The 2009 National DIY Competition, jointly organized by Anywlan.com and PConline, has been successfully completed. Now, we will provide detailed production methods for some award-winning works for everyone to learn and refer to, while also enhancing the hands-on ability of netizens. We will recommend some great works to everyone in several installments. If you have any good improvement suggestions for the antenna, please feel free to post them below.

Today, we will first introduce a flat antenna made of 18DB gain copper wire. We would like to thank the author CN. Link for their wonderful work. It s better to have fun alone than to have fun with others.

. I also hope that everyone can apply the content of this article to make a good antenna.

1. Antenna Overview and Drawing Preparation

The drawing of this antenna is sourced from a personal collection dug up by AnyWLAN moderator "Kite" from abroad.

. According to the information, the theoretical gain of this antenna is around 18.2db. After I DIY it, I tested the actual gain to be between 15-117db, which is very close to the theoretical gain. However, the two key issues that affect my DIY effect are that the copper wire length may not be accurate, and there are many welding points for the antenna, which may cause errors at the welding points. Another reason may be that the reflector is not flat. I think as long as we find a good reflector and have good welders, the antenna will definitely produce very good results!

Flat antenna

Schematic diagram (there are drawings available for download at the end of the article)

DIY antennas require attention to detail and patience, as the precision of antenna manufacturing processes and material selection will directly affect the gain of the antenna.

. Especially for directional antennas used in long-distance wireless communication, the deviation during production is one millimeter, and the difference can be significant up to one kilometer away. There are design drawings available for download at the end of the article.

2. Material Collection and Tool Preparation

1. Copper or aluminum wire with a diameter of 2mm should be preferred because of its low resistance and strong antioxidant capacity.

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2. Nylon cable ties, please refer to the following for specific uses;

Flat antenna

Cable ties for fixed antennas (available at hardware stores)

3. CCTV cable ties used to support oscillators and reflectors;

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4. A reflector plate larger than 392 * 308mm can be made using a computer case cover (this is what a forum expert uses), thin iron sheet, or aluminum plate. Because I couldn `t find such a large aluminum plate at that time, I used two iron sheets riveted together to make the reflector plate. How to rivet the two iron sheets together is skillful.

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1) Combine the two cut iron sheets together so that they do not shake;

2) Cut several sections of aluminum wire with a length of 5mm and a diameter of about 1-2mm;

3) Use nails or other sharp objects to make a small hole in the iron sheet that has been joined together. The diameter of the small hole should be just enough to insert the aluminum wire prepared in the previous step. After passing through two layers of iron sheet, the aluminum wire should expose the same length on each side.

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4) Use a hammer to diagonally strike the exposed aluminum wire on one side, and control the curvature yourself so that it does not fall out;

5) Continue to strike the exposed aluminum wire on the other side diagonally with a hammer until the aluminum wire becomes inactive;

6) Place the iron sheet on a flat surface, use a hammer to strike the aluminum wire vigorously, and after the aluminum wire is loosened, the two iron sheets are riveted together!

Flat antenna

Rivet two iron sheets

5. In addition, prepare a hammer, pliers, vernier caliper, signature pen, file, solder paste, soldering iron, solder wire, art knife, and calculator.

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III. Manufacturing Steps

1. First, make the two long sides of the antenna, and pay attention to the accuracy of the length when cutting the copper wire.

. Tip: When bending copper wire, you can file a small opening at the bend with a file.

DIY Antenna

File a small opening

DIY Antenna

After filing the opening, the bending angle of the copper wire can be more accurate

After filing the opening, the angle of the copper wire can be more accurate, and it is also convenient for us to bend the copper wire.

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DIY antenna

Accurate measurement is the first element.

. Whether its the length at the time of cutting or the angle at the time of bending, DIY antenna should be marked at the welding position for precise welding. During the production process, it is important to keep the copper wire vertical. After cutting the copper wire with pliers, there will usually be a little extra at the cutting edge. So the copper wire head also needs to be polished flat to further reduce the length error after welding.

