Ghazaany, Tahereh S.
Abd-Alhameed, Raed A.
Jones, Steven M.R.
Noras, James M.
KeywordHelical antennas; Tuning; Antenna radiation patterns; Capacitors; Loaded antennas; Micromechanical devices; Vertical polarisation; Electrically small antenna; ESA; Omni-directional antenna; Tunable antenna
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AbstractA miniaturized conical helix antenna is presented, which displays vertical polarization with electrically small dimensions of 10mm×10mm×45mm. The resonance of the antenna is made tunable by adding a variable digital MEMS capacitor load at the bottom of the helix, giving a tuning range of 316 MHz to 400 MHz. The antenna demonstrates considerable impedance matching bandwidth and gain over the entire tuning frequency band. Most importantly, the antenna is capable of compact, flexible and easy integration into a wireless device package or for platform installation.
VersionNo full-text in the repository
CitationZhu F, Ghazaany TS, Abd-Alhameed RA et al (2014) Miniaturized tunable conical helix antenna. In: Proceedings of the 2014 IEEE Radio and Wireless Symposium. 19-23 Jan 2014, Newport Beach, CA, USA: 100-102.
Link to publisher’s versionhttps://doi.org/10.1109/RWS.2014.6830109
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Improved bandwidth low-profile miniaturized multi-arm logarithmic spiral antennaZhu, Shaozhen (Sharon); Ghazaany, Tahereh S.; Abd-Alhameed, Raed A.; Jones, Steven M.R.; Noras, James M.; Suggett, T.; Van Buren, T.; Marker, S. (2014)
Model and design of small compact dielectric resonator and printed antennas for wireless communications applications. Model and simulation of dialectric resonator (DR) and printed antennas for wireless applications; investigations of dual band and wideband responses including antenna radiation performance and antenna design optimization using parametric studiesAbd-Alhameed, Raed A.; McEwen, N.J.; Mujtaba, Iqbal M.; Elmegri, Fauzi (University of BradfordFaculty of Engineering and Informatics, 2015)Dielectric resonator antenna (DRA) technologies are applicable to a wide variety of mobile wireless communication systems. The principal energy loss mechanism for this type of antenna is the dielectric loss, and then using modern ceramic materials, this may be very low. These antennas are typically of small size, with a high radiation efficiency, often above 95%; they deliver wide bandwidths, and possess a high power handling capability. The principal objectives of this thesis are to investigate and design DRA for low profile personal and nomadic communications applications for a wide variety of spectrum requirements: including DCS, PCS, UMTS, WLAN, UWB applications. X-band and part of Ku band applications are also considered. General and specific techniques for bandwidth expansion, diversity performance and balanced operation have been investigated through detailed simulation models, and physical prototyping. The first major design to be realized is a new broadband DRA operating from 1.15GHz to 6GHz, which has the potential to cover most of the existing mobile service bands. This antenna design employs a printed crescent shaped monopole, and a defected cylindrical DRA. The broad impedance bandwidth of this antenna is achieved by loading the crescent shaped radiator of the monopole with a ceramic material with a permittivity of 81. The antenna volume is 57.0 37.5 5.8 mm3, which in conjunction with the general performance parameters makes this antenna a potential candidate for mobile handset applications. The next class of antenna to be discussed is a novel offset slot-fed broadband DRA assembly. The optimised structure consists of two asymmetrically located cylindrical DRA, with a rectangular slot feed mechanism. Initially, designed for the frequency range from 9GHz to 12GHz, it was found that further spectral improvements were possible, leading to coverage from 8.5GHz to 17GHz. Finally, a new low cost dual-segmented S-slot coupled dielectric resonator antenna design is proposed for wideband applications in the X-band region, covering 7.66GHz to 11.2GHz bandwidth. The effective antenna volume is 30.0 x 25.0 x 0.8 mm3. The DR segments may be located on the same side, or on opposite sides, of the substrate. The end of these configurations results in an improved diversity performance.
Ultra-Wideband Dual-Polarized Patch Antenna with Four Capacitively Coupled FeedsZhu, F.; Gao, S.; Ho, A.T.S.; Abd-Alhameed, Raed A.; See, Chan H.; Brown, T.W.C.; Li, J.; Wei, G.; Xu, J. (2014-02-28)A novel dual-polarized patch antenna for ultra-wideband (UWB) applications is presented. The antenna consists of a square patch and four capacitively coupled feeds to enhance the impedance bandwidth. Each feed is formed by a vertical isosceles trapezoidal patch and a horizontal isosceles triangular patch. The four feeds are connected to the microstrip lines that are printed on the bottom layer of the grounded FR4 substrate. Two tapered baluns are utilized to excite the antenna to achieve high isolation between the ports and reduce the cross-polarization levels. In order to increase the antenna gain and reduce the backward radiation, a compact surface mounted cavity is integrated with the antenna. The antenna prototype has achieved an impedance bandwidth of 112% at (|S11| ≤ -10 dB) whereas the coupling between the two ports is below -28 dB across the operating frequency range. The measured antenna gain varies from 3.91 to 10.2 dBi for port 1 and from 3.38 to 9.21 dBi for port 2, with a 3-dB gain bandwidth of 107%.