Toshiba RF Receiver for HDTV Presentation 13: 02/24/2005 Team: Josue Caballero, Brett DiCio, Daniel Hooper, Efosa Ojomo, George Sewell

Work Scheduled 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

Work Accomplished Worked on mathematical model describing transformer system Built four test elements Tested elements in lab

Mathematical Models Needed a way to describe each element so that certain goals could be achieved –Inductance –Bandwidth –Flux Linkage Developed a simplified model based on a very short solenoid

Solenoid Model A very short solenoid should have a self inductance similar to a wound wire loop. Lsolenoid = [(μ0) (N^2) (A)]/L Self inductance of a solenoid is equal to the permeability of free space times the number of turns squared times the cross-sectional area divided by the length of the solenoid.

Why? Inductance of the element determines the frequencies that can pass through it. Too high and there will be no transmission in the UHF band. However, bandwidth is logarithmic, while inductance is linear (like resistance) SO, the more current is pushed through the inductive element, the wider the bandwidth.

Solenoid Model Shortcomings The solenoid model is good, however it cannot tell us about the magnetic field outside itself This is important because we will need to determine variability based on position compared to the second (receiving) element.

In the works… Using the Biot-Savart Law, it is possible to find magnetic field density (in Teslas) of any point in space around a current loop. Using this magnetic field description, magnetic flux and coupling can be determined.

For next week… Further develop mathematical model Tweak experimental designs based on results Obtain better wire for experiments