Strip Monopole Research Articles

Planar compact triple-band monopole antenna for IEEE 802.16m WiMAX application

Planar compact monopole antenna design with triple-band operation for the IEEE 802.16 m worldwide interoperability for microwave access (WiMAX) system is proposed. By adding C- and L-shaped monopole strips to the antenna, excitation of multiresonant modes can approximate the 2.6, 3.5, and 5.5 GHz bands required for WiMAX (IEEE 802.16 m) operations. The obtained impedance bandwidths across the operating bands approach 168/325/1208 MHz for the 2.6/3.5/5.5 GHz bands, respectively. The proposed uniplanar antenna reduces the antenna size by at least 15%, since overall antenna volume is only 22 × 28 × 0.8 mm3 (0.19 λo × 0.243 λo × 0.007 λo, at 2.6 GHz). The measured peak gains and radiation efficiencies approximate 3.0/4.2/4.5 dBi and 77/76/83% in the 2.6/3.5/5.5 GHz band, respectively, and exhibit a nearly omni-directional pattern in the XY-plane.

Hybrid dielectric resonator integrated pyramidal horn antenna

AbstractThis article presents the design, simulation, and fabrication of hybrid dielectric resonator integrated pyramidal horn antenna (HDRIPHA) operating from frequency range of 10–18 GHz to cover most of the existing Ku‐band microwave frequencies. The designed HDRIPHA is analyzed and optimized using power modeling software CST Microwave Studio ®. The designed HDRIPHA assembly consists of hybridizing a circular sector dielectric resonator (DR) with a printed strip monopole, which is simply fed inside the horn with cavity back. The combination effect of two radiators produces multiple resonances frequency and provides wideband 51.65% of 10 dB return loss impedance bandwidth centered at 15.1 GHz. The designed HDRIPHA provides an average gain of 15 dBi with flexibility in the impedance bandwidth, and the far‐field radiation characteristics appear to be satisfied within the operating bandwidth. Both simulation and measurement results for the gain, reflection characteristics, and radiation patterns of the designed HDRIPHA over the operating frequency range of 10–18 GHz are presented. The measured results were compared and have been found to have good agreement as predicted in the simulated results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1299–1303, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27586

A MICROSTRIP-FED MULTIBAND SPIRAL RING MONOPOLE ANTENNA WITH IMPROVED RADIATION CHARACTERISTICS AT HIGHER RESONANT FREQUENCIES

A novel approach for the design of a compact multiband monopole antenna for improving radiation characteristics at higher resonant frequencies is presented. The proposed structure consists of a conventional printed monopole loaded with spiral ring resonators and fed by microstrip. When at higher resonant frequency, the electrical length of the conventional monopole antennas is relatively large and the surface currents distribute on the patch periodically which will degrade the omnidirectional property. To achieve good radiation characteristics at the upper bands, two spiral ring strips are inserted into the microstrip line on the difierent layer and connected through via hole. Thus, the direction of surface currents on the spiral ring strips changes with the alteration of spiral structure and their efiects on the radiation pattern are reduced. The radiation pattern is mainly contributed by the surface current on the microstrip line and very good stable radiation pattern can be obtained within all the operating bands. In comparison to the previous printed strip monopole structures, the miniaturized Antenna dimension is only about 28 mm£20 mm£1mm. The experimental results show that the proposed antenna can provide operating bands which meet the required bandwidths speciflcation of 2.4/5.2GHz WLAN and 3.5GHz WiMAX standard. Detailed design considerations of the proposed Antenna are described, and both the simulated and measured results of the proposed Antenna are also presented and discussed.

A COUPLED-FED ANTENNA FOR 4G MOBILE HANDSET

A novel coupled-fed antenna with compact branch- structure for 4G mobile phone is proposed in this paper. In the proposed design, a driven monopole strip and coupled branch- strips are developed to produce difierent operation band. The prototype of the proposed antenna was fabricated, tested and discussed. Simulation and measurement results reveal that the proposed antenna can provide two wide frequency bands (698»960MHz, and 1710»2690MHz), which covers multi-band for LTE700/GSM850/GSM900/DCS1800/PCS1900/UMTS/LTE2300/ LTE2500. The proposed antenna with compact size of 34£12£6:5mm 3 is suitable for today's mobile phone application.

