Antenna Gain (antenna + gain)

Distribution by Scientific Domains


Selected Abstracts


Probe-fed microstrip antennas loaded with very high-permittivity ceramics

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2006
Y. Hwang
Abstract This article reports the feasibility study of miniaturizing probe-fed microstrip patch antennas by dielectric loading. The loading materials are barium tetratitanate ceramics of very high dielectric constant (,r = 38, 80). It is shown that, simply through loading, the antenna sizes are greatly reduced; however, the antenna performances are deteriorated. For instance, the antenna gain becomes lower. Then enhancement of the antenna performances follows. A substrate,superstrate structure is used to recover the gain. Both the experiments and the finite-difference time-domain (FDTD) simulations demonstrate that the gain and impedance bandwidth can be retrieved such that they are comparable to those of conventional microstrip antennas loaded with low permittivity materials (,r < 3). © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006. [source]


Protection of FS receivers from the interference produced by HEO FSS satellites in the 18,GHz band: Effect of the roll-off characteristics of the HEO system satellite antenna beams

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 3 2008
Anna Carolina Finamore
Abstract This paper focuses on the protection of fixed service (FS) receivers from the aggregate interference produced by the satellites of multiple highly elliptical orbit satellite systems (HEOs). It analyzes the protection given to FS receivers operating in the 18,GHz frequency band by the power flux-density (pfd) mask contained in Article 21 of the 2003 edition of the Radio Regulations [International Telecommunication Union, 2003.]. This mask establishes the maximum allowable value for the pfd produced by any of the satellites of a non-geostationary system at the Earth's surface. The protection offered to FS receivers by this mask is analyzed in four interfering environments, each containing three identical HEO systems. Four types of HEO systems, with different orbital characteristics, are considered: three having satellites that operate only in the northern hemisphere and one having satellites that operate in both hemispheres. All satellite antennas are assumed to radiate 0.3° spot beams. Each HEO satellite is modelled so that the maximum pfd it produces at the Earth's surface just meets the RR Article 21 mask and the analysis takes into account the roll-off characteristics of the satellite antenna beams. To reflect the multiplicity of possibilities concerning the geographical location and technical characteristics of the victim FS receiver (e.g. latitude, longitude, azimuth and elevation of its receiving antenna, antenna gain, receiver noise temperature, etc.) a number of cases were evaluated. The concept of interference in excess [Int. J. Satellite Commun. Networking 2006; 24: 73,95] was used to combine the results corresponding to FS receivers located at the same latitude and having the same receiving antenna elevation angle but for which the location longitude and the azimuth of the pointing direction of its receiving antenna are randomly chosen. Results are expressed in terms of the cumulative distribution function of the interference in excess. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Efficient and high-gain aperture coupled superstrate antenna arrays for 60 GHz indoor communication systems

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2010
Hamsakutty 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 novel compact CPW-fed planar monopole antenna with modified stair-style ground for ultra-wideband applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2010
Y.-B. Yang
Abstract In this article, a simple and compact CPW-fed planar monopole antenna for ultra-wideband applications is presented and investigated. The proposed antenna with a small size of 26 mm × 26 mm × 1 mm is composed of a gourd-like radiation element fed by a CPW feed line, and a modified stair-style ground. The proposed antenna has been successfully designed, fabricated, and measured. The measured results show that the antenna achieves a wide impendence bandwidth from 3.1 to 15.2 GHz with return loss less than ,10 dB. In addition, it exhibits a nearly omnidirectional radiation pattern, stable antenna gain, and good time-domain characteristics across the operation band. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2100,2104, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25378 [source]


A size reduced CRLH resonant antenna based on interdigital capacitors with defected ground structure

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2010
M.-J. Lee
Abstract A new composite right/left-handed (CRLH) resonant antenna with interdigital capacitors for a size reduction is proposed in this letter. This antenna consists of three sectional patches, two interdigital lines (capacitors) with a defected ground, and two shorting pins. A rectangular patch is split into three sections and each section is coupled with an interdigital line. When the proposed antenna is operated in the LH resonant mode, the antenna size is reduced by 33% and the antenna gain is increased by 7 dB as compared with one without defected ground structures. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2142,2145, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25362 [source]


