Com-Power CGO-5100A - Manual

Comb Generator
Features
Description
Application
The CGO-5100 Comb Generator is a radiated reference
signal source. It is a self-contained source of signals con-
sisting of frequency harmonics at 100 MHz intervals, and
is usable from 1 GHz up to at least 18 GHz. The signals
generated by CGO-5100 are stable and can be used as ref-
erence signals for validating OATS (Open Area Test Sites)
that are utilized for EMC testing. The Comb Generator
CGO-5100 has internal circuitry, which is designed to make
its output stable, precise and close to the emission limits
for FCC Part 15 and EN 55022.
The CGO- 5100 Comb Generator has an omni directional
built-in antenna, which works in conjunction with the
chassis of the unit. The circular chassis of the Comb Gen-
erator helps radiate the signal uniformly in all directions
in the horizontal plane. The built-in antenna of the CGO
5100 provides improved signal stability, however it cannot
provide conducted reference signals.
The CGO- 5100 Comb Generator is powered by a recharge-
able internal battery pack. The internal power eliminates
the need for an external power cable and its effect on the
radiated signal pattern or level. When the battery voltage
drops below a reliable operating level, the RF circuit is
shut off automatically. This feature prevents an invalid
output from the Comb Generator. When fully charged,
the battery allows continuous use of the Comb Generator
for up to 18 hours. The Comb Generator and its charger
are shipped with a custom wooden storage box
Reference Source for OATS Verifi cation
Usable Frequency Range to 18 GHz
Amplitude Variation Less Than ± 2 dB
Auto RF Shutoff With Low Battery Voltage
Omni-directional
Com-Power Corporation (714) 528 - 8800 www. com-power.com [email protected]
CGO- 5100A
Radiated emissions measurements for EMC are usually
conducted on an Open Area Test site (OATS) or an an-
echoic chamber. OATS and chambers must be calibrated
before use in accordance with published calibration pro-
cedures at regular intervals. These calibration methods
are too elaborate and time consuming to be performed
before each test to ensure that the data taken is con-
sistent and accurate. However, the generally specifi ed
one-year calibration cycle is too long to fi nd out about
any problem with the site or associated test equipment.
The Comb Generator is a tool to solve these problems.
The test engineer should keep a daily log of a few Comb
Generator radiated readings before starting his test. He
is able detect potential problems with site by monitoring
any change in the readings. For example, any problem
or change with antenna, cables, preamplifi er, attenuator
or receiver will be refl ected in the Comb Generator data
with the same setup. The same method can be utilized
when EMC emissions measurements for a product varies
with sites. The Comb Generator can be used to determine
if the test sites are causing the variation. Without such
a reference source, it would be extremely diffi cult to
compare several sites.
The comb Generator can also be used to check the
shielding effectiveness of an enclosure.