A Build-in Self-Test Technique for RF Low-Noise Amplifiers

A built-in self-test (BIST) technique suitable for RF low-noise amplifiers (LNAs) is presented in this paper. With fully integrated amplitude detectors and logarithmic amplifiers, the BIST module can be employed as a generic platform for gain extraction of the device-under-test (DUT) without expensive testing instruments, while maintaining a reasonable hardware overhead and minimum loading effects to the DUT. Using a 0.18-mum CMOS process, a 5-GHz variable-gain LNA with the proposed BIST module is implemented. Based on the experimental results, on-chip gain extraction of the LNA has been demonstrated with an error less than 1 dB for various gain modes. The additional chip area required for the BIST functionality measures 0.042 mm², which is considerably small compared with the physical size of the RF amplifiers.