Low‐profile, electrically small meander antenna using a capacitive feed structure

This article describes a capacitive feed (C‐feed) for small, low‐profile linear antennas. A meander line, which is the radiating element, in such antennas with a metallic back conductor electromagnetically couples a metallic feed plate placed between the meander line and the back metal (ground). This antenna has a very small leakage current on the outer surface of the coaxial cable and can control the imaginary part of the input impedance. The impedance characteristics and the antenna gain of −10 dBi are discussed based on simulated and measured results, which demonstrate successful achievement in the impedance and antenna gain for a RFID tags etc.