Plastronics Development of Low-Profile Conformal Antenna for IoT Sensors
Résumé
A compact and conformal cylindrical antenna
for IoT sensor applications is presented. Plastronics
development using Laser Direct Structuring (LDS) process is
carried on to optimize the space occupied by the antenna.
Specific LDS-compatible polycarbonate (PC) thermoplastic is
used as a substrate. The dipole antenna stands on the outer
surface of a 17 mm high cylinder with a diameter of 48 mm.
The antenna operates in the European ISM band (868 MHz),
which implies a very low profile length dimension of (0.14 λ)².
The cylindrical holder is mounted in an industrial light fixture
in order to be connected to a compact sensor board. Good
agreement between simulations and measurements is found
with a dipole-like radiation pattern and a maximum of 1 dBi
measured gain. The 22 MHz bandwidth (S11 < -10 dB) satisfies
the European ISM band IoT protocols LoRa and SigFox.