GS-BT2416C2_0709 STMICROELECTRONICS [STMicroelectronics], GS-BT2416C2_0709 Datasheet - Page 9

• Manufacturer Part Number: GS-BT2416C2_0709
• Description: Bluetooth class 2 module with embedded SPP SW
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

GS-BT2416C2.AT1
5.1
Figure 3.
Antenna on PCB
Antenna reference
RF output pin must be connected to an antenna which could be:
●
●
●
●
●
Figure 6.
Tools for calculating the characteristic impedance, based on the physical and mechanical
characteristics of the pcb , can be easily found on the web.
Trace width
PCB
thickness
Antenna directly printed on the pcb
Integrated antenna as, for example, Antenova 30-30-A5839-01 , Murata
ANCV12G44SAA127, Pulse W3008 , Yageo CAN4311153002451K.
External antenna connected by means a SMA connector
Despite of the type of antenna chosen, the connection between the RF out pin and the
antenna must be executed in such a way that the connection trace must be matched to
have characteristic impedance (Z0) of 50 ohm to get the maximum power transfer.
Matching for 50ohm is depending on the various factors , elements to be taken into
consideration are:
–
–
–
–
Type of material, i.e. FR4
The electrical characteristics of the material ,i.e. the εr , electric constant at
2.4GHz
Mechanical dimensions of the pcb and traces ,i.e. pcb thickness , trace/ reference
ground thickness, trace width , trace thickness
Just to give an example , using a 1mm thick FR4 board , with an εr = 4.3 at
2.4GHz , with Cu thickness of 41 µm, the resulted width of 50ohm strip-line is 1.9
mm ( Microstrip type calculation).
Parameters for trace matching
Figure 4.
ε
r
(
Dielectric constant
Antenna examples
(Figure
3)
)
Figure 5.
(Figure
Application information
SMA connector for
external antenna
5)
Reference ground
(Figure
Trace thickness
4)
9/32