The monopulse comparator (MC) is considered one of the important modules of the automated target detection and direction finding system. The present work proposes two new aperture coupled monopulse antenna arrays for single and dual plane tracking. The proposed monopulse array consists of a 4-element linear aperture coupled antenna (ACA) array and a microstrip line comparator circuit as a feeding network. The designed monopulse arrays cover the entire n78 (3.3-3.8 GHz) sub-6 GHz band with a bandwidth (BW) of > 18 %. The gain in sum patterns of single and dual plane monopulse arrays are 5.9 and 8.5 dBi at 3.5 GHz. The two arrays achieve a null depth of < -24.1 and < -25.4 dB between the sum and difference patterns.