Internal cellular handset antenna with a curved metal pattern for decreased near‐field radiation

AbstractNear‐field radiation characteristics of an internal cellular handset antenna with a curved metal pattern are studied.The antenna's metal pattern comprises a simple strip monopole for the GSM1800/1900 operation. The strip monopole is smoothly curved to avoid right‐angle or abrupt bendings such that smooth variations of the excited surface currents thereon can be obtained. In this case, it is expected that the antenna's near‐field radiation can be decreased. When compared with a corresponding monopole antenna with one or more right‐angle bendings, the obtained results show that the proposed antenna can have lower specific absorption rate values by at least 1.0 dB, which is mainly owing to the decreased near‐field radiation. Detailed results are presented and discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1927–1932, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26958

Compact Coupled-Fed PIFA Employing T-Shaped Monopole with Two Stubs for Eight-Band LTE/WWAN Internal Mobile Phone

A compact antenna for eight-band LTE/WWAN operation internal mobile phone has been proposed in the paper. The proposed antenna is a three-dimensional structure, having a small size 15 × 40 × 3.8 mm3 on the top of the system circuit board. The designed antenna is formed by a T-shaped monopole with two stubs, a coupling strip, shorting strip and branch strip. It can generate two wide operating bands, including not only GSM1800/1900/UMTS2100/ LTE2300/2500 (1710–2690 MHz) but also LTE700/GSM850/900 (698–960 MHz). Based on the system ground plane of the antenna, the desired lower band can be achieved by the coupling strip and shorting strip, meanwhile, optimizing the two stubs of the T-shaped monopole can adjust the lower bandwidth accordingly. While the upper band can be obtained by the branch strip and T-shaped monopole with two stubs. Detailed operating principle and main parameters of the proposed antenna are also studied and discussed in this article. Finally, the simulated and measured results, such as return loss, antenna gain and radiation efficiency, are presented for the proposed antenna to demonstrate the reliability of the scheme.

Integration of monopole slot and monopole strip for internal WWAN handset antenna

AbstractA novel internal handset antenna formed by a monopole slot and a monopole strip for the wireless wide area network (WWAN) operation in the 824–960 and 1710–2170 MHz bands is presented. The monopole strip is disposed in the monopole slot, and both are embedded in the system ground plane of the handset with a small board space of 9 × 40 mm2 at about the bottom edge of the circuit board. The monopole strip serves as a feed for the monopole slot and also functions as an efficient radiator. In the proposed design, the monopole slot generates a quarter‐wavelength slot mode in the antenna's lower band, while the monopole strip contributes its quarter‐wavelength mode in the antenna's upper band. By including a vertical strip that can be enclosed inside the handset casing or be a part of the bezel surrounding, the periphery of the handset casing and connected to the bottom edge of the system ground plane, the impedance matching of the excited slot mode can be greatly improved. In this case, the proposed antenna can provide two wide operating bands with good impedance matching to cover the pentaband WWAN operation. Detailed operating principle of the integrated monopole slot and monopole strip for the internal WWAN handset antenna is described. The proposed antenna is also fabricated and obtained results are presented and discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1718–1723, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26870

A compact asymmetric coplanar strip fed dual‐band antenna for DCS/WLAN applications

AbstractA compact asymmetric coplanar strip (ACS) fed dual‐band antenna suitable for DCS/WLAN applications is presented. Dual‐band operation is achieved by modifying the signal strip of the ACS monopole. Parametric studies indicate that operating frequencies of the antenna are determined by the dimensions of the strip monopole. Measurements on the optimized antenna printed on an FR4 substrate with εr = 4.4 and height = 1.6 mm indicate good radiation characteristics with moderate gain. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1087–1089, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26731

Low‐profile, small‐size, wireless wide area network handset antenna close integration with surrounding ground plane

