Arc-shaped Strip Research Articles

DESIGN OF A COMPACT ACS-FED DUAL BAND ANTENNA FOR BLUETOOTH/WLAN AND WIMAX APPLICATIONS

In this paper, a compact asymmetric coplanar strip (ACS)-fed printed monopole dual- band antenna for 2.4 GHz bluetooth, 5.2/5.8 GHz wireless local area network (WLAN) and 3.5/5.5 GHz worldwide interoperability for microwave access (WiMAX) applications is presented and investigated experimentally. The proposed antenna is composed of a ACS-fed monopole, an arc-shaped strip and an omega-shaped strip, which occupies a compact size of 18 × 22 mm 2 including the ground plane. By properly selecting the positions and lengths of these strips, dual frequency operation with wide impedance bandwidth characterstics can be achieved. The proposed antenna has been validated experimentally and found to have nearly onmidirectional radiation patterns in the H-plane, nearly bi-directional behaviour in the E-plane and acceptable peak gain across operating bands.

Planar Broadband Circularly Polarized Antenna With Square Slot for UHF RFID Reader

Novel circular polarization (CP) design of planar broadband antenna with square slot for UHF RFID system is proposed and experimentally studied. By insetting the arc-shaped strip into the square slot, the proposed CP design can easily be achieved with the impedance bandwidth ( RL ≥ 10 dB) of about 142 MHz (15.3% @ 931 MHz) and the 3 dB axial-ratio (AR) bandwidth of about 166 MHz (17.7 % @ 940 MHz) for UHF RFID applications. The measured peak gain and radiation efficiency are about 6.8 dBic and 98% across the operating band, respectively, with nearly bidirectional pattern in the XZ- and YZ-plane.

Planar UWB monopole antenna with dual band-notched characteristics for UWB applications

A simple and compact circular ultra-wideband (UWB) planar monopole antenna with dual band-notched characteristics is presented. By inserting a pair of two slots in the ground plane as well as adding a pair of arc-shaped parasitic strips around the radiating element, two notched frequency bands in the WiMAX/WLAN are achieved. Experimental results show a VSWR<2 bandwidth of 7.6 GHz for nondefected antenna and two highly rejected bands in the frequency region of 3.3–3.7GHz and 5–6GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:241–245, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27301

A quasisemicircular wide-slot antenna with 3.5-/5.5-GHz dual band-notched characteristics for ultrawideband applications

A novel ultrawideband (UWB) wide-slot antenna with dual-notched bands is presented and investigated in this article. The radiator is a quasisemicircular slot excited by a fork-shaped stub. By introducing an arc-shaped slot and a pair of arc-shaped strips on the ground, the 3.5- and 5.5-GHz dual band-rejected filtering properties for worldwide interoperability for microwave access and wireless local area network signals can be achieved well. Measured results demonstrate that the proposed antenna can operate well over UWB frequency band ranging from 2.85 to over 12 GHz, while providing dual-notched bands (VSWR > 2) covering 3.23–3.71 GHz and 5.03–6.34 GHz. In addition, nearly omnidirectional radiation patterns, stable gain, and moderate group delay variation can also be observed in the operating bands. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1602–1605, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26901

Miniaturized Tapered Slot Antenna With Signal Rejection in 5–6-GHz Band Using a Balun

A miniaturized elliptically tapered slot antenna fed by a novel balun is proposed for directional ultrawideband (UWB) applications. The feeding configuration consists of a stepped microstrip line and a folded slotline connected with a circular slot. An arc-shaped parasitic strip is printed inside the circular slot. This design achieves the minimization of the physical size and the capability of signal rejection at 5-6 GHz with significant gain suppression of 15 dB. Both simulated and measured results confirm the advantage of the design in reducing the size of the antenna while maintaining the UWB performance with band-notched function.

A Novel Arc-Shaped Printed Antenna for WLAN Applications

In this paper, a low profile printed antenna with dual-band operation for wireless localarea network (WLAN) applications is presented. It provides two separate impedance bandwidths of0.49GHz (2.3-2.79GHz) and 2.22GHz (4.92-7.14GHz). The proposed microstrip-fed antennaconsists of two arc-shaped strips with a nipped stub and a defected ground plane. The proposedantenna occupies a small size (40mm×25mm×1.59mm) and is fabricated and measured. Good omnidirectionalradiation patterns and enough gains across the operation bands are obtained. Thesimulated results are in good agreement with the measured. The effects of the key structureparameters on the antenna performances are also analyzed and presented.

