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Wave Ratio (wave + ratio)
Selected AbstractsCharacteristic analysis of reverse-L-shaped microstrip-fed large-bandwidth printed slot antennaINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 6 2002Yong-Woong Jang Abstract The characteristics of a reverse-L-shaped microstrip-fed structure is analyzed using the finite difference time domain method, and the characteristics of the proposed antenna are compared with a conventional antenna. The return loss, radiation resistance, and voltage,standing wave ratio in the frequency domain are calculated by Fourier transforming the time domain results. When the proposed feed structure is used, the bandwidth is extended in proportion to the slot width and the radiation resistance has the low value. When the slot width is 16 mm, the experimental bandwidth is approximately 50% (,10 dB , S11) at the center frequency of 2.3 GHz. In addition, the experimental data for the impedance and radiation pattern of the antenna are described. They are in good agreement with the calculated results. © 2002 Wiley Periodicals, Inc. Int J RF and Microwave CAE 12, 496,502, 2002. Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mmce.10055 [source] Compact high-gain printed loop-antenna array integrated into a 5-GHz WLAN access pointMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2010Tzi-Chieh Hong Abstract A printed, planar loop-antenna array having a compact structure and high-gain, directional radiation properties for WLAN operation in the 5 GHz band is presented. The antenna-array design is composed of four-folded loops arranged to be of 2 × 2 configuration, printed on both sides of a 1.6-mm thick FR4 substrate, and one system printed circuit board (PCB) serving as an efficient reflector for the loops. The antenna array is set within the boundary of the PCB (size of 50 mm ×65 mm) and stacked there above by a separation distance of 5.4 mm only. That's, the design integrates the system PCB of an access point (AP) into an internal antenna solution for compact outdoor AP applications. The results show that good input matching with voltage standing wave ratio (VSWR) below 1.5 over the 5150,5825 MHz band can be achieved. Directional radiation patterns with peak gain at about 10 dBi were also obtained. Details of the antenna design are described and discussed. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2261,2267, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25487 [source] Efficient and high-gain aperture coupled superstrate antenna arrays for 60 GHz indoor communication systemsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2010Hamsakutty Vettikalladi Abstract Efficient and high-gain aperture coupled patch antenna arrays with superstrate at 60 GHz are studied and presented. It is noted that adding a superstrate with a specific size will induce a significant effect on antenna gain and radiation patterns. This capability is applied on the design of 2 × 2 and 4 × 4 arrays for high-gain application. The maximum measured gain of a 2 × 2 superstrate antenna array is 16 dBi with an efficiency of 63%, which is 4 dB higher than that of a classical 2 × 2 array at 60 GHz. The 2:1 measured voltage standing wave ratio (VSWR) bandwidth is 6.8%. Also the maximum gain measured for a 4 × 4 superstrate antenna array is found to be 19.7 dBi with an estimated efficiency of 51%. The radiation patterns are found to be broadside all over the frequency band with very low back radiation. Hence aperture coupled superstrate antenna array is a good candidate for high-efficient high-gain application at 60 GHz. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2352,2356, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25455 [source] A highly integrated Ka-band transceiver module with two channelsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2010Zhigang Wang Abstract A compact Ka-band square-wave modulation transceiver module with two receiving and transmitting channels is presented. This module consists of 15 monolithic microwave integrated circuits, two dielectric resonator oscillators, a E-plane waveguide filter, a coupler, two power dividers, and over 200 components, and works at two Ka-band operating frequency points. The developed Ka-band transceiver module is fabricated using advanced packages techniques, which has a compact size of 120 mm × 60 mm × 20 mm and exhibits greater than 500 mw output power with amplitude imbalance of two output ports less than 30 mw, switch rise time and fall time less than 4 ns, isolation of transmitting two channels more than 63 dB, and voltage standing wave ratio of receiving ports better than 1.3. