A Graphene-Based Rectangular-Notched UWB Antenna with Reconfigurable Notch

This paper presents an ultra-wideband monopole antenna integrated with a new configuration of electromagnetic band gap (EBG) structure. The operating frequency band of the ultra-wideband antenna is 3.1 GHz–10.6 GHz whereas the dual rejected centre frequencies are 5.2 GHz and 5.8 GHz. These two notched bands are to eliminate interference with wireless local area networks. The new proposed EBG structure is composed of a double inversed U-shape slotted patch and edge-located via. By using this new EBG structure, a high notching selectivity can be achieved for both bands. Compared to conventional mushroom-like EBG structure, the proposed configuration of the EBG structure can reject dual band instead of single band and it is 73 % smaller. The detailed theoretical explanations supported by electromagnetic full-wave simulations and confirmed by experimental measurements are introduced.

Band notched circular monopole antennas for ultra-wide band applications are proposed in this paper. The proposed antennas in this paper can reject worldwide interoperability for microwave access WiMAX band (3.3–3.8 GHz) and wireless local area network WLAN band (5–6 GHz). Antennas utilises mushroom-type electromagnetic band gap (EBG) structures and I-slot embedded edge located via (ELV) EBG structures to achieve band-notched designs. The advantages of band notched designs using EBG structures like notch-frequency tuning, dual-notch antenna designs and stable radiation pattern are also verified. Various antenna designs with slot in EBG structures, variations in placement of EBG structures, number of EBG structures and ELV type EBG structures are simulated. About 30% reduction in size of EBG structures is obtained if conventional mushroom type EBG is replaced by proposed I-slot embedded ELV-EBG structure. Fabricated and measured results are in good agreement with simulated ones.

In this letter, a dual-band dipole antenna, both in the strip and the wired structures, for possible 4G long-term evolution (LTE) and wireless local area network (WLAN) applications is presented. The proposed antenna bandwidth covers the low and the high bands of WLAN (2.4 GHz, 5 GHz) and TD-LTE (1880–2655 MHz) in dual-band frequency, the impedance bandwidth in the low and the high bands are 63% (1.6–3.1 GHz) and 15% (4.75–5.55 GHz) respectively. The omnidirectional radiation patterns are desirable for WLAN and LTE communications. The maximum gains of 6.23 dBi and 5.13 dBi in both WLAN bands are adequate for stable gain applications. To avoiding the dissemination of the outer surface of the coaxial cable a copper cylinder is employed as a balun. Simple structure, use of printed circuit technology and FR4 material in the construction of the proposed antenna make it economical and easily-fabricated. The proposed antenna is also designed with the wired structure for similar purposes. Finally, the strip prototype of the antenna is implemented. Experimental results along with the simulation results have validated the merits of the proposed antenna involving simple and inexpensive structure, simultaneously covering WLAN and LTE frequency bands and almost high and stable gain in both bands.

This paper proposes a reconfigured horn antenna with reduced side-lobe radiation by using electromagnetic band gap (EBG) structure. A mushroom-like structure with a circular-shaped patch as unit cell is designed to achieve a complete EBG. The EBG structure is lined on the metal wall along the E-plane of the horn antenna. This causes the surface waves on the metal wall to be suppressed, resulting in lower side-lobe emission. A conducting wedge is inserted on the gap between the EBG structure and waveguide feed aperture to achieve impedance matching in the antenna. In addition, the proposed horn antenna is suitable for high power systems due to a purely metallic construction of the EBG structure.

In this paper, we present an equivalent circuit (EC) based technique which combined with the numerical method to optimize the EBG structures with simple square-loop frequency selective surfaces (FSSs), they can take on in-phase reflection characteristic in some broad-band electromagnetic band gap (EBG) structures. By using the multilayered FSSs in this type of EBG structure, the surface waves and current could stopped effectively. The geometry and working of the antenna with this EBG structure are detailed and the design method is proposed.