PRINTED BLUETOOTH AND UWB ANTENNA WITH DUAL BAND-NOTCHED FUNCTIONS

A novel hybrid design of Bluetooth and UWB antenna with dual band-notched functions is proposed. The proposed antenna structure consists of a microstrip-fed main patch and electromagnetically coupled parasitic patch with arc-shaped strips, achieving Bluetooth and UWB performance. Additionally, the split ring resonator (SRR) slot etched on the main patch and the square patch close to microstrip feedline are aimed to obtain dual notched bands. The numerical and experimental results exhibit that the designed antenna operates over the wide frequency band from 3 to more than 12GHz, while showing the extra resonant mode at 2.4-GHz Bluetooth and the band rejection performance at 3.5-GHz WiMAX and 5.2-GHz WLAN.

A Printed Band-Notched UWB Antenna Using Quasi-Self-Complementary Structure

A quasi-self-complementary antenna (QSCA) for band-notched ultrawideband (UWB) application free from interference with existing wireless local area network (WLAN) systems is proposed. The designed band-notched UWB operation can be obtained by choosing the size of the parasitic arc-shaped strip opposite to the quarter-circular patch. The proposed antenna has advantages of low cost, easy design and compact size. Details of the proposed design and experimental results of the constructed antennas are presented.

Cavity-backed Archimedean spiral antenna with strip absorber

The characteristics of an Archimedean spiral (ARSP) antenna backed by an extremely shallow cavity (0.07 wavelength at the lower operating design frequency of 3 GHz) are analysed. It is revealed that the presence of the cavity causes noticeable variation in the antenna characteristics at low frequencies. To restore the wideband characteristics inherent to the ARSP, a ring-shaped strip absorber (R-ABS) is placed under the spiral arms. It is found that the wideband antenna characteristics are successfully restored with the use of the R-ABS. Subsequently, the R-ABS is divided into two arc-shaped strip absorbers and the volume of each is reduced by decreasing the arc-angle ARC from 180deg (corresponding to an R-ABS) to 0deg (corresponding to a cavity without an absorber). It is shown that when the arc-angle is chosen to be greater than deg ARC =90=, the antenna characteristics obtained for = ARC =180= are reproduced. Theoretical results are confirmed using results from experimental work.

Integrated optical NIR-evanescent wave absorbance sensorfor chemical analysis.

A new, long-path integrated optical (IO) sensor for the detection of non-polar organic substances is described. The sensing layer deposited on a planar multimode IO structure is built by a suitable silicone polymer with lower refractive index (RI). It acts as a hydrophobic matrix for the reversible enrichment of non-polar organic contaminants from water or air. Light from the near-infrared (NIR) range is coupled into the planar structure and the evanescent wave part of the light field penetrating into the silicone layer interacts with the enriched organic species. As a result, light is absorbed at the characteristic frequencies of the corresponding C-H, N-H or O-H overtone and combination band vibrations of the analytes. To perform evanescent field absorbance (EFA) measurements, the arc-shaped strip waveguide structure of 172 mm interaction length was adapted to a tungsten-halogen lamp and an InGaAs diode array spectrograph over gradient index fibers. Dimethyl-co-methly(phenyl)polysiloxanes with varying degrees of phenylation were prepared and used as sensitive coating materials for the IO structure. Light attenuation in the arc-shaped waveguides is high and typical insertion losses in the range of 14-18 dB were obtained. When the coated sensors were brought in contact with aqueous samples, the light transmission decreases, which is due to the formation of H(2)O micro-emulsions in the silicone superstrates. Nevertheless, after reaching constant light transmissions, absorbance spectra of aqueous trichloroethene samples were successfully collected. For gas measurements, where water cross sensitivity problems are absent, the sensitivity of the IO device for trichloroethene was tested as a function of the RI of the silicone superstrate. The slope of the TCE calibration function increases by a factor of 10 by using a poly(methylphenylsiloxane) layer with a RI of 1.449 instead of poly(dimethylsiloxane) (RI: 1.41). A comparison of the IO-EFA and an earlier developed fiber-optic EFA sensor for trichloroethene measurements in the gas phase showed an increase in sensitivity per unit length of the waveguide by a factor of up to 120.