Time domain analysis of an active multi-conductor CRLH transmission line using FDTD method for millimeter-wave frequencies

A novel conceptual structure for field-effect transistors with its time domain analysis is introduced. This new structure considers all drain, gate, and source electrodes to be CRLH transmission lines, thereby resulting an active multi-conductor CRLH transmission line, which is a new design of transistors with novel characteristics. Time domain analysis of this new structure is based on a fully distributed finite-difference-time-domain (FDTD) algorithm in the leap-frog format. Such an algorithm was used just for passive CRLH transmission lines. However, by applying some changes on the algorithm, it can be implemented on the mentioned active transmission line types. Amplification matrix of the proposed algorithm is obtained to evaluate its numerical stability. Next, the algorithm is applied to a 0.15 x 75 mu m pHEMT model transistor with designed values of its left-handed elements, and then, the obtained results are verified by a comparison with semi-distributed simulation on Agilent ADS software. Finally, s-parameter analysis show that this new idea can improve gain, bandwidth, and stability of a transistor.