Computer Modelling of Compact 28/38 GHz Dual-Band Antenna for Millimeter-Wave 5G Applications

A four-element compact dual-band patch antenna having a common ground plane operating at 28/38 GHz is proposed formillimeter-wave communication systems in this paper.Themultiple-input-multiple-output(MIMO)antenna geometry consists of a slotted ellipse enclosed within a hollow circle which is orthogonally rotated with a connected partial ground at the back.The overall size of the four elements MIMO antenna is 2.24λ×2.24λ(at 27.12GHz).The prototype of four-element MIMOresonator is designed and printed using Rogers RTDuroid 5880 withε_(r)=2.2 and loss tangent=0.0009 and having a thickness of 0.8 mm.It covers dual-band having a fractional bandwidth of 15.7%(27.12-31.34 GHz)and 4.2%(37.21-38.81 GHz)for millimeter-wave applications with a gain of more than 4 dBi at both bands.The proposed antenna analysis in terms ofMIMOdiversity parameters(Envelope Correlation Coefficient(ECC)and Diversity Gain(DG))is also carried out.The experimental result in terms of reflection coefficient,radiation pattern,gain and MIMOdiversity parameter correlates very well with the simulated ones that show the potential of the proposed design for MIMO applications at millimeter-wave frequencies.

Compact ultra-wideband monopole antenna with dual-band notched function

A kind of compact ultra wideband （UWB） monopole antenna with dual-band notched function is presented.The proposed antenna,using ＂C＂ and ＂L＂ apertures embedded in the annular ring patch and ground patch,gets two bandnotched characteristics in WiMAX3.5 GHz and WLAN 5.5 GHz.The size of antenna is 24 mm × 36 mm × 1.6 mm.The simulation results show that waveband range of the antenna is 2.7-10.6 GHz for S11 ＜-10 dB and the band-notched wavebands are 3.2-3.8 GHz and 5.1-6 GHz.So it has miniaturization,ultra-band and band-notched characteristics.Meanwhile,the radition pattern,directivety and gain are perfect,which meets the practical need.

Novel dual-band antenna for multi-mode GNSS applications

A novel dual-band antenna is proposed for mitigating the multi-path interference in the global navigation satellite system（GNSS） applications. The radiation patches consist of a shortedannular-ring reduced-surface-wave（SAR-RSW） element and an inverted-shorted-annular-ring reduced-surface-wave（ISAR-RSW）element. One key feature of the design is the proximity-coupled probe feeds to increase impedance bandwidth. The other is the defected ground structure band rejection filters to suppress the interaction effect between the SAR-RSW and the ISAR-RSW elements. In addition, trans-directional couplers are used to obtain tight coupling. Measurement results indicate that the antenna has a larger than 10 d B return loss bandwidth and a less than 3 d B axial-ratio（AR） bandwidth in the range of（1.164 – 1.255） GHz and（1.552 – 1.610） GHz. The gain of the passive antenna in the whole operating band is more than 7 d Bi.

RECONFIGURABLE DUAL-BAND CIRCULARLY POLARIZED MICROSTRIP PATCH ANTENNA FOR WIRELESS APPLICATIONS

A new design of reconfigurable single-feed circular patch microstrip antenna for dual-band circular polarization application is proposed. The dual-band functionality is realized through incorporating cross-slots of equal slot length in the circular patch and utilizing two PIN diodes to switch the slots on or off. A pairs of tuning stubs are used to tune the circular polarization performance. The design process is presented and good results were obtained.

Printed elliptical slot UWB antenna for dual-banded application

Based on the analysis of printed elliptical slot (PES) UWB antenna,a dual-banded PES antenna is designed for WLAN and UWB bands at 2.4 GHz.The design cooperates two important wireless commutation system antennas into one printed antenna.In the design,a circular slot structure is presented,which is suitable for the band ejection.Characteristics of the designed antenna are analyzed and key parameters,such as S11,S21 and VSWR are measured.E-field distribution of the surface is simulated and analyzed.

An Analysis of Mutual Interference in Radar Systems Using Dual-Band (Ka / X) Antennas

An analysis of mutual interfering sources on RF systems using dual-band (Ka / X) radar is presented. The purpose of this paper is to improve operational performance of the system from the point of view of EMC design. The experimental dual-band antenna system have decreased the disturbing effects of most mutual interfering sources.

