Strip Monopole Research Articles

Broadband Planar Antenna Combining Monopole Element with Electromagnetic Bandgap

New structure of broadband planar antenna, combining monopole elements with electromagnetic bandgap (EBG) structures, is proposed. The antenna has a simple single layer structure and unique beam pattern. Antenna is fabricated on a surface of a single layer dielectric substrate and back side of the substrate is covered with metal layer. At the center of the substrate, an inverted L monopole strip is fabricated and on both sides of this monopole, EBG unit cells are placed. By tuning monopole length and EBG bandgap frequency, the monopole resonates even if metal layer exists close to the monopole radiator. Three types of EBG, one dimensional (1D), square two dimensional (2D) and hexagonal 2D, are tested. By combining monopole strip with hexagonal 2D-EBG, the bandwidth of prototype antenna, whose return loss is less than 10dB, is 840MHz in 5GHz band. To control beam patterns of antenna, parasitic elements are placed close to the monopole radiator and EBGs. These parasitic elements work as directors of quasi Yagi-Uda antenna and radiation gain at lower tilt angles is improved.

Internal Coupled-Fed Shorted Monopole Antenna for GSM850/900/1800/1900/UMTS Operation in the Laptop Computer

A simple shorted strip monopole with a coupling feed for penta-band WWAN (Wireless Wide Area Network) operation in the laptop computer is presented. With the coupling feed, which effectively compensates for the large inductive reactance of the antenna, a dual-resonance excitation for the antenna's lower band at about 1 GHz is achieved; the obtained bandwidth reaches 500 MHz, allowing the antenna to easily cover GSM850/900 operation. Also, a wide operating band is achieved for the antenna's upper band at about 1.9 GHz with a bandwidth of 540 MHz, hence easily covering GSM1800/1900/UMTS operation. With two wide operating bands achieved, the antenna occupies a thickness of 5 mm only and a small area of 9 times 79 mm2 (not including the ground plane), making it very promising to be embedded inside the casing of the laptop computer as an internal WWAN antenna. The proposed antenna is studied in detail in this study.

Wideband monopole antenna for DVB-T applications

A novel asymmetric fork-like monopole antenna for digital video broadcasting-terrestrial (DVB-T) signal reception for application in the UHF band is presented. The proposed antenna consists of two two-branch strip monopoles on a rectangular ground plane with a concave. The concavity in the ground pattern serves as an effective means for the gap between the radiating element and the ground plane for impedance matching. The influence of various parameters on antenna characteristics has been investigated. Results show a wide bandwidth of 461 MHz (451 912 MHz) or 70 of DVB-T centred frequency (655 MHz). The proposed antenna has omnidirectional radiation patterns in the yz-plane. Details of the proposed antenna design and experimental results of the constructed prototypes are presented.

Ultrawideband Band-Notched Folded Strip Monopole Antenna

We propose a new band-notched folded strip monopole antenna for ultrawideband applications. This antenna is composed of a forked-shape radiator and a 50 Omega microstrip line. To achieve band-rejected filtering property at the WLAN bands, the forked-shape strips are folded back and result in a pair of coupled lines on the radiator. The length and gap width of the coupled lines primarily determine the notched frequency of the antenna. Based on the band-notched resonance, an equivalent circuit model is proposed for the antenna and the calculated antenna input admittance agrees with the full-wave simulation data. With the help of the dimensionless normalized antenna transfer function, the radiation characteristics are investigated thoroughly. The transmission responses of a transceiving antenna system and their corresponding transient analysis are discussed at the end of this paper.

A WIDEBAND HYBRID PRINTED MONOPOLE/RECTANGULAR PATCH ANTENNA

This paper deals with a novel hybrid antenna configuration for broadband application. Broadband performance is achieved by electromagnetically exciting a planar rectangular patch with rear-mounted strip monopole antenna. The antenna has an overall dimension of 40.5 × 45 × 3.2 mm3 including the feed line and the ground plane. The reflection and radiation characteristics of the prototype antenna exhibits a 2:1 VSWR bandwidth of 40%, an average gain of ~ 7.1 dBi and good radiation coverage. The parametric analysis of the antenna and the design criteria for a compact broad band are also presented in this paper.

