Datasheet

 2016-2019 Microchip Technology Inc. DS50002489D-page 17
RN4870/71
4.2 RN4870U Module
Figure 4-4 shows the physical dimensions of the
RN4870U module. Figure 4-5 illustrates the
recommended PCB layout, and Figure 4-6 shows the
recommended mounting details.
A low-impedance ground plane ensures the best radio
performance (best range, lowest noise). Pin 30
(BT_RF) is a 50 ohm connection that can be connected
to an external antenna such as a PCB trace antenna, a
component (chip) antenna, or through a host PCB 50
ohm microstrip trace. This trace can be extended to
include passive parts for antenna attenuation padding,
impedance matching, or to provide test posts. It is
recommended that the microstrip trace be as short as
possible for minimum loss and best impedance
matching. If the microstrip trace is longer, a 50 ohm
impedance is recommended.
FIGURE 4-4: RN4870U MODULE DIMENSIONS