L-shaped Strip Research Articles

A Novel CPW-Fed UWB Antenna with Band-Stop Function

A novel coplanar waveguide-fed (CPW) ultrawideband (UWB) antenna with band-stop function is presented in this paper. The proposed antenna comprises a CPW-fed slot rectangular patch with an open stub ground plane, and two inverted L-shaped strip conductors are fabricated on the back plane. The overall size of the antenna is 25 × 25 × 1.6 mm2, and it achieves good impedance matching and radiation gain. Simulated and measured results show that the designed antenna operates at 2.9 GHz–13.08 GHz with band rejection in the frequency band of 7.7 GHz–9.05 GHz for satellite applications, and the proposed antenna is suitable for UWB wireless communication applications.

A NOVEL SINGLE FEED OMNIDIRECTIONAL CIRCULARLY POLARIZED ANTENNA WITH WIDE AR BANDWIDTH

A novel omnidirectional circularly polarized (CP) antenna with single feed is proposed for 2.4GHz WLAN applications. Based on the zeroth-order resonance (ZOR) mode of epsilon negative (ENG) transmission line (TL), the antenna excites uniform vertically polarized E-fleld just as the monopole does. A modifled Alford loop with electromagnetic coupling fed by L-shaped strip consists of four curved branches, which is placed on the top of the antenna and generates an equivalent horizontally polarized magnetic dipole mode. Once the two orthogonally polarized components are equal in amplitude but difierent in phase by 90 - , omnidirectional CP wave can be obtained. The measured results show that the impedance bandwidth (S11 < i10dB) is 6% (2.38{2.53GHz), and the 3-dB axial ratio bandwidth in the azimuth plane is very wide which achieves 54% (1.60{2.80GHz). Additionally, the 3-dB axial ratio beamwidth is over 50 - for radiation pattern in elevation plane. Moreover, the antenna achieves excellent omnidirectional right-hand CP performance with a variation of 0.5dB in the azimuth plane and an average gain over 1.5dB across the operating band, which are well applied to the wireless system.

A NEW COMPACT MICROSTRIP-FED MONOPOLE ANTENNA FOR TRIPLE BAND WLAN/WIMAX APPLICATIONS

A new compact printed tri-band antenna for WLAN/WiMAX applications is presented. The proposed antenna consists of three inverted L-shaped strips whose geometry looks like a bent fork. These strips are attached to the feed line through a horizontal strip. By optimizing the geometries of the inverted L-shaped strips, distinct resonant points can be effectively created for different frequency bands. The overall size of the proposed antenna is 18 × 33 mm 2 . Simulated and measured results show that the presented antenna can cover 2.5/3.5/5.5 WLAN and WIMAX bands with fairly stable radiation patterns. The antenna structure is simple, small, easily configurable and tuneable, and therefore suitable for practical applications.

A circularly polarised planar slot antenna for UWB applications

A printed rectangular slot antenna for circular polarisation (CP) is presented in this letter. The slot is excited by a CPW feed terminated on a circular disc. Inverted L-shaped strips are attached to the corners of the slot to obtain the desired CP characteristics. A slant rectangular slit cut in the circular disc enhances the CP behaviour. The antenna has a measured impedance bandwidth from 2.5 GHz to 15.0 GHz (143%), whereas the measured 3-dB axial ratio bandwidth (ARBW) is from 4.36 GHz to 6.15 GHz (33%). An improved version of the antenna is also proposed with simulated ARBW of 52% (4.35 GHz to 7.4 GHz) and measured ARBW of 44% (4.7 GHz to 7.35 GHz). The antenna can be useful for applications requiring CP over this frequency range and linear (vertical) polarisation over the rest of the impedance bandwidth.

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.

