Multiplexer Module (TX2A/TX4A)
18 November 1996
MUX-18
Table 8: Antenna Characteristics
Parameter
Conditions
min.
typ.
max.
Unit
L_ANT
Antenna inductance range, within which
the antenna can be tuned to resonance
using the tuning coil on the RF Module
26.0
27.0
27.9
µ
H
Q_ANT
Recommended quality factor of antenna
coil for proper operation
100
-
A_ANT_
TX/RX
Quality factor of TIRIS Standard
Antennas, when used together with the
Multiplexer
55
-
4.3 Connecting Cable
We recommend that the cable between the RFM and the Multiplexer is low resistive (for
example: RF Litz wire 120 x 0.1 mm, or loudspeaker cable with at least the same cross-sectional
area) with a maximum length of 30 cm. If the connecting cable is longer than 20 cm it will affect
the quality factor and inductance.
4.4 Antenna Resonance Tuning
In order to achieve the high charge-up field strength, the antenna resonator frequency must be
tuned to the transmitter frequency f_TX (tuning to resonance).
