Elliptical Monopole Research Articles

Designs of ultra wideband (UWB) printed elliptical monopole antennas with slots

AbstractPrinted elliptical monopole antennas are discussed for ultra wideband (UWB) applications. To enhance the design flexibility of the UWB antennas, two slots are incorporated along the edges of the elliptically shaped monopole. By adjusting the size of the slots, the overall performance of the proposed antenna can be improved. Full wave electromagnetic simulations have been used to investigate the effects of different parameters (feed‐line length, monopole shape, etc.) on the antenna performance. To verify the design concept, a prototype antenna was designed on the Rogers' RT/Duroid 5880 substrate, fabricated and characterized experimentally. The measured properties of the antenna, including return loss, radiation pattern, and gain, show good agreement with the predicted UWB behavior. Moreover, as a result of the flexibility provided by the proposed designs, an antenna that incorporates a notch frequency within the UWB band is easily achieved. This notch‐filter antenna design is also presented along with its simulated performance. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 466–471, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24943

UWB Elliptical Monopoles With a Reconfigurable Band Notch Using MEMS Switches Actuated Without Bias Lines

Two CPW-fed elliptical monopoles were fabricated on liquid crystal polymer (LCP) with reconfigurable rejection band (band-notch) characteristics in the frequency range between 5 and 6 GHz. The first antenna uses a lambda/2 long, U-shaped slot and the second antenna uses two symmetrically placed lambda/4 long, inverted L-shaped stubs as resonating elements. Microelectromechanical system (MEMS) switches are used to activate and deactivate the resonating elements without the need of dc bias lines due to a novel design of the switch geometry. Transmission line models and surface current distributions are used to explain the effect of the added resonating elements. Reflection coefficient radiation pattern and gain measurements are presented to verify the design concepts featuring a very satisfactory performance.

Printed elliptical monopole with shaped ground plane for pattern stability

A novel planar elliptical disc monopole antenna for universal mobile communication systems (UMTS) and ultra-wideband (UWB) dual network applications is presented. Printed on a FR4 dielectric substrate and excited by a microstrip transmission line, the antenna has a shaped ground plane featuring a wide impedance bandwidth with excellent omnidirectional pattern stability.

Modified Rhombic Monopole Antenna for Low Loss Frequency Notched UWB Applications

An elliptical base rhombic monopole antenna and frequency notched EBRM are proposed for low loss omni-directional ultra-wideband applications. The impedance bandwidth of simple rhombic monopole is improved with the help of semi-elliptical base and optimized for impedance matching of the order of –15 dB within impedance bandwidth. Frequency notched EBRM is realized by a U-shaped slot and optimized for WLAN. The measured results confirm impedance matching level of –15 dB, notched function with insertion level of 1.68 dB and omni-directional coverage over the impedance bandwidth.

A Novel Tri-Band-Notched Monopole Antenna

A novel tri-band-notched monopole antenna for UWB application has been presented in this paper. The tri-band-notched characteristics are obtained by etching a complementary split-ring resonator (CSRR) inside the radiate patch of printed elliptical monopole antenna (PEMA) and inserting a U-Shaped slot in the ground plane respectively. As a practical example, the proposed antenna (working from 2.7 to 12 GHz) is demonstrated and its VSWR and radiation patterns are measured. It is also proved that the triband rejection characteristics at 3.47, 5.75, and 8 GHz can be obtained by etching two types of slots.

A Novel Band-Notched Elliptical Ring Monopole Antenna with a Coplanar Parasitic Elliptical Patch for UWB Applications

A novel band-notched ultra wide-band antenna with a coplanar parasitic elliptical patch in an elliptical ring is presented in this paper. Printed on a dielectric substrate of FR4 with relative permittivity of 4.4 and fed by a 50Ω microstrip line, the proposed monopole antenna demonstrate a 10 dB return loss bandwidth of 2.91–11.91 GHz, with a band-notched at 5.15–5.98 GHz band and good radiation patterns. The proposed antenna is utilize the coplanar parasitic elliptical patch to reject the frequency band (5.15–5.85 GHz) limited by IEEE802.11a and HIPERLAN/2. The parameters which affect the performance of the antenna in terms of its frequency domain characteristics are investigated in this paper.

Design Aspects of Printed Monopole Antennas for Ultra‐Wide Band Applications

This paper presents the design equations for lower band‐edge frequency for all the regular shapes of printed monopole antennas with various feed positions. The length of the feed transmission line is a critical design parameter of these monopole antennas. Design curves for the length of the feed transmission line for various lower band‐edge frequencies for all these regular shaped monopoles have been generated. A systematic study has been presented to explain the ultra‐wide bandwidth obtained from these antennas with an example of elliptical monopole antenna.

