ENGR 1202- E01 Project: Bluetooth Antenna Fabrication in the

Microelectronics Clean Room

Team 4: Team member 1, Team member 2, Team member 3, Team member 4, Team member 5, Team member 6

Agenda

• Problem Statement and Design Criteria

• Research Results Cellular Phone Systems Bluetooth Wi-Fi GPS RFID

• Team choice for Design• Antenna Calculations• Clean room safety • Antenna Fabrication

The Process of Making an Antenna

Conductor Material Decision Matrix

Calculation for Antenna length Antenna Design

• Cost Analysis • Big Picture Issues • Possible Improvements• Conclusion

Source: http://sll.sdsu.edu/studentorgs/images2007/meeting-agenda-clipart.jpg

Problem statement: Research, design, and fabricate a set of planar antennas

Maximum size of 20mm x 20mm and minimum size of5mm x 5mm

The antenna design shouldn’t have any sharp corners

Conductors include aluminum, copper, gold, and silver. The best conductor to use must be determined.

The antenna can either be Bluetooth/Wi-Fi, RFID, Cell phone or GPS compatible.

http://cyber.mpnodes.info/files/2012/02/rfid_circuit.jpghttp://i3.squidoocdn.com/resize/squidoo_images/http://courantblogs.com/technology/

http://www.arkepsilon.com/wp-content/

The size of the antenna should be calculated from the equation λ=C/f

λ= antenna’s length (m) C = speed of light (3*10^6 m/s) f= frequency (Hz)

Problem statement:

Frequency Bluetooth 2400 – 2597 MHzWI-FI 2400 – 2597 MHzRFID 865 - 868MHzGPS 1575.42 MHzCell phone 1850-1990 MHz

Research Results - Cellular Phone Systems Cellular phones are called cellular

because the zone in which they operate are divided into cells.

Each cell typically encompasses 10 square miles (or 26 square kilometers).

The MTSO switches all of the phone connections to the normal land-based phone system, and controls all of the base stations in the region.

Cellular Phones typically operate in the 1850 – 1990 MHz frequency band.

Cell phone systems have proven to be vital in the developing world. According to The Economist, two thirds of money transfers in Kenya are via phone.

Source: http://atlanta.cbslocal.com/2012/04/29/metro-atlanta-school-systems-eye-cell-phone-towers-for-revenue/

Research Results- Bluetooth

Bluetooth is a technology that enables short-range wireless communication between different electronic devices .

Bluetooth wireless technology transmits data using low-power radio waves and operates on the ULB (within the 2.45-gigahertz band).

Bluetooth’s purpose is to create a single digital wireless protocol to connect multiple devices while also resolving synchronization issues between them.

Source: http://presentsoftware.blogspot.com/2010/10/bluetooth.html

Research Results - Wi-Fi

Wi-Fi is a short nickname for wireless fidelity and it is often refers to wireless Internet.

Wi-Fi can be used for accessing the Internet.

Wi-Fi wireless technology operates at high frequencies in either the 2.45 or 5 GHz band.

Source: http://digitalhouston.ning.com/Services

http://www.arkepsilon.com/wp-content/

Research Results - GPS

GPS stands for Global Positioning System, and it is a technology that can show an exact position anytime and anywhere .

GPS satellites work by orbiting the earth and transmitting signal information to the GPS receiver on earth.

GPS (NAVSTAR) satellites transmit two low power radio signals. These are labeled L1 and L2, which are 1575.42 MHz and 1227.60 MHz respectively.

Source: www8.garmin.com

Soruce: http://i3.squidoocdn.com/resize/squidoo_images/

Research Results - RFID RFIDs are small electronic devices

that consist of a small chip and an antenna, and it stands for Radio-Frequency Identification.

Every chip is able to carry 2,000 bytes of data or less.

RFID’s purpose is to provide a special identifier for an object that can be scanned to save the identifying information.

RFID systems currently operate in the Low Frequency at 125 KHz, High Frequency at 13.56 MHz, and Ultrahigh Frequency bands at 860 to 930MHz.

Source: http://www.wired.com/wiredscience/2010/03/rfid/

Team ChoiceWe decided to make a quarter wavelength copper Bluetooth

antenna

Decision points included: Bluetooth for its diverse applications making it easier to sell with higher profit. Copper for its low cost and decent conductivity. Quarter wavelength as it lowers cost and works well with small range Bluetooth devices.

