Patent ID: 7355413
Filing Date: 2008-04-08
Classification: G01R

Abstract:
1. A testing method for measuring electromagnetic interference of noise on a to-be-tested printed circuit board, comprising: a) injecting a signal simulating expected noise of a predetermined device mounted on the to-be-tested printed circuit board, into said to-be-tested printed circuit board, in a condition in which at least said predetermined device is not actually mounted on said to-be-tested printed circuit board; and b) measuring electromagnetic interference of said signal, wherein: in said injecting a), a noise injecting arrangement is applied to inject the signal simulating the expected noise to said to-be-tested printed circuit board, said noise injecting arrangement comprising: a signal generator as a noise source; a coaxial cable connected to an output of said signal generator; an impedance matching device, connected to the other end of said coaxial cable, and transmitting a noise-simulating signal transmitted through the coaxial cable to a power supply line and a ground line of said to-be-tested printed circuit board for said predetermined device; and, wherein: said impedance matching device comprises: an SMA connector connecting between said coaxial cable and said impedance matching device; a copper plate for mounting components thereon; a ground connecting copper plate for connecting between said impedance matching device and a ground line of said to-be-tested printed circuit board; an electric wire connecting between said impedance matching device and a power supply line of said to-be-tested printed circuit board; and a matching circuit for matching impedance between said signal generator and said to-be-tested printed circuit board.