UBB27
UBB27
27 MHz - 3,3 GHz
Made in Germany
English
Page 8
RF-Analyser
High Frequency Analyser for Frequencies
from 800 MHz to 2.7 (3.3) GHz
Manual
© Gigahertz Solutions GmbH
Made in Germany
UBB27
Safety instructions
Please read this manual carefully before using this instrument for the first time! It contains
important information for use, safety and maintenance of the antenna.
Do not allow the antenna to contact water. Do not use it outdoors while it rains. Clean its
outside only, and with a slightly moist cloth. No cleaning agent or spray! Before cleaning
remove the antenna from the instrument.
There are no user-serviceable parts inside the instrument.
The antenna is sensitive to heat, shock and touch. Do not leave it exposed to the sun or hot
surfaces. Do not let it drop. Do not open it.
Use it only for purposes it has been designed for. Use it only with instruments or accessories
recommended or supplied with it.
© Gigahertz Solutions GmbH
Made in Germany
UBB27
English
Design of the antenna
and its elements
1) HF-Analyser, for illustration, not supplied.
2) Resonator (“large monopole“)
3) Indicator lights (LED’s)
Red = contact to circuitry and power supply ok
green = contact of the resonator ok
4) Ground plane for shielding radiation from sources below, including the instrument itself.
5) Ferrites for enhancement of the electric characteristics of the
antenna.
6) Casing for the circuitry (incl. Filter and compensation).
7) Mechanical holding fixture fitted for our HF-Analysers.
8) Antenna cable with further ferrites.
9) SMA connector
6 © Gigahertz Solutions GmbH
UBB27
Made in Germany
Assembly
Insert the holding fixture into the crossed slot in the front section of
the HF-Analyser. Connect the antenna cable to the antenna input of
the HF-Analyser. Try not to bend the cable too sharply.
Note of caution:
For technical reasons the resonator is a very delicate part: The
slim foot end should be as slim as possible from a technical
point of view. Avoid touching it, even though a slight inclination
does not influence to measurement significantly.
Technical instructions for the use of the UBB27
The two LED’s indicate functionality of the antenna with the instrument when the instrument is switched on:
The green LED checks the internal circuitry of the antenna and is
on only when it is ok. At the same time it indicates an adequate
power supply.
The red LED verifies the antenna is correctly connected to the
instrument. The red LED turns on if the connectors and contacts
are ok.
Both LED’s are part of an analogue circuit. When the power be-
comes “low“, they do not go off completely, instead they become
dimmer.
The power for the active circuits of the UBB27 is supplied by the RF
analyser (HFE35C or HF59B) through the antenna socket.
The power consumed by the UBB27 alone is higher than that of
the instrument itself. The time one battery charge can power the
instrument plus antenna therefore is reduced to less than half. For
long term recordings use the external power supply.
As long as the display does not show “low batt”, the measure-
ments are reliable, regardless of the reduced brightness of the
LED’s.
Directional pattern / reception characteristic of
the UBB27
The directional pattern of reception of the antenna held upright resembles a lying doughnut, like indicated in the following drawing:
© Gigahertz Solutions GmbH 7
Made in Germany
UBB27
Its best reception is:
Isotropic (uniform over the whole circumference) in the perpendic-
ular plane around the resonator axis,
For vertically polarized radiation sources.
Its sensitivity decreases with an increased angle of incidence to the
ground plane. The radiation from below is shielded by the ground
plane. This considerably reduces the distortions of the radiation field
to be measured. It also isolates the antenna from the instrument,,casing, connectors and the measuring technician below the
antenna.
Power densities of horizontally polarized sources in the horizontal
plane will be displayed as lower values by up to – 10 dB. To better
analyze a horizontally polarized TV transmitter, turn the UBB27 horizontally with the ground plane in the direction of the transmitter (like
a wheel rolling towards the source to be measured).
Directional pattern and reception characteristics are similar to those
of the so-called bi-conical antennas, with the UBB held vertically
corresponding to the bi-conicals, and their “cages” upwards and
downwards. An advantage of the UBB over the bi-conical antenna
is the measurements are more reproducible. This is because of the
downward shielding of the ground plane
Note of caution concerning far field conditions
Please remember, that this antenna (and the LogPer as well) has
been designed for far field conditions and provides reliable data
only when those prevail.
Where does the far field begins? From 1.5 to 10 times the wave
length. A simple rule of thumb for this complex subject. (2.5 wave
lengths) gives
27 meters at 27 MHz
2.7 meters at 270 MHz
27 centimeters at 2.7 GHz.
