Miniaturised CP wideband antenna with split elliptical patch and LRH cells

摘要

A novel miniaturised antenna with a split elliptical patch and three left/right handed (LRH) cells is proposed. The antenna has a wideband circularly polarised (CP) characteristic and it is easy to perform the impedance matching. A simple microstrip line is used to excite the antenna and another microstrip line is matched by a proper chip resistor. By splitting the elliptical patch and adjusting the position of three LRH cells, an improved CP characteristic and a wide impedance bandwidth are achieved. Compared to the referenced antenna, the lower resonant frequency is decreased and the higher resonant frequency is increased. Also, the miniaturisation, wideband width and broadband CP are achieved. The measured results demonstrate that this structure achieves 69% (2.4-4.93 GHz) of the 3-dB axial ratio bandwidth and 107.9% (1.8-6.23 GHz) of the 10 dB return loss bandwidth. The antenna performs an average gain of over 2.7 dB across the CP region.