NRF2402G Nordic VLSI, NRF2402G Datasheet - Page 23

• Manufacturer Part Number: NRF2402G
• Manufacturer: Nordic VLSI

PRODUCT SPECIFICATION
nRF2402 Single Chip 2.4 GHz Radio Transmitter
PERIPHERAL RF INFORMATION
Antenna output
The ANT1 and ANT2 output pins provide a balanced RF output to the antenna. The pins
must have a DC path to VDD_PA, either via a RF choke or via the center point in a balanced
antenna. Differential load impedance between the ANT1 and ANT2 pins, 100 +j175 , is
recommended for maximum output power.
example 50 ) can be matched to nRF2402 by using a simple matching network.
Antenna matching networks
The recommended 50
improving higher harmonic suppression.
A somewhat simpler matching network is shown in Figure 15.
This network utilizes one component less and uses few inductors, but performance of this
network requires very careful PCB ground plane layout. The value of capacitor C
dependent on PCB ground plane layout and parasitics in the layout, and must hence be
matched to a given application layout. The value of C
1.8pF. C
regulatory limits.
Nordic Semiconductor ASA
Revision: 2.1
out
must be tuned while checking that the harmonics output is below frequency
nRF2402
nRF2402
-
VDD_PA
VDD_PA
Figure 15 High pass antenna matching network
Figure 14 Low pass antenna matching network
Vestre Rosten 81, N-7075 Tiller, Norway
matching network is shown in Figure 14. This is a low pass network
ANT2
ANT1
ANT2
ANT1
2.2nF
Page 23 of 32
2.2nF
4.7pF
4.7pF
Antennas with lower load impedance (for
3.3nH
1.0pF
1.0pF
-
22nH
3.6nH
out
Phone [phone]
will typically be in the range 1.0pF –
10nH
5.6nH
1.0pF
1.0pF
4.7pF
Cout
1.5pF
- Fax [phone]
RF output
RF output
March 2006
out
is