Electromagnetic Bandgap (EBG) structures are increasingly utilized by a variety of microwave and optical devices as filters for unwanted signals. One such application is their incorporation in power distribution network (PDN) of electronic circuits where the EBG structure replaces one of the reference voltage planes thus forming a shielded EBG structure. The EBG induces a wide (on the order of few GHz) omni-directional stopband in the operating frequency range of the PDN which mitigates the so called simultaneous switching noise (SSN) on the power plane. The challenging aspect in designing an EBG for such applications is to achieve a wide stopband centered at low GHz frequencies while maintaining a reasonably small unit cell size and a low profile. Indeed, the dimensions of the unit cell of the EBG structure for low frequency designs can become relatively large with respect to the size of the host dielectric substrate. Therefore, availability of a systematic design approach that can provide a fast and accurate means of performance prediction to enable geometry tweaking and design optimization will be of critical importance in utilizing EBG structures in such applications.

This paper presents a circularly polarized printed circuit board (PCB) patch antenna using mushroom-like electromagnetic band gap (EBG) structure for gain enhancement. Unlike the popular method of using artificial magnetic conductor (AMC) or EBG structure as the ground of the antenna, we place the mushroom-like EBG structure around the patch antenna to avoid increasing the number of PCB layers. The EBG structure works in-phase reflection around 24.25 GHz by optimizing design. Limited by the size of the antenna, only twelve EBG units can be distributed around the corner-cut square circularly polarized patch antenna. Simulation results show that gain of the antenna enhances 0.8 dB and cross polarized gain reduces about 15 dB, moreover, the axial ratio is also improved.

This paper presents a design of a dielectric resonator antenna (DRA) for millimeter-wave applications. An electromagnetic band gap (EBG) structure is used in the antenna design to enhance the antenna characteristics. The simulated with and without EBG results of the designed antenna is calculated to show the parameters such as impedance bandwidth, reflection coefficient, and gain. The parameters of the proposed antenna have improved after the periodic unit cell structure (EBG) introduction. The obtained reflection coefficients of the proposed antenna with and without EBG structure are −30.5 dB and −20.8 dB, respectively. In the presence of an EBG structure antenna shows a peak gain of 25 dBi, which is higher than the without EBG (8 dBi) structure. The designed antenna resonates at 33 GHz with an impedance bandwidth of 700 MHz. The Ansys HFSS software is used to design and simulate the proposed antenna.

In this paper a novel microstrip antenna is proposed using electromagnetic band gap (EBG) structure for mobile and wireless applications. It covers two mobile bands ranging from (2.20–2.29) GHz and (2.29–2.30) GHz. An extremely compact size EBG structure is applied in a square shape. After applying EBG structure to the proposed design, performance characteristics such as percentage bandwidth and return loss enhance by 5.1% and 5% respectively. Also by changing the feed and shorting pole (via) position, the same structure is used for ISM (2.45 ± 0.05) GHz band with resonant frequency 2.45 GHz. The measured and simulated results show very good agreement. The design structure is fabricated using FR4 substrate with dielectric constant 4.4, loss tangent 0.02 and thickness 1.6 mm.

Electromagnetic Bandgap (EBG) structures have been successfully applied for suppressing the Simultaneous Switching Noise (SSN) between the power and ground planes. Aimed at the relative narrow bandwidth and the poor performance in low frequency of the conventional Uniplanar-Compact EBG (UC-EBG) structure, a novel EBG structure formed by adding spiral-shaped metal strips on the conventional UC-EBG is proposed. This new EBG structure significantly enhance the equivalent inductance between the neighboring nuit cells, as well as change the character of the stop-band. Simulation results show that the new EBG structure can achieve a bandwidth reach 4.35GHz.This stop-band is 47.5% wider than the conventional UC-EBG structure, and 17.5% wider than the reference EBG structure in literature. The excellent SSN suppression is achieved between 0.18-4.53GHz in the depth of -40dB.

