User's Manual

GWM400 Product Technical Specification and User Guide
3.8 RF Antenna Interface
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 GWM400_HID_v02 2017-07-05
Confidential / Prelimenary
Page 25 of 38
3.8 RF Antenna Interface
An external RF antenna is connected via the GWM400’s SMA connector (jack) that is also the
antenna reference point (ARP).
Figure 7: 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). GWM400 withstand
a total mismatch at this connector when transmitting with maximum RF power.
Additional ESD protection to the antenna connector is provided. DC voltage must not be ap-
plied 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.
For mobile and fixed operation configurations the antenna gain, including cable loss, must not
exceed the limit 2.51 dBi for all the supported bands.
The antenna's character impedance should be 50
. It it recommended that the antenna should
have VSWR <=2:1, within the working band frequency range.
SMA connector (jack)