2-18 GHz dual-polarised tightly coupled dipole array with ±75° scanning range

The authors proposed an ultrawideband (UWB) dual-polarised tightly coupled dipole array (TCDA). A split X-shaped resistive frequency selective surface (FSS) is utilised, which can get more admirable impedance matching. The proposed antenna can achieve active voltage standing wave ratio (VSWR) below 2.9 when scanning up to +/- 75 degrees and +/- 60 degrees in the E and H planes from 2 to 18 GHz, respectively. Furthermore, two rectangular patches served as directors are designed, which can provide stronger forward radiation to reduce the loss of resistive FSS for radiation efficiency. As a result, the average radiation efficiency is above 84% and the lowest radiation efficiency is 70%. Moreover, the overall antenna profile is 15 mm (0.1 lambda at the largest working wavelength). To validate the design method, a 16 x 16 array prototype is fabricated and measured. Good agreement is achieved between the simulations and measurements.