FREQUENCY-DEPENDENT CHARACTERISTICS OF MILLIMETER-WAVE INTEGRATED CIRCUIT ELEMENTS ON ANISOTROPIC SUBSTRATES

A SERIOUS LACK OF EFFICIENT COMPUTER AIDED DESIGN (CAD) PROCEDURES EXISTS FOR HIGH-PERFORMANCE MONOLITHIC MILLIMETER WAVE INTEGRATED CIRCUITS, THAT OPERATE BETWEEN 30 AND 100 GHZ. THIS IS DUE TO THE HIGH-FREQUENCY BEHAVIOR OF THE VARIOUS (PASSIVE) COMPONENTS AND HIGH SPEED INTERCONNECTORS OF THE SYSTEM, AS WELL AS TO THE ANISOTROPY OF THE SUBSTRATE. THIS BEHAVIOR IS NOT SIGNIFICANT AT LOWER FREQUENCIES. THEREFORE, CUT-AND-TRY DESIGN PROCEDURES BECOME EXTREMELY TIME-CONSUMING, INEFFICIENT, AND SOMETIMES UNRELIABLE. A TYPICAL MILLIMETER WAVE INTEGRATED CIRCUIT INVOLVES VARIOUS TYPES OF DISCONTINUITIES, SUCH AS THE BENDS AND DISCONTINUITIES. NEVERTHELESS, IT IS A WELL KNOWN FACT THAT ANY IMPEDANCE OR GEOMETRICAL CHANGE CAUSES THE EXCITATION OF HIGHER ORDER (EVANESCENT) MODES AND ENERGY LOSS THROUGH RADIATION AND SCATTERING. AT HIGHER FREQUENCIES THESE SPURIOUS EFFECTS BECOME EVEN MORE PRONOUNCED, AND MUST BE ACCURATELY TAKEN INTO ACCOUNT AS AN INTEGRAL PART OF SYSTEM DESIGN. WE PROPOSE TO DEVELOP AN ACCURATE AND RIGOROUS ANALYSIS OF MONOLITHIC MILLIMETER WAVE INTEGRATED CIRCUIT ELEMENTS WITH COMPLEX GEOMETRIES ON ANISOTROPIC SUBSTRATES. THE MODEL WILL BE BASED ON THE METHOD OF MOMENTS, WHICH EMPLOYS AN EFFICIENT DYADIC GREEN'S FUNCTION FOR ANISOTROPIC SUBSTRATES. THE GREEN'S DYADIC FUNCTION HAS BEEN RECENTLY DEVELOPED BY THE AUTHORS IN ANOTHER (SBIR) PROJECT. ANTICIPATED BENEFITS/POTENTIAL APPLICATIONS - AMONG THE USERS OF OUR RESEARCH WOULD BE DESIGNERS OF MICROWAVE AND MILLIMETER WAVE SYSTEMS, AS WELL AS DESIGNERS OF HIGH-SPEED DIGITAL MICROELECTRONIC DEVICES. THE THEORETICAL COMPLEXITY OF THE PROBLEM HAS PREVENTED THESE PEOPLE FROM HAVING A SYSTEMATIC, ACCURATE, AND RELIABLE COMPUTER CODE.