Broadband proximity coupled microstrip antenna for direct broadcast satellite reception using PBG structures

Antennas for direct broadcast satellite (DBS) reception often consist of a parabolic reflector and a LNB. The main disadvantage of these conventional antennas is that the feed and the signal-processing unit are realized in different technologies, namely the feed in hollow waveguide technology and the signal-processing unit in planar waveguide technology. Recently, to feed reflector antennas, microstrip antennas have been designed and developed. This leads to the feature that the production of the whole reception unit consisting of planar feed and the signal-processing unit can be done on the same PCB in microstrip technology. For DBS reception, the design of microstrip antenna has to be done in frequency range from 10.75 GHz to 12.75 GHz and for simultaneous reception of horizontally and vertically polarized waves. Therefore, the required bandwidth is about 17%, whereas the bandwidth of conventional microstrip antennas is about 3%-10% only. In this paper a broadband proximity coupled microstrip antenna have been designed. The bandwidth of this antenna has been improved using photonic band gap (PBG) structure. Results of simulation show that the bandwidth of this antenna is about 17%. Also PBG structure has been increased the gain as much as 1.5 dB.