AbstractAn internal wireless wide area network (WWAN) handset antenna having a low profile of 3 mm, small footprint of 30 × 10 mm2, and closely integrated with surrounding ground plane is presented.The antenna volume is 0.9 cm3 only and can provide two wide‐operating bands to cover the desired 824–960 and 1710–2170 MHz bands. The major portion of the antenna is printed on the main circuit board of the handset, and the antenna has a simple structure formed by a strip monopole and a parasitic shorted strip monopole. Two techniques are applied in the proposed design to achieve penta‐band WWAN operation with a small antenna size. The first technique is to load a proper chip inductor at a proper position in the shorted strip monopole, which supports a resonant mode for the antenna's lower band with a resonant length much smaller than 0.25‐wavelength. The second one is to use a band‐stop matching circuit disposed on the main circuit board of the handset. The combined effects of the two techniques are discussed in this article. Also, the proposed antenna shows low near‐field radiation characteristic and meets the specific absorption rate and hearing‐aid compatibility requirements for practical handset applications. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:623–629, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26633

Compact, printed, dual‐feed, shorted monopole antenna for concurrent 2.4‐ and 5‐GHz WLAN operation

AbstractA compact and printed monopole antenna having two feeding ports to operate in the 2.4‐ and 5‐GHz bands respectively for concurrent dual‐band operation is proposed.The monopole and the ground plane thereof were formed on a single‐layered FR4 substrate of thickness 1 mm and with the dimensions 30 mm × 37 mm. The main radiating element is of a bent, two‐branched strip monopole, placed 2 mm away from the antenna ground. Each branch provides one resonant path such that two operating bands are generated. It was found that by feeding the monopole on the opposite sides with two shorting portions set therein between, the single antenna can be excited by the 2.4‐ and 5‐GHz radio signals at the same time with the port decoupling below −20 dB. The antenna is simple in structure and has constant strip width. Details of the design prototypes are discussed in the article. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:188–193, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26502

Multiresonance coplanar waveguide-fed monopole antennas with meander strips for GSM/GPS/PCS/DCS/WCDMA applications

A multiband multiresonance coplanar waveguide (CPW)-fed monopole antenna is proposed in this article. The antenna consists of various monopole strips of including a meander strip, a w-shape strip, and an m-shape strip for the multiresonance operation and miniaturization of antenna. The operation modes are associated with the length and shape of loading strips, in which the lower frequency bands vary along a long meander and the higher bands along an m-shape. Experimental results showed that the impedance bandwidths of the multiresonant antenna less than −10 dB return loss were 8.4, 2.5, 17.6, and 19.3 % with omni-directional radiation patterns at 860, 1570, 1860, and 2140 MHz, respectively, and those antenna gains were −2.13, −0.77, 1.25, and 2.45 dBi, respectively. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2438–2441, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26276

Small-Size Loop Antenna With a Parasitic Shorted Strip Monopole for Internal WWAN Notebook Computer Antenna

A simple meandered loop antenna with a parasitic shorted strip monopole, both printed on a thin dielectric substrate and folded to occupy a small size of 50 × 10 × 4 mm3, for the internal penta-band WWAN notebook computer antenna is presented. The antenna can provide two wide operating bands to cover the GSM850/900 operation (824-960 MHz) and the GSM1800/1900/UMTS (1710-2170 MHz) operation. The lower band is formed by two resonant modes, one half-wavelength loop mode contributed by the meandered loop and one quarter- wavelength monopole mode contributed by the parasitic shorted strip. The upper band is mainly formed by two higher-order loop resonant modes, with their good impedance matching obtained owing to the parasitic shorted strip. Further, in order to decrease the effects of the display ground and keyboard ground of the notebook computer on the antenna performances, two linear slits are embedded in the keyboard ground near the two connection hinges between the two grounds. The two linear slits function as current traps and can effectively reduce the excited surface currents on the keyboard ground. This leads to decreasing size of the effective notebook computer ground plane seen by the antenna. Thus, degrading ground plane effect on the performances of the internal WWAN antenna can be greatly reduced.

