  Magnetic field measurement including a temperature compensation is essential
for a magnetic field sensor. This study investigates a magnetic surface
acoustic wave (MSAW) sensor in a reflective delay line configuration with two
acoustic propagation paths with and without magnetic field sensitive layer. The
delay in path with sensitive layer leads to magnetic field detection and the
one without enable temperature measurement and thus compensation for the first
path. The developed sensor is based on a ZnO/LiNbO$_3$ Ycut (X-direction)
layered structure as Love wave platform. Love wave as a shear wave being more
favorable for magnetic detection. Co-Fe-B is considered as sensitive layer to
detect magnetic field changes and is deposited on the top of ZnO, but only on
one of the two paths. We combined an original configuration of connected IDTs
with a high electromechanical coupling coefficient (K$^2$) mode to improve the
signal amplitude. The achieved sensor exhibits a high temperature and magnetic
field sensitivity of -63 ppm/$^\circ$C and -781 ppm/mT, respectively. The
temperature compensation method for magnetic field measurement is demonstrated
using a differential measurement by subtracting the delay times obtained for
the two paths with and without the sensitive layer. Finally, The sensor
exhibited good repeatability at various temperatures. Moreover, the device
developed allows in addition to the multisensor functionality, the radio
frequency identification (RFID) which is necessary for the deployment of sensor
networks.
