Atec Rohde-Schwarz-ESIB Series User Manual

Page 4

EMI Test Receivers ¸ESIB

Up to 2 MHz, the ¸ESIB family
uses ﬁ xed-tuned ﬁ lters; from 2 MHz to
1000 MHz, the preselection ﬁ lters oper-
ate as tracking ﬁ lters.

An autorange function is available for
the automatic setting of attenuation and
gain in the RF and IF signal paths. This
function ensures the correct combina-
tion of attenuation and gain depending
on the test level or any overload of a sig-
nal stage caused by pulses or sinusoi-
dal signals. So the operator is not bur-
dened with the internal workings of the
test receiver.

To measure extremely small voltage
levels occurring, for example, in EMI
measurements on vehicle antennas in
line with CISPR 25, the ¸ESIB family
offers a 20 dB preampliﬁ er from 9 kHz to
7 GHz (above 7 GHz as option
¸ESIB-B2). The preampliﬁ er is locat-
ed between the RF preselection and the
input mixer to be protected against over-
load. With this preampliﬁ er, the inher-
ent noise of the ¸ESIB is lowered to
such an extent that the RFI ﬁ eld strength
obtained in an overview measurement
using the peak detector, a log- periodic

antenna (e.g. ¸HL 223) and a 10 m
connecting cable clearly remains below
the EN 55022 quasi-peak limit (Fig. 1).

Fig. 2 shows the SCAN table stipulated
for commercial EMI measurements as a
function of the prescribed CISPR band-
widths.

To achieve high sensitivity in measure-
ments in line with MIL-STD-461D RE 101
in the frequency range from 30 Hz, the
unavoidable feedthrough of the 1st LO
at the input mixer is suppressed by self-

Fig. 1:
Sensitivity in 30 MHz to 1000 MHz range at 120 kHz IF bandwidth,
with peak detector and transducer factors for antenna + cable, dis-
played with limit lines for quasi-peak

Fig. 2:
Scan table for CISPR bands A to C/D

Fig. 3:
Inherent noise from 30 Hz to 100 kHz with limit values in line with
MIL-STD-461D RE 101, using the Shielded and Calibrated Magnetic
Field Pickup Coil ¸HZ-10

Figs. 4 to 7:
Example of transducer set: combination of antenna + cable

ESIB_dat_en.indd 4

04.01.2006 13:27:20