A Novel Approach to Beam Steering Using Arrays Composed of Multiple Unique Radiating Modes

A novel approach to beam steering is presented using an array composed of elements each supporting a unique radiating mode. The one-dimensional (1-D) beam synthesis properties of the novel ideal multiple mode dipole array are quantified using Fourier synthesis and shown to have significant improvement in scan range compared to a conventional linear dipole reference array. A hybrid phased array composed of multiple mode subarrays is also proposed and shown to be an efficient tradeoff between performance improvement and design complexity. Reasonable agreement is obtained between the simulated and measured impedance and radiation pattern properties of a fourelement multiple mode array. Finally, a 16-element hybrid phased array composed of four four-element multiple mode subarrays is fabricated and measured. The array is shown to have a 3-dB scan range of ±68°, which is in good agreement with the simulated value of ±69° at the design frequency of 4.6 GHz. Additionally, the 3-dB bandwidth of the array is more than 1 GHz at broadside. This bandwidth reduces to approximately 300 MHz at the widest scan angles, which is consistent with an equivalent conventional linear array.