Broadbanding of Electrically Small Hemispherical Helix Antennas

Novel wireless communication systems such as IoT devices and B5G are widely spreading, high performance electrically small antennas which is wireless interface of RF module is strongly demanded. As relationship between miniaturization of antenna and realization of high performance is trade-off, research and development for electrically small antennas are important. Though spherical helix antennas have been proposed as antennas that the size is possible to reduction by theoretical limitation, practical improvement of the antenna performance is required. This paper denotes broadbanding of the hemispherical helix antennas using an equivalent circuit with loss factor, and discuss the affects of loss factor on the wideband characteristics.