DA14531MOD

Final

Datasheet

Revision 3.1

31-May-2021

CFR0011-120-00

17 of 32

© 2021-2021 Dialog Semiconductor

8

Design Guidelines

The DA14531 SmartBond TINY

™ Module comes with an integrated PCB trace antenna. The

antenna area is 12x4 mm.

The antenna’s Voltage Standing Wave Ratio (VSWR) and efficiency

depend on the installation location.

The radiation performance of the PCB trace antenna depends on the host PCB layout. The maximum

antenna gain is -0.5 dBi when installed on a 50x50 mm reference board, as shown in Figure 19. The

radiation pattern is omnidirectional. The RF front end is optimized to achieve the maximum possible

efficiency for various installation positions of the module on a host PCB. To obtain similar

performance, follow the guidelines described in the following sections.

8.1

Installation Location

For optimum performance, install the module at the edge of a host PCB with the antenna edge facing

out. The module can be located on either of the outer corners or the middle of the host PCB with

equivalent performance.

The antenna should have 4 mm free space in all directions. Copper or laminate in the proximity of the

PCB trace antenna will affect the efficiency of the antenna. Laminate or copper under the antenna

should be avoided as it severely affects the performance of the antenna. The antenna keep-out area

can be seen in Figure 9.

Metals close to the antenna will degrade the antenna

’s performance. The amount of degradation

depends on the host system

’s characteristics.

Table 10 summarizes the antenna efficiency at different installation locations on a host PCB as

shown in Figure 8.

Position # 1 (Left)

Position # 2 (Middle)

Position # 3 (Right)

Freq

Antenna efficiency

Antenna efficiency

Antenna efficiency

[MHz]

[%]

[dB]

[%]

[dB]

[%]

[dB]

2405

52

-2,8

40

-4,0

40

-4,0

2440

46

-3,4

34

-4,7

41

-3,9

2480

50

-3,0

40

-4,0

52

-2,8

Figure 8: Installation Locations for Optimum Antenna Performance