The "2009 National DIY Competition" jointly held by Anywlan.com and PConline has been successfully completed. Now, we are presenting the detailed production methods of some award-winning works for everyone to learn from and refer to, which can also enhance the practical ability of netizens. We will recommend some excellent works to you in several installments. If you have any good improvement suggestions for the antenna, please leave a reply below. Today, we will first introduce a planar antenna made of copper wire with a gain of 18DB. Here, we would like to express our gratitude to the author CN.Tink for his wonderful work. It is more delightful to enjoy alone than to enjoy with others. We also hope that everyone can use the content of this article to make a good antenna. I. Antenna Overview and Drawing Preparation The drawing of this antenna is sourced from the personal collection of the Anywlan moderator "Fengzheng" who retrieved it from abroad. According to the data, the theoretical gain of this antenna is about 18.2db. After I made it through DIY, the measured actual gain is between 15-17db. Therefore, it is very close to the theoretical gain. The two key issues affecting the effect of my DIY are that the length of the copper wire may not be accurately measured. Since this antenna has many welding points, the error may occur at the welding points. Another reason may be that the reflector is not flat. I think as long as a good reflector and a skilled welder are found, the effect of this antenna will definitely be very good! Planar Antenna Schematic Diagram (The drawing is available for download at the end of the article) When making an antenna through DIY, one needs to be careful and patient. The meticulousness of the antenna manufacturing process, the selection of materials, etc. will directly affect the gain of the antenna. Especially for directional antennas used in long-distance wireless communication, a deviation of one millimeter during the manufacturing process can lead to a significant difference at a distance of one kilometer. The design drawing is available for download at the end of the article. II. Material Collection and Tool Preparation 1. Copper wire or aluminum wire with a diameter of 2mm. Copper wire is preferably chosen because of its low resistance and strong oxidation resistance. 2. Nylon cable ties. For the specific use, please read on. Planar Antenna Cable ties for fixing the antenna (available at hardware stores) 3. The outer skin of the closed-circuit television cable, which is used to support the vibrator and the reflector. 4. A reflector larger than 392*308mm. It can be a computer case cover (a certain expert on the forum used this), or thin iron sheet or aluminum plate. Since I couldn't find an aluminum plate of that size at that time, I riveted two iron sheets together to make the reflector. There are some skills in how to rivet the two iron sheets together: 1) Put the two cut iron sheets together and make sure they are aligned and do not shake. 2) Cut several sections of aluminum wire with a length of 5mm and a diameter of about 1-2mm. 3) Use a nail or other sharp object to make a small hole in the combined iron sheets. The diameter of the small hole is preferably just large enough to insert the aluminum wire prepared in the previous step. After the aluminum wire passes through the two layers of iron sheets, the same length should be exposed on each side. 4) Use a hammer to knock the exposed aluminum wire on one side obliquely. Master the bending degree yourself, as long as it doesn't fall out. 5) Use the hammer to continue knocking the exposed aluminum wire on the other side obliquely until the aluminum wire does not move. 6) Put the iron sheets on a flat ground and use a hammer to hit the aluminum wire hard. After the aluminum wire spreads out, the two iron sheets are riveted together! Planar Antenna Riveting two iron sheets 5. In addition, you also need to prepare a sledgehammer, pliers, vernier calipers, a felt-tip pen, a file, soldering paste, a soldering iron, solder wire, a utility knife, and a calculator. III. Production Steps 1. First, make the two long sides of the antenna. Pay attention to the accuracy of the length when cutting the copper wire. A little tip: When bending the copper wire, you can file a small notch at the bending position with a file. DIY Antenna File a small notch with a file DIY Antenna After filing the notch with a file, the bending angle of the copper wire can be more accurate. After filing the notch with a file, the bending angle of the copper wire can be more accurate, and it is also convenient for us to bend the copper wire. DIY Antenna Accurate measurement is the first element. Whether it is the length during cutting or the angle during bending. DIY Antenna Mark the welding positions to facilitate accurate welding. DIY Antenna Everyone must keep the copper wire vertical during the production process. 