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Slot Antennas (slot + antennas)

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Engineering100%

Selected Abstracts

Microstrip-fed slot antennas backed by a very thin cavity

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2007
Andrea Vallecchi
Abstract Slot antennas with a backing cavity for unidirectional radiation are investigated with the aim of achieving a thin structure capable of reasonably broadband operation. By tuning together the slot length and the cavity cross-section, a very low-profile cavity-backed slot (CBS) is demonstrated. The cavity thickness of this slot antenna is about 10 times smaller than conventional one-quarter wavelength cavities, which would allow constructing this antenna even with standard cost-effective multilayer planar technology. The high gain and fairly wideband operation are the major advantages of the proposed configuration, which features a bandwidth of about 10% at a center frequency of 1.8 GHz with radiation efficiency in excess of 80%. Measured data are presented and compared with simulation results obtained by both the method of moments (MoM) and the finite integration technique (FIT). © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 247,250, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22073 [source]

Two-dimensional beam-scanning using tapered slot antennas and piezoelectric transducers

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 4 2006
Sang-Gyu Kim
Abstract A wideband phased array is demonstrated using antipodal exponentially-tapered slot-antenna (ATSA) arrays operated by piezoelectric transducer (PET)-controlled phase shifters. A 4 × 4 ATSA array is designed to scan two-dimensionally across the entire X -band. The phase shifters for 2D scanning consist of two sets of multiline phase shifters controlled by the PET for scanning in both planes. The 2D phased array has an antenna gain greater than 8 dBi, including all losses due to the phase shifters and transitions, and shows a wide beam-scanning capability greater than 30° in both the E -plane and the H -plane. © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006. [source]

A reconfigurable design for bandwidth enhancement of circularly polarized slot antennas

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2010
Tsung-Hsun Hsieh
Abstract A reconfigurable design is proposed to improve the circular polarization (CP) operating bandwidth of an annular-ring slot antenna fed with an L-shaped coupling strip. The design involves four voltage-controlled varactor diodes, which are placed below the slot and symmetrically distributed along the circumference of the slot. When all antenna dimensions remain constant, the CP operating frequency of the slot antenna can be decreased by varying dc voltage values. In addition, theses CP operating frequencies, which are corresponding to different dc voltage values can form a successive frequency band, and the available CP bandwidth is thus improved. Experimental results indicate that with the reconfigurable design, the 3-dB axial-ratio CP bandwidth can be increased by a factor of 4 for the annular-ring slot antenna with a reflector. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1377,1380, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25192 [source]

On-chip slot antennas in 0.18 ,m CMOS for wireless application

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2008
Liang Jiang
Abstract Two on-chip slot antennas resonating near 30 GHz with different widths (10 and 100 ,m) in standard 0.18 ,m CMOS are presented. S21 between two 10 ,m width slot antennas and between two 100 ,m width ones both with ,3 mm distance through free space is measured. The results indicate that designing on-chip slot antennas with standard CMOS process is feasible, which will support farther improvement of CMOS integration. The slot antennas can be used in compact and low cost transceivers for short range wireless communications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1187,1191, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23325 [source]

Microstrip-fed slot antennas backed by a very thin cavity

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2007
Andrea Vallecchi
Abstract Slot antennas with a backing cavity for unidirectional radiation are investigated with the aim of achieving a thin structure capable of reasonably broadband operation. By tuning together the slot length and the cavity cross-section, a very low-profile cavity-backed slot (CBS) is demonstrated. The cavity thickness of this slot antenna is about 10 times smaller than conventional one-quarter wavelength cavities, which would allow constructing this antenna even with standard cost-effective multilayer planar technology. The high gain and fairly wideband operation are the major advantages of the proposed configuration, which features a bandwidth of about 10% at a center frequency of 1.8 GHz with radiation efficiency in excess of 80%. Measured data are presented and compared with simulation results obtained by both the method of moments (MoM) and the finite integration technique (FIT). © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 247,250, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22073 [source]