The Design and Construction of an Antenna Booster (Wi-fi Antenna Booster)
CHAPTER ONE
AIMS AND OBJECTIVES OF PROJECT STUDY
AIMS:
- To construct a Wi-Fi antenna booster which enhances the signal strength (increases it by 24dBi) and extends the range of Wi-Fi signals (by 200 metres).
- This Wi-Fi antenna booster would be constructed out of components which are relatively lower in cost than their off-the-shelf counterparts.
OBJECTIVES:
- To enable the user of this device enjoy a seamless, uninterrupted and reliable communication.
- To enable the user of this device to trap wireless signals that is beyond the reach of their inbuilt wireless card.
- To enable the user of this device obtain/enjoy stronger signal strengths across longer ranges.
CHAPTER TWO
LITERATURE REVIEW
HISTORY OF ANTENNA BOOSTERS TO PRESENT DATE
The history of antenna boosters can be traced back to the 19th century when the term “repeater” originated with telegraphy, and referred to an electromechanical device used to regenerate telegraph signals (Loring, 1878). Use of the term has continued in telephony and data communications.
In telecommunication, the term repeater has the following standardized meanings:
An analog device that amplifies an input signal regardless of its nature (analog or digital), A digital device that amplifies, reshapes, retimes, or performs a combination of any of these functions on a digital input signal for retransmission. (Federal Standard 1037C) From the definitions above we can see that an antenna booster is very synonymous to a repeater, they basically perform the same functions.
In computer networking, because repeaters work with the actual physical signal, and do not attempt to interpret the data being transmitted, they operate on the physical layer, the first layer of the OSI model.
Before the invention of electronic amplifiers, mechanically coupled carbon microphones were used as amplifiers in telephone repeaters. After the turn of the century it was found that negative resistance mercury lamps could amplify, and they were used ( Sungook, 2001). In 1916 the audion tube repeater was invented and this made transcontinental telephony practical. In the 1930s vacuum tube repeaters using hybrid coils became commonplace, allowing the use of thinner wires. In the 1950s negative impedance gain devices were more popular, and a transistorized version called the E6 repeater was the final major type used in the Bell System before the low cost of digital transmission made all voiceband repeaters obsolete. Frequency frogging repeaters were commonplace in frequency-division multiplexing systems from the middle to late 20th century.
In 1985, the IEEE 802.11 technology originated, this was as a result of a ruling by the US Federal Communications Commission (FCC) that released the Industrial Scientific and Medical (ISM) band for unlicensed use (Encyclopedia Brittanica). In 1991, NCR, a computer company that had become a subsidiary of AT&T (former American Telephone and Telegraph Company) invented the precursor to 802.11 intended for use in cashier systems. The first wireless products were under the name WaveLAN.
Vic Hayes is known as the “father of Wi-Fi”. He was involved in designing the initial standards within the IEEE. (Chamy, 2002)
In 1999, the Wi-Fi Alliance was formed as a trade association to hold the Wi-Fi trademark under which most products are sold. (Wi-Fi Alliance)
The term Wi-Fi, was first used commercially in August 1999, (US Patent and Trademark Office) and was coined by a brand-consulting firm called Interbrand Corporation.
Wi-Fi for the home began in earnest in 1999 with the release of routers, or wireless access points, that used technology based on the first two commercial wireless standards: 802.11a and 802.11b. Computer networking by wire was already standardized under the code IEEE 802, so Wi-Fi as a subset of computer networking became IEEE 802.11. Deciding to start at the beginning of the alphabet for naming the first Wi-Fi protocol, the IEEE called the first commercial Wi-Fi protocol 802.11a.
CHAPTER THREE
METHODOLOGY
EQUIPMENTS AND MATERIALS
The equipments, tools and software used for fabrication in this project include;
- Vice
- Dip Trace PCB layout software
- Pliers
- Work station
The devices to be constructed in this project can be divided into three main parts namely;
- The biquad antenna
- The booster circuit and
- The USB connector circuit
The Biquad Antenna
The materials required to build the biquad antenna include; 123 X 100
- square section of PCB with the biquad design etched on it, short length of CNT-400 or LMR-400 low loss coax (approximately 300 mm long), 250 mm of 2.5 mm2 copper wire (approximately 1.5 mm diameter), SMA connector.