Antenna production

Polish the head cut

3. Mark the positions of the welding points on the two long sides and use a file to polish the areas that need to be welded for ease of welding:

DIY antenna

Measure the welding positions

There are 3 welding points on each side, and the distance between them is measured to be 83.1mm. Mark them in advance

Antenna production

Use a file to recess the welding positions for ease of welding

4. Produce 4 welding points with a length of 55mm and 2 with a length of 52mm.

Copper wire, both ends of the copper wire should also be polished flat.

Antenna production

Cut copper wire

5. Making the middle part of the antenna, which may seem simple, is actually the most tedious part of the entire production process. The conventional approach is to first bend the copper wire in this way, and then weld two small joints in the middle. However, doing so increases the number of solder joints, and the slope is difficult to grasp, resulting in greater errors.

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Antenna fabrication

The middle part of the antenna

This is our improved method: divide the middle part into two sections, leave the joints and weld them together, which will greatly reduce the trouble of fabrication.

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Antenna production

Improved middle part

6. Weld the 4 long and 2 short copper wires that were just prepared onto the two long sides, ensuring that the length after welding is exactly the same as on the drawing.

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Antenna production

Both sides of the antenna

7. Finally, weld all the parts that need to be welded according to the drawing. The finished product of the oscillator part is as follows:

Antenna production

After welding and assembling the antenna

8. Cut several sections of the closed-circuit wire skin with a utility knife with a length of 21mm. The drawing requires a distance of 20mm between the oscillator and the reflector plate. Why cut 21mm? Because when fixing with wire ties, the wire skin must be slightly recessed. To reduce the error caused by the recessed part, I cut a length of 21mm.

Antenna production

Cable TV cable sheath used to support the antenna 9. The next step is to fix the oscillator onto the reflector. We first use a pen to mark the location where the hole needs to be drilled, drill a small hole with a nail, and make sure that the size of the hole is not larger than the head of the cable tie, otherwise it cannot be fixed. Then, we use a cable tie to tie the oscillator.

Antenna fabrication

Fixed antenna

Antenna fabrication

Use zip ties to clamp the back of the antenna, so that the entire oscillator can be firmly fixed on the reflector plate

10. Welding schematic diagram of the feed line and feed source, be sure to read and understand the diagram before starting.

. In 2.4G wireless systems, coaxial cables with a resistance of 50 ohms are used, and cables with a resistance of -5 ohms or higher generally have less attenuation.

Baren

Welding schematic of antenna and feeder, with Baren (click on the small image to enlarge)

11. Baren actual welding diagram, also known as balanced unbalanced converter, partially has impedance transformation function.

. Usually used for connecting symmetrical oscillators with coaxial cables. Please pay attention to welding the above points according to the instructions and avoid short circuits or open circuits.

balun

Each position should be welded tightly, and attention should be paid not to short circuits or open circuits

Antenna production

The front of the finished antenna

4. Data comparison (all tested in the same outdoor location and AP)

1. First, the built-in 2200BG wireless network card data and download test of the laptop, with a download speed of only 11.5KB/s

Wireless router antenna

The download speed of the built-in network card in this laptop is only 11.5KB/s

2. Replace it with Sagem 760n wireless network card and 2db omnidirectional antenna After downloading and testing, the speed increased to 570KB/s. After replacing the network card with a 2db omnidirectional antenna, the speed increased to 570KB/s. After replacing the Sagem 760n and InLing antenna gain data and downloading tests, the speed after replacing the BaLing antenna was 1MB/s The speed after replacing the Ba Ling antenna is 1MB/s

4. Finally, the gain data and download test of the Sagem 760n and the newly made 18db copper wire antenna: after replacing the copper wire flat antenna, the speed has increased to 1.17MB/s

Wireless antenna

After replacing the copper wire flat antenna, the speed has increased to 1.17MB/s

5. Summary

The 18DB copper wire antenna is relatively simple to make, but the key is the welding difficulty. For those who are not good welders, achieving a gain of 15-117db is already very good. In addition, the flatness of the reflector plate and whether the cutting size of the copper strip meets the standards also have a great impact.

. We look forward to netizens creating a fully qualified 18db copper wire antenna.

18DB Copper Wire Flat Antenna Manufacturing Drawing Download: Attachment