Mushroom-like Electromagnetic Band Gap Structure Research Articles

A wideband, thin profile and enhanced gain microstrip patch antenna modified by novel mushroom-like EBG and periodic defected ground structures

This paper presents a wideband, thin-profile and enhanced-gain microstrip patch antenna improved by using a novel mushroom-like Electromagnetic Band Gap (EBG) structure and forming periodic Defected Ground Structures (DGS) on the ground plane. The proposed antenna operates between 9.56 and 14 GHz and has 4.44 GHz–10 dB impedance bandwidth. With A4, the gain of the reference antenna is increased by 64.4%, while a 38% bandwidth is also achieved. The parametric analyses carried out on the metallic part area of the novel EBG patch indicated that when the area of the used EBG patches are approximately three quarters or less of the conventional ones, greater gain values for the designed antenna are obtained. This relation between the EBG patches and the antenna gain can be pointed out as the novelty of the study. The results were analysed by the simulations carried out with CST Microwave Studio and were verified by measurements from manufactured prototypes.

Mushroom like EBG to improve the Gain and Broadband of Patch Antenna for Ku-Band Satellite Application

In order to increase the gain of the patch antenna , a Mushroom-like EBG(Electromagnetic Band Gap ) structure is used . EBG structures enhance the patch antenna’s characteristics of directivity, bandwidth and efficiency . Initially, we determined frequency band gap characteristics of mushroom-like EBG unit cell value by using ANSYS software . The periodic arrangement of such mushroom-like EBG structure was not limited by any inter connecting microstrip lines . Different patches of similar configuration were arranged in a pattern to better improvement in an antenna performance . The final design shows an effective increase in Gain . The current distributions on those metal patches are nearly uniform, allowing for substantial gains throughout the working bandwidth. Keywords—EBG , mushroom-like EBG, ANSYS software ,Broadband .

Wideband and dual-band antennas with band-notched using electromagnetic band-gap structure

This paper presents a single-element microstrip spade-shaped patch antennas with a partial ground plane, integrated with an electromagnetic band-gap (EBG) structure, and fed with a microstrip feedline to achieve wideband, dual-band and band-notched characteristic. Two similar mushroom-like EBG structures built into the wideband antenna were used to suppress a specific band, resulting in dual-band. The wide-band antenna achieved a broad bandwidth of 9GHz from 5-14GHz, with a maximum gain of 6.8dBi. Based on the simulation and measured results, the wide-band antenna offers 89% fractional bandwidth for a voltage standing wave ratio less than 2 (VSWR < 2). The EBG provides a band-notch with a bandwidth 3GHz from 8-11GHz, leaving dual-band with bandwidths of 2GHz and 1.5GHz centred at 7GHz and 11GHz, respectively. Surface current distribution and parametric studies were conducted to better understand the behaviour and influence of the EBG parameters. The simulation results were validated through experimental measurement, and both agreed well. The antennas could be used for 5G wireless communication and filtering.

Design of an omnidirectional transmit/receive antenna pair using mushroom‐like electromagnetic band‐gap structure

This paper presents a transmit-receive (T/R) antenna pair with omnidirectional and broadband radiation performance. The proposed antenna combines a patch with mushroom-like electromagnetic band-gap (EBG) structures. The mushroom structures are utilized to enhance the radiation characteristics such as impedance bandwidth, directivity, and gain. Two T/R antennas with 3 × 3 and 5 × 5 arrays working in K-band are designed and fabricated, the transmit (TX) and receive (RX) antennas are printed on a single-layer grounded dielectric substrate. Both the TX and RX antennas consist of an array of mushroom-like EBG structures around the monopole microstrip antenna, which is loaded with four stubs and fed by a 50 Ω coaxial probe. The dimensions of the fabricated prototype 3 × 3 array antenna are 3.58 λ 0 × 1.61 λ 0 ( λ 0 -the wavelength in free space at 24 GHz). The TX/RX measured impedance bandwidth ( ∣ S 11 ∣ < −10 dB) are 9.58% (23.6 ~ 25.9 GHz), 12.08% (22.8 ~ 25.7 GHz), respectively. The measured peak gain is 3.45 dBi at 24.8 GHz. For the 5 × 5 array antenna, the aperture size is 5.58 λ 0 × 2.61 λ 0 . The measured impedance bandwidth ( ∣ S 11 ∣ < −10 dB) is 9.17% (23.65 ~ 25.85 GHz) and 12.71% (22.65 ~ 25.7 GHz) for the TX and RX, respectively. The measured peak gain increases by nearly 2 dB. Measurement results show that both antennas have a TX/RX isolation level better than 20 dB and achieve monopole-like omnidirectional patterns over its operating frequency band.

