Gain in efficiency and miniaturization is an issue for portable neutron detectors. $^{157}$ Gd, $^{155}$ Gd and $^{113}$Cd nuclei show the highest neutron capture cross-sections available in the stable element list. They are then a subject of interest for neutron detection and could be considered as suitable competitors with regards to detectors using $^3$He, $^{10}$B, $^6$Li or proton recoils. A neutron detector using a Gd converter and a CdZnTe diode is studied to address portable neutron detection. To exploit the low energy signature from the Gd, a reliable compensation technique with a guard sensor has been designed. Some innovations have been done on algorithmic part and sensor part of the system. The concept has been experimentally proved. It has notably been demonstrated that a Tb cover on the guard sensor allows a reduction of the overcompensation and then a maximization of the sensitivity of the detector.