ZE51/61-2.4 RF module User Guide
1VV0300868
Rev.4 – 23/06/201
1
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved
page 42 of 54
VII.2.
Antenna matching
Impedance matching can be required to deliver the maximum possible power from the module to the antenna and
vice versa. This is typically accomplished by inserting a matching network into a circuit between the source and the
load.
This matching network must be established as close as possible to the ZE51/61 module.
Hereafter an example of matching network used on the DIP interface board :
Symbols
Reference
Package
Value
Comments
Z
1
*
Resistor 0603
0
ohm ZE51-2.4/DIP-WA
Monolithic Ceramic
capacitor COG
0603 1.5
pF
ZE61-2.4/DIP-WA
Z
2
, Z
3 *
- -
Not
mounted
ZE51-2.4/DIP-WA
- -
Not
mounted
ZE61-2.4/DIP-WA
Track 1,
Track 2
Coplanar Waveguide
Track 1 length (as short as possible)
Track 2 length (as short as possible)
Plated holes
Ground vias :
drill of 0,35 mm
pad of 0,75 mm
Antenna
connection
Coaxial cable Pad:
Hot point: 2*2mm
Ground pad:2*4mm
Or a specific SMA connector can be used.
*: These values should be measured and optimized with a Network Analyzer. If no impedance matching is
necessary, replace Z
1
by a 0 ohm resistor, and let Z
2
and Z
3
not mounted.
See the layouts §VI.3 to have an idea of the antenna matching implantation.
Antenna
Connection
Z
3
Z
2
J29 RF
Input/Output
Z
1
Track 1
Track 2