Two Novel Meander-Perforated Plane EBG Structures For 5G Applications

With the advance of 5G network, antennas are required to meet better performance as it’s the key element of 5G network. Meta-surface structure has been demonstrated to be an effective method to improve the performances of an antenna. Whereas, most of the meta-surface structures cannot be applied to 5G applications properly according to the recent research. In this paper, we propose two novel meander-perforated plane (MPP) electromagnetic bandgap (EBG) structures which are named TMPP-EBG and GMPP-EBG. The meander-shape slot of TMPP and GMPP is etched on the top and ground layer respectively. The two novel MPP-EBG structures can be applied to millimeter-wave 5G spectrum from 24GHz to 28GHz. Compared with the conventional mushroom-like EBG structure, the simulated results presented that TMPP-EBG enhances the bandwidth of S21 from 1GHz to 2.5GHz with the same size and GMPP-EBG achieves 14% size reduction with the same resonant frequency.

Electromagnetic Absorbing Materials

Electromagnetic absorbing materials can be classified into: conventional absorbers, metamaterial absorbers , and reconfigurable absorbers. This paper includes a short survey on these types and there applications. It also includes the design of a thin electromagnetic absorber. The absorber is based on mushroom-like electromagnetic band gap structure with square patches. A simple procedure is developed to design the absorber. The design is checked by simulation using HFSS package. The effect of changing dimensions of the structure on absorption is evaluated. The results of the parametric study were used to trim the design and get more accurate dimensions of the structure.

Suppression of Wideband Simultaneous Switching Noise Through Application of a Partial Electromagnetic Band-Gap Structure in Multilayer Printed Circuit Boards

Adding mushroom-like electromagnetic band-gap (EBG) structures to split power planes can produce wideband suppression of ground bounce noise in high-speed printed circuit boards. Practical equations are used to estimate the stop-band performance of EBG structures within parallel power planes. In this article, a mushroom-like EBG and power-bus structure are derived using the modified nodal analysis (MNA) method. Equations calculated using the MNA method are easily programmable. The partial EBG structures developed in this article can suppress noise from electromagnetic (EM) interference within parallel plates in the power bus. Several examples below show that similar results can be obtained in measurements, in EM simulations software, and in derived equations. The proposed structure enhanced the suppression of simultaneous switching noise coupling (≤-40 dB) within the range of 260 MHz to 10 GHz.

Radiation control of microstrip patch antenna by using electromagnetic band gap

In this paper, two compact electromagnetic band gap (EBG) antennas are proposed by combining a rectangular antenna with a mushroom-like EBG structure and with a novel triple side-slotted EBG (TSSEBG). Both prototype antennas can scan the main beam in the elevation (E) (−20° < φ < 20°), (−17° < φ < 17°) and horizontal (H) (−18° < θ < 18°), (−15° < θ < 15°) planes, respectively. The main beam scanning was conducted by using band-stop and band-pass properties. The band-stop property was achieved by connecting the vias to the ground plane of the antenna, whereas the band-pass property was realized by disconnecting the same vias, thereby yielding the beam steering into the pass-band sector. Unlike usual beam steering, this technique does not suffer from gain degradation, and the gain of the main lobe is approximately stable for the steering angles. The antenna performance was enhanced due to suppress surface waves. Moreover, the number of vias was reduced significantly in the proposed TSSEBG instead of the mushroom-like EBG. The compact EBG and TSSEBG antennas have directivity (10 and 10.5) dBi, gain (9.86 and 10.16) dB, and efficiencies of 96.5% and 93%, respectively, with the operating frequency at 6 GHz.

Wideband Beam Steering Antenna Array of Printed Cavity-Backed Elements With Integrated EBG Structure

The letter concerns the design of a wideband printed antenna array element based on a cavity-backed patch radiator with an incorporated U-slot. An additional 2 × 3 mushroom-like electromagnetic bandgap structure is introduced in the E-plane in close proximity to the patch element on the same single-layer substrate. The proposed array unit cell design is optimized for operation in the 12% relative bandwidth in C-band and the 80° conical beam steering sector. Both simulated and experimental data demonstrate considerable wideband beam steering performance improvement compared to the basic design (without isolating structure) characteristics, provided by achieved array elements decoupling. Research results predict for the 12% relative bandwidth broadside reflection coefficient magnitude |Γ| ≤ 0.3, and maximum for the 80° conical beam steering sector |Γ| ≤ 0.37.

Radiation pattern control of microstrip antenna in elevation and azimuth planes using EBG and pin diode.