CHAPTER FOUR
TESTING AND OPERATION
This chapter takes a look at the tests carried out during the fabrication of the various parts of this device and the operation of the device. The tools used for the tests in this project includes
- EnGenius Wireless software
- USB Wi-Fi Adapter
- Digital multimeter
- A computer system
- A wireless router or radio
Testing
Before making use of the booster system it is necessary to check the booster output voltage if it is consistent with the desired output. The input voltage is 5v from the USB port this also is tested by plugging the device to a computer system then the multimetre is set to DC voltage and the multimetre cables placed on the USB port to read its output voltage.
Antenna Testing: For antenna testing, we will attempt to illuminate the test antenna (often called an antenna-under-test) with a plane wave. This will be done by using a source (transmitting) antenna with known radiation pattern and characteristics, in such a way that the fields incident upon the test antenna are approximately plane waves. The setup for the antenna testing process include:
- A source antenna and transmitter- This antenna will have a known pattern that can be used to illuminate the test antenna. For this project a
CHAPTER FIVE
CONCLUSION
The aim of this project which was to construct a Wi-Fi antenna booster which enhances the signal strength by 24dBi and extends the range by 200 metres using relatively cheap components was achieved. The Wi-Fi booster system was able to trap wireless signals through the biquad antenna which has a gain of 12dBi and was amplified by the booster resulting in an overall gain of 24dBi. This booster design is new and made from local components which are affordable. If this prototype is developed upon and mass produced there will be affordable Wi-Fi boosters in Nigeria and it can even be exported. There is also room for further work and improvement on the design especially considering that this booster can be designed to broadcast wirelessly thereby acting as a repeater to many computers instead of one as constructed.
In conclusion, with this device users can now enjoy a seamless, uninterrupted and reliable data communication. They can also trap wireless signals that are beyond the reach of their inbuilt wireless card and they can obtain/enjoy stronger signal strengths across longer ranges.
PROBLEMS ENCOUNTERED
There were numerous problems encountered in this project work. Firstly it was to ascertain the kind of design to use, the first consideration was to use a four-legged transistor known as BFG480W. After downloading the datasheet and checking for the availability in Nigeria, it was discovered that such a transistor was not in stock in Nigeria. It needed to be shipped from Philips Semiconductors Company in the US, considering the cost and the aim of the project which is to introduce an affordable design, this was discarded. After much research and consultation with my project supervisor and other experts in the field, the idea of using a three transistor array dropped. This idea was followed through till the end of this project work.
Another challenge was to adapt the signals coming from the coaxial cable to a USB connector which would be connected to the USB port of a computer this is only necessary when the booster system is to be used on a laptop since on a desktop there is an SMA antenna port on the wireless card. This challenge was overcome by using a USB adapter module.
Other challenges include crimping the coaxial cable to its connector, soldering the coaxial cable to the biquad antenna and unavailability of test equipments like spectrum analyzer, simple bolometer (a device for measuring the energy of incident electromagnetic waves), signal generator.
RECOMMENDATION
This project write up should serve as an aid to any subsequent project work on design and construction of a Wi-Fi antenna booster. This project work should not end here companies, entrepreneurs and investors should take it up from here so that we can enjoy a seamless, uninterrupted and reliable data communication across long ranges. With this project work improved upon a device that will be very useful can be created which will rival other available boosters in the market, especially with its affordability.
References
- Chamy, Ben (December 6, 2002). “CNET Vision series”. CNET.
- http://news.cnet.com/1200-1070-975460.html. Retrieved 27/2/2014.
- Federal Standard 1037C: Telecom Glossary 2000 Published August 7 1996
- Loring, A.E (1878) A Handbook of the Electro-Magnetic Telegraph New York; D Van Nostrand. Pp. 53-54
- Marshall, Trevor Biquad 802.11b Antenna www.martybugs.net Retrieved 4/6/2014
- “u gook, Ho g Wireless; fro Mar o i’s Bla k-Box to the Audion MIT
- Press p.165 ISBN 0262082985
- Techniks www.techniks.com/how-to Retrieved 11.45am 3/5/2014
- The Telegraph – Say hello to India’s first wirefree city
- US Patent and Trademark Office.
- Vrushali V. Kadu et al (IJAEST) International Journal of Advanced Engineering Sciences and Technologies Vol. No. 2, Issue No. 1, 047-051. www.ijaest.iserp.org. @2011
- “Wi-Fi (wireless networking technology)”. Encyclopædia Britannica. http://www.britannica.com/EBchecked/topic/1473553/Wi-Fi. Retrieved 27/2/2014.
- “Wi-Fi Alliance: Organization”. http://www.wi-fi.org/organization.php. Retrieved 21/3/2014.
- Wikipedia IEEE_802.11b http://en.wikipedia.org/wiki/IEEE_802.11b-1999
