Chapter 2: Hardware Interface Description
May 31, 2008 Module Hardware Description 33
Antenna InterfaceThe W24 antenna connector is the RF interface to the WLAN network.
The antenna interface consist of an MMCX type connector, which has impedance matched to 50Ω
at the relevant WLAN 802.11 b/g frequencies.
The antenna or antenna application must be installed properly to achieve best performance.
Table2-15 gives the antenna interface specifications.
It is the Integrator's responsibility to design the antenna or antenna assembly used with the W24.
This will highly affect the RF performance of the W24 (signal quality, current consumption etc.).
The following guidelines should be followed:
•Make sure that the antenna or antenna assembly matches the Antenna Interface
Specifications.
•Use low loss RF cable and connectors keeping cable runs to a minimum.
•In order to prevent mutual interference between the GSM and the WLAN antennas in stacked
configuration, a minimum distance that provides a 30dB isolation is required. To achieve the
required 30dB isolation between the antennas, a distance of about 7cm from each other
should be kept when using a monopole isotropic antenna with 0dBi and appropriate return
loss.
Table 2-15:Antenna Interface Specifications
Parameter Specifications
WLAN 802.11b/g band 2400 MHz - 2483.5MHz
Gain 0 dBi
Impedance 50Ω
VSWR Less than: 2.5:1