What is Single Negative (SNG) Metamaterials

This chapter presents metamaterial-based wearable, that is, textile-based, antennas for Wi-Fi, WLAN, ISM, BAN and public safety band applications, which have been designed, fabricated, and tested. Textile substrates like polyester and polypropylene are used to design and fabricate these antennas. The metamaterial inclusions are directly used to load the different microstrip patch antennas on the same substrate, which significantly enhances the gain and bandwidth with considerable size reduction. The microstrip patch antenna generates sub-wavelength resonances under loading condition due to the modifications of its resonant modes. The DNG and SNG metamaterials are used to load the microstrip patch antennas for size reduction by generating the sub-wavelength resonances. The simulated and measured results are found to be in good agreement for all the presented wearable antennas. The bending effect on antenna performance due to human body movements is also presented in this chapter.