Antenna diagnostis method and device

A method of diagnosing at least one antenna of a resonant circuit associated with an amplifier comprising a first transistor (HS1) connected to a supply voltage and a second transistor (LS1) connected to a ground and an amplifier output (OUT1), the first transistor (HS1) and the second transistor (LS1) being mounted symmetrically and the amplifier output (OUT1) being located between the two transistors, said device comprising means for evaluating a current flowing in a connection of each of said transistors, characterized in that it comprises the following steps:

• generation of a signal by only one of the transistors and excitation of the antenna (L) concerned by said signal, for a predetermined period of time,
• evaluation of the current in each of the connections equipped with means for evaluating a current,
• evaluation of the amplifier output potential,
• performance of a diagnosis by comparing the results of the evaluations carried out with the results corresponding to the measurements obtained when the antenna concerned is in normal operating conditions.