Dual-band Dual-polarized Antenna Research Articles

DUAL-BAND DUAL-POLARIZED CIRCULAR MICROSTRIP PATCH ANTENNA WITH THE CURVED SLOTS ON THE GROUND

A center-feed dual-band dual-polarized circular microstrip antenna employing the curved slots on the ground is proposed. The proposed antenna radiates ϕ-polarization by introducing 10 units of curved slots symmetrically on the ground and θ-polarization by the coaxial probe at the center. The measured results show that the proposed antenna provides two resonant bands, TM01 and TM02 modes, covering the frequency bands of the WLAN (2.4-2.484 GHz) with an omnidirectional right-handed circular polarized (RHCP) radiation pattern and the WiMAX (3.3-3.6 GHz) with an omnidirectional horizontal polarized radiation pattern, respectively. In addition, the effects of the unit number of the curved slots and the width of the slots on the frequency ratio of these two resonant frequencies are studied. Furthermore, for the low profile of 0.056λ0 and good omnidirectional characteristic, the antenna is suitable for the modern multi-band wireless communication systems.

A Compact Dual-Band Dual-Polarized Loop-Slot Planar Antenna

This letter presents a compact dual-band dual-polarized loop-slot planar antenna. The antenna consists of a rectangular loop, a coplanar waveguide (CPW), and a microstrip line. The dual-band characteristic is realized using two different type resonant modes of the loop-slot antenna, namely, a loop basic mode in the lower band and a slot basic mode in the higher band. A CPW is used to excite vertical polarization modes and a microstrip line is used to excite horizontal polarization modes to achieve dual-polarized performance. The overall dimension of the prototype is only $55 \times 57~\hbox{mm}^{2}$ . The proposed antenna is built and tested. It has two common $-10~\hbox{dB}$ impedance bandwidths of 420 MHz (2.34-2.76 GHz) and 660 MHz (3.22-3.88 GHz) to cover 2.4 GHz WLAN band and 2.5/3.5 GHz WiMAX bands, respectively, and the isolation between the two ports is better than 21 dB in the dual-band. The antenna has stable radiation patterns and gains in both bands. The antenna also has the merits of compact dimension, low cross-polarization, and low cost.

Dual-Band Dual-Polarized Compact Bowtie Antenna Array for Anti-Interference MIMO WLAN

Smart antennas have received increasing interest for mitigating interference in the multiple-input-multiple-output (MIMO) wireless local area network (WLAN). In this paper, a dual-band dual-polarized compact bowtie dipole antenna array is proposed to support anti-interference MIMO WLAN applications. In the antenna array, there are 12 antennas, six for horizontal polarization and six for vertical polarization. In order to achieve dual linear polarizations and beam switching, six horizontal antennas are placed in a sequential, rotating arrangement on a horizontal substrate panel with an equal inclination angle of 60 ° to form a symmetrical structure, while the other six antennas for vertical polarization are inserted through slots made on the horizontal substrate panel. Furthermore, six pairs of meandered slits are introduced to reduce the mutual coupling between horizontal antennas in the lower band. A prototype of the array with a dimension of 150 × 150 × 60 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> is manufactured and exhibits the characteristics of high isolation, good front-to-back ratio, and average gains of 4.5 and 5 dBi over the 2.4- and 5-GHz band, respectively. The MIMO performance of the array is analyzed and evaluated by mutual coupling, the total active reflection coefficient (TARC) and the envelope correlation coefficient. The anti-interference capability of the array is also investigated by the experiment.

Dual-band dual-polarized printed antenna for wireless communication

A novel dual-band dual-polarized antenna design with high isolation and low cross-polarization is presented. An arc-coupled annular ring and a special coaxial-fed slot patch are employed as the radiating elements at lower and upper bands, respectively. Measurements show that the 10-dB impedance bandwidths reach 27.9% (1.66–2.19 GHz) and 18.4% (5.09–6.12 GHz). The port isolation for both bands is better than 30 dB. Moreover, stable and symmetrical radiation patterns at slanted polarizations are achieved, and the measured cross-polarization level is less than dB within the above-mentioned bands.

Design of wideband dual-band dual-polarized dipole for base station antenna

This article put forward a novel dual-band dual-polarized magneto-electric dipole antenna excited by F-shaped strips. The proposed antenna achieved a common impedance bandwidth of 25.5% and 39.5% in the lower and the upper bands at both input ports, ranged from 0.75 GHz to 0.97 GHz and from 1.73 GHz to 2.59 GHz respectively. The antenna has good performance in isolation, which is more than −32 dB between the two input ports, and the gain of the antenna is average 4.3 dB and 7.8 dB in the lower and upper bands. The antenna has a stable broadside radiation pattern with low cross polarization and low back lobe radiation over the operating band. Metallic side walls on the ground are added for better performance in gain and radiation pattern.

