User Manual

ZE51/61-2.4 RF module User Guide

1VV0300868 Rev.4 – 31/03/2011

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. Here after an example of

matching network between a ZE51/61-2.4 module and an antenna.

Symbols Reference Package Value Comments

L1 Coil

0603 or

0402

These values should be measured and

optimized with a Network Analyzer. If no

impedance matching is necessary,

replace L1 by a 0 Ohm resistor, and let

C1 and C2 not mounted.

C1, C2 Capacitor

0603 or

0402

Track 1,

Track 2

Coplanar Waveguide

 Track 1 length (as short as possible)

 Track 2 length (as short as possible)

Via

Ideally, ground vias and the RF output Via will have :

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.

See the layouts §VI.3 to have an idea of the antenna matching implantation :

 Antenna connection via a SMA connector (Top View)

Antenna

Connection

J29 RF

Input/Output

Track 1 Track 2