Study On The Miniaturization Of Microstrip Antennas Based On Metamaterial

Modern wireless communication devices are required to be miniaturized, while antenna is an important part of communication system. Many scientists and engineers focus on how to achieve better performance at lower frequency on microstrip antennas in a small area.As a composite or structured material that exhibits properties not found in naturally occurring materials or compounds, Metamaterial is an important approach to implement miniaturization of microstrip antenna.In this thesis, two methods are used to implement miniaturization of microstrip antenna. Load different types of structural elements on traditional media substrate to achieve the miniaturization. After the traditional media substrate is filled with the Metamaterial, microstrip antenna's physical size primarily depends on constitutive parameters of Metamaterial. Therefore, the mutual constraints between the microstrip antenna's physical size and resonant frequency are avoided.Numerical simulation shows that traditional microstrip antenna's physical size is 14.98mm by 9.29mm at lOGHz. While using the first method, if 4 SRR (Split-Ring Resonator) structure under patch is loaded, the resonant frequency is down to 8.9GHz; if 6 SRR structure is loaded, the resonant frequency is down to 8.5GHz. Compare to the same patch size, the resonant frequency decreases by 11% and 15%, so miniaturization of the microstrip antenna is achieved. Further studies have shown that if 4 SR (spiral resonator) structure in the same place is loaded, which allows the resonant frequency down to 5.9GHz; if 6 SR structure is loaded, the resonant frequency can be reduced to 5.8GHz. In the same patch, the resonant frequency decreases by about 42%. Effects on miniaturization become pronounced.While using the second method, theμ-negative meta-materials is realized by filling substrate with 8 spiral resonators (SR), which can miniaturize the low frequency antenna, and the resonant frequency is from 2.45GHz down to 434MHz. Not only miniaturization of the microstrip antenna is achieved, but also dual-band work can be obtained.