Planar branched monopole antenna for UWB applications

AbstractDevelopment of a compact microstrip‐fed, branched monopole antenna for ultra wide band (UWB) applications is presented. By suitably embedding branches on the top edge of the strip monopole, an UWB response can be easily achieved by merging different resonances. The simulated and experimental results demonstrate that the proposed antenna achieves more than 3:1 impedance bandwidth for 2:1 VSWR criteria. The antenna exhibits nearly omni directional radiation characteristics and moderate gain in the entire band. The proposed antenna is printed on a FR4 substrate of εr = 4.4 and thickness h = 1.6 mm and having an overall dimension of 65 × 35 mm2 including the ground plane. The parameters that affect the performance of the antenna are presented and discussed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 45–47, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22045

Wide band dumbbell‐shaped patch antenna

AbstractThe design and radiation characteristics of a wide band dumbbell‐shaped patch excited by planar strip monopole with truncated ground plane is proposed in this letter. The antenna can be easily modified for dual band operation by adjusting the location of the patch over the planar monopole. The antenna offers a bandwidth of 35 and 9% at 3.2 and 5.3 GHz bands, respectively. The overall area of the antenna including the 50 Ω line feed is only 65 × 65 mm2. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2295–2296, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21926

Compact CPW-fed monopole antenna for 5 GHz wireless application

A compact and simple coplanar waveguide (CPW)-fed monopole antenna for 5 GHz wireless communication is proposed. By properly adjusting the lengths of both the monopole strip and the inverted L-shaped ground, the designed antenna, with, including ground plane, only 9×9.5 mm2, can operate at the desired 5.2 or 5.8 GHz band. The electromagnetic coupling effect between the radiating strip and the ground on excitation of the resonant mode has been studied. Prototypes of the proposed antenna have been constructed and experimentally studied. Measured results show a −10 dB impedance bandwidth and an average antenna gain of 400 MHz and >6 dBi, respectively.

Optimum design of the printed strip monopole

A monopole antenna, printed on low-cost laminate and fed by a microstrip line, is examined. These types of antennas are becoming popular in view of their broad bandwidth and low-profile structure, enabling easy integration as a terminal antenna. The move away from a classical ground plane (with normal radiator) is one of the attractive features of these antennas, but the full effects of the radiator and ground plane being on opposite sides of the same laminate are often not investigated. The effect of these ground planes on the impedance bandwidth and radiation pattern is investigated experimentally and numerically.

Novel bi-arm rolled monopole for UWB applications

This work presents a bi-arm rolled monopole for ultrawide-band (UWB) applications. The roll monopole is constructed by wrapping a planar monopole. The impedance and radiation characteristics of the proposed roll monopole are experimentally compared with a rectangular planar monopole and strip monopole. Furthermore, the transfer responses of transmit-receive antenna systems comprising two identical monopoles are examined across the UWB band. The characteristics of the monopoles are investigated in both time and frequency domains for UWB single-band and multiple-band schemes. The study shows that the proposed bi-arm rolled monopole is capable of achieving broadband and omnidirectional radiation characteristics within 3.1-10.6 GHz for UWB wireless communications.

Analysis of a Strip Monopole Mounted Near an Edge or a Vertex

The strip monopole model is used in the problem of a wire attached to an arbitrary conducting surface segmented with triangular patches. Some segmentation methods for the patches are described for the problem when the junction is near an edge or a vertex. Only a few triangular patches on the surface are segmented to get more equilateral triangles when the strip monopole is added on the surface. The advantages of applying these segmentation methods are illustrated with several representative examples, which show good versatility and efficiency for solving the problems of wire/surface junctions.

Multiple meander strip monopole antenna

A novel multiple meander strip monopole antenna is presented. By iteratively meandering the vertical strip, compactness and broadband characteristics for the monopole antenna were achieved simultaneously. The designed monopole antenna with a radiation element volume of 14/spl times/14/spl times/14 mm/sup 3/ has the measured bandwidth ratio of 3.87:1, from 2.83 to 10.96 GHz for VSWR/spl les/2, with fairly frequency-insensitive omni-directional radiation characteristics.