An important issue in wireless communication systems, which is related to the antenna gain degradation in case of changing the main direction of the antenna radiation pattern, this variation is not approval in many communications systems. In order to improve antenna radiation performances, Electromagnetic band gap (EBG) - antenna with radiation pattern control capability is presented. Mushroom-like EBG structure for suppressing surface waves has been combined, with the switching diode to produce the radiation pattern control with improving antenna characteristics of gain, directivity and efficiency. EBG of several cells are surrounded the patch antenna and placed symmetrically for the two opposite sides, generating different radiation patterns control ability in both the elevation (E) (-20° &amp;lt; φ &amp;lt; 20°) and azimuth (Z) planes (−18° &amp;lt; θ &amp;lt; 18°). At the ground plane of antenna the diodes have been switched ON and OFF states, the EBG sector properties in stop band (connecting vias) and pass band (disconnecting vias) are altered. Using CST Microwave Studio (CST MWS) the results show the flexibility in radiation pattern control for the Z and E planes using only four diodes. Antenna directivity of 10 dBi, gain 9.86 dB and efficiency 96.5% at the operating frequency of 6 GHz, more results for all direction has been stated in Table1. Significantly, unlike a conventional beam steering, this method does not suffering from gain degradation and the main lobe gain is approximately constant for all steerig angles.

Mushroom-Like EBG to Improve Patch Antenna Performance For C-Band Satellite Application

In order to suppress the surface waves excitation that are caused by thick substrate in a patch antenna, a mushroom-like EBG (Electromagnetic Band Gap) structure is used. Such structures enhance its characteristics of gain, directivity, bandwidth and efficiency. Firstly, we determined frequency band gap characteristics of mushroom like EBG unit cell value by using CST software with 3mm (0.06λo) for covering 6 GHz. The periodic arrangement of such mushroom-like EBG structures was not limited by any interconnecting microstrip lines. Four columns of EBGs shifted inwards to antenna edges by 0.3mm (0.06λo) or a gap of its design around the patch from the left and right sides. Different configurations were also examined in order to get the better improvement in antenna performance. The final design of this mushroom-like shifted periodic structure shows an effective increase in the directivity by 77%, gain by 108%, bandwidth by 29% and the efficiency by 20% for the antenna. This structure has diversified application possibility for wireless and satellite communications.

Low‐profile high‐gain slot antenna with Fabry‐Pérot cavity and mushroom‐like electromagnetic band gap structures

A novel low-profile high-gain slot antenna based on a modified Fabry-Perot cavity (FPC) and a mushroom-like electromagnetic band gap (EBG) structure is proposed and discussed. The low-profile FPC composed of a planar artificial magnetic conductor and frequency selective surfaces is utilised to enhance gain. Moreover, the mushroom-like EBG structure rather than a traditional reflector is used to reduce the profile and to increase gain. Eventually, an antenna prototype operating at the WLAN system coverage IEEE 802.11a (5.15–5.35 GHz) is fabricated and exemplified to validate high radiation performance. The measured results show that the proposed antenna achieves a high gain of up to 10.6 dBi at 5.25 GHz and an −10 dB impendence bandwidth for S 11 ranging from 5.08 to 5.51 GHz.

Design of Compact 4 × 4 UWB-MIMO Antenna with WLAN Band Rejection

A compact 4 × 4 UWB-MIMO antenna with rejected WLAN band employing an electromagnetic bandgap (EBG) structure is presented in this paper. The MIMO antenna is electrically small (60 mm × 60 mm), printed on a FR4_epoxy substrate with the dielectric constant of 4.4 and a thickness of 1.6 mm. A mushroom-like EBG structure is used to reject the WLAN frequency at 5.5 GHz. In order to reduce the mutual coupling of the antenna elements, a stub structure acting as a bandstop filter is inserted to suppress the effect of the surface current between elements of the proposed antenna. The final design of the MIMO antenna satisfies the return loss requirement of less than −10 dB in a bandwidth ranging from 2.73 GHz to 10.68 GHz, which entirely covers UWB frequency band, which is allocated from 3.1 to 10.6 GHz. The antenna also exhibits a WLAN band-notched performance at the frequency band of 5.36–6.34 GHz while the values of all isolation coefficients are below −15 dB and the correlation coefficient of MIMO antenna is less than −28 dB over the UWB range. A good agreement between simulation and measurement is shown in this context.

A Design of EBG-PIFA for RFID Applications in UHF Band

One of the longstanding problems in planar inverted F antenna (PIFA) is its efficiency, which reduces as PIFA is placed too close to the ground. In this paper a kind of mushroom-like Electromagnetic band gap (EBG) structure with three conductor layers is designed In the UHF band, which has smaller unit cells and thinner thickness compared to classical ones. This kind of mushroom-like EBG structure is used as the reflector of PIFA with capacitor structure. It is demonstrated that PIFAs with EBG grounds have higher radiation efficiency than those with PEC ground. At the same time, no significant changes in the antenna resonance frequency and the radiation patterns are found. The theoretical prediction is well verified by results of both simulation and experiment.

Model and Mechanism of Miniaturized and Stopband-Enhanced Interleaved EBG Structure for Power/Ground Noise Suppression

An interleaved electromagnetic bandgap (EBG) structure is investigated to be with a compact size and wide stopband bandwidth for suppressing power/ground noise in power distribution networks. A design concept of the interleaved EBG structure is given to improve both lower and upper bound cutoff frequencies through varying the pitch of the power and ground vias and validated by measured results. An equivalent circuit model of the 1-D EBG structure