Small pifa for ZigBee and wlan application

A multiband printed PIFA with an I-shaped strip and an inverted L-shaped strip, to be electromagnetic compatible with a nearby conducting box, has been proposed. By introducing a T-shaped strip, the upper band in the WLAN and HIPERLAN/2 bands is obtained. The proposed antenna is successfully simulated, designed, and measured, showing good matched impedance, omnidirectional radiation pattern, and constant gain. For return loss less than 10 dB, the proposed antenna operates at lower band with a bandwidth of 150 MHz for ZigBee operation, and at upper band with a bandwidth of 800 MHz for WLAN and HIPERLAN/2 applications. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1074–1077, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27511

A WIDEBAND MAGNETO-ELECTRIC DIPOLE ANTENNA USING CPW STRUCTURE

A new wideband magneto-electric dipole antenna using coplanar waveguide (CPW) structure is proposed in this paper. The proposed antenna consists of a pair of horizontal triangular patches and two vertically oriented L-shaped strips. By introducing triangular patches working as an electric dipole, the antenna can operate in a wide band. With the use of L-shaped strips equivalent to a magnetic dipole, the antenna is low in proflle. A microstrip feed line is located between the two L-shaped strips to form a coplanar waveguide structure and excite the antenna. By carefully adjusting the gap between the feed line and the strips, the impedance bandwidth can be improved largely. A parametric study is performed to provide information for designing and optimizing such an antenna. A prototype is fabricated and measured. The simulated and measured results show that the impedance bandwidth for SWR less than 2 of the proposed antenna is 58.7% (1.95{3.57GHz). Due to the complementary nature of the antenna, the proposed antenna has a unidirectional radiation pattern with low-polarization and low back-lobe radiation over the whole operating band. Furthermore, the gain of the antenna is stable across the entire bandwidth.

COMPACT TRI-BAND RECTANGULAR MEANDER ANTENNA WITH ASYMMETRICAL L-SHAPED STRIPS FOR WLAN/WIMAX APPLICATIONS

A novel meander antenna with tri-band operation is presented for WLAN and WiMAX applications. The proposed antenna consists of a rectangular meander with two asymmetrical L-shaped strips. The rectangular meander is used for the lower band operation at 2.5GHz. The left L-shaped strip is employed to generate the higher resonant mode at about 5.5GHz, while the right L-shaped strip is employed to create a new resonant mode at 3.5GHz and enhance the bandwidth of the middle band operation. Prototype of the proposed antenna has been constructed and experimentally studied. The measured 10dB return loss bandwidths at the resonant frequency of 2.5, 3.5, and 5.5GHz can be up to 520MHz (2.18{2.70GHz), 800MHz (3.34{4.14GHz) and 830MHz (5.07{5.90GHz), respectively. The antenna is simple in conflguration and has a compact dimension of 37 £ 42 £ 1mm 3 .

A NOVEL TRIPLE-BAND RECTANGULAR RING ANTENNA WITH TWO L-SHAPED STRIPS FOR WIMAX AND WLAN APPLICATIONS

A low-proflle microstrip planar monopole antenna with triple-band operation for WiMAX and WLAN applications is proposed in this paper. The antenna has a simple structure which consists of a rectangular ring patch, two inverted L-shaped strips extending from the rectangular ring patch, and a microstrip feed line. By adding two L-shaped strips on the rectangular ring patch, three resonant modes can be excited independently. The antenna has a simple structure and a compact size of 21 £ 33 £ 1:6mm 3 . The measured i10dB impedance bandwidth of the proposed antenna covers 2.39{ 2.51GHz, 3.26{4.15GHz, and 5.0{6.43GHz, which can fully cover the 2.4/5.2/5.8GHz WLAN bands and 3.5/5.5GHz WiMAX bands. A prototype is fabricated, and then measured. The experimental and simulation results show good impedance bandwidth, radiation pattern and stable gain across the operating bands.

