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920MHz Band Wireless Device (Korea) USERS MANUAL EM-9121 Rev. 1
4.2 ANTENNA
■
ANTENNAS FOR WL40KR SERIES
Following two antennas are available for the wireless I/O WL40KR series.
Select either antenna according to the usage scenes and their respective characteristics.
WL40KR series do not use the diversity function.
Figure 4.3 Sleeve antenna
Figure 4.4 Rooftop antenna
• Sleeve antenna
An indoor-use antenna to attach to a wireless device. Tilting the antenna up to 90° deflects radio wave.
• Rooftop antenna
An antenna with a 2.5-m coaxial cable to install away from a wireless device.
This antenna is waterproof and suited for outdoor use as well.
To fully exhibit the characteristics of the monopole rooftop antenna, a ground plane equivalent to the electric ground is needed.
Attach its magnet base on a metal plate (recommended dimensions: 500 mm × 500 mm or more).
The gain of the rooftop antenna is less than that of the sleeve antenna for approximately 2.5 dB.
However the rooftop antenna has the advantage that it can be installed in a high location, which is effective for the reachability of
radio wave.
The specifications of the antennas are as shown in the table below.
[Table 4.3] Specifications of antennas for wireless devices
ITEM
SPECIFICATIONS
Type
Sleeve antenna
Rooftop antenna
Installation environment
Indoor
Outdoor
Cable length
–
2.5 m
Antenna type
Dipole
Monopole
Gain
3 dBi max. (
*
)
2 dBi max. (
*
)
Waterproof property
Non-waterproof
Waterproof (IPX6)
Directionality
Non-directional in horizontal plane
Non-directional in horizontal plane
Dimensions
195 mm (7.68 inch) (including connector)
80 mm (3.15 inch) (including base)
*
The performance of the antennas may be affected by the installation environment.
4.3 COAXIAL CABLE
A coaxial cable is available for extension of the rooftop antenna.
The table below shows specifications of the coaxial cable (Oki Electric Industry Co., Ltd.).
[Table 4.4] Specifications of coaxial cable
ITEM
SPECIFICATIONS
Type
Extension cable for rooftop antenna
Cable length
7.5 m (including connector)
Frequency
0 – 6 GHz
Impedance
50 Ω (nominal)
Cable loss
Approx. 3.1 dB in 800 MHz band
Approx. 3.5 dB in 1000 MHz band
Connector
SMA, non-waterproof
*
Cable
RG58
*
The connector is not waterproof. For its metal material, apply insulation treatment (e.g. taping).