2. After we cut off the copper wire with pliers, there is usually a little extra at the cutting edge. So the head of the copper wire also needs to be sanded flat to further reduce the length error after welding. Antenna Production Sand the cutting edge of the head. 3. Mark the positions of the welding points on the two long sides, and sand the places that need to be welded with a file to facilitate welding: DIY Antenna Measure the welding positions. There are 3 welding points on each side, and measure that the distance between them is 83.1mm. Make marks in advance. Antenna Production File the welding position in advance to make it a little concave to facilitate welding. 4. Make 4 pieces of copper wire with a length of 55mm and 2 pieces of copper wire with a length of 52mm. Both ends of the copper wire also need to be sanded flat. Antenna Production Cut copper wire 5. Make the middle part of the antenna. This part seems simple, but in fact, the "vibrator" is the most cumbersome part in the whole production process. The conventional method is to bend the copper wire like this first, and then weld two small joints in the middle respectively. However, if this is done, the number of welding points is increased, and the slope is not easy to grasp, resulting in a larger error. Antenna Production The middle part of the antenna This is our improved method: Divide the middle part into two sections, leave good joints, and then weld them together. This will greatly reduce the trouble of production. Antenna Production The improved middle part 6. Also weld the 4 long and 2 short copper wires prepared just now to the two long sides. Pay attention that the length after welding should be exactly the same as that on the drawing. Antenna Production The two sides of the antenna 7. Finally, weld all the parts that need to be welded according to the drawing. The finished product of the vibrator part is as follows: Antenna Production The antenna after welding and assembly 8. Use a utility knife to cut several sections of the outer skin of the closed-circuit television cable with a length of 21mm. The drawing requires that the distance between the vibrator and the reflector is 20mm. Why cut it to 21mm? Because when fixing it with a cable tie, the outer skin of the cable will inevitably be a little concave. In order to reduce the error caused by the concave part, I cut it to a length of 21mm. Antenna Production The outer skin of the cable television cable used to support the antenna 9. Next, fix the vibrator to the reflector. First, mark the positions where holes need to be drilled with a pen, and drill small holes with a nail. Pay attention that the size of the hole should not be larger than the head of the cable tie, otherwise it cannot be fixed. Then tie the vibrator with a cable tie. Antenna Production The fixed antenna Antenna Production Fasten the cable tie on the back of the antenna, so that the whole vibrator can be firmly fixed to the reflector. 10. The welding schematic diagram of the feeder and the feed source. Pay attention to understand the diagram clearly before starting to work. In a 2.4G wireless system, a coaxial cable with a resistance value of 50 ohms is used. Generally, a cable with a specification of -5 or above has a relatively small attenuation. Balun The welding schematic diagram of the antenna and the feeder, with the addition of the balun (click the small picture to enlarge) 11. The actual welding diagram of the balun. The balun is also called a balanced-unbalanced converter, and it has the function of impedance transformation in part. It is usually used to connect between a symmetrical vibrator and a coaxial cable. Everyone should pay attention to welding according to the instructions above, and be careful not to cause a short circuit or an open circuit. Balun Weld each position firmly, and be careful not to cause a short circuit or an open circuit. Antenna Production The front side of the finished antenna IV. Data Comparison (All tested at the same outdoor position and under the same AP) 1. First, test the data and download speed of the built-in 2200BG wireless network card of the laptop. The download speed is only 11.5KB/s. Wireless Router Antenna The download speed of the built-in network card of the laptop is only 11.5KB/s. 2. After replacing it with a Sagemcom 760n wireless network card and a 2db omnidirectional antenna and testing the download speed, it is increased to 570KB/s. Wireless Router Antenna After replacing the network card and the 2db omnidirectional antenna, the speed is increased to 570KB/s. 3. Test the gain data and download speed after replacing it with a Sagemcom 760n and an octagonal prism antenna. The speed after replacing it with the octagonal prism antenna is 1MB/s. Antenna The speed after replacing it with the octagonal prism antenna is 1MB/s. 4. Finally, test the gain data and download speed of a Sagemcom 760n and the newly made 18db copper wire antenna: The speed is increased to 1.17MB/s after replacing it with the copper wire planar antenna. Wireless Antenna The speed is increased to 1.17MB/s after replacing it with the copper wire planar antenna. V. Summary The production of this 18DB copper wire antenna is relatively simple. The key is that the welding is troublesome. For those who are not good at welding, it is already very good to achieve a gain of 15-17db. In addition, the flatness of the reflector and whether the cutting size of the copper strip meets the standards also have a great impact. We look forward to netizens making a completely qualified 18db copper wire antenna.