Experimental Study of Stacked Rectangular Microstrip Antenna for Dual-Band

A dual-band characteristic of stacked rectangular microstrip antenna is experimentally studied. It is a probe fed antenna for impedance matching with 50Ω coaxial cable. This antenna works well in the frequency range (2.86 to 4.63 GHz). It is basically a low cost, light weight medium gain antenna, which is used for mobile communication. The variations of the length and width (1mm) of the stacked rectangular patch antenna have been done. And it is found dual resonance with increasing lower resonance frequency and almost constant upper resonance frequency with increases of the length & width of rectangular microstrip antenna. The input impedance and VSWR, return loss have been measured with the help of Network analyzer.

Analysis of Rectangular Notch Antenna for Dual-Band Operation

In this paper a design of single layer rectangular notch microstrip antenna for dual-band is proposed and experimentally investigated. This antenna is excited by microstrip line. Direct microstrip coupling with proper matching transformer has been used. Design is made for optimized notch dimension for two resonant frequencies. These resonance frequencies change with the variation in length and width of the notch. The input impedance and VSWR have been measured with the help of Network analyzer. It is found that the input impedance and VSWR depends variation in length and width of the notch microstrip antenna.

Aperture Coupled Microstrip Antenna for Dual-Band

This paper presents air gap aperture coupled microstrip antenna for dual-band operation over the frequency range of (2.9 to 6.0 GHz). This antenna differs from any other microstrip antenna with their feeding structure of the radiating patch element. Input signal couples to the radiating patch trough the aperture that exists on the ground plane of microstrip feed line. The dual-band achieved by variation of air gap [2 mm to 6 mm] between single patch antenna and aper-ture coupled microstrip antenna. The main advantage of this type antenna is increased the bandwidth of the antenna as compared to a single layered patch antenna. The two resonant frequencies can vary over a wide frequency range and the input impedance is easily matched for both frequencies. The obtain ratios of resonance frequencies are variable from 2.1 GHz to 1.1 GHz with increasing the air gap between single patch and aperture coupled microstrip antenna. The measured return loss [–14 dB] exhibits an impedance bandwidth of 35%. The input impedance and VSWR return loss have been measured with the help of Network analyzer.

Electromagnetic coupling reduction in dual-band microstrip antenna array using ultra-compact single-negative electric metamaterials for MIMO application

In this paper, an ultra-compact single negative（SNG） electric waveguided metamaterial（WG-MTM） is first investigated and used to reduce the mutual coupling in E ＆ H planes of a dual-band microstrip antenna array. The proposed SNG electric WG-MTM unit cell is designed by etching two different symmetrical spiral lines on the ground, and has two stopbands operating at 1.86 GHz and 2.40 GHz. The circuit size is very compact, which is only λ_0/33.6 ×λ_0/15.1（where λ_0 is the wavelength at 1.86 GHz in free space）. Taking advantage of the dual-stopband property of the proposed SNG electric WG-MTM, a dual-band microstrip antenna array operating at 1.86 GHz and 2.40 GHz with very low mutual coupling is designed by embedding a cross shaped array of the proposed SNG electric WG-MTM. The measured and simulated results of the designed dual-band antenna array are in good agreement with each other, indicating that the mutual coupling of the fabricated dual-band antenna array realizes 9.8/11.1 d B reductions in the H plane, 8.5/7.9 d B reductions in the E plane at1.86 GHz and 2.40 GHz, respectively. Besides, the distance of the antenna elements in the array is only 0.35 λ_0（where λ_0 is the wavelength at 1.86 GHz in free space）. The proposed strategy is used for the first time to reduce the mutual coupling in E ＆ H planes of the dual-band microstrip antenna array by using ultra-compact SNG electric WG-MTM.

Dual-band multi-beam reconfigurable terahertz antenna based on graphene frequency selective surface

In this paper,a dual-band graphene-based frequency selective surface(GFSS)is investigated and the operating mechanism of this GFSS is analyzed.By adjusting the bias voltage to control the graphene chemical po-tential between 0 eV and 0.5 eV,the GFSS can achieve four working states:dual-band passband,high-pass lowimpedance,low-pass high-impedance,and band-stop.Based on this GFSS,a hexagonal radome on a broadband omnidirectional monopole antenna is proposed,which can achieve independent 360°six-beam omnidirectional scanning at 1.08 THz and 1.58 THz dual bands.In addition,while increasing the directionality,the peak gains of the dual bands reach 7.44 dBi and 6.67 dBi,respectively.This work provides a simple method for realizing multi-band terahertz multi-beam reconfigurable antennas.

