The invention relates to a radio frequency (RF) system and method for improving the detection efficiency of an identification system including a transponder and a reader.The system (1) comprises an interrogator reader device (3) having an interrogator coil antenna (4) and a transponder (2) having a transponder coil antenna (5) and a microchip (6) Advantageously, the interrogator reader device (3) comprises a detection portion (11) including a sensitive signal gain detector (SSGN) for detecting just the presence of the transponder coil antenna (5) in case of misplacement of the transponder or broken link between the transponder coil antenna (5) and the microchip (6).The invention allows remedying to those potentially dangerous situations that might lead to a misdetection of the transponder (2).