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A Compact Size and Small Frequency Ratio CPW-FED Circular Slot Antenna for GPS/WLAN Dual-Band and Circular Polarizations
Chia-Yen Wei;Ji-Chyun Liu;Tian-Fu Hung;Sheau-Shong Bor;Chi Chiang Chen
PIER C , 2011, DOI: 10.2528/PIERC11050410
Abstract: This paper presents a novel dual-band circularly polarized CPW-fed circular slot antenna with two open-ground rings. The proposed antenna is constructed with two opened-ground rings facing in opposite directions and embedded in the circular slot, and the enhanced feed strip of CPW. By way of adjusting the relevant parameters, we can obtain the dual-band at 1.57 GHz and 2.46 GHz respectively. A smaller frequency ratio of 1.56 is presented. The measured -10 dB return loss impedance bandwidth are 380 MHz (24.68%) for 1.57 GHz band and 210 MHz (8.33%) for 2.46 GHz band. The measured -3 dB axial ratio bandwidth for 1.57 GHz and 2.46 GHz bands are 13.38% and 8.13%, the polarization of radiation patterns are RHCP and LHCP for each band and the antenna gain are 3.72 and 3.21 dBic respectively.
A Dual-Band CPW-FED L-Slot Antenna with Both Linear and Circular Polarizations
Chien-Jen Wang;Yun-Jui Lee;Kun-Chou Lee
PIER C , 2011, DOI: 10.2528/PIERC11042804
Abstract: A design procedure for a dual-band CPW-fed linearly and circularly polarized (CP) antenna based on the L-shaped slot antenna is presented in this paper. The slot antenna and the feeding structure are fabricated on the same plane of the substrate so that circuit processes and position alignment can be simplified. By shortening the length of one arm of the L-slot, an additional mode with two orthogonal electrical fields with a phase difference of 90 degree is excited, so that the circularly polarized wave can also be excited. The enhancement of the resonant bandwidth is achieved by utilizing a stub-protruded feedline, adding one finger slit at the other arm slot, and tuning the dimension of the ground plane. A bandwidth of 22.0% (2.23-2.78 GHz) is achieved with an axial ratio < 3 dB for the optimized case.
CPW-Fed Slot Antenna for Wideband Applications  [PDF]
T. Shanmuganantham,K. Balamanikandan,S. Raghavan
International Journal of Antennas and Propagation , 2008, DOI: 10.1155/2008/379247
Abstract: A new coplanar waveguide (CPW)-fed wideband printed slot antenna is presented, and the impedance characteristics of this antenna with different sizes of tapers are discussed. The effect of tapering angle with the resonant frequency is also observed. The fundamental parameters of the antenna such as bandwidth, return loss, gain, radiation pattern, and polarization are obtained. All meets the acceptable antenna standards. The measured input impedance bandwidth (return loss < −10 dB) of the prototype antenna is 52% (4.27–7.58 GHz). The radiation patterns are bidirectional in both planes. This antenna can be part of various wireless communication systems.
Spiral Tuning Stub CPW-Fed UWB Slot Offset, Edge Cleft and Edge Slotted Antennas  [PDF]
A. A Jamali, A Gaafar, A. A. Abd Elaziz
Wireless Engineering and Technology (WET) , 2011, DOI: 10.4236/wet.2011.23021
Abstract: After the release of the unlicensed Ultra Wideband (UWB) spectrum 3.1 GHz to 10.6 GHz for the commercial purposes by the Federal Communications Commission (FCC), industries and academia pay much attention due to its properties of excellent immunity to multi-path interference, high secured data rate, low power consumption, and simple configuration. The feasible UWB antenna design face some challenges including the ultra wide impedance matching, omni directional radiation pattern, constant gain, high radiation efficiency, low profile, compact antenna size and easy manufacturing. since the CPW fed planar slot antennas have the advantages of wide bandwidth, simple structure, less radiation loss, low cost and easy integration of monolithic microwave integrated circuits (MMIC). In general two parameters affect planar slot antennas impedance bandwidth, the slot width and feed structure. CPW-Fed Slot Antenna with Triangular Tuning Stub, the slot shape could be bow-tie slot, wide rectangular slot, circular slot and hexagonal slot. The impedance tuning can also be performed by using coupling techniques like inductively and capacitively coupled slots, dielectric resonator coupling and other techniques such as using photonic band gap (PGB). Using these techniques, large impedance bandwidth could be obtained but they are quite complicated. Planar slot antennas have two parameters that affect impedance bandwidth, the slot width and the feed structure. The optimum feed structure gives the good impedance matching and the wider slot gives more bandwidth. The proposed antenna in this paper is designed with a compact rectangular slot and a rectangular spiral feeding structure at the interior portion of the feed. The antenna is cleft and slotted at the edge and the effects is studied. The antenna only one of its kinds in structure, small in size and simple design due to less number of design parameters compared with the existing ultra wideband antennas in the literature. The bandwidth, gain, directivity and other antenna parameters are at acceptable level. IE3D method of moments based simulation software is used for this analysis. The proposed antenna design and its experimental result details is presented and discussed.
