lowcost vector network analyzer for biomedical applications

A lowcost and portable vector network analyzer (vna) which covered operating frequency between 1mhz to 3ghz is used for vector reflection coefficient and standing wave ratio (swr) of the various microstrip antennas. this paper presents measurements of various ultra wideband (uwb) microstrip antennas for applications in biomedical field. selection of antenna is an important key for detection of different situations in biological signals. measurements of antennas were performed by using minivna tiny which operates by radiating an electromagnetic wave through an antenna and measuring standing wave ratio (swr) and return loss. however, the minivna tiny is lowcost components and easytoproduce antennas. the results indicate the good performance for uwb systems, especially microwave medical imaging applications. however, this device may enable for a low cost steppedfrequency system for use in tissue spectroscopy, field monitoring, and potentially in breast tumor detection.