EMVs/RemoteControl

... remote control ...

Antenna fitting

The system transmits in the Industrial, Scientific and Medical (ISM) Band which is in the range of 433.05 to 434.79 MHz.

The antenna should be 1/4 the corresponding wavelength with an infinite ground plane. As it is not an ideal system, we will measure the antenna characteristics and trim it to the proper length. We will use an Agilent E5071C analyser to measure the reflection (s11) of the antenna to its driver.

In order to do so:

• remove the jumper between the antenna and the RF chip
• calibrate the analyser:
  • select cal -> calibrate -> 1-port cal
  • connect the cylindrical dongle's open port and select open
  • do the same for short and load
  • select done
• connect the BNC cable between the analyser and the emitter board

- start : 100 MZ - stop : 800 MHz - Connecter à la plaque

avec un marker, chercher le trou dans s11 mettre un marqueur à 433 MHz

arriver à -10dB

résultat : longueur 18.5 cm (lambda/4 = 17.7 cm)