Filtenna Design for 5.8 GHz DSRC and 5.9 GHz WAVE Coexistence

In this manuscript a filtenna designed for automotive applications in ITS system environment is presented. The proposed device is a compact circularly polarized patch antenna characterized by high gain. The latter is enabled by the use of a parasite coupling mechanism. The antenna itself is integrated with a compact filter, realized etching out properly designed spirals from the feeding line. The resulting structure is a low profile and compact filtenna, suitable for transmitting DSRC signals at 5.8GHz while at the same time blocking the WAVE protocol data allocated at 5.9GHz. This implementation is extremely compact, scalable and suitable for On-Board Units deployment. Experimental simulations confirm a maximum gain at 5.8GHz of 5.1dBi, while at the rejected frequency (5.9GHz) it has a value around 0.5dBi. A good discrimination between LH and RH polarization at 5.8GHz is shown (15.6dB), thus validating the design and making the device suitable for DSRC operation.