Embroidered partially reflective surface (PRS) antenna

The design of a moderate gain embroidered antenna using the resonant cavity concept is presented. The patch as the main radiator and the partially reflective surface (PRS) structure as the superstrate are realized using an industrial embroidery machine. The PRS consists of periodic cross-slots (9 × 9 unit cells) in order to have a durable embroidered structure. The groundplane is made of a conductive woven fabric. The fabricated antenna has a relatively broad 1 dB-gain-bandwidth (10%) and a directive pattern (3 dB beam-width of 40° at the center frequency). Despite the higher losses in the conductive thread due to the resonant cavity effect, this antenna has a maximum realized gain of 6.8 dBi, which is typically 3 to 6 dB more than other embroidered single patch antennas.