Texas Instruments 2000 LF Series, Application Note

Page: 15 / 38

Lit Number: 11-06-21-068
Page (9)
For an antenna to function correctly with a particular RF Module, the parameters must
match those in Table 1
RF Module
Inductance
(µH)
Inductance
Range (µH)
Q
RI-RFM-104B 27 26 ~ 28 100
RI-RFM-007B 27 25.5 ~ 28.5 100
RI-ACC-008B 27 12 ~ 80 60 ~ 120
RI-STU-MRD1 47 46 ~ 48 20
RI-RFM-003B 116 115 ~ 117 200
RI-STU-S251B 27 26 ~ 27.9 100
Table 1. RF Module Antenna Characteristics
4.1 Determining Self Inductance
The unit of measurement for inductance is the Henry (H). The values for Series 2000
antennas are in the micro-Henry (µH) range
4.1.1 By Calculation
For S2000 Series readers, antenna inductance can be calculated using the software
utility “ADU.exe” (Antenna Design Utility). This program is available from your local
Texas Instruments RFID representative and is shown in Figure 10.
Note:
Because of the different characteristics of various wire types,
some experience with this program is required. By modelling and
then constructing different sized loops, you can determine what
offsets are required for the wire you are using, to get the exact
inductance