Input impedance and radiation pattern of a resonant dipole embedded in a two‐dimensional periodic leaky‐wave structure

Abstract

Array scanning method (ASM) is employed to study the input impedance and radiation pattern of a twodimensional periodic leaky-wave antenna (LWA). The antenna consists of a narrow horizontal strip dipole of arbitrary length underneath a two-dimensional (2D) periodic screen of metallic patches, which acts as a partially reflective surface (PRS), and backed by a ground plane. First, the Green's function in the presence of the 2D array of metallic patches is calculated by means of the ASM and then the current distribution and input impedance of the source dipole are calculated through the electric field integral equation and method of moments. The far-field pattern is computed using the reciprocity theorem. Compared to the Hertzian dipole, which is the only type of source that has been considered in the literature, the resonant dipole substantially improves the performance of periodic LWA in terms of radiated power, efficiency and bandwidth. Numerical results are given for a resonant dipole over the frequency range of 60-70 GHz and compared with those obtained from commercial softwares, FEKO ® and Ansys HFSS ® , showing an excellent agreement with considerable improvement in terms of memory usage and computational speed.

Field calculation of electric dipole excitation of a metafilm printed on a finite‐thickness dielectric slab using the susceptibility homogenization method

“…The formulae (8)- (18) can all be used in the MPIE formulation to calculate the fields due to any arbitrary finite source which is located in the vicinity of a planar metafilm printed on a dielectric half-space. As stated before, in practical applications, the metafilm is usually printed on a finite thickness dielectric slab.…”

“…As shown in Figure 1, the total parts under the periodic array, which contain the dielectric slab and the half-space under it, can be replaced by a homogenous halfspace with effective relative dielectric constant ε r,eff . Therefore, Green's function formulae (8)- (18) can also be used in this case by replacing ε r2 = ε r,eff .…”

“…This can be solved using one of the electric field integral equation or mixed potential integral equation (MPIE), if the electric field or potential Green's functions are known, respectively. Although the array scanning method [14][15][16][17][18] is the most accurate way to calculate the potential Green's functions for periodic surfaces located in multilayer media, it is very numerically demanding. If the periodic surface has periodicity much less than the wavelength in the surrounding medium, the surface susceptibility homogenization method can lead to a rapid and almost accurate way to analyse this problem [19], [20].…”

On the input impedance of probe‐fed electromagnetic bandgap antennas based on lattice modes

“…Rigorous full-wave analysis of the input impedance calculated by means of the Array Scanning Method in conjunction with different types of electric field integral equations to solve the MoM has been developed in refs. [20,21] for 1-D periodic shielded microstrip and 2-D periodic leaky-wave structures respectively.…”