Direct method (TTL) applied to general planar devices and structures of millimeter waves

Abstract

Listen

Translate article

The direct and concise method of the Transverse Transmission Line (TTL) is applied for the unilateral, antipodal and bilateral finlines asymmetric in the plane-E, with semiconductor substrates, including the conductor thickness. The effective dielectric constant, the attenuation constant, and the characteristic impedance are developed. Some of these structures are applied to devices as coupler and impedance transformer. In the TTL method, the Maxwell's equations in Fourier transform domain, are used to obtain the electromagnetic fields in terms of the transversal electromagnetic fields. By applying the boundary conditions and using the moment method and the Parseval's theorem, an homogeneous equations system is obtained with two variables. The complex propagation constant is obtained by setting the determinant of the system matrix equal to zero. The effective dielectric constant is determined by means of the relation between the phase constant and the wave number of the free space. For evaluating the characteristic impedance, the definition that relates the transmitted power and the voltage across the slots is used. Computer programs are developed in FORTRAN 77 language, and the results in 2D and 3D are obtained using a Pentium microcomputer, of the effective dielectric constant, the attenuation constant, and the characteristic impedance with parameters such as the operating frequency, the thickness of the semiconductor substrate and its conductivity, and the slots widths and their location. These results are compared with references and the agreement is quite good.