Detection of cosmic rays using microwave radiation at the Pierre Auger Observatory

The discovery of microwave radiation from the passage of charged particles has opened a new window for the detection of ultra high energy cosmic rays. The main potential advantages of this technique are the possibility to instrument a large area with a duty cycle of detection close to 100% and no atmospheric attenuation, all this using relatively cheap equipment. Cosmic ray detection in the GHz band is being pursued at the Pierre Auger Observatory with three different set-ups: MIDAS and AMBER are prototypes of an imaging parabolic dish detector, while EASIER instruments the surface detector units with a radio receiver of wide angular coverage. The status of microwave R&D activities at the Auger Observatory, including the first detections of cosmic ray air showers by EASIER, will be reported.