Hardware and physical integration guideline PCR Sensor A111
Page 9 of 32
2022-03-08
© 2022 by Acconeer
– All rights reserved
footprint will have a lesser impact on the directivity and therefore some vias and short traces are
preferably placed there while still satisfying regulatory compliance.
If the PCB assembly process allows, connect all ground pads without thermal reliefs as shown in Figure
6 a-b. Figure 7 shows the simulated relative RLG for the different routing examples in Figure 6. Omitting
thermal reliefs as in Figure 6a can increase the boresight RLG by approximately 2 dB, provided there
are no other interfering components or PCB traces close to the sensor. A small drop of approximately
0.5 dB is seen when placing decoupling capacitors (metric 1005) as shown in (Figure 6b).
Figure 6. A111 routing examples with vias placed close to sensor for maximizing ground plane size. (a)
Without GND thermal reliefs, (b) with decoupling capacitors and without GND thermal reliefs, (c) with
GND thermal reliefs. Trace to copper clearance is 0.127 mm (5 mil) and via pad diameter is 0.45 mm.
Figure 7. Relative RLG loss with and without A111 thermal reliefs.
a
b
c
