Specifications

EMC-CS-2009.1
© Copyright Ford Motor Company – All Rights Reserved Page 94 of 121
February 11, 2010
j) Above 4000 MHz (10⋅fs), only three antenna locations and electric field probe positions must be evaluated. Repeat
steps e) through g) for the remainder of the calibration frequencies as indicated in Table C1. One of the probe locations
shall be the center of the working volume and one of the antenna positions shall be the typical receive antenna position
as described in step i).
The receive antenna shall be moved to a new location within the working volume of the chamber for each change in
probe location. The receive antenna shall be oriented in a different direction for each position (a change in angle of
20 degrees or greater is recommended). The electric field probes do not have to be oriented along the chamber axis
during calibration as long as the electric field probe axes remain consistent with each probe position. A proper
separation distance shall be maintained between the antenna and probe at each probe location. It is recommended
that each probe location be at least 1 m (minimum distance 0.25 m) from any previous location.
k) Normalize each of the maximum electric field probe measurements (each of the 24 rectangular components below
10 fs, and 9 rectangular components above 10 fs) to the square-root of the average input power using the data from
step g).
Input
z
Max
z
Input
y
Max
y
Input
x
Max
x
P
E
E
P
E
E
P
E
E
=
=
=
t
t
t
Where:
zyx
Max
E
,,
= Maximum measurement from each probe axis (24 or 9 measurements)
zyx
E
,,
t
= Normalized maximum measurement from each probe axis
P
input
= Average input power to transmit antenna during the tuner rotation at which EMax x, y, z was recorded
l)
For each calibration frequency below 10 fs (4000 MHz), calculate the average of the normalized maximum of each
probe axis of the electric field probe measurements:
()
()
()
8EE
8EE
8EE
zz
yy
xx
∑
=
∑
=
∑
=
tt
tt
t
t
m)
For each calibration frequency below 10 fs (4000 MHz), calculate the average of the normalized maximum of all the
electric field probe measurements:
()
24EEEE
iziyix
24
∑
++=
t
t
t
t
i = 1, 2, to 8 (number of probe locations)
Note: < > indicates arithmetic mean, i.e.,
()
24EEEE
iziyix
24
∑
++=
t
t
t
t
represents the sum of the 24 rectangular electric field normalized maximums divided by the number of measurements.
n)
Repeat step l) for each frequency above 10 fs (4000 MHz), replacing 8 with 3.
o)
Repeat step m) for each frequency above 10 fs (4000 MHz), replacing 24 with 9.