Abstract: An antenna (L) diagnostic device of a resonant circuit associated with an amplifier includes a first transistor (HS1) and a second transistor (LS1) connected and an amplifier output (OUT1). The first transistor (HS1) and the second transistor (LS1) are mounted symmetrically and the amplifier output (OUT1) is located between the two transistors. The device includes: elements for measuring a current flowing in a connection of each of the transistors; first elements for generating an input signal connected to the first transistor; second elements for generating an input signal connected to the second transistor; and electronic elements (8) with an output supplying an output signal representative of the potential (V_OUT1) at the amplifier output. A method for diagnosing an antenna implementing such a device is also described.

Abstract: An electric circuit for controlling the access and immobilizing a vehicle has a first antenna driver (12) for driving a first antenna (19) for emitting a signal (100) in the event of identification of an ID transmitter (3) for access control of a vehicle. A second antenna driver (24) is provided for driving a second antenna (21) for emitting a signal (104) in the event of identification of an ID transmitter (3) for the immobilizer of the vehicle. In addition, the electric circuit has a receiver device (14) for receiving a signal captured by an antenna (21) for the identification of an ID transmitter (3) for the immobilizer. The first antenna driver (12) and the receiver device (14) are commonly integrated into a semiconductor chip (1).

Abstract: Through a microcontroller, control signals are transferred to a transmitting and receiving unit or configuration data are transferred. Through the transmitting and receiving unit, in a first operating state transmission signals are issued, while controlling the control signals of the microcontroller. Upon a first specified event, the transmitting and receiving unit is switched to a second operating state through a one-time transfer of corresponding configuration data by the microcontroller. In the second operating state, the transmitting and receiving unit automatically transmits repeated transmission signals. The microcontroller immediately switches to a current-saving or non-current, inactive operating state after said microcontroller has switched the transmitting and receiving unit to the second operating state.

Abstract: An electric circuit for controlling the access and immobilizing a vehicle has a first antenna driver (12) for driving a first antenna (19) for emitting a signal (100) in the event of identification of an ID transmitter (3) for access control of a vehicle. A second antenna driver (24) is provided for driving a second antenna (21) for emitting a signal (104) in the event of identification of an ID transmitter (3) for the immobilizer of the vehicle. In addition, the electric circuit has a receiver device (14) for receiving a signal captured by an antenna (21) for the identification of an ID transmitter (3) for the immobilizer. The first antenna driver (12) and the receiver device (14) are commonly integrated into a semiconductor chip (1).