This document is the property of KYMATI GmbH and must not be copied or disclosed without its written authorisation.
- KYMATI GmbH – 2021
KY.MAN.0105 (6.0)
KY-LOC 1D.02.01 User Manual
Doc.- No.: KY.MAN.0105
Version:
6.0
Date:
14.12.2021
Page:
34 of 83
7
Operational Limitations
7.1
Fresnel Zone Clearance
To prevent performance degradation, the Fresnel zone clearance (at least of 1
st
order) between
two sensors should be respected. The following notation is used hereafter:
Figure 19: First Fresnel Zone
The Fresnel Zone is the grey area shown in Figure 19. It is mainly depending on the system
frequency and the distance between the two sensors.
The maximum radius of the first Fresnel zone can be computed with the following formula,
where it has already been predefined that the device operates at f = 61 GHz:
,
=
1
2
√
=
1
2
=
4
√ = 0.035√
F
1, max
(max. radius of the Fresnel Zone) is in units of meters, as well as the antenna distance
d.
Distance [m]
Max Radius of Frenzel Zone [m]
50
0.25
100
0.35
300
0.61
500
0.78
Table 4: Maximum radius of Fresnel zone at different distances.
This also implies that the two sensors have to be mounted in such a way that there is still some
spacing to neighbouring objects, in order to respect the Fresnel zone clearance.
Objects obstructing the Fresnel Zone can cause signal degradation depending on the amount
of the obstruction. E.g. it shall be avoided to place any objects in the field of view of the sensor
or mount the sensor in locations close to obstacles, which might affect the overall range
performance and/or the measurement quality.
7.2
Line of Sight Clearance
The most important technical aspect for the system is to have a continuous Line of Sight (LOS)
condition between the remote device and the relay device at any time. A proper Line of Sight
analysis during the first time shall be made taking also possible temporary objects into account.
Sensor #1
Sensor #2
d: distance between antennas
F
1
: radius of
1
st
Fresnel Zone
