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User manual
Antenna model: AT3000
Rev 6.0 – September 2014
Clampco Sistemi is a registered trademark of
Calzavara SpA
– via Corecian, 60 – 33031 – Basiliano (Italy) http://www.clampco-sistemi.com/
therefore characterize each antenna-ferrite bead cable system by means of a table that shows the numerical value
of such transfer for a significant set of frequencies.
Figure 7
: AT3000 Antenna factor (typical) at antenna port
It should be noted that the calibration of the antenna factor, particularly for what is concerned to the lowest
frequencies (up to 200 MHz), does not include cable and/or antenna handle contributions, in order not to
constrain the antenna factor to a particular E-field configuration, i.e., field polarization, coupling among antennas
or with cables. For this reason, the antenna and the cable should be oriented orthogonally to the polarization of
the field under measurement, and displaced in order to avoid coupling effects.
Note on Antenna Factor: for the convenience of those who use the system connected to a spectrum analyzer, the
transfer characteristic of the system described above is usually represented in terms of
antenna factor
, i.e., of the
value to be added to the indication in dBμV of the signal received by the spectrum analyzer (50 port), in order to
obtain the intensity value of the incident electric field on the antenna in dBμV/m. For example, if a certain signal at
the frequency of 1 GHz appears on the spectrum analyzer with an amplitude of 76 dBμV (about –31 dBm), and the
calibration table supplied with the system shows an antenna factor = 44 dB at 1 GHz, then the amplitude of the
incident field is equivalent to 76+44=120 dBμV/m, that is 1 V/m.
In fact, it should be noted that the above calculation is only strictly valid if the signal is measured directly at the
antenna output. To obtain the overall antenna factor of the system, including the RF cable, it is necessary to add
the value in dB of the attenuation on this cable (assessed at the respective frequencies and obtained from the
relative certificate) to the antenna factor values shown in the table supplied with the system.
Содержание AT3000
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