This paper presents an RF resonator integrated into a guided structure, and remotely interrogated with an antenna presenting a significant increase in the quality factor relative to the resonator alone. The principle consists of self-maintaining the excitation of the resonant loop scatterer used to encode the information by using multiple reflections delayed in time with the guided dielectric. Indeed, a type of Fabry-Pérot structure recovers part of the incident wave to re-excite the resonant loop and thus increases the quality factor of the total structure. This increase is particularly useful for identification or sensor applications, for example in chipless RFID. Increasing the quality factor has some advantages, such as facilitating the temporal separation of the signal coming from the resonators from the quasi-optical reflections of objects in the vicinity of the tag. It also allows more information to be encoded or the resolution of the sensor to be increased by having narrower frequency peaks. Based on this approach, an increase in the quality factor can be as much as 55% in the lossless case, and in measurement with a lossy dielectric, an increase of 23% has been obtained