On the Design of Circular Fractal Antenna with U-Shape Slot in CPW-Feed  [PDF]
Raj Kumar
Wireless Engineering and Technology (WET) , 2010, DOI: 10.4236/wet.2010.12012
Abstract: A new ultawideband circular fractal antenna with notched-band characteristics is presented. A notched-band characteristic is achieved by employing a U-shape slot in 50 Ω feed lines. The ultra-wideband impedance matching and compact size have been obtained by using CPW-feed technique and the fractal concept. The measured result of proposed fractal antenna exhibits the ultra wideband characteristics from 3.0 to 18.0 GHz at VSWR 2:1 except notched-band frequency. The proposed antenna has been analyzed theoretically and experimentally with respect to design parameters. The measured radiation pattern of fractal antenna is nearly omnidirectional in azimuth plane throughout the operating frequency. This antenna is useful for UBW communication system.
Design of CPW-FED Dual-Band Circularly-Polarized Annular Slot Antenna with Two Perturbation Strips
Qiong Chen;Hui-Li Zheng;Juhang Hu;Shugang Jiang
PIER C , 2012, DOI: 10.2528/PIERC12021612
Abstract: A new CPW-fed dual-band circularly-polarized (CP) annular slot antenna with two perturbation strips is proposed. The structure of the annular slot, along with two concentric annular-ring patches, can achieve dual-band input impedance matching. And circular polarization at the operation bands can be achieved by using the two perturbation strips placed on the backside of the antenna. To reduce the resonant frequencies, a third strip protruded from the ground plane is introduced. Both the simulated and measured results show that the impedance bandwidths determined by 10-dB return loss are about 29.1% for the lower band (1.92-2.61 GHz) and 12.1% for the upper band (3.21-3.65 GHz). And the AR bandwidths are about 7.5% and 11.0%, respectively.
Compact Dual-Band Dual-Sense Circularly-Polarized CPW-FED Slot Antenna
Xin Qian Zhang;Yong-Chang Jiao;Wei Hua Wang
PIER Letters , 2012, DOI: 10.2528/PIERL12062903
Abstract: A CPW-fed slot antenna for achieving dual-band dual-sense circular polarization is introduced. The dual-band circularly polarized operations are generated by the slots loaded in the two opposite corners and the halberd-shaped strip connected at the end of the signal line of the CPW. The left-hand and right-hand circularly polarized performances can be achieved simultaneously for the lower and the upper band, respectively. The measured impedance bandwidth for 10-dB return loss at 2.5 and 3.5 GHz operating bands can be up to 1100 MHz and 260 MHz, respectively. The measured 3-dB axial ratio bandwidths are 30.8% for lower band (LHCP) and 3.1% for upper band (RHCP), which are completely inside their respective impedance bands. The designed antenna has a simple uniplanar structure and occupies a compact size of 40×40 mm, including the finite ground CPW feeding mechanism. Moreover, the antenna gain variations across the two operating bands are less than 1 dB.
A Broadband CPW-FED T-Shape Slot Antenna
Jun-Ju Jiao;Gang Zhao;Fu-Shun Zhang;Hong-Wei Yuan;Yong-Chang Jiao
PIER , 2007, DOI: 10.2528/PIER07070904
Abstract: A novel broadband design of a coplanar waveguide (CPW) fed T-shape slot antenna is proposed and experimentally studied. The size of the proposed antenna is reduced by over 26% compared to the reported wide slot antenna. The obtained results show that the impedance bandwidth, determined by 10-dB return loss, of the proposed slot antenna can be as large as 5690MHz or about 121% centered at about 4.695 GHz. The design considerations for achieving broadband operation of the proposed slot antenna are described, and experimental results are presented.
Dual-Band CPW-FED Circularly-Polarized Slot Antenna for Dmb/Wimax Application
Feng-Xiang Wu;Wei-Mei Li;Si-Ming Zhang
PIER Letters , 2012, DOI: 10.2528/PIERL12022802
Abstract: A novel dual-band circularly-polarized slot antenna fed by a coplanar waveguide (CPW) is presented for digital multimedia broadcasting (2.6 GHz) and Worldwide Interoperability for Microwave Access (3.5 GHz) application. The circular polarization in the lower band is achieved by the slots loaded in two opposite corners, and corner truncation of the square slot can offer a current path for the upper band. Experimental results show that the measured impedance bandwidths (VSWR ≤ 2) are 18.5% for the lower band and 19.1% for the upper band, and the measured 3 dB axial-ratio bandwidths are 22.3% and 18.3%, with respect to 2.6 GHz and 3.5 GHz, respectively.
CPW Fed Hexagonal Patch Shape with Hexagonal slot Ultra Wideband Antenna  [cached]
Suman Gill,J S Ubhi
International Journal of Computers & Technology , 2012,
Abstract: In this paper hexagonal patch shape with hexagonal slot, ultra wideband antenna is proposed. The total dimensions of antenna are 55×43.5mm. Sides of hexagonal patch are taken 13mm each and hexagonal slot sides are taken as 3mm each. The antenna resonates at two frequencies in ultra wideband range (UWB). There is enhancement in BW in upper range ultra wideband frequency from 6.2 GHz to 8.2GHz due to hexagonal slot cut in hexagonal patch. The design is carried out using Computer Simulation Technology (CST) Microwave Studio (MWS) suite. Co-Planar Waveguide (CPW) feed is used to feed antenna.
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