Note: Inside the Near field the electrical and the magnetic field
should be measured separately (one cannot calculate e.g. the magnetic field strength from the electric field strength and vice versa).
Under far field conditions a single measurement gives the power
density (in W/m², mW/m² or μW/m²).
How to perform measurements
Under most measuring conditions the antenna is to be held vertically.
The instrument should be held relatively high with an outstretched
arm to reduce the field distortions from the measuring technicians
body. If one holds it directly in front of oneself, then the body partly
shields the radiation from the backside.
The measurement itself is executed the same way as with a logarithmic-periodic antenna, except that there is no need to point it in
all directions, as the UBB is omni-directional in the plane perpendicular to the resonator. For further detail refer to the instruction
manual for the specific instrument in use.
8 © Gigahertz Solutions GmbH
UBB27
Made in Germany
The UBB27 in most typically shows higher readings than a
LogPer antenna, for two reasons:
With its smaller dimensions it can show so-called “hot spots”,
highly localized areas of intense radiation due to multiple reflec-
tions etc, without “spatial averaging”. This often accounts a factor
of 2 to 4 in interior situations.
Sources in the expanded frequency band below that specified for
the LogPer antennas may contribute to the total immission.
It is calibrated to a slightly higher average readings so that the
lower edge of its specified tolerance band still never goes below
the reading of a comparative measurement with a logper-antenna
even in frequency bands where it is in its specified plus tolerance.
Measurements obtained with the UBB27 are as accurate as those
obtained from the LogPer antenna. Please Note: The latter has a
narrower tolerance band, because of a lower volatility of their frequency band curve, which on the other hand is much narrower. In
addition they are much bigger and provide average power densities
over a wider area. Both can be and should be used when evaluating
the immission in a given situation. It is significant to note which
technique was used for each measurement.
“Rattling tone” for marking of un-pulsed transmitters
When using the HF59B in audio analysis mode with the UBB27
attached (The switch “Signalanteil” or “Signal” set to “Voll” or
“Full”), one will almost always hear a rattling tone. This is because
sources of un-pulsed radiation are almost always present in the
very broad frequency range of the UBB27. The loudness of it is
proportionate to the percentage of un-pulsed radiation in the total
signal received. The marking is done with a frequency of 16 Hz
(very low). An audio sample can be down-loaded as a MP3 file
from our home page.
Limits for using the RF amplifier HV10
Only the HF59B can supply enough Power for the UBB27 plus the
HV10. The battery life decreases by ~20%.
The external attenuator DG20_G3, may be used with the UBB27
plus either HFE35C or HF59B.
Accuracy
By itself, the UBB27 inaccuracy range of +/- 3 dB extends from approx. 85 MHz up to 3.3 GHz. The antenna continues to work beyond
that, but with increasing attenuation.
We state the total accuracy of our HF analyzers for the complete
assembly of analyzer plus antenna in a far field under well defined
conditions. (An “average measurement” with the complete assembly
placed on a non-conductive support). The measurement inaccuracies for the complete assembly are the following:
HFE35C plus UBB27 stays the same, and
HF59B plus UBB27 increases moderately to +/- 4.5 dB.
Below 85 MHz the tolerance level of the setup for the calibration
becomes predominant and limits the accuracy achievable for the
© Gigahertz Solutions GmbH 9
Made in Germany
UBB27
demonstration of the instrument. A simulation, which demonstrated
an excellent correlation of actual measurement and simulated signals in the frequency band above the lower limit, proves a very good
linearity down to 27 MHz. Without verification we cannot guarantee
the accuracy. Frequencies below 27 MHz are damped out by an
internal, extremely steep high pass filter.
NOTE: The UBB27 causes a noise of up to 5 μW/m² in the ”Min”
range. With the HF59B this can be reduced significantly by using
the “Pulse” mode.
EN: Rev. 2.4 (02/18)
10 © Gigahertz Solutions GmbH
Made in Germany
Hersteller / Manufacturer / Fabricant / Produttore:
Gigahertz Solutions GmbH
Im Kessel 2, 90579 Langenzenn, GERMANY
www.gigahertz-solutions.de / com
Your local partner /
UBB27
RTK AB
Granberga 9
186 91 Vallentuna
Sweden
Tel +46 8 510 25 510
Sms +46 709 273 324
Webb www.rtk.se
Mail info@rtk.se
© Gigahertz Solutions GmbH
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