Applications of planar multiple-slot antennas for impedance control, and analysis using FDTD with Berenger´s PML method

Folded- and multiple-slot antennas have been used for quasi-optical arrays. However, there is lack of information of these antennas, especially on finite substrates. CPW-fed folded- and multiple-slot antennas are analyzed using the FDTD technique with improved absorbing boundary condition (perfectly matched layer (PML) method). The effects on the effective dielectric constant and input impedance due to the substrate thickness have been investigated. A method of controlling the resonant impedance is also presented.