الفهرس 
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Abstract
Multi-band pass filters (BPF) and ultra wide band pass filters (UWB) have become the most
important components to meet the requirements of wireless communication applications, such
as the global system for mobile communication (GSM), wideband code division multiple
access, wireless local area network (WLAN), long term evolution and cognitive radio. Many
communication systems require multi-function capability in the filter aspects of systems; the
method currently used is filter banks which take up a lot of board space. It is thought that
reconfigurable filters hold the key to replacing filter banks in order to save board space and
thus potentially increasing functionality of the systems. The first aim of this research is to
develop multi band pass filters with small size without affecting its electrical performance. So,
a compact tri-band pass filter (BPF) at 0.75 GHz, 2.1 GHz, and 3.5 GHz is introduced using a
modified tri-mode Psi (Ψ)-shape resonator connected by λ/4 transmission lines. The particle
swarm optimization algorithm (PSO) is used to optimize the filter parameters to design, and to
improve the filter performance with regard to a given measurement of quality. The
conventional tri-band pass filter is optimized to achieve low insertion loss and high return loss.
Moreover, a compact tri-band pass filter is proposed using fractal structure to compact the size.
The proposed design achieved better performance with low insertion loss and decreased the
physical area by approximately 40%. A mathematical analysis is performed to calculate the
center resonance frequencies of the proposed designs for the tri-band pass filter (BPF). The
two implemented designs are simulated, fabricated, and measured. All measured results are
consistent with the analysis and the simulations. Then the compact tri-band pass filters is
designed with two type of DGS to improve its performance and to eliminate higher order modes
frequency to reduce the interference. Both DGS designs are studied and analyzed to get the
optimum dimensions that can improve the filter’s response. After that the proposed tri-mode
resonator is used to implement UWB-BPF with fixed and reconfigurable notch bands. The
advantage of the psi shape resonator is that it generates different poles and zeros with different
configurations. So, it is used firstly with open termination to get UWB-BPF pass band of (1.4-
3 GHz) then with the help of short terminations the UWB-BPF pass band is from 0.84 GHz to
3.28 GHz and the intrinsic zero of the tri-mode resonator generates a notch band at 2.1 GHz.
Finally, the configurability is achieved by using PIN diodes due to their superior performance
in wideband and high frequency applications.