The circular microstrip sensor (20 mm× 20 mm) is proposed at 8.1 GHz. The microstrip antenna is designed and analyzed on CST software; the FR-4 dielectric substrate is used. The three important parameters of microstrip sensor are ground plane, dielectric substrate and radiating patch. In present era, more diseases increasing day by day due to more taking the sugar and salt such as diabetes, kidney failure. The proposed design based on microstrip patch antenna as a sensor to control this type of diseases. In this study, all the parameters are analyzed on CST software such as reflection coefficient, voltage standing wave ratio (VSWR), E-Field, H-Field, surface current, current density, axial ratio.