Compact Elliptical Monopole Antenna With Impedance Bandwidth in Excess of 21:1

A compact CPW-fed monopole antenna composed of an elliptical monopole patch and a coplanar trapeziform ground plane is introduced. The simulated and experimental results demonstrate that this antenna achieves a ratio impedance bandwidth of 21.6:1 for VSWR les 2, and exhibits a nearly omnidirectional radiation pattern, while its area is only about 0.19 lambda1 times 0.16 lambda1 where lambda1 is the wavelength of the lowest operating frequency. By comparing with various designs, it is shown that its bandwidth broadening comes from three factors: the optimum elliptical monopole shape, a trapeziform ground plane and a tapered CPW feeder.

Compact hollowed printed monopole antenna with extremely wide bandwidth

AbstractA compact hollowed printed monopole antenna with an extremely wide bandwidth is introduced, which is composed of a hollowed elliptical monopole patch and a trapeziform ground plane, both printed on the same side of a substrate, and is fed by a tapered CPW feeder in the middle of the ground plane. The simulated and experimental results agree well and demonstrate that this antenna achieves a measured impedance bandwidth from 0.44 to 10.6 GHz (24.1:1) for VSWR ≤ 2, and exhibits a nearly omnidirectional radiation pattern, while its area is only about 0.20λl × 0.13 λl, where λl is the wavelength of the lowest operating frequency. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2883–2886, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22829

PLANAR ELLIPTICAL UWB ANTENNA WITH BAND-NOTCH CHARACTERISTICS

A coplanar waveguide-fed planar elliptical monopole antenna suitable for use in ultra-wide band communication systems is presented. Antenna exhibits a wide impedance bandwidth from 2.64–10.9 GHz with an omni-directional radiation pattern. Further, a notched band centered at 5.45 GHz is obtained within the wide bandwidth by inserting a narrow horizontal slit inside the patch. The notched frequency can be easily tuned by varying the slit parameters. The slit provides significant reduction in gain in the notch band with little effect on the antenna operation at other frequencies. The time domain studies on the antenna shows a linear phase response throughout the band except at the notched frequency. The transient analysis of the antenna indicates very little pulse distortion confirming its suitability for pulsed systems.

Ultrawideband Printed Elliptical Monopole Antennas

Parametric study of ultrawideband printed elliptical monopole antennas have been presented. Design curve for the length of the feed transmission line for various lower band edge frequencies has been generated. Variation of bandwidth with ellipticity ratio of these configurations has also been studied. Experiments have been performed to measure bandwidth and radiation patterns of these configurations, which tally well with simulated results. The elliptical configuration with ellipticity ratio of 1.1 gives ultrawide impedance bandwidth ratio of 12.4:1 as compared to 10.2:1 of the circular monopole antenna. This antenna introduces minimum ringing and distortion/dispersion of the pulse in time domain

Ultra wideband printed monopole antenna

AbstractAn ultra wideband printed planar elliptical monopole is reported. The antenna has a simple printed structure, mounted perpendicular to a small metallic ground plane. The proposed antenna can be used for multiband operation, with omnidirectional radiation pattern in azimuth plane. The antenna operates over an extremely wide impedance bandwidth of more than 25:1, determined by 10 dB return loss and covers almost all present day wireless communication systems: Advanced mobile phone system, global system for mobile communication, digital communication system, universal mobile telecommunication system, and broadband wireless metropolitan area network system for operation in the 2–11 GHz band. This article presents the design, analysis, and experimental results for the proposed antenna. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1082–1085, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22343

Elliptical planar monopole antenna with extremely wide bandwidth

A planar monopole antenna with an extremely wide bandwidth is introduced, which is composed of an elliptical monopole patch and a trapeziform ground plane, both printed on the same side of a substrate, and is fed by a tapered CPW feeder in the middle of the ground plane. The simulated and experimental results demonstrate that this antenna achieves a ratio impedance bandwidth of 21.6:1 for VSWR≤2, and exhibits a nearly omnidirectional radiation pattern, while its area is only about 0.19λl×0.16λl where λl is the wavelength of the lowest operating frequency.

Wideband Antenna for Underground Soil Scout Transmission

The underground soil scout system introduces a need for a small-size antenna capable of adequate radiation efficiency in soils of different moisture contents at the frequency 0.869 GHz. Such an underground antenna is created for the first time. The high permittivity of soil is utilized to downsize the instrument. A prototype design of an underground single-ended elliptical monopole antenna (USEMA) is presented and the performance measured in different soil moisture contents in a soil container. The suggested antenna has good radiation efficiency in a wide soil moisture range