In any wireless communication network and system an antenna is an important element along the propagation path of an electrical signals. Antenna module is a vital component of automated driving systems, it should function as needed in dGPS, HD map correction services, and radio and navigation systems. The main scope of this engineering research work involves the evaluation and determining the performance parameter and characteristic of the GPS/GLONASS patch vs RF GPS L1(1.57542 GHz) patch antenna characteristic. FEKO simulation studies are carried out to extensively compare, make an assessment and evaluate the characteristic and performance parameter, such as the average/passive gain of the proposed antenna in the presence of background noise. Prior to the start of the FEKO simulation studies, a physical mechanical dimension measurements via a Digital instrumentation were conducted for the following: Radiating Element Size: The actual length (L), and width (W), Substrate Material Size: The substrate length (Lsub), width (Wsub), and height (h). The proposed antenna model for GPS only patch antenna operating at 1.57542 GHz and the dual band patch antenna resonating at 1.5925 GHz are developed. To be specific, this work presents the design, modeling, determining passive gain of the RF GPS L1 patch vs. dual band patch antenna with intended targeted applications within the automotive system and space. Simulation are undertaken to generate the RF GPS L1 patch and dual band patch antenna structure respectively for the sole purpose of evaluating the performance of the proposed dual band antenna. Simulation are performed rather than mathematical modelling. The emphasis of this paper is how to obtain the equivalent amount of total passive gain in a GPS vs. that of dual band antenna.