Compact Dual-Band Dual-Polarized Antenna for MIMO LTE Applications

A system of two dual-band dual-polarized antennas is proposed. It operates in two bands, 700 to 862 MHz and 2.5 to 2.69 GHz, thereby making it suitable for LTE applications. The design is composed of two compact orthogonal monopoles printed close to each other to perform diversity in mobile terminals such as tablets or laptops. For each band, two orthogonal polarizations are available and an isolation higher than 15 dB is achieved between the two monopoles spaced byλ0/10 (whereλ0the central wavelength in free space of the lower band). A good agreement is observed between simulated and experimental results. The antenna diversity capability is highlighted with the calculation of envelope correlation and mean effective gain for several antennas' positions in different environment scenarios.

Single-Feed Dual-Band Dual-Linearly-Polarized Proximity-Coupled Patch Antenna

In this paper, two novel single-feed dual-band dual-polarized microstrip antennas, fed by proximity coupling, are presented. The first approach begins with a new patch antenna that provides dual-band dual-polarized operation by means of an open-circuit stub, added at the open end of the feed line. By adding a stub to the end of the feed line, one can make an antenna with two resonant frequencies. The first resonant frequency is approximately the same as that in the initial design, but the second frequency depends on the stub's length, the stub's location, and the location of the feed point across the patch's width. Moreover, the variation of the feed-line location with respect to the patch's length has no significant effect on the first resonance frequency, while the second frequency changes. The second approach that is studied to realize a dual-band dual-polarized design utilizes a microstrip-gap proximity-coupled feed mechanism. Further insight is sought through the investigation of the surface-current densities on the proposed patch antennas at their resonant frequencies. The radiation performance - including radiation pattern, cross polarization, and gain - is satisfactory within two bands. The CST simulation results and measurement results showed good agreement with each other.

Single-Feed Dual-Band Dual-Mode and Dual-Polarized Microstrip Antenna based on Metamaterial Structure

A novel single-feed dual-band dual-mode and dual-polarized microstrip antenna based on metamaterial structure is proposed. The composite right/left-handed transmission line (CRLH TL) theory is used to design this antenna. Dual-mode can be obtained by exciting the antenna with a monopolar radiation in the n = 0 mode and a patch-like radiation pattern in the n = +1 mode, respectively. As the geometry of the radiating patch does not affect the infinite wavelength mode, circular polarization (CP) is obtained for the n = +1 mode by truncating the square radiating patch with the n = 0 mode, linear polarization (LP) staying unchangeable. Results of a fabricated one illustrate that this antenna is valuable in practical application for its low-profile, easy fabrication, radiation pattern selectivity and polarized diversity.

A Dual-Band High-Gain Resonant Cavity Antenna With Orthogonal Polarizations

In this letter, a new study on the theory and the design of a dual-band dual-polarized high-gain resonant cavity antenna (RCA) is presented. The RCA includes two layers of orthogonal dipole arrays each located at a designated height above the ground plane of a microstrip patch antenna. A prototype is fabricated, and the measured results confirm the theory. The measured prototype has a lower-band gain of 19.6 dBi with the vertical polarization (V-pol) at 10 GHz and the upper band gain of 18 dBi with horizontal polarization (H-pol) at 11.6 GHz. The cross polarization (Xpol) is better than -27 dB at each band. It is demonstrated that the separation between the two bands is controlled arbitrarily.

Dual Polarized Array Antenna for S/X Band Active Phased Array Radar Application

A dual-band dual-polarized microstrip antenna array for an advanced multi-function radio function concept (AMRFC) radar application operating at S and X-bands is proposed. Two stacked planar arrays with three different thin substrates (RT/Duroid 5880 substrates with e r =2.2 and three different thicknesses of 0.253 ㎜, 0.508 ㎜ and 0.762 ㎜) are integrated to provide simultaneous operation at S band (3～3.3 ㎓) and X band (9～11 ㎓). To allow similar scan ranges for both bands, the S-band elements are selected as perforated patches to enable the placement of the X-band elements within them. Square patches are used as the radiating elements for the X-band. Good agreement exists between the simulated and the measured results. The measured impedance bandwidth (VSWR≤2) of the prototype array reaches 9.5 % and 25 % for the S- and X-bands, respectively. The measured isolation between the two orthogonal polarizations for both bands is better than 15 ㏈. The measured cross-polarization level is ≤?21 ㏈ for the S-band and ≤?20 ㏈ for the X-band.

Circular formed dual-band dual-polarized patch antenna and a method for designing compact combined feed networks

Firstly, a novel method of designing compact combined feed networks is introduced here to convert 4-port Dual-band Dual-polarized Patch Antenna (DDPA) into 2-port DDPA. It is shown that by using this method excitation of unwanted modes is blocked and good return losses for operation bands of the obtained 2-port DDPA are achieved. The calculations of method are based on transmission line model. Secondly, a 4-port aperture coupled DDPA is presented in new circular form; GSM and DCS bands are chosen as operation bands. Then, the introduced method in the first section is used to the 4-port DDPA presented in the second section and a compact 2-port DDPA suitable for application in GSM/DCS systems is obtained. Details of the design and the experimental results are presented.

Progress in dual-band dual-polarization shared-aperture SAR antennas

The progress in dual-band dual-polarization (DBDP) shared-aperture antennas for the synthetic aperture radar (SAR) application in the last decade is reviewed. Several designs of DBDP SAR antenna arrays are introduced with their main performances, then their comparison is summarized. In addition, some techniques enhancing DBDP antenna performances are presented.

DUAL-BAND DUAL-POLARIZED ARRAY FOR WLAN APPLICATIONS

This paper presents a dual-band dual-polarized antenna array design for WLAN applications. Four double-dipole elements are orthogonally interleaved to facilitate operation in both the standard WLAN frequency bands (IEEE 802.11b and IEEE 802.11a) simultaneously. The two linear polarizations have separate ports. The presented design is characterized by dual-band operation, reasonably good front-to-back ratios, average gains of 5.2dBi and 6.2dBi over the 2.4 and 5.2GHz bands respectively, stable end-flre radiation patterns and very low cross-polarization levels.

Design of an S/X dual-band dual-polarised microstrip antenna array for SAR applications

A novel design of dual-band dual-polarised microstrip antenna arrays for synthetic aperture radar applications with a frequency ratio of about 1:3 is presented. Stacked microstrip dipoles and square patches are used as the radiating elements at S- and X-bands, respectively. The microstrip dipoles are proximately coupled and the square patches are probe-fed. Experimental data show good agreement between simulated and measured results. The measured impedance bandwidth (VSWR≤2) the prototype array reaches 8.9% and 17% for S- and X-bands, respectively, and the measured isolation between polarisations for both bands are better than −20 dB. The measured crosspolarisation level is ≤−26 dB for the S-band and ≤−31 dB for the X-band. The work verifies the practicability of the dual-band dual-polarised microstrip antenna array design, using the combination of microstrip dipoles and patches, and good bandwidth and isolation performance of the prototype array has been achieved.

Dual-band dual-polarised microstrip antenna array for SAR applications

A novel dual-band dual-polarised microstrip antenna array for synthetic aperture radar applications with a dual-frequency ratio of about 1:3 is presented. Microstrip dipoles and square patches are used as the radiating elements at S- and X-bands, respectively. The measured bandwidth of VSWR<2 reaches 8.9% and 17% for S- and X-bands, respectively. The measured cross-polarisation levels are <−26 dB for the S-band and <−31 dB for the X-band.

PBG‐assisted shared‐aperture dual‐band aperture‐coupled patch antenna for satellite communication

AbstractDesign and development of a photonic bandgap (PBG)‐assisted shared‐aperture dual‐band orthogonal aperture‐fed rectangular microstrip patch antenna element, which is suitable for a portable very small aperture terminal (VSAT), are presented in this paper. The dual‐band dual‐polarized antenna element achieves 21% input impedance bandwidth at the S‐ and C‐bands. A comparison of the antenna with and without 2D PBG grids shows that the inclusion of PBG structures (PBGSs) improves the antenna performances. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 289–292, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20968

A DUAL-BAND DUAL-POLARIZATION MICROSTRIP ANTENNA ARRAY PROTOTYPE

A compact, lightweight, dual-band dual-polarization antenna array prototype is developed as a demonstration of advanced design concept for use in future's synthetic aperture radar (SAR) antenna systems. The radiator elements share the same radiation aperture and minimize the dimensions of the planar antenna array. Parasitic windowed patch and patch elements are used to extend the operating bandwidth. Balanced feed line schemes of probe type and slot coupling are applied to increase the polarization purity. Dummy slot technique is developed to reduce the cross polarization level and the complexity of feeding lines. Good agreement between measured data and predicted results validates the design approach.

A compact dual‐band dual‐polarized antenna element for GSM/DCS/UMTS base stations

AbstractA dual‐band dual‐polarized antenna suitable for operation in telecommunication base stations is presented. One of the bands covers the GSM band, while the other covers both the DCS and UMTS bands. The design is compact and yields good radiation characteristics, with excellent isolation between polarizations and bands. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 29–33, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11277

A compact dual-band dual-polarized patch antenna for 900/1800-MHz cellular systems

A novel compact design for achieving dual-band dual-polarized radiation suitable for applications in the 900/1800-MHz cellular systems is presented. The proposed antenna consists of a rectangular ring patch (for the 900-MHz operation) and a notched rectangular patch (for the 1800-MHz operation), which are printed on the same layer, and each patch is aperture-coupled by two H-shaped coupling slots to generate two orthogonal linearly polarized waves. By further incorporating a properly designed feed network, the proposed antenna shows good port decoupling of less than -39 dB and -34 dB for dual linear polarizations in the 900- and 1800-MHz bands, respectively. Details of the antenna design and experimental results are presented.

Very small aperture terminal broadband shared-aperture planar antennas

The design and development of a shared-aperture dual-band, dual-polarized, dual-aperture coupled rectangular microstrip patch antenna element is presented, which is suitable for portable very small aperture terminals. Detailed parametric studies of the locations of orthogonal coupling slots and their influences on the isolation and impedance bandwidth of the antenna element are performed. The experimental results are presented. The prototype dual-band dual-polarized antenna element achieves a 21% input impedance bandwidth at the S- and C-bands. The design and development of a four-element array with such an antenna element is also presented. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 13: 180–193, 2003.