A study of different pixel implementations working around 300 GHz is presented. They are monolithically integrated in a standard low-cost CMOS process with a high performances read-out chain for signal processing. All the different pixel configurations are compliant with the integrated metal stack and the imposed density rules of the technology. A test-chip, composed of a total of 17 cases of study, will be evaluated including a matrix of 9×9 pixels allowing real-time imaging. Significant improvement has been made on the detector, thanks to antenna/nMOSFET codesign, and on the signal processing chain. A S11 of -18.2 dB with 5.8-dBi gain and a radiated front-to-back ratio of 10.1 dB are achieved regarding integrated antenna performances.