On the Use of U-Slots in the Design of Dual-and Triple-Band Patch Antennas
The general method of using U-slots to design dual- and triple-band patch antennas is described. In this approach, one starts with a broadband patch antenna, which can consist of one or more patches. When a U-slot is cut in one of the patches, a notch is introduced into the matching band, and the antenna becomes a dual-band antenna. If another U-slot is cut in the same patch or in another patch, a triple-band antenna results. This method is applied to the L-probe-fed patch, the M-probe-fed patch, as well as the coaxially fed and aperture-coupled stacked patches. It is found that the patterns and gains of the dual-and triple-band antennas are similar to those of the original broadband antenna. Because the band notches introduced by the U-slots occur within the bandwidth of the antenna without slots, this method is suitable when the frequency ratios of the adjacent bands are small, usually less than 1.5.
Available from: Trevor S Bird
- "such as using air substrate or cavity backed patches to raise antenna gain   , using parasitic patches  or U-shaped slots embedded on the patch  to expand the bandwidth, and employing metamaterial  or multilayer substrates  to increase the radiation efficiency, to name just a few. Other types of elements employed for mobile satellite applications include printed dipoles   , the quasi-Yagi , the Vivaldi antenna , the dielectric resonator antenna (DRA) , the comb-line antenna , the curl antenna  and the spiral antenna . "
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ABSTRACT: Two large and low-profile panel antenna arrays, used as receiving and transmitting antennas for mobile satellite communications, are described. The receiving and transmitting arrays have overall dimensions of 120 cm × 20.7 cm × 1.3cm and 107.5 cm × 20.4 cm × 1.7 cm, respectively. They exhibit high gains and adequate efficiencies, due to integrated array designs. For the receiving panel array, a method using a number of high-efficiency subarrays, combined with a novel active integrated global feed network, is proposed. For the transmitting panel array, a number of high-efficiency subarrays, together with a novel compact waveguide feed network, is employed. Based on the above techniques, two large panel antenna arrays were successfully developed. We present the detailed designs of the subarrays, the passive and active feed networks, and the vertical transitions. Simulated and experimental results showed that the designed receiving and transmitting panel arrays achieved measured gains and efficiencies of 34.1 dBi and 48.2%, and 33.5 dBi and 36.3%, respectively, in each band. This indicated that the proposed antenna panels are good candidates for future satellite communications applications.
IEEE Antennas and Propagation Magazine 12/2012; 54(6):256-268. DOI:10.1109/MAP.2012.6387841 · 1.32 Impact Factor
Available from: Jawad K. Ali
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ABSTRACT: The C shaped structures and alike have been widely used in numerous antenna designs for various applications. In this paper, a printed slot antenna has been introduced as a candidate for use in the dual band wireless communication applications. The antenna slot structure is to be composed of two or more C shaped slots with different lengths combined together to form a single slot structure. The antenna has been fed with 50 Ohms CPW, and the slot structure is to be etched on the ground plane. Performance evaluation of the proposed antenna design has been carried out using a method of moments based EM simulator, IE3D. Simulation results show very interesting results. The antenna with two C-slot structure offers a dual band resonant behavior meeting the requirements of the 2.4/5.2 GHz WLAN. The resulting percentage impedance bandwidths of the modeled antenna at the center frequencies of 2.51 GHz and 5.21 GHz are 22.70 (2.29 GHz to 2.86 GHz), and 4.80 (5.11 GHz to 5.36 GHz) respectively. In addition, the antenna with three C-slot structure possesses a dual frequency resonant behavior covering the 2.45/5.8 GHz WLAN applications. The resulting percentage impedance bandwidths at the center frequencies of 2.45 GHz and 5.71 GHz are 11.80 (2.32 GHz to 2.61 GHz), and 7.2 (5.53 GHz to 5.94 GHz) respectively. Parametric study has been carried out to explore the effects of antenna parameters on its performance. Besides the satisfactory radiation characteristics, the simple structure of the proposed antenna makes it an attractive choice for antenna designers.
Progress In Electromagnetics Research Symposium, PIERS 2012 in Kuala Lumpur; 01/2012
Available from: jpier.org
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ABSTRACT: With the development of China's Compass Navigation Satellite System (CNSS), the demand for terminal antennas is quite urgent. In CNSS system, dual-band antennas are more attractive, because they can provide both the navigation and communication functions. In addition, since the CNSS antennas operate at low frequencies, they are not easy to be installed due to their usually large volumes, limiting their practical application. In this paper, we present a dual-band miniaturized CNSS microstrip antenna based on high-permittivity ceramic substrate. This antenna works at S Band (2492±5 MHz, right- handed circular polarization, RHCP) and L Band (1616 ± 5 MHz, left-handed circular polarization, LHCP). Numerical results show that the impedance bandwidth (S 11 < -10 dB), 3 dB axial ratio bandwidth and antenna gain at L Band are about 26 MHz,6.5MHz and 3.22 dB, respectively. While the impedance bandwidth (S11 < -10 dB), 3 dB axial ratio bandwidth and antenna gain at S Band are about 127 MHz, 28MHz and 4.72 dB, respectively. An experiment was carried out to verify our design and the measured results agree well with the simulation ones. In addition, by using high-permittivity ceramic (ε r = 16) as the substrate, the antenna keeps its performances with a reduced size by 80% comparing with the conventional ones using low-permittivity substrates. This makes it suitable for practical applications.
Progress In Electromagnetics Research C 01/2012; 30:213-223. DOI:10.2528/PIERC12041714 · 1.23 Impact Factor
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