A shorted square-ring slot antenna with a branched slot for the 1575 MHz and 2.4 GHz dual-band operations

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009
Chin-Long Tsai
Abstract A shorted square-ring slot antenna with a branched slot is presented for the 1575 MHz and 2.4 GHz dual-band operations. This proposed antenna can be designed by two steps. First, the shorted square-ring slot antenna is designed for circular polarization in the GPS band. Then, a branched slot is added to the original structure to result linear polarization in the 2.4 GHz band. Because the added branched slot almost has no influence in the GPS band's characteristics, the design rule is very simple. The impedance and axial ratio bandwidths for the GPS band is 23.3% and 4.2%, respectively. Besides, the AR and antenna gain is 1.23 dB and 2.3 dBic at the frequency of 1575 MHz. The impedance bandwidth for the 2.4 GHz band is 4.5% and antenna gain at the center frequency of 2.445 GHz is 2.8 dBi. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 402,405, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24073 [source]


An efficient CMOS on-chip ladder reflector antenna for inter-chip communications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2009
Bo-Tao Jiang
Abstract This article presented a new ladder reflector antenna on chip (AOC) which consisted of an active dipole and reflector array. The ladder structure was very easy to fabricate with the standard CMOS process. A ladder reflector antenna operating at the 24 GHz ISM band was designed with a standard 0.18 ,m six metal layers CMOS process. The whole antenna had a dimension of 0.025 mm × 2.84 mm. The measurement results showed that the ladder reflector antenna got a return loss of ,7.25 dB and a gain of 6.25 dBds at 24 GHz, as well as a ,5 dB impedance bandwidth of 16.2,30 GHz. The measured S12 indirectly proved the simulated radiation patterns. The data taken from the experiment indicated that the ladder reflector increased the antenna gain and effectively enhanced the energy radiating to the outside of the chip. It's very useful for the wireless interconnect for inter-chip communications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 59,63, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24000 [source]


Gain enhancement in embedded microstrip antennas

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2008
M. Fallah-Rad
Abstract A microstrip antenna embedded inside a dielectric medium representing the building material is investigated for its gain. It is shown that coupling the embedded antenna to a parasitic patch, placed outside the embedding material, can increase the antenna gain significantly. In addition, by properly selecting the antenna depth inside the embedded material its radiation characteristics can be made less sensitive to the material parameters of the surrounding. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 269,271, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23070 [source]


CP-microstrip coplanar patch antenna for satellite reception

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2008
Wojciech J. Krzysztofik
Abstract A design of a broadband circularly polarized coplanar-square-patch antenna, CSPA, for Iridium satellite reception via handset is proposed and experimentally studied. With the introduction of some asymmetry in the structure to a single-feed coplanar-sqaure-patch microstrip antenna, it is possible to excite two orthogonal degenerate resonant modes for circular polarization (CP) radiation. Experimental results of constructed prototypes show that the obtained 3-dB axial-ratio bandwidths can reach as large as 8.5%. The proposed antenna has a peak antenna gain of about 4.2 dBi, with efficiency 85% for frequencies within the CP. Some prototypes of the proposed CP design CSPA antennas have been implemented and experimental results are presented and discussed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 372,375, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23071 [source]


A circular CPW-FED slot antenna for broadband circularly polarized radiation

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2007
I-Chung Deng
Abstract The design of a circular slot antenna for obtaining broadband circularly polarized (CP) radiation using a coplanar waveguide (CPW) feed is presented. The operation of the proposed antenna is achieved by protruding metallic mono-strip from the circular ground plane towards the slot center at , = 0° and feeding antenna using a 50-, CPW with a protruded single strip at , = 270°. In this design, the impedance bandwidth and 3 dB axial-ratio bandwidth can reach as large as 50 and 36%, respectively. The peak of antenna gain is about 3.9 dBi, with gain variations <1 dBi for the frequencies within CP bandwidth. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2728,2733, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22881 [source]