Ultrawideband Dielectric Resonator Antenna With WLAN Band Rejection at 5.8 GHz

A novel compact ultrawideband (UWB) dielectric resonator antenna (DRA) with a band rejection at 5.8 GHz is proposed and studied. The antenna is composed of a thin monopole printed antenna loaded with DR that is housed into a dielectric substrate and an L-shaped parasitic strip connected to the ground plane. The L-shaped strip and metallic sheet are utilized to improve impedance bandwidth. A modified metallic sheet underneath the dielectric resonator has been applied to create a band rejection at frequency 5.8 GHz. The measurement results exhibit acceptable performances in terms of reflection coefficient, radiation pattern, efficiency, and realized gain.

DESIGN OF A COMPACT DUAL BAND ANTENNA FOR WIRELESS COMMUNICATIONS

A compact and planar dual band antenna for wireless com- munication is presented. The impedance bandwidth of the proposed an- tenna can cover Bluetooth (2.4{2.484GHz) and ultrawideband (UWB: 3.1{10.6GHz) bands. It is composed of a semi-bevelled-rectangle patch and a bended L-shaped strip and fed by a microstrip line. The an- tenna is built on a FR4 substrate with only 21mm £ 35mm surface area included the ground plane. Details of the antenna design and the measured results included voltage standing wave ratio, radiation patters, peak gain, etc., are presented and discussed.

Compact Ultrawideband Monopole Antenna With an Inverted-L-Shaped Coupled Strip

We present a compact, ultrawideband, and planar monopole antenna that is composed of a C-shaped radiator and an inverted-L-shaped coupled strip extending from the ground plane. A wideband impedance bandwidth is achieved; the monopole antenna itself operates over a higher frequency range, while an increased electrical length due to the combination of the radiating element with the L-shaped strip operates over a lower frequency range. Furthermore, a coupling effect between both structures improves the impedance matching. The impedance bandwidth measured from 2.3 to 10.8 GHz includes the WiMAX (2.30-2.39, 2.50-2.69, 3.4-3.8, and 5.72-5.85 GHz), WLAN (2.4-2.48 and 5.15-5.875 GHz), S-DMB (2.605-2.655 GHz), and UWB (3.1-10.6 GHz) bands.

Very compact broad band-stop filter using periodic L-shaped stubs based on self-complementary structure for X-band application

Self-complementary structures are used to design a novel compact band-stop filter for X-band applications. By cutting a rectangular slot with five pairs of L-shaped protruded strips inside the slot on the ground plane and by inserting five pairs of L-shaped stubs in the microstrip transmission line, the self-complementary structure is created, hence a constant and flat impedance bandwidth at the X-band can be produced. The operating frequencies of the filter can be easily controlled by changing the dimensions of the protruded L-shaped strips and stubs, without changing the area taken up by the structure. Experimental results show good agreement with simulation results and demonstrate that excellent stop-band performance could be obtained through the proposed band-stop filter.

A compact tri-band patch antenna with notched ground for WLAN/WiMAX communication

A compact tri-band patch antenna resonant at 2.45, 3.5, and 5.5 GHz is proposed for wireless local area network (WLAN)/worldwide interoperability for microwave access (WiMax) applications in this paper. The antenna has an asymmetric structure with total dimension of 25 × 18 × 1.5 mm3, where a C-shaped metal strip and an inverted L-shaped strip are designed as radiation elements. The measured −10 dB return-loss bandwidths cover 2.35–2.5, 3.07–3.85, and 4.6–7 GHz, which meets the IEEE 802.11b/g/a standard for WLAN and IEEE 802.16e standard for WiMax applications. Measured radiation patterns at 2.45, 3.5, and 5.5 GHz also show good agreement with simulated results.

A Printed CPW-Fed Monopole Antenna with Circularly Polarized Characteristic

This letter presents a circularly polarized antenna with a printed monopole structure fed by a coplanar waveguide (CPW) line. Circular polarization (CP) radiation of the proposed design is achieved by introducing an inverted L-shaped strip connected to the square radiation loop and an L-shaped slit embedded in the ground plane. A parametric study has been carried out to investigate the effects caused by different widths and lengths of both the strip and the slit. Both simulated and measured results are provided to validate the CP performance of the monopole antenna.

