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

摘要

Abstract: The direct and concise method of the TransverseTransmission Line (TTL) is applied for the unilateral,antipodal and bilateral finlines asymmetric in theplane-E, with semiconductor substrates, including theconductor thickness. The effective dielectric constant,the attenuation constant, and the characteristicimpedance are developed. Some of these structures areapplied to devices as coupler and impedancetransformer. In the TTL method, the Maxwell's equationsin Fourier transform domain, are used to obtain theelectromagnetic fields in terms of the transversalelectromagnetic fields. By applying the boundaryconditions and using the moment method and theParseval's theorem, an homogeneous equations system isobtained with two variables. The complex propagationconstant is obtained by setting the determinant of thesystem matrix equal to zero. The effective dielectricconstant is determined by means of the relation betweenthe phase constant and the wave number of the freespace. For evaluating the characteristic impedance, thedefinition that relates the transmitted power and thevoltage across the slots is used. Computer programs aredeveloped in FORTRAN 77 language, and the results in 2Dand 3D are obtained using a Pentium microcomputer, ofthe effective dielectric constant, the attenuationconstant, and the characteristic impedance withparameters such as the operating frequency, thethickness of the semiconductor substrate and itsconductivity, and the slots widths and their location.These results are compared with references and theagreement is quite good. !9