Planar strip monopole with a chip‐capacitor‐loaded loop radiating feed for LTE/WWAN slim mobile phone application

AbstractA small‐size wideband internal mobile phone antenna formed by a planar strip monopole with a chip‐capacitor‐loaded loop radiating feed for achieving eight‐band long term evolution/wireless wide area network operation in the 698–960 and 1710–2690 MHz bands is presented. The antenna is suitable to be disposed on a small no‐ground board space (15 × 45 mm2) of the system circuit board and enclosed by an L‐shaped system ground plane of the mobile phone. On the protruded ground of the L‐shaped system ground plane, a universal series bus connector for the data port of the mobile phone can be accommodated without affecting the antenna performances. The antenna also shows a low profile of 3 mm above the circuit board, which makes it very promising for slim mobile phone applications. The proposed antenna was fabricated and tested. Measured and simulated results are presented. The specific absorption rate results of the antenna are also analyzed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:952–958, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25845

A PRINTED 2.4 GHZ/5.8 GHZ DUAL-BAND MONOPOLE ANTENNA WITH A PROTRUDING STUB IN THE GROUND PLANE FOR WLAN AND RFID APPLICATIONS

The design of a simple microstrip fed folded strip monopole antenna (FSMA) with a protruding stub in the ground plane for the application in WLAN and RFID is presented. The antenna has two resonant paths, one in the radiating element (folded strip) and the other in the protruding stub of the ground plane. It supports two resonances at 2.4 GHz and 5.81 GHz, which are the center frequencies of WLAN and RFID. Effectively consistent radiation pattern and large percentage bandwidth have been observed. The measured percentage fractional bandwidth at 2.4 GHz (2.05 GHz to 2.86 GHz) is 32.99, and the percentage fractional bandwidth at 5.81 GHz (5.55 GHz to 6.14GHz) is 10.11. The proposed antenna is simple and compact in size, providing broadband impedance matching, consistent radiation pattern and appropriate gain characteristics in the WLAN and RFID frequency regions.

PLANAR MULTI-BAND T-SHAPED MONOPOLE ANTENNA WITH A PAIR OF MIRRORED L-SHAPED STRIPS FOR WLAN/WIMAX OPERATION

A novel compact design of planar T-shaped monopole antenna with multi-band operation for WLAN/WiMAX system is proposed. By insetting a pair of mirrored L-shaped monopole strips, multi resonant modes close to 2.45/3.5/5.5GHz band are excited to meet the speciflcations of WLAN/WiMAX system. And, the obtained impedance bandwidth across the operating bands can reach about 160/1100/2690MHz for the 2.45/3.5/5.5GHz bands, respectively. Only with the antenna size of 30£42£0:8mm 3 , the proposed monopole antenna has the compact operation with more than 20% antenna size reduction. The measured peak gains and radiation e-ciencies are about 3.2/3.5/5.4dBi and 72/98/96% for the 2.45/3.5/5.5GHz band, respectively, with nearly omni-directional pattern in the XY -plane.

Planar Printed Strip Monopole With a Closely-Coupled Parasitic Shorted Strip for Eight-Band LTE/GSM/UMTS Mobile Phone

A planar printed antenna comprising a driven strip monopole and a parasitic shorted strip, both of comparable length and closely coupled to each other, suitable for eight-band LTE/GSM/UMTS operation in the mobile phone is presented. The proposed antenna is mainly configured along the boundary of the no-ground portion on the system circuit board of the mobile phone to achieve a simple and compact structure. Also, the edge of the no-ground portion facing the system ground plane on the circuit board is not necessarily a straight line, leading to more degrees of freedom in allocating the required no-ground portion on the circuit board for printing the antenna. The driven strip monopole and the parasitic shorted strip both contribute their lowest and higher-order resonant modes to form two wide operating bands centered at about 830 and 2200 MHz to respectively cover the LTE700/GSM850/900 operation (698-960 MHz) and GSM1800/ 1900/UMTS/LTE2300/2500 operation (1710-2690 MHz).

