A111-001-R datasheet(22/35 Pages) ACCOONEER

22 / 35 page

A111 Pulsed Coherent Radar (PCR)

Datasheet, v2.8

2022-06-22

Page 22 of 35

Layout Recommendations

The sensor antennas are of a folded dipole type, with its main ground reference being the internal

package ground plane, extending below the whole area of the sensor. To further enhance the

directivity of the sensor, the package ground plane should be extended by soldering all GND pads to

the PCB top layer ground. In terms of regulatory compliance, any openings in the ground plane inside

the A111 footprint must be significantly smaller than the wavelength (5 mm in free space) to

effectively shield off any disturbance.

Figure 9.1 shows the simulated relative radar loop gain (RLG) as function of ground plane side length,

assuming a square ground plane. As the ground plane size increases, the RLG increases because of

increased antenna directivity. Constructive and destructive interference results in a non-monotonic

increase in RLG.

Figure 9.1. Simulated relative radar loop gain as function of ground plane side length (x). Ground

plane is a solid square ground plane.

VIO_1a and VIO_1b are internally connected and connecting both on the PCB is recommended as

well. Likewise, VIO_2a, VIO_2b and, VIO_3a, VIO_3b are internally connected and connecting both

is recommended on the PCB as well. It is recommended to have decoupling capacitors on the supplies

placed as close as possible to the supply terminals. A1 µF decoupling capacitance on each supply pin

pair is recommended.

More detailed PCB layout guidelines can be found in the “Hardware and physical integration

guideline”.

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