Antenna Measurement - Deepace KC901V Manual

During the adjustment, user should try to seize the good timing to lock the screw
to fix the parameters.
Attention:
Port matching has a great influence on duplexer's attenuation. There will be
some tiny differences of the results by using different instruments. There also will be
differences after changing the connections between instrument and duplexer. There
are differences too for different repeaters and antennas' impedance and its actual
performance will be worse than the expected performance. In the first test, user
needs to sum up the experience according to the actual performance after put the
repeater in.
Concatenate the attenuator (about 10dB) with instrument's input port to im-
prove the matching. Increase the output attenuation (SHIFT+Po. ATT) to 10dB. It's
good to reduce the influence, which is from instrument's nonlinearity, to the test re-
sult.

4.2 Antenna Measurement

attention
The output port of the KC901V may transmit up to 10dBm(10mW). When the
antenna is tested, the output of the 901V will be transmitted through the antenna to
the air. Regulated output attenuation (SHIFT+Po.ATT) can reduce emission, but 901V
must be recalibrated (Re CAL).
4.2.1 Antenna Standing Wave Ratio testing
When measuring SWR, set the instrument into S11 and adjust the Format as
VSWR. User needs to be away from the antenna after setting the center and span.
Antenna's standing wave ratio is related with the field environment. So user should
choose a open outdoor environment, such as the roof. The cables should be as short
as it can be. If the RF cable is a bit long, disconnect the end which is connected to an-
tenna, and then do the user calibration to it.
The 13.56 MHz antenna, which RFID usually uses, almost can't connect to the
instrument directly. In this case, users can make a small ring-type antenna by them-
selves. Use this ring-type antenna to close to RFID antenna, then the standing wave
will change. Sum up the experience properly, the antenna, which is under the test, its
performance can be judged according to the changes of the standing wave.
4.2.2 Cable canceling
When measuring antenna, due to the limitation of the field environment, some-
times the calibration can't be done on the antenna's port. So it can't remove the in-
fluence from the coax automatically. In this situation, if user hope to know antenna's
RF parameters, they can enter the cable length into the instrument. The instrument
cancelation the cable.
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