This paper presents a dedicated UHF reader antenna to be mounted inside a pharmaceutical cabinet for RFID reading of UHF tags attached to pharmaceutical items. The proposed solution is based on a group of four circularly polarized patch antennas. The antennas' simulated and measured performances are presented. Experimental tests of self-standing tags and of tags attached to medical objects were performed and demonstrate a good detection score, confined to the interior of the cabinet in order to avoid undesired detections on the outside.