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 615,618, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25005 [source] A novel ultrawideband planar antenna with dual band-notched performanceMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2010Meng Zhang Abstract In this article, a novel and compact ultrawideband (UWB) planar antenna is presented. This antenna consists of an annular patch and a 50 , microstrip feed line. The 3.5/5.5 GHz dual band-notched characteristic gets achieved by etching a C-shaped slot in the patch and complimentary split ring resonator (CSRR) structure in the ground. The measured results show that the proposed antenna can achieve the voltage standing wave ratio (VSWR) requirement of less than 2.0 in very UWB frequency range from 3.05 to 23.8 GHz with dual band-rejection performance of 3.4 to 4.0 GHz and 4.92 to 6.0 GHz. Measured VSWR of the proposed antenna is in good agreement with the simulated result. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 90,92, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24856 [source] Wideband printed dipole antenna using a novel PBG structureMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2009H.-W. Yuan Abstract A wideband printed dipole antenna with an integrated balun feed is given. To further get larger bandwidth capabilities of this antenna, a novel low-cost smaller unit-cell planar photonic bandgap (PBG) structure is etched onto the antenna surface, and a better dipole antenna is fabricated. Through optimizing the sizes of PBG structure, a 56.7% bandwidth is obtained where voltage standing wave ratio (VSWR) is less than 1.5 while a 36% bandwidth is obtained from initial structure. Agreement between calculations and measurements is very good. The result indicates that the novel design may obtain better wideband characteristic. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1862,1865, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24466 [source] A novel compact band-notched planar monopole antenna from 3 to 40 GHzMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2009F. Zhang Abstract A novel and compact ultra-wideband (UWB) microstrip-fed monopole antenna with frequency band notch function is presented in this study. Different from the conventional methods, a new method of inserting a lune-shaped disk into the annular structure to achieve a notched band is proposed in this letter. The center frequency of the notched band can be adjusted with ease by tuning the length of the lune-shaped disk. The designed antenna satisfies the voltage standing wave ratio (VSWR) requirement of less than 2.5 in the frequency between 3 and 40 GHz while showing the band rejection performance in the frequency band of 4.65 to 5.81 GHz. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1401,1403, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24377 [source] A compact spiral stripline-loaded monopole antenna with a vertical ground planeMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2008Truong Khang Nguyen Abstract In this letter, we propose a compact spiral stripline-loaded monopole antenna on a vertical ground plane. The measured results show that the antenna has a fractional bandwidth of 12.1% for a voltage standing wave ratio (VSWR) less than 2 at the center frequency of 1.10 GHz, as well as a good omni-directional radiation pattern. The small size of 0.04 ,o × 0.04 ,o × 0.04 ,o makes it promising for use as an internal antenna in mobile handsets. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 250,252, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23043 [source] Hybrid mode matching and auxiliary sources technique for horn antenna analysisMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2007S. G. Diamantis Abstract A hybrid technique for the analysis of horn antennas is described based on a rigorous description of the horn aperture-free space discontinuity. The transition from the feeding waveguide to the radiating aperture is analyzed by using the mode matching technique (MMT) employing a stepped-waveguide approach. The discontinuity between the horn aperture and the free space is modeled by combining the method of auxiliary sources with the MMT for the stepped waveguide section. Results for the input standing wave ratio are given and compared with the available measurements, which demonstrate the very good performance of the method. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 734,739, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22233 [source] Genetic algorithm optimization of a multisectional corrugated conical horn antennaMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2003Dooyeong Yang Abstract This paper presents the design of a wideband corrugated multisectional conical horn using a genetic algorithm (GA). The GA optimizes the length, flare angle, and first slot depth of each section of the horn in order to match the admittance, reduce the voltage standing wave ratio (VSWR) of the horn, and generate the desired pattern. A VSWR of less than 1.6 is obtained over the frequency range 11,18 GHz. The optimized multisectional conical horn antenna has four sections, is less than 7, long, and has very low sidelobe levels. The ratio between ratio between the co-polarization and the cross-polarization patterns is greater than 60 dB. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 352,356, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11058 [source] | ||||||||||