A TERMINATION SCHEME FOR HIGH-SPEED PULSE-PROPAGATION ON A SYSTEM OF TIGHTLY COUPLED COPLANAR STRIPS

A realistic termination scheme is proposed for closely coupled N-condu ctor microstrips. The design aims to achieve satisfactorily low signal reflection and good fabrication feasibility for the planar MMIC (Mono lithic Microwave Integrated Circuit) process. The matched termination network (MTN) for a lossless three-line coupled microstrip structure i s presented. High-speed pulse transmission along terminated tightly co upled microstrip lines is analyzed using modal analysis in the frequen cy domain. Theoretical results for the propagating and reflected wavef orms are obtained by applying the inverse discrete Fourier transform ( IDFT) to the system responses. These responses are obtained by applyin g the theory of multiconductor transmission lines to a dispersive data base which has been computed using the spectral-domain approach (SDA). The response of a six-line closely coupled microstrip circuit termina ted by the proposed termination scheme is measured using the HP8510D n etwork analyzer. The measured results show that the reflected signal i s below -30 dB and the results are in good agreement with the theoreti cal waveforms.