Internal low-profile metal-plate monopole antenna for DTV portable multimedia player applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2007
Yeon-Sik Yu
Abstract A low-profile metal-plate monopole antenna for mobile handset operating over Digital-TV (DTV; 470,850 MHz) frequency band is proposed. The antenna consists of a folded rectangular patch and two slits, and has a small volume of 65 × 25 × 5 mm3. The measured return loss for the proposed antenna at DTV frequency band is better than 10 dB. The antenna has omni-directional or monopole-like radiation patterns, with good antenna gain even for such a compact size. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 593,595, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22219 [source]


A wideband planar monopole microstrip antenna with coupled parasitic lines

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2006
Lu Lu
Abstract A wideband microstrip-fed monopole antenna with two shorted inverted-L coupled lines is presented. The proposed antenna has a large impedance bandwidth covering the range from 3.22 to 11.68 GHz. The radiating elements only occupy a small area of 9.3 × 8.2 mm2. The gain and bandwidth of the antenna are predicted using a commercial finite-element method software package. For frequencies across the operating bands, the proposed antenna displays monopolelike radiation patterns and good antenna gain, given its small physical size. The predicted results show good agreement with measured data. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1507,1509, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21718 [source]


Compact CPW-fed dual folded-strip monopole antenna for 5.8-GHz RFID application

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2006
Wen-Chung Liu
Abstract A coplanar waveguide (CPW)-fed monopole antenna with dual folded strips for the radio frequency identification (RFID) application is presented. The proposed antenna has a very compact size, with, including ground plane, only 14 × 8 mm2, and can operate at the 5.8-GHz band with measured impedance bandwidth and average antenna gain of 450 MHz and ,5.5 dBi, respectively, and also monopolelike radiation patterns. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1614,1615, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21686 [source]


CPW-FED shorted F-shaped monopole antenna for 5.8-GHz RFID application

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2006
Wen-Chung Liu
Abstract A novel coplanar waveguide (CPW)-fed F-shaped planar monopole antenna obtained by embedding folded slots in a rectangular patch on a single-layer substrate is proposed. To expand the impedance bandwidth and miniaturize the antenna size for suitable use in 5.8-GHz radio frequency identification (RFID) systems, a branch of the F-shaped antenna is shorted. The designed antenna including ground plane is only 16.8 mm in height and 13 mm in width and can operate in the 5.8-GHz frequency band with measured impedance bandwidth and average antenna gain of 640 MHz and 4 dBi, respectively, as well as broadside radiation patterns. These properties make this antenna suitable for RFID tags. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 573,575 2006; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.21410 [source]


High-gain broadband patch antenna with a cavity ground for 5-GHz WLAN operation

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2004
Saou-Wen Su
Abstract A novel broadband patch antenna with an equilateral-triangular cavity ground for achieving enhanced antenna gain over a large bandwidth is presented. A constructed prototype covering the 5.2/5.8-GHz (5150,5350/5725,5875 GHz) WLAN bands and showing a high antenna-gain level of about 9.8 dBi is demonstrated. Across the operating band, the prototype also shows good radiation characteristics with reduced cross-polarization and backward radiation. Details of the proposed antenna design and obtained experimental results are presented. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 397,399, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20151 [source]


Broadband circularly polarized inverted-L patch antenna

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2003
Che-Wei Su
Abstract An innovative design of a corner-truncated inverted-L patch antenna for achieving circular polarization (CP) operation over a wide bandwidth is presented. The antenna has a thick air-layer substrate; however, it can be easily excited using a probe feed with a short probe pin. CP operation is obtained by selecting an optimal size of the truncated corners, and good impedance matching over a wide bandwidth is obtained by using a beveling technique on the vertical portion of the inverted-L patch. For a prototype constructed for wireless local area network (WLAN) operation in the 2.4-GHz band (2.4,2.484 GHz), the obtained CP bandwidth (3-dB axial ratio) reaches about 7%, and the measured antenna gain is about 8.0 dBi across the CP bandwidth. Details of the antenna design and the experimental results are presented. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 134,136, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10995 [source]


