BA45F56xx Wireless Transceiver Application
AN0571EN V1.00
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November 5, 2020
315MHz
433MHz
470MHz
868MHz
Unit
C4
1.5
1
1
N.C.
pF
C5
100
100
100
100
pF
C6
12
10
8
N.C.
pF
C7
24
22
15
3.3
pF
C8
15
12
8
5.6
pF
C9
100
68
68
68
pF
C10
N.C.
N.C.
N.C.
N.C.
—
L1
18
15
15
0R
nH
L2
18
15
15
8.2
nH
L3
18
8.2
5.6
3.3
nH
L4
82
68
47
18
nH
L5
100
82
82
82
nH
Table 3. RF Impedance Matching Component Values
Antenna Type Selection
A commercially available 50
Ω
SMA connector Dipole or Patch can be used as shown in Figure 9.
Figure 9. Dipole Antenna
Or a
λ/4
length single core copper stranded wire can be used as shown in Figure 10.
Figure 10. Spring Antenna
If it is required to etch an antenna directly onto the circuit board, refer to the notes in the next
chapter.
PCB Layout Note
Component Placement
When locating components, priority should be given to the RF signal paths. Components and
component PADs should be located as close to the device as possible. The shorter the distance
between the tracks, the better.
When placing component leave room for the VCC and GND lines.