This paper presents a printed rectangular slot microstrip antenna array of two elements based on an Electromagnetic Band Gap (EBG) structure. The proposed EBG structure is invented to improve the isolation between the radiating elements for multiple-input multiple-output (MIMO) application. Single and two slotted rectangular microstrip antennas are designed on an FR-4 substrate with a dielectric constant (εr) of 4.3 and loss tangent (tanδ) of 0.025 with thickness of 1.6 mm. The proposed EBG structure is designed as one planar row of 24 slots. The proposed array performance is tested numerically using Computer Simulation Technology Microwave Studio (CSTMW) of Finite Integration Technique (FIT) formulations. The antenna performance in terms of reflection coefficient (S11), isolation coefficient (S21), radiation patterns, boresight gain and Envelope Correlation Coefficient (ECC) are investigated before and after introducing the EBG structure to identify the significant enhancements. The proposed EBG structure is located between the radiating antenna elements to reduce the mutual coupling of the proposed antenna array. The edge to edge separation distance of the proposed antennas is λ0/16, where the λ0 is the free space wavelength at 2.45 GHz. The simulated results show a significant isolation enhancement from –6 dB to –29 dB at the first resonant frequency 2.45 GHz and from –10 dB to –25 dB at the second resonant frequency 5.8 GHz after introducing the EBG structure to the antenna array.

An ultra-wideband (UWB) band-stop filter (BSF) is presented using novel design to tune the resonant frequency by micro-electromechanical systems' (MEMS) switch, based on electromagnetic band-gap (EBG) and coplanar-waveguide (CPW) structures. The model of the compact BSF is cascaded by three EBG resonators. The BSF is operated from 15 to 20 GHz with good stop rejection and sharp roll off frequency. Its stop rejection levels are −30 dB in both the lower and upper stop-band, and return loss is less than 0.5dB in the stop-band. A tunable BSF is designed by tuning the frequency using a folded MEMS switch. The center frequency of stop-band of BSF is changed from 5 to 15GHz, by tuning the switch height of MEMS switch.

Patch antenna arrays are used extensively due to their low profile structure, light weight and low cost. Patch antenna arrays have been widely used for a variety of wireless applications. However, a major drawback of this type of antenna arrays is mutual coupling and bandwidth. Mutual Coupling losses can be reduced effectively by placing Electromagnetic band gap (EBG) structures, also called photonic band gap (PBG) structures. In this paper, different types of Electromagnetic Band Gap (EBG) structures are proposed to be placed in between the patch antenna arrays to reduce the mutual coupling loss. These EBG structures are designed as small as possible because of system compactness. Hence the design of novel compact hybrid EBG structures are more challenging for wireless applications. In this paper various hybrid EBG structures showed with and without vias are compared with the defined antenna parameters.KeywordsEBG structurespatch antenna arraysmutual coupling lossstructure realizationband passstop bandcompact sizebandwidthvias

A novel and compact planar ultra wide band (UWB) filter is presented. Stepped impedance resonator (SIR) is used as multi mode resonator (MMR). MMR is fed by inter digital coupled lines. Coupled lines are designed such that to ensure low insertion loss over a wide frequency range. SIR (i.e., MMR) produces three resonant modes in the UWB frequency range ensures wide pass band. To avoid the potential interference caused by the co-existing wireless services is mitigated by incorporating band notch characteristics. In addition to UWB pass band, GSM 1800 band for GSM mobile communication with center frequency at 1850MHz is also achieved. Filter exhibits narrow pass band from 1800MHz to 1950MHz and UWB pass band from 3.5 GHz to 10 GHz with reference to 3 dB. At band notch frequency filter exhibits high attenuation level up to 40 dB and ensures less interference caused by co-existing wireless local area network (WLAN) band from 5.6 GHz to 5.9 GHz. GSM 1800 Band is obtained by loading shorted stub to the MMR without disturbing the UWB pass band response. S-parameters of the filter depict good UWB characteristics along with GSM 1800 pass band. Proposed filter is designed based on RT/Duroid 5880 substrate with dielectric constant 2.2 and thickness 0.785 mm. Proposed filter design is aimed to be a compact over reported UWB filter (i.e., surface area of 0.24λ 0 × 0.14λ 0 (Where λ 0 is the free space wavelength at the 6.85 GHz)).

This paper presents a way in which a broadband EBG structure can be formed by stacking uniform EBG (electromagnetic band gap) structures. The design is validated by using it with a broadband monopole antenna. The paper shows the applications of stacked EBG structure. The performance of the antenna with the stacked EBG is compared with that of a uniform EBG.