A conical-pattern annular-ring microstrip antenna with a photonic bandgap ground plane

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2001
Shun-Yun Lin
Abstract A probe-fed annular-ring microstrip antenna with a photonic bandgap (PBG) ground plane operating in the higher order mode of TM21 for conical-pattern radiation is experimentally demonstrated. The antenna studied is printed on a thin FR4 substrate (relative permittivity 4.4) and, owing to the PBG ground plane used, significant improvements in the antenna performances are observed. The obtained impedance bandwidth is doubled, and the antenna gain is enhanced by about 7 dBi. Details of the experimental results are presented and discussed. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 159,161, 2001. [source]


Performance comparisons for adaptive LEO satellite links

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 3 2006
William G. Cowley
Abstract This paper considers the potential to achieve improved throughput in time-varying satellite links which have flexibility in information bit rate and/or transmit power. We assume that other parameters of the link budget such as antenna gains and operating frequency are fixed. Simple results are derived, which illustrate what improvements in data throughput or power consumption are possible under two low-earth orbit scenarios: inter-satellite links and satellite to ground communications. Copyright © 2006 John Wiley & Sons, Ltd. [source]


Multi-band chip antenna for WiMAX applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2010
Shun-Yun Lin
Abstract A novel chip antenna for dual-/tri-band operation is presented in this article. The design consists of a pair of forked metal strips with different lengths. The longer strip is folded onto an FR4 base to simultaneously introduce the quarter- and half-wavelength modes as the first two operating bands. By varying the included angle between the sections of strip on the opposite base layers, the frequency ratio of the first two operating modes is adjusted over a large range of 1.34,2.29. In addition, the shorter excited strip introduces the quarter-wavelength mode as the third operating band. The tri-band operation with a small dimension of 13 × 5 × 0.8 mm3 for 2.5/3.5/5.5 GHz WiMAX applications is implemented. Experimental results show that the proposed antenna has good omnidirectional radiation patterns and steady antenna gains over all operating bands. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1286,1290, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25211 [source]


Broadband dual-band CPW-fed closed rectangular ring monopole antenna with a vertical strip for WLAN operation

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2008
Li Zhang
Abstract A novel CPW-fed closed rectangular ring monopole antenna with a vertical strip is proposed for WLAN applications. The antenna with a very simple structure is easily fabricated. The measured results explore broadband dual-frequency operation with (10 dB) impedance bandwidths of 23.4%, range from 2.24 to 2.82 GHz, and 22.9%, ranging from 4.86 to 6.18 GHz, at bands of 2.48 and 5.76 GHz, respectively, which cover the 2.4/5.2/5.8 GHz WLAN operating bands. Also, good omni-directional radiation patterns and antenna gains over the operating bands have been obtained. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1929,1931, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23514 [source]


A planar dual-meander-line antenna for multiband mobile handsets

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2006
Hai-Ming Hsiao
Abstract A planar dual-meander-line antenna consisting of three branch strips for a low-profile GSM/DCS/PCS/WLAN multiband mobile handset is proposed. The branch strips are designed to operate as quarter-wavelength structures at 900 and 2000 MHz, respectively, and the obtained impedance bandwidths are 120 MHz (about 13.2%) and 924 MHz (about 44.4%) for covering the required bandwidths of the GSM (890,960 MHz) and DCS/PCS/UMTS/WLAN (1710,1880/1850,1990/1920,2170/2400,2484 MHz) bands. The proposed antenna can be mounted on top of a mobile phone with a low profile of 20 mm from ground plane. The measured antenna radiation patterns are approximately omnidirectional across the multiresonant bands. Peak antenna gains for operating frequencies across the GSM/DCS/PCS/UMTS/WLAN multiple bands are measured to be 1.8 and 2.9 dBi, respectively, with gain variations within 0.5 dBi. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 883,888, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21507 [source]