To achieve precise measurements, a vector network analyzer can compensate for the instrument's systematic flaws, the features of cables, adapters, and test fixtures. To check the vector reflection coefficient of microwave devices, we used a low-cost portable VNA (NanoVNA) analyzer with a frequency range of 50 kHz to 4.4 GHz. VNAs are more versatile than oscilloscopes and may be used to explore a wide range of frequency components based on scattering characteristics, smith charts, phase response, and complex numbers. We did some experimental investigations for reported filters and antenna to evaluate the NanoVNA performance and suitability, especially its nonlinear scattering responses.