Printed circuit board design is another important part of Protel 98. In this process, you can use the powerful functions provided by protel98/protel99se to realize the layout design of the board and complete the difficult wiring work.
1. Impedance matching refers to the proper matching between the signal source or transmission line and the load. According to the access mode, there are two modes of impedance matching: serial and parallel; according to the source frequency impedance matching, it can be divided into low frequency and high frequency.
PCB design techniques have an impact on the following three effects:
In high-speed designs, the characteristic impedance of the controllable impedance plates and lines is one of the most important and common problems. First, let's look at the definition of a transmission line: a transmission line consists of two conductors of a certain length, one for transmitting signals and the other for receiving signals (remember that the "loop" replaces the concept of "ground"). In a multi-layer board, each line is part of the transmission line and the adjacent reference plane can be used as a second line or loop. The key to a line becoming a "perfect" transmission line is to keep its characteristic impedance constant throughout the line.