Internal monopole antenna integrated with a shielding metal case for UMTS mobile devices

An integration design of an internal monopole antenna and an RF shielding metal case for application in UMTS mobile devices is proposed. The monopole antenna is a low-profile (only 3.5-mm) T-shape strip monopole placed above and integrated (through short-circuiting) to the shielding metal case, which is flush with the top edge of the system ground plane of the mobile device. With the integrated shielding case, which provides a coupling-free region for the nearby components such as the RF module, RF circuitry, and battery in the mobile device, possible coupling between the monopole antenna and the nearby components can be avoided. The proposed integration design can thus lead to no degrading effects on the performances of the internal monopole antenna employed in the mobile device. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 162–165, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21293

Bent planar monopole operating at GSM/DCS/PCS/IMT2000 quad‐bands

AbstractIn this paper, a compact antenna operating in the GSM/DCS/PCS/IMT2000 quad‐bands is presented. By bending the meandered monopole into three equal and perpendicular sections, then coupling the bent monopole with another strip monopole antenna, the designed novel antenna covers the required bandwidths of GSM (890–960 MHz), DCS (1710–1880 MHz), PCS (1850–1990 MHz) and IMT2000 (1900–2025 MHz). © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 170–172, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11319

Parametric study of dual-band operation in a microstrip-fed uniplanar monopole antenna

The design of an antenna consisting of two strip monopoles printed on the same side of an electrically thin dielectric substrate, and incorporating the use of a 50 Ω microstrip feed line with an open-circuited tuning stub, is presented. The proposed antenna is designed to have dual-band operation suitable for applications in DCS (1710–1880 MHz) and WLAN (2400–2484 MHz) bands. The dual-band antenna is simple in design, and the lengths of the antenna's larger and smaller strips can easily control the lower and upper operating frequencies, respectively. The influence of various parameters on antenna characteristics has been investigated using simulation software and experimental results. Optimal results and omnidirectional radiation patterns are given for the proposed antenna operating in the 1800 MHz/2450 MHz bands. Details of the dual-band design and design parametric study are presented and discussed.

A miniature monopole antenna for mobile communications

Strip monopole antennas printed on high-permittivity substrate are studied experimentally. Compared with the case without the dielectric slab, the resonant frequency of the monopole antenna is decreased by 50% when the antenna is fabricated on material of dielectric constant equal to 80. A wide impedance bandwidth of 35% can be achieved. The radiation patterns of the antennas and gain are insensitive to the dielectric constant of the substrate. The effect of the characteristic of the antennas by changing both the width of the dielectric material and the width of the strip of the monopole antenna is investigated. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 262–263, 2000.

A novel impedance‐tuned monopole antenna

The insertion of coplanar stubs within printed strip monopole antennas allows for tuning of resonant frequencies and corresponding impedances. Manipulation of stub and antenna dimensions allows the creation of antennas with a single impedance‐matched resonance or with two matched resonances with a specified frequency ratio.

Stripline-fed printed triangular monopole

A design of stripline-fed printed triangular monopole with broadband operation is presented. Results show that the triangular monopole with a flare angle of 60° (i.e. an equilateral triangular monopole) has the widest bandwidth, ~2.1 – 3.0 times that of a simple strip monopole, and this equilateral triangular monopole also operates at a length of only ~0.63 times that of a simple strip monopole. Details of the results are presented.

Monopole strip antenna excited by coplanar waveguide

A monopole strip antenna which consists of an open ended strip and a three-section coplanar waveguide feed is proposed and its structure and some attractive features are described. The main advantages provided by the antenna and their dependence on the width and length of the strip are confirmed experimentally.

Low profile cavity antenna with small pitch angle helix feed

A simple, circularly polarised, cavity-backed antenna is described which has a two turn low pitch angle helix feed. The helix is terminated in a strip monopole for improved axial ratio. The antenna is approximately one third of the size of an equivalent conventional monofilar helix antenna.