
Cinterion
®
Java Terminals Hardware Interface Overview
3.15 RF Antenna Interface
39
EHSxT_BGS5T_HIO_v03
2016-05-26
Confidential / Released
Page 39 of 50
3.15
RF Antenna Interface
An external RF antenna is connected via the Java Terminals’s female SMA connector that is
also the antenna reference point (ARP).
Figure 14:
Antenna connector
The system impedance is 50
. In any case, for good RF performance, the return loss of the
customer application’s antenna should be better than 10dB (VSWR < 2). Java Terminals with-
stand a total mismatch at this connector when transmitting with maximum RF power.
Additional ESD protection to the antenna connector is provided. No DC voltage must be applied
to the antenna circuit to protect it from damage.
Please note that the terminal should be installed and operated with a minimum distance of
20cm between the antenna connected to the terminal and any human bodies. Also, the trans-
mitter must not be co-located or operating in conjunction with any other antenna or transmitter.
The allowed maximum antenna gain (including cable loss) for stand-alone situation is given be-
low in
.
Table 17:
Allowed maximum antenna gain (including cable loss)
Module
850MHz
900MHz
1800MHz
1900MHz
2100MHz
EHS6T USB
EHS6T LAN
3.42dBi
4.18dBi
9.64dBi
2.51dBi
15.54dBi
BGS5T USB
2.15dBi
2.15dBi
2.15dBi
2.15dBi
na
EHS5T RS485 and
EHS5T-US RS485
3.10dBi
6.10dBi
12.30dBi
2.50dBi
12.30dBi