CIRCULARLY POLARIZED MAGNETIC DIPOLE ANTENNA WITH SHALLOW AND EMBEDDED STRUCTURE FOR AIRBORNE GPS APPLICATIONS

摘要

A new circularly polarized magnetic dipole antenna with shallow and embedded structure is designed for operation at the global positioning system (GPS) L2 band. The antenna consists of two pairs of orthogonal magnetic dipoles and a simple microstrip feed structure. The four sides of the antenna are grounded with sheet metals, leading to the antenna being insensitive to the surrounding environment. It forms a closed and firm box. The proposed antenna can be integrated with the metallic aircraft without any gaps. It has a low profile of only 0.04 0, where 0is the free-space wavelength of the GPS L2 band (1227.5 MHz). A prototype has been designed, fabricated and found to have an impedance bandwidth of 5.92% and a 3-dB axial-ratio bandwidth of about 2.61% at GPS frequency of 1227.5 MHz. In addition, a model which includes the proposed antenna and a metallic aircraft is simulated. The results show that the metallic aircraft has small effect on the antenna. The antenna is suitable for airborne GPS applications. (c) 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:902-906, 2015