Pillar array-type parabolic reflector antenna driven by air-lifted monopole fed by CB-CPW for 2.4 GHz applications

A parabolic reflector antenna consisting of an air-lifted monopole, a reflector pillar array, and a director on a ground plane is demonstrated for 2.4 GHz applications. The monopole is fed by conductor backed coplanar waveguide (CB-CPW) for easy connectivity with other on-board components. The apex of the parabolic reflector is located 0.2 lambda from the monopole and the reflector pillar array has a space of approximately 0.1 lambda each other. The antenna with 7 pillar reflectors shows a directivity of 8.0 dBi, has a less reflector weight compared to the solid wall counter part by approximately 75%, and has less cross talk with the CPW feeding line. With an additional pillar in the opposite side of the apex 0.2 lambda from the monopole, an enhanced directivity has been obtained when the lateral reflector span is small e.g. for 3, 5 pillars, while little or degraded directivity has been observed when the reflector span is large e.g. for 7 pillars. Transmission test using two identical antennas show a transmission gain of -23.9 dB with a distance of 3lambda.