商互操作性 5）增强射程
在硬件设计中，天线设计是比较有讲究，常用的低成本设计方式是 PCB 板载天线设计方式，但 PCB 板载天 线在实际中应该如何设计，才能达到很好的收发效果呢？下面跟随蓝牙模块厂家云里物里一起来看下，以 下有四种蓝牙天线设计可供参考： 蓝牙天线设计之倒 F 型天线： 倒 F 型天线的天线体可以为线状或者片状，当使用介电常数较高的绝缘材料时还可以缩小蓝牙天线尺寸。 作为板载天线的一种，倒 F 型天线设计成本低但增加了一定体积，在实际应用中是最常见的一种。天线一 般放置在 PCB 顶层，铺地一般放在顶层并位于天线附近，但天线周围务必不能放置地，周围应是净空区。 如下图：