A 100GHz Bandwidth Matched Chip to PCB Transition Using Bond Wires for Broadband Matching

Abstract

A transition between a microstrip line on a radio frequency integrated circuit (RFIC) made of silicon and a microstrip line edged on a printed circuit board (PCB) consisting of Rogers 3003 substrate is presented. This transition uses a specially designed an optimized arrangement of bonding wires to achieve a matched bandwidth of nearly 100 GHz. this extremely large bandwidth is needed for applications in frequency flexible or very broad band systems [S. Trotta et al., 2007] or for ultra high frequency devices [2] to be operated on a PCB, which is mandatory for commercial usage. The parasitic inductance of a bond wire does not become a problem at moderate frequencies. Newer technologies like automotive radar [B. Dehlin et al., 2006], [S. Trotta et al., 2007] or point to point transmitters operate at several dozens of gigahertz. At these frequencies connections by bond wires represent a major problem, because the impedance of the bond wire increases approximately linearly with frequency [Sang-Ki Yun et al., 1995]. Equation (1) shows that even moderate inductances provoke very large impedances at a frequency of 100 GHz, hindering efficient transmission of waves. The dramatic influence of these inductances, even for frequencies as moderate as 10 GHz, is shown in [A. Chandrasekhart et al., 2003].