Gain enhanced conformal patch antenna with defected ground for aircraft applications

摘要

This study describes a design of conformal patch antenna for airborne applications especially in measuring the velocity of ocean and river current. By considering the decorrelation time, precipitation, resolution, and size of the antenna, the current system operates within the C-band frequency range of 5.05-5.45 GHz. This design has achieved a bandwidth of 7.7% that helps in increasing the cross-range resolution. A maximum gain of 10 dB is achieved at the bore side angle. The normalised side lobe level (SLL) of -26 dB reduces aliasing by achieving higher pulse repetition rate. Defected ground structure (DGS) is used for suppressing higher harmonics and its effect has been explained with simulation results. As most aircrafts are made of carbon fibre composites (CFC), this antenna has been checked by mounting on CFC sheets for real-time analysis and shows good performance in terms of both measured and simulated results. The transmission line model of the proposed patch antenna and impedance matching network is also described with the corresponding circuits. The characteristic mode analysis is carried out to study the intuitive behaviour and to optimise the performance of patch antenna by analysing the performance metrics of different current modes.