Carbon-Fiber-Stitched Substrate in Coaxial-Fed-Patch-Antenna for Removing Hole in Feeder

Abstract

There are many studies about using structural antennas for aircrafts; these structures have disadvantages such as being thick or requiring complex manufacturing processes. In this study, we propose using a carbon-fiber-stitched substrate for designing a micro-strip-patch antenna without the defect of having a hole for the feeder. We constructed an antenna without increased thickness or a complicated manufacturing process, using a carbon-fiber feeder. The effect of the carbon-fiber feeder on the antenna was confirmed by simulation, revealing that the antenna performance hardly changed when the radius of the feeder was 0.6 mm, which was the same as that of the feeder of the connector; similarly, the resistivity of the feeder was like that of the carbon fiber. If the radius of feeder was not 0.6 mm, there would be a loss due to the outgoing power. It has been, however, confirmed that the carbon-fiber feeder could be used as an antenna feeder via additional impedance matching. To reduce the outgoing power loss, the antenna performance was measured again after performing additional impedance matching. The antenna with the carbon-fiber feeder had a reflection loss of - 19.3 dB at 9.11 GHz and a maximum gain of 4.7 dBi. Therefore, it was verified that the carbon-fiber stitched substrate could be used for the coaxial-fed patch antenna, also eliminating the defects of the feeding line.