الفهرس 
Chapter 1Only 14 pages are availabe for public view
 |  | from | 174 |  |  |
| | | from | 174 | | |
Abstract
The objective of this thesis is to study the main properties of Left-handed materials (LHM’s) for
improvement the performance of the passive microwave circuits especially the microwave resonators. All
different configurations of the proposed microwave resonators were designed with ANSOFT’s High
Frequency Structure Simulator (HFSS), what resolve the electromagnetic fields in all the structure that is
going to be analyzed. A metamaterial Zeroth-order Resonator (ZOR), based on Metal-Insulator-Metal
(MIM) capacitor, constructed by two-layers substrate is presented. Compared to monolayer structure, the
proposed structure achieves lower transmission frequency, compact dimensions and more freedom in the
design process. The structure has been designed, fabricated and tested. The measured return loss, at 2
GHz operating frequency, is -22 dB and the unloaded Q factor is around 250.
Next, we propose a stop-band notch filter, which rejects the narrow frequency band of the Wi-MAX 802.16d (3.4 GHz to 3.6 GHz) and keeps the remaining UWB spectrum (3.1-3.4 and 3.6-3.9 GHz) unchanged. The proposed filter has been realized using the metamaterial technology based on the CRLH metamaterial structures. The filter has been designed, simulated, optimized and fabricated using conventional MICs technologies. The simulation and the measurement results have been compared.
A tunable CRLH ZOR resonator based on the latest resurgent of ferroelectric materials has been presented. The dielectric properties of the ferroelectric thin film, and the thickness of the ferroelectric film, play a fundamental role in the frequency or phase tunability and the overall insertion loss of the circuit. The ZOR resonator is designed, and simulated by the full-wave analysis software. The response shows a variation of electromagnetic characteristics with the applied electric field, ferroelectric thickness and the operating temperature.
We propose a design of diplexer based on Dual Composite Right-Left Handed metamaterial (DCRLH-
MTM). The diplexer is practically a 3 port structure having one input and two output ports, the 3-
port is constituted with a T-junction. The structure consists of two notch filter having different stop band
with a common input port (diplexer input) and output ports of two filters acts as diplexer output. The
frequency response is obtained and the performance of the diplexer is investigated. The target frequency
to separate is GSM 900/1800 MHz .Finally, we mention the potential future applications for
metamaterials and points out some of the challenges to meet for leading MTMs to a possible scientific
and technological revolution.