Small-size printed loop-type antenna integrated with two stacked coupled-fed shorted strip monopoles for eight-band LTE/GSM/UMTS operation in the mobile phone

A small-size internal printed antenna formed by a loop-type antenna integrated with two stacked coupled-fed shorted strip monopoles is presented.The proposed antenna has a small uniplanar structure of 40 × 15 mm2 (600 mm2) for eight-band LTE/GSM/UMTS operation in the mobile phone. The loop-type antenna comprises a driven monopole and a coupled portion short-circuited to the system ground plane of the mobile phone; the driven monopole alone contributes a resonant mode for the antenna's upper band, whereas the driven monopole and shorted coupled portion together provide a loop-type resonant path to generate a resonant mode for the antenna's lower band. Two stacked strips are then integrated with the loop-type antenna, with the two strips coupled-fed by the driven monopole and short-circuited to the ground plane through the shorted coupled portion. That is, two stacked coupled-fed shorted strip monopoles are formed and incorporated with the loop-type antenna in an integrated configuration. The two strip monopoles contribute two additional resonant modes to incorporate those generated by the loop-type antenna to achieve the desired wide lower band (698–960 MHz) and upper band (1710–2690 MHz) for eight-band LTE/GSM/UMTS operation. Details of the proposed antenna are presented. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1471–1476, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25257

Printed Single-Strip Monopole Using a Chip Inductor for Penta-Band WWAN Operation in the Mobile Phone

A single-strip monopole capable of generating two wide operating bands at about 900 and 1900 MHz covering GSM850/900/1800/1900/UMTS penta-band WWAN operation in the mobile phone is presented. The monopole has a simple structure of an inverted-L shape to be printed on the no-ground region of the system circuit board of the mobile phone. By simply embedding a chip inductor at the proper position in the strip monopole, the first two resonant modes of the monopole can have a frequency ratio of about 1 to 2 (instead of 1 to 3 for the traditional monopole) to respectively cover the desired wide 900 and 1900 MHz bands. In addition, the total strip length can be less than the required 0.25 wavelength (about 0.17 wavelength in this design) for the fundamental resonant mode excitation of the proposed monopole; this behavior is owing to the embedded chip inductor compensating for the increased capacitance seen at the feeding point with the decreasing strip's resonant length. The SAR of the proposed monopole placed at the bottom position of the mobile phone is found to meet the SAR limit for practical applications.

Planar Dual U-Shaped Monopole Antenna With Multiband Operation for IEEE 802.16e

A novel compact design of a planar dual U-shaped monopole antenna with multiband operation for the IEEE 802.16e Worldwide Interoperability for Microwave Access (WiMAX) system is proposed. With the use of dual U-shaped monopole strips, multiresonant modes close to 2.6/3.5/5.5-GHz band are excited to meet the specifications of the WiMAX system (IEEE 802.16e) . The obtained impedance bandwidth across the operating bands can reach about 220/1660/1480 MHz for the 2.6/3.5/5.5-GHz bands, respectively. Only with the antenna size of 25×30×0.8 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , the proposed monopole antenna has the compact operation with more than 35% antenna size reduction. The measured peak gains and radiation efficiencies are about 3.5/4.1/5.5 dBi and 68%/66%/95% for the 2.6/3.5/5.5-GHz band, respectively, with nearly omnidirectional pattern in the xy plane.

Chip‐inductor‐embedded small‐size printed strip monopole for WWAN operation in the mobile phone

AbstractA simple small‐size printed strip monopole embedded with a chip inductor for covering all the five operating bands of GSM850/900/1800/1900/UMTS for wireless wide area network (WWAN) operation in the mobile phone is presented. The antenna consists of a chip‐inductor‐embedded longer radiating strip and a shorter radiating strip. With a 10‐nH chip inductor embedded, the longer radiating strip has a length of about 46 mm only (about 0.14 wavelength at 900 MHz), yet supports a wide resonant mode at about 900 MHz for the antenna's lower band to cover GSM850/900 operation. The shorter radiating strip has a length of about 30 mm (about 0.2 wavelength at 2000 MHz) and provides a wide resonant mode at about 2000 MHz for the antenna's upper band to cover GSM1800/1900/UMTS operation. With the five operating bands covered, the two radiating strips occupy a small printed area of about 350 mm2 on the system circuit board of the mobile phone. Details of the proposed antenna are described, and the specific absorption rate results of the antenna are also analyzed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 966–971, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24225