Abstract: The branch line coupler has many applications such as phase shifters, vector modulators, amplifiers and mixers and etc. The conventional branch line coupler consists of four arms each have μ ...

This study presents a precise method for monitoring shear crack development in concrete using acoustic emission analysis ...

These tones were also recorded on the chest using another electret microphone housed into an acoustic coupler. The attenuation of each tone was calculated by the power ratio between the one measured ...