Specifications

WM_PRJ_Q2400_PTS_001 - 003
6th November 2002
confidential ©
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Antenna
pad
Round pad
Antenna pad
Antenna connection by spring contact. Antenna connection by coaxial cable.
Note:
•
The WISMO™ Quik Q2403 Series does not include an antenna switch for
a car kit but this function can be implemented externally and it can be
driven using a GPIO.
•
The antenna cable and connector should be chosen in order to minimize
losses in the frequency bands used for GSM 900MHz and
GSM1800MHz.
•
0.5dB can be considered as a maximum value for loss between the
module and an external connector.
2.19.1.1 Antenna directly connected to the module: matching circuit
The goal of the matching circuit is to link the antenna (impedance ZA) to the
receiver and transmitter access of the module (impedance ZL = 50 Ohm real).
Matching
circuit
Z
L
= 50 Ohm
Receiver +
WISMO module
Z
A
The matching circuit is composed by four elements implemented (see Figure
15 and Figure 16) on the module connecting the "Antenna pad" to the "Round
pad" (access to the receiver and the transmitter).
The four elements of the matching circuit are not yet defined, and depend on
each antenna and mechanical integration. The matching circuit must be
verified in both frequency bandwidths: 900 MHz (880 to 960 MHz) and 1800
MHz (1710 to 1880 MHz).