Transmission Line Design for Testing High-Speed Integrated Circuits with Differential Signals

We present a broadband differential transmission line design for a printed circuit board (PCB) used to test an analog processing-based equalizer integrated circuit (IC). The transmission line is accurately designed and characterized with the aid of differential, common-mode, and mode conversion Sparameters in the frequency range of interest. The designed transmission line structure is to be used with a die-on-board (DOB) PCB. The PCB designed on Rogers RT duroid 6010M laminate is used to validate an IC, which will be wire-bonded to the PCB, that has 16 broadband signals of up to 25GBd baud rate each. A detailed discussion on the design and simulation of the on-PCB transmission line is given. Simulated mixed-mode S-parameters of the transmission line for a frequency range of 100MHz to 25GHz confirm the broadband performance of the PCB.