Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE credits
As communication services are growing, especially for keeping communication on high speed traffic, more efficient use of the available electromagnetic radio spectrum is required. In order to achieve this aim on communication spectrum, filters are required to be steeper. Metamaterials are a special kind of artificial structure that is not found in nature. The significant characteristic of metamaterials is the negative refractive index for operation frequency. Based on the specials structure of metamaterials and microwave theory, steeper filters can be obtained with low losses and relatively small sizes.
In this thesis work, two kinds of structure are utilized in connection with different substrates to realize a steeper band-pass filter. The first structure consists of interdigital capacitors and open stub inductors on the same metal layer and was simulated by the software Advanced Design System (ADS). The second structure, which was simulated by the software High Frequency System simulator (HFSS), consists of microstrip lines gaps on the top metal level and complementary split-ring resonators on the bottom metal level.
A comparative analysis of these two structures has been carried out in connection with their suitability for the design of the steeper band-pass filter. Based on the characteristics of two kinds of structure, interdigital capacitors and open stub inductors structure had a better performance for designing steeper band-pass filter, having center frequency 923 MHz and bandwidth 4MHz, than the structure of microstrip lines and complementary split-ring resonators.
2013. , 52 p.