Continental Automotive GmbH MARSKEYLESS ユーザーズマニュアル
DAIMLER MARS EIS ECU
– Homologation of LF-Driver Part
Author:
Dept.:
Sebastian Henke
E-B-D2-HW
Doc. name:
Process
Process
Hardware Description
DAI_MARS_EIS_Homologation.docx
Doc.
version
1.1
Page:
15/31
This document is confidential. Its contents are not to be exploited, passed on or disclosed to third parties without our express permission. All rights are reserved.
Hella
8
3
0
3
E
N_G
E
(
2
0
0
4
-0
9
)
5 LF-Antennas
The LF antennas generate the magnetic field that is needed for wireless communication between car
electronic components and the UID that is carried with by the end-user.
electronic components and the UID that is carried with by the end-user.
Each LF antenna that is plugged to the ECU is a LCR resonant circuitry:
Fig. 16 LF Antenna, RLC resonant circuit
Fig. 17 LF-Antenna, Impedance Z
The LF antennas transmit the LF challenge signals (data) and the LF carrier wave signals. They are
activated by the MAR EIS ECU using a controlled current.
activated by the MAR EIS ECU using a controlled current.
ALL LF Antennas have the same efficiency.
The efficiency of all antennas is H
max
(@l=1m, @I
ANT
=500mA) =77,5 dBµA/m.
The general measurement of the efficiency of the antennas is shown is this picture: