User's Manual

10
Atmel AVR2092
8427A-AVR-10/11
5 PCB layout description
This section describes critical layout details to be carefully considered during a PCB
design. The PCB design requires an optimal solution for the following topics:
Create a solid ground plane for the antenna. The PCB has to be considered as a
part of the antenna; it interacts with the radiated electromagnetic wave
Isolate digital noise from the antenna and the radio transceiver to achieve
optimum range and RF performance
Isolate digital noise from the 16MHz reference crystal to achieve optimum
transmitter and receiver performance
Reduce any kind of spurious emissions below the limits set by the individual
regulatory organizations
The REB232ED PCB design further demonstrates a low-cost, two-layer PCB solution
without the need of an inner ground plane.
The drawing in Figure 5-1 sho
ws critical sections using numbered captions. Each
caption number has its own subsection below with detailed information.
Figure 5-1. Board layout – RF section.