Study of measurements and prediction models for signal attenuation in vegetation media at microwave frequencies.
The effects of vegetation media on the planning and design of radio links at microwave and millimeter wave frequencies are considerable and must be accounted for by radio system operators and users. This paper presents a study of propagation models for the excess attenuation of signals caused by suc...
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| Main Authors: | , |
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| Format: | Conference or Workshop Item |
| Published: |
2009
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| Subjects: | |
| Online Access: | http://eprints.uthm.edu.my/400/ http://eprints.uthm.edu.my/400/1/17_full_mahmoud.pdf |
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| Summary: | The effects of vegetation media
on the planning and design of radio links at
microwave and millimeter wave frequencies
are considerable and must be accounted for
by radio system operators and users. This
paper presents a study of propagation
models for the excess attenuation of signals
caused by such media whose mathematical
descriptions have been optimized using
measured data. This paper shows that one of
the models which expresses the attenuation
as a function of frequency and depth of
vegetation gives close predictions for the
two broad generic cases of trees 'in-leaf and
'out-of leaf . Measurements have been made
to determine the extent of attenuation of
millimeter-wave signals when propagated
through vegetation. Methods for predicting
such attenuation exist, but are either
deterministic in form or therefore complex
to implement or are completely empirical
and take no account of measurement
geometry. A new semi-empirical model is
presented here which is based on
measurements of vegetation attenuation
presented previously, and has some account
of the measurement geometry. This model is
compared with measured data and is shown
to give considerably better agreement. |
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