Magnetic H field for a rectangular loop antenna

iliefinis

Hi,

1. The problem statement, all variables and given/known data

How can I calculate the magnetic H field for a rectangular loop antenna (L x W) at a distance of x, which is made from copper tape with 30 um thickness and width of the tape from 1 to 5 cm. For the same antenna made ​​of wire I applied next formula:
H=(I*L*W)/(4π√((L/2)^2+(W/2)^2 +x^2 ))*(1/((L/2)^2+x^2 )+1/((W/2)^2+x^2 )) (RFID Handbook Second Edition 4.1.1.1 Path of field strength H(x) in conductor loops pp 65)

2. Relevant equations

I need an formula for magnetic H field for a rectangular loop antenna (L x W made from copper tape)

or

formula for calculating the magnetic H field for a rectangular conductor?

3. The attempt at a solution

I tried this solution but I do not know if it is the best approach

http://www.ntmdt.com/spm-basics/view...ctangular-wire

PS: I sorry for my bad English