Design of Wide‐Beam Leaky‐Wave Antenna Arrays Based on the Bilinear Transformation of IIR Digital Filters and the Z Transform

Abstract

In the pioneering work, the radiation diagrams of leaky wave antenna arrays can achieve attenuation nulls and gains at specific angles by manually placing the zeros and the poles in the Z domain of the corresponding discrete linear time‐invariant (LTI) system. This handcrafted design procedure does not allow radiation diagrams with wide beams since the interaction between poles involved in the wide beam and their corresponding leaky modes cannot be easily handled. To overcome this limitation, this paper describes a novel method for designing radiation diagrams of leaky‐wave antenna arrays based on the theory of IIR discrete filters. The proposed method relies on the design of discrete filters with the prototypes of analog low‐pass filters defined by Butterworth and Chebyshev type I polynomials, whose roots along with the bilinear transformation provide the location of the poles and the zeros of the discrete LTI system and, therefore, the parameters of the leaky‐wave antenna array. Results with different designs and a comparison with other approaches show the utility and effectiveness of this novel method to design wide‐beam leaky‐wave antenna arrays.

A segmented periodic slot array leaky‐wave antenna for beamforming applications

“…Filter-synthesis techniques using leaky wave antennas have also recently been used to realize flat-top patterns. 26 LWAs based on half-mode SIW for SLL reduction were proposed in Lu et al, 27,28 while in Yang et al 29 a LWA based on a composite right/left handed (CRLH) waveguide was used. In these works, the SLLs was reduced by modifying the leaky-wave excitation magnitude through dimensional changes in the waveguide, however, they lack phase control over the aperture.…”

“…Similarly, a double‐layer vertical stacked SIW LWA was proposed for flat‐top beams in Monavar et al, 25 but the design also lacks broadside radiation due to the stopband. Filter‐synthesis techniques using leaky wave antennas have also recently been used to realize flat‐top patterns 26 …”