1. Toshiba RF Project Presentation 12: 02/17/2005 Team: Josue Caballero, Brett DiCio, Daniel Hooper, Efosa Ojomo, George Sewell

2. Last week Met with Professor Cook Sought sources of material for building an RF Transformer Obtained copies of the Amateur Radio Handbook Researched air-core coupling transformers

3. Planned for Last Week Meet with Professor Cook tomorrow Research more on RF transformers Possibly build an RF transformer Test the RF transformer (dependent)

4. RF Transformers Devices that transfer energy from one circuit to another by electromagnetic induction Very short range Used for impedance matching to achieve maximum power transfer Used to suppress undesired signal reflection

5. Transformer

6. Meeting with Professor Cook Discussed why an antenna was not good for our situation with Toshiba –High bandwidth and variety of frequencies –Distance between transmitter and receiver under one wavelength Determined that Toshiba’s current solution works more like a transformer than an antenna

7. Meeting with Professor Cook contd… Air cored transformers do not wrap around a piece of ferrite material –Simple coils floating in space –Lower gauge wire beneficial, maintains shape better –If stability is a problem, the wire can be reinforced on top and bottom by some form of housing. Coupling is the process of both sides of the transformer meshing without touching –Increases efficiency and reliability –Decreases the necessary signal strength for good reception

8. Meeting with Professor Cook contd… Other design notes –Parallel capacitance with the transformer can adjust reception for a specific frequency –Transformer strength can be adjusted by moving the coupled parts closer and further apart –May need two separate reciever transformers for VHF and UHF frequencies –Need to use adjustable capacitors for best results

9. News from Toshiba Toshiba will allow an easy means of switching between channels on the receiver We may include as many or few test per station Toshiba’s current solution uses copper wire with an extremely thin clear-coat insulation

10. For Next Week Obtain a spool of copper wire Build a test-transformer (basic design) Design a coupling transformer Test coupling transformer Research equations and methods for performing calculations on bandwidth Learn about tuning capacitors

11. References http://www.minicircuits.com/appnote/howxf merwork.pdf#search='rf%20transformershttp://www.minicircuits.com/appnote/howxf merwork.pdf#search='rf%20transformers Harris Electric Supply CO Inc