Frequency reconfigurable tapered slot antennas for wideband narrowband and multiband applications

Abstract

Presented in this thesis are reconfigurable tapered slot antennas for wideband-narrowband and wideband-multiband reconfigurations. The presented approaches give benefits in reducing the interference level at the receiver. These reconfigurations enable RF front end to have better flexibility in wireless communication systems. After compiling considerable research on previous similar schemes in the literature, five new reconfigurable tapered slot antennas are presented and discussed, in order to contribute to the present state of knowledge in the field. Firstly, a wideband to narrowband reconfiguration is proposed by using a switched feed technique. The second design integrates wideband and multiband operations using a resonator technique. This antenna is capable of wideband, dual-band and triple-band functionalities. In the third design, a wide to multiband operation is achieved by using an internal loading technique. This is done by feeding the tapered slot antenna with a coplanar waveguide (CPW) to slot-line transition feed incorporating matching stub. The fourth design is a wide and a multiband antenna using dual port technique. The advantage of using this technique enables it to operate wideband and multiband function simultaneously. The fifth and final approach is the best proposed design. The design shows an improved structure of wideband tapered slot antenna that can switch to multiband slot dipole antenna using single port. The main advantage of this design is that multiband (single, dual and triple) operations are easily obtained and have shown to be more flexible in obtaining different operating frequency bands. The design has adopted in and out part of the antenna technique to achieve the frequency reconfiguration. The superiority of the proposed design over the other designs is stable radiation pattern in almost all different operating modes. The wideband frequency range is from 1-3.7 GHz. The resonance frequency of the single-band is at 2.4 GHz. In the dual-band, the resonance frequency of the first band is at 2.1 GHz, while the second resonance frequency is at 3.2 GHz. The low, mid and high resonance frequencies of the triple-band are at 1.5 GHz, 2.5 GHz, and 3.3 GHz, respectively. This design supports applications such as Global System for Mobile Communication (GSM), Universal Mobile Telecommunications System (UMTS), Wireless Fidelity (WiFi), Wireless Local Area Network (WLAN), Worldwide Interoperability for Microwave Access (WiMAX) and Long-Term Evolution (LTE) bands.