This paper presents a new type of electromagnetic interference (EMI) measurement system. An EMI Camera LSI (EMcam) with a 12×4 on-chip 250×50µm² loop antenna matrix in 65nm CMOS is developed. EMcam achieves both the 2D electric scanning and 60µm-level spatial precision. The down-conversion architecture increases the bandwidth of EMcam and enables the measurement of EMI spectrum up to 3.3GHz. The shared IF-block scheme is proposed to relax both the increase of power and area penalty, which are inherent issues of the matrix measurement. The power and the area are reduced by 74% and 73%, respectively. EMI measurement with the smallest 32×12µm² antenna to date is also demonstrated.