BIM3B-869.85-64 RADIOMETRIX, BIM3B-869.85-64 Datasheet - Page 8

• Manufacturer Part Number: BIM3B-869.85-64
• Description: TRANSCEIVER, 869.85MHZ
• Manufacturer: RADIOMETRIX

Specifications of BIM3B-869.85-64

• Rohs Compliant: YES

Other types of antennas are feasible but tend to have drawbacks at these frequencies. Helical and tuned
loop antennas are both very compact but tricky to set up, and can be impractical at 868MHz because of
their very small size. Microstrip patch antennas are relatively large in area, directional, and have gain.
Note: Where the specified antennas are mounted on the PCB and/or in close proximity to metalwork
(module casing, components, PCB tracking etc), the antenna radiation pattern may be seriously affected.
Radiated power may be significantly increased in some directions (sometimes by as much as 10dB) and
correspondingly reduced in others. This may adversely affect system performance where good all-round
coverage is desired.
Care should also be taken to ensure that this effect does not increase the radiated power in any direction
beyond that allowed by type approval regulations. Where this occurs the antenna may need to be
relocated. In extreme cases a resistive attenuator of appropriate value may be required between the
module and antenna.
Radiometrix Ltd, BiM3B Data Sheet
Base-loaded whip
1/4-wave whip
L
Fig. 5: Antenna configurations
RF
RF
shortened wire, rod, PCB track etc.
with loading coil.
SMT inductor may be used if reqd.
wire, rod, PCB track
or a combination of these
L (mm) = 71250 / freq(MHz)
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