6 Hardware description: Smart Remote 3 nRF51 product example
Doc. ID 4414_003 v1.2
Page 52
Pin
Label
Description
P1_5
GND
Ground
P1_6
NC
No connection
P1_7
NC
No connection
P1_8
NC
No connection
P1_9
GND
Ground
P1_10
NC
No connection
6.3.8 Matching network
The design is using an integrated balun from Johanson Technology for converting from differential to single-
ended signal and transforming the impedance to 50 Ω.
Layout of the matching network, component size, and component values are exactly as given in the
application example found on
Johanson Technology
's website. This reference matching network layout is also
available for download from
Johanson Technology
.
6.3.9 Antenna
The product example has an integrated chip antenna from Johanson Technology.
Go to
Johanson Technology
for more information on the chip antenna. The antenna is tuned to be resonant at
2.44 GHz, and the impedance is matched to the 50 Ω output of the balun with the use of two series inductors
(
L1
= 3.3 nH,
L2
= 1.5 nH) and a shunt capacitor to ground (
C4
= 1.2 pF). The antenna in this design is tuned
for this layout only, and with the same plastic casing. If the layout and/or the casing is changed, it is likely the
antenna must be retuned. The antenna can be retuned by adjusting the values of
L1
,
L2
and
C4
. The exact
values of the components must be determined by measurements with a vector network analyzer.
Figure 41: Matching network and antenna circuit
6.3.10 Schematics, bill of materials, PCB layout files, production files
Hardware files for the Smart Remote 3 nRF51 product example are available in a zip package.
The hardware files for the Smart Remote 3 nRF51 product example will be located in the following folder in
the hardware files zip package:
\nRFready Smart Remote 3 for nRF51 series x_x_x\nRF6933 - nRF51 Product
Example x_x_x
.
