MICRF610TR MICREL [Micrel Semiconductor], MICRF610TR Datasheet - Page 18

• Manufacturer Part Number: MICRF610TR
• Description: 868-870 MHz ISM Band Transceiver Module
• Manufacturer: MICREL [Micrel Semiconductor]

Layout
Recommended Land Pattern
Figure 12 shows a recommended land pattern that
facilitates both automatic and hand assembling.
Micrel, Inc.
December 2005
Figure 13. Recommended Land Pattern (TOP VIEW)
18
Layout Considerations
Except for the antenna input/output signal, only digital and
low frequency signals need to interface with the module.
There is therefore no need of years of RF expertise to do a
successful layout, as long as the following few points are
being followed:
•
•
•
Proper ground is needed. If the PCB is 2-layer, the
bottom layer should be kept only for ground. Avoid
signal traces that split the ground plane. For a 4-
layer PCB, it is recommended to keep the second
layer only for ground.
A ground via should be placed close to all the
ground pins. The bottom ground pad should be
penetrated with 4-16 ground vias.
The antenna has an impedance of ~50 ohm. The
antenna trace should be kept to 50 ohm to avoid
signal reflection and loss of performance. Any
transmission line calculator can be used to find the
needed trace width given a board build up. Ex: A
trace width of 44 mil (1.12 mm) gives 50
impedance on a FR4 board (dielectric cons=4.4)
with copper thickness of 35µm and height (layer 1-
layer 2 spacing) of 0.61 mm.
M9999-120205
MICRF610