Greetings All,
I've been reading Albert A. Smith's book, Radio Frequency Principles and
Applications, and ANSI C63.5 trying to work out the formula of the
determination of
maximum received field, EdMax. In Smith's book, the one of the formula's I am
trying
to work out is on page 51, equation (3.21) and in ANSI C63.5, similar formulas
are in
Annex A, equation (A.1).
I am getting the same EdMax values up to 100MHz in Table 2 of ANSI 63.5, but
for
whatever reason, for frequencies greater than 100MHz, EdMax's are completely
different. I am not sure what is happening to get such erroneous results.
For my own edification, I've been attempting to work through the equations to
see if
I can get the same values as in ANSI C63.5 Table 2, with little success.
Hopefully,
someone with a little more math experience can help me. For those who don't
have the
book or ANSI C63.5 the equations are as follows. I have used the Greek
variable names
instead of their symbols, to reduce the chance of them not being formatted
correctly
in different browsers.
For the horizontal plane -
EdhMax = ((49.2)^0.5 * {(d2^2 + d1^2*|rho,h|^2 + 2*d1*d2|rho,h|*cos[(phi) -
(beta)*(d2-d1)]}^0.5)/(d1*d2)
d1 = [R^2 + (h1 - h2)^2]^0.5
d2 = [R^2 + (h1 + h2)^2]^0.5
h1 is the height of the transmit antenna, h1 = 2 meters
h2 is the height of the receiving antenna, h4 = 4 meters
R is the antenna distance between the transmit and receive antenna, R = 10
meters
rho,h = {sin(gamma) - [( K - j60*(lambda)*(sigma) -
(cos(gamma))^2)]^0.5}/{sin(gamma)
+ [( K - j60*(lambda)*(sigma) - (cos(gamma))^2)]^0.5} = |rho,h|*(exp)^j(phi)
|rho,h| is the magnitude
K is the relative dielectric constant of the ground plane. K =1 for perfect
conductor
sigma is the conductivity of the ground plane, siemens per meter (S/m). sigma =
infinity for perfect conductor
gamma is the grazing angle. gamma = arccos[(h1 + h2)/R]
phi is the phase angle of reflection coefficient
beta = 2*pi/(lambda)
lambda is the wavelength, meters.
Many thanks in-advance,
Richard
=====
Richard Georgerian
Compliance Engineer
email: richa...@ieee.org
=====
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