Source :http://libcom.org/files/images/blog/profit.jpgSource: http://www.officialpsds.com/images/thumbs/

Antenna Length CalculationFor a Bluetooth quarter-wavelength antenna:

Clean Room Safety All members must pass the safety test before entering the clean room

The garments are required to keep the clean room from contamination

Rubber gloves and goggles are needed when working with chemicals

For any questions about the chemicals, there are MSDS sheets available

Clean Room Safety GarmentsHood

Mask

Body Cover

Shoes Cover

Gloves

Goggles

Rubber Gloves

Decision MatrixCopper was chosen as the conductor

Strong points included: Low Cost Good Conductivity

Dimensional Drawing Quarter Wavelength for 2448.5MHz

Antenna Length is 30.61mm

Mask Creation

A mask diagram was made for the photolithography process using AutoCAD 2010 Squares were made to be 8.5mm X 9.5mmDesign was put into an array and then printed to a inkjet transparency

Photolithography

Each wafer was placed in acetone for 5 minutes, methanol for 5 minutes, and then rinsed and dried with nitrogen.

For the photolithography, the photoresist was spun at 4k rpm after applying the Mircoposit 1813 photoresist. Next, there was a 1 minute soft-bake at 115 degrees Celsius. The wafers were aligned, and then the UV lamp was turned on for an exposure of 120-125 mJ/cm2

Conductor Etch

Etching of the wafers was done with appropriate etch solutions. The wafers were then rinsed well in DI water prior to insertion into the dryer.

Dicing and Final Product

The wafers were saw cut with the Micro Automation 1100 diamond saw by lining up the vertical lines and horizontal line to saw each antenna separately.

Big Picture Issues Can Bluetooth EM waves cause brain tumors?

Research indicates that Bluetooth has the lowest risk of causing brain tumors.

Bluetooth has a SAR value of around 0.001 watts/kg, which is very low. (*)

Can Bluetooth benefit society? Research indicates that Bluetooth headsets can

significantly reduced car accidents. Some car insurance companies are even covering headsets. (**)

Source: http://www.nccn.com/images/brain%20tumor.jpg Source: http://www.gurusoftware.com/images/GuruNet/SocietyLogo.jpg

Possible Improvements Lowering cost of antenna:

Improving antenna design to maximize space on the wafer. Make margins around design smaller to maximize space

Bettering our marketing and sales potential: Research new emerging technologies that use Bluetooth . Devise new and effective business strategies to promote

and sell our antennas.

Source: http://www.newenglandcontrols.com/ckfinder/userfiles/images/logos/AreYouWireless.jpg

Source: www.etftrends.com/wp-content/uploads/2012/03/Technology.jpg

ConclusionPlanar Antennas are the only devices that can transmit and receive radio frequency waves from a chip.

We successfully built quarter-wavelength Bluetooth antennas for $1.02 each.

Bluetooth Planar Antennas will likely grow in demand: Works well in close range and low power devices. Works in the ULB. Cheapest and most efficient solution for simplifying local

electronic communications.

Source: http://www.coshpald.com/High-Potential-Leadership-Accelerator.html

References“Vital For the Poor.” The Economist. 10-16 Nov. 2012, 52.

"How Cell Phones Work." HowStuffWorks. N.p., n.d. Web. 30 Aug. 2012. <http://electronics.howstuffworks.com/cell-phone.htm>. Franklin, Curt, and Julia Layton. "How Bluetooth Works." HowStuffWorks. N.p., n.d. Web. 03 Sept. 2012. <http://electronics.howstuffworks.com/bluetooth2.htm>. "Bluetooth Technology and Wi-Fi." Bluetooth Technology and Wi-Fi. N.p., n.d. Web. 02 Sept. 2012. <http://www.bluetooth.com/Pages/Wi-Fi.aspx>. "How RFID Works." HowStuffWorks. Ed. Kevin Bonsor, Candace Keener, and Wesley Fenlon. N.p., n.d. Web. 08 Sept. 2012. <http://electronics.howstuffworks.com/gadgets/high-tech- gadgets/rfid.htm>. " What Is a GPS? How Does It Work?" What Is GPS? Everyday Mysteries. N.p., n.d. Web. 16 Sept. 2012. <http://www.loc.gov/rr/scitech/mysteries/global.html>. * “Cell Phones.” American Cancer Society. N.p., n.d. Web. 16 Sept. 2012.

< http://www.cancer.org/cancer/cancercauses/othercarcinogens/athome/cellular-phones>

** “Insurer Gives Drivers Bluetooth Headset To Help Reduce Accidents.” Reuters. 2 March 2012. Web. 15 Nov. 2012.  <http://www.reuters.com/article/2009/03/03/idUS28648+03-Mar-2009+PRN20090303>