Conical Beam Array Antenna With Polarization Diversity

This study designed a 2×2 circular disc array antenna with omnidirectional radiation pattern and polarization diversity. Each disc element was located above a circular slot fed by an L-shaped strip, in which the switching between two orthogonal linear polarizations (LP) and circular polarization (CP) were realized by controlling two pin diodes. To allow conical beam for all polarization senses, a meticulously designed cross-shaped feeding network is proposed, and besides showing a suffficient 10 dB return loss bandwidth that covers the 2.4 GHz band of WLAN operation, good cross-polarization level (XPL) were measured when the array operated in all available polarization senses.

Novel dual-band circularly polarized wideband antenna for WLAN and WiMAX

A novel design of dual circularly polarized antenna for application in Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) is proposed in this paper. This antenna characterizes a small size and exact circularly polarized (CP) bandwidths for practical application. A new interdigitated structure is put forward to realize dual-band circular polarization, which is made up of a T-shaped strip and a quasi L-shaped strip. The coupling of the two branches of the strips makes it get two circularly polarized bands, and an L-shaped slot is used to enhance the polarization effect. The measured results show that the impedance bandwidth is approximately 34.4% (2.65–3.75 GHz) for the lower band and 26.5% (4.9–6.4 GHz) for the upper band, and the 3 dB axial ratio bandwidth is successfully covering the WiMAX (3.3–3.6 GHz) and the HIPERLAN/1 (5.15–5.35 GHz).

Wideband circularly polarised antenna on slot-loaded ground plane

A wideband circularly polarised antenna is presented. It features an inverted L-shaped monopole, an inverted U-shaped strip and a slot-loaded ground plane. The ground plane and U-shaped strip share the same layer, and the L-shaped strip is printed in the opposite layer. The U-shaped strip is useful in increasing the return-loss bandwidth, and the slot on the ground is found crucial to widen the axial-ratio bandwidth. With a proper length of the slot, the experimental results show that the antenna has a return-loss bandwidth of 2.0 GHz (2.05–4.05 GHz) and an axial-ratio bandwidth of 1.8 GHz (2.0–3.8 GHz).

A design for circularly polarized ring slot antennas backed by thin grounded substrate

This article presents a design for circularly polarized ring slot antennas backed by a metal plate with a small separated distance.The antenna is excited through a shorted L-shaped coupling strip, and good circular polarization performance can be obtained as long as the vertical arm of the L-shaped coupling strip is properly stretched. Both simulated and measured results demonstrate that the reflector-backed slot antenna gives an opposite polarization sense to its counterpart without the reflector. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1768–1770, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26885

Printed Internal Pentaband WWAN Antenna Using Chip-Inductor-Loaded Shorting Strip for Mobile Phone Application

A compact size on-board printed antenna using capacitive coupled-fed excitation to generate multiple resonant modes for penta-band WWAN operation (GSM850/900/GSM1800/1900/UMTS2100) is presented in this paper. The proposed antenna occupies only a small footprint of 15 × 25 mm2on one corner of the circuit board and a protruded ground of 10 × 15 mm2is displaced with close proximity to the antenna portion. The proposed antenna has a very simple structure which is composed of two separate strips: a loop strip with an inserted chip inductor and an L-shaped feeding strip. The loop strip is shorted to the ground and generates a resonant mode at 890 MHz to cover the GSM850/900 band (824–960 MHz) while the feeding strip contributes to the GSM1800/1900/UMTS210 band (1710–2170 MHz) operation. With such a small size, the proposed antenna can achieve compact integration on the circuit board of the mobile phone, thus the proposed scheme is quite suitable for the slim mobile phone application. Good agreements between simulations and measurements are obtained. Details of proposed antenna are presented and some key parameters are studied.