User's Manual

5. WORKING WITH ANTENNAS
MARS-24E requires special installation and tuning of external antennas. Refer to the ReaderManager User Guide (40-01-
006-DOC) for the antenna matching, tuning and testing instructions using the Reader Setup Wizard tool.
MARS’ external antennas are suitable for applications where one or many reading points are required. They
are designed to be used as free standing antennas, integrated into non-metallic (preferably plastic) housings, or
even embedded into desk tops or shelves.
Once antennas are placed in the position they are to be used, it is essential that they are  xed in place and
tuned. The tuning is to be done only once at installation. All antennas (except the small round antenna 30
mm radius) have an adjustable capacitor that allows for tuning.
5.1 MATERIALS
The material upon which an antenna is mounted and the positioning of the antenna itself can have a signi cant
e ect on antenna performance.
The e ect of materials and antenna position on antenna operation may be determined as follows:
• Place an antenna on a styrofoam block and tune for maximum voltage at the antenna center using an
Antenna Tuning Probe, digital voltmeter and a trimming tool. Then place the antenna on/into the installation
position, retune and measure the maximum voltage again. Compare the voltage values.
• A di erence of 10% or less is acceptable. If the voltage reduces by more than 10%, this indicates that
the material is adversely a ecting the antenna. The user should determine if the reduction in operation is
acceptable by measuring read range and stacking operation. If the reduction is not acceptable the antenna
must be relocated.
• Alternatively the use of a plastic spacer of 5 mm minimum thickness between the mounting material and the
antenna is recommended where the mounting material is adversely a ecting the antenna.
Antenna performance may be a ected by conductive and metallic materials in the immediate vicinity of the
antenna.
Metal, metallic or metallized objects placed next to the reader antenna may change the characteristics of the
antenna a ecting the tuning operation and reducing the read range.
It is recommended that the antenna should not be placed closer than 35 cm to any metallic object that is of a
similar or larger size to the antenna.
Small metallic objects such as jewelry or coins put on the antenna will have almost no a ect on the antenna
performance.
If metallic conveyor rollers are a part of an application it is advised to replace them with plastic parts if possible
or apply shielding techniques as required.
Materials such as wood, laminated MDF, HDF or plywood have a limited conductivity. If an antenna is mounted
into these materials some reduction in the read range can be expected.
07-Jul-07 63-70-006-DOC 31
MARS-24E
User Manual