Signal processing system with BIST function, testing method thereof and testing signal generator

A testing method, that generates a high-frequency testing signal by a translational filter, the translational filter comprising a mixer having a high-frequency side and a low pass filter coupled to a low-frequency side, the testing method comprising:

• providing an oscillation signal for controlling the mixer;
• providing a testing signal to the low-frequency side, so as to generate a high-frequency testing signal at the high-frequency side of the mixer;
• in a testing mode, up-converting by the translational filter the testing signal to the high-frequency testing signal to a signal input end of a module under test;
• and
• in a normal operation mode, providing by the translational filter a bandpass filtering function controlled at least in part by the oscillation signal for the module under test.

A testing signal generator, configured to provide a high-frequency testing signal to a signal input end of a module under test, comprising:

• an oscillation signal generator, configured to generate an oscillation signal;
• a translational filter, comprising a baseband filtering circuit and a mixer that is controlled by the oscillation signal, the mixer having a high-frequency side and a low-frequency side, the high-frequency side being coupled to the signal input end of the module under test, a low pass filter of the baseband filtering circuit being coupled to the low-frequency side;
• and
• a testing module, configured to provide a testing signal to the low-frequency side, so as to generate a high-frequency testing signal at the high-frequency side of the mixer,
• wherein the translation filter provides a bandpass filtering function controlled at least in part by the oscillation signal for the module under test in a normal operation mode and up-converts the test signal to generate a high-frequency testing signal at the high-frequency side of the mixer in a test mode.