A compact dual-band radiation system

Complex magnetically insulated transmission line oscillator(MILO),as an important development direction,can enhance the power efficiency and generate dual-band high power microwaves(HPMs).A complex MILO and a preliminary dual-band radiation system have been proposed in our previous studies.However,the axial length of the dual-band radiation system is too long to meet the compact requirements.In this paper,a compact dual-band radiation system is presented and investigated numerically.The compact dual-band radiation system comprises a dual-band cross-shaped mode converter and a dual-band coaxial conical horn antenna.It can convert two coaxial TEM mode microwaves(1.717 GHz and 4.167 GHz)generated by the complex MILO into the coaxial TE11 mode microwaves,and then radiate them into the air.At 1.717 GHz,the gain of the antenna is 17.9 dB,and the total return loss and diffraction loss are 1.50%and 0,respectively.At 4.167 GHz,the gain is 19.4 dB,and the total return loss and diffraction loss are 1.17%and 0.78%,respectively.The power handling capacity of the antenna is 5.1 GW at 1.717 GHz and 2.0 GW at 4.167 GHz.Comparing with the original structure,the length of the dual-band radiation system is reduced by 45.2%.

Frequency-Diversified Space-Efficient Radiating Surface Using Convolved Electric and Magnetic Currents for Highly Dense Multiband Antenna-Frontend Integration

We propose and investigate a methodology based on convolved electric and magnetic currents for the generation of multi-band responses over a space-shared radiating surface.First,a single wideband antenna operation principle based on inter-leaved dipole and slot modes is studied and analyzed using full-wave simulations followed by a qualitative time domain analysis.Subsequently,a 2×2 dual-band radiating unit is conceived and developed by closely arranging single wideband antennas.In this case,multimode resonances are generated in a lower frequency band by a proper convolving and coupling of the magnetic and electric currents realized in the gaps between the antennas and on the surface of the antennas,respectively.This methodology can be deployed repeatedly to build up a self-scalable topology by reusing the electromagnetically(EM)connected radiating surfaces and gaps be-tween the radiating units.Due to the efficient reuse of the electromagnetic region for the development of multiband radiation,a high aperture-reuse efficiency is achieved.Finally,as a proof of concept,a 2×4 dual-band array operating in Ku-and Ka-bands is devel-oped and fabricated by a linear arrangement of the two developed radiating units.Our measurement results show that the proposed antenna array provides impedance and gain bandwidths of 30%and 25.4%in the Ku-band and 10.65%and 8.52%in the Ka-band,respectively.

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.

Filtering antennas: from innovative concepts to industrial applications

A filtering antenna is a device with both filtering and radiating capabilities.It can be used to reduce the cross-band mutual coupling between the closely spaced elements operating at different frequency bands.We review the authors’work on filtering antenna designs and three related dual-band base-station antenna arrays as application examples.The filtering antenna designs include single-and dual-polarized filtering patch antennas,a single-polarized omni-directional filtering dipole antenna,and a dual-polarized filtering dipole antenna for the base station.The filtering antennas in this paper feature an innovative concept of eliminating extra filtering circuits,unlike other available antennas.For each design,the filtering structure is finely integrated with the radiators or feeding lines.As a result,the proposed designs have the advantages of compact size,simple structure,good in-band radiation performance,and low levels of loss,and do not contain complicated filtering circuits.Based on the proposed filtering antennas,single-and dual-polarized dual-band antenna arrays were developed.Separate antenna elements at different frequency bands were used to achieve the dual-band performance.The cross-band mutual couplings between the elements at different bands were reduced substantially using the antenna inherent filtering performance.The dual-band arrays exhibited better performance as compared to typical industrial products.Some of the proposed technologies have been transferred into the industry.

Design of a kind of wideband filtering antenna based on defected ground structure

Given the flaws in traditional cascading design of the filtering antennas, a kind of filtering antenna based on the defected ground structure （DGS） is proposed. It adopts the method of co-design to integrate the filter and the antenna into one substrate, resulting in a miniaturized size of 34 mmx30 ram. In the design, the structure with dumbbell shape is etched on the ground of dual-band antenna, aiming for the low-pass property of the filtering antenna. The simulated results show that the filtering antenna＇s co-design can effectively enlarge the bandwidth of the pass-band and suppress the bandwidth of T-patch, whose pass-band can cover the bandwidths of wireless local area network （WLAN） 21~ GHz, wideband code division multiple access （WCDMA） 2.1 GHz, long term evolution （LTE） 2.3/2.5/2.6/2.8 GHz etc. In addition, the filtering antenna＇s physical module is fabricated and measured, whose test results are basically consistent with the ones of simulation. Moreover, the filtering antenna with liner polarization has a good radiation pattern of omni-direcfion, and can be applied to the terminals of wireless mobile system.