Tapering Impact on the Spatial and Frequency Responses of Broadband Asymmetrically Routed Phased Arrays

Asymmetrical feeding networks can be used to amplify the beam squint phenomena of the phased arrays and to make their frequency domain behavior very angle-dependent. The aim of this paper is to demonstrate the analogy between the far field of a side-fed uniform linear array (ULA) and its frequency response in the beam steering direction. Indeed, by using simplified array equations, we show that the beam pattern of an asymmetrical series-fed ULA is similar to the frequency response observed at the steering angle. Furthermore, we show that amplitude tapering which is used to reduce the sidelobe level (SLL) of the array also reduces the corresponding sidebands of the frequency response in the given steering angle, to facilitate frequency domain filtering. Moreover, a modified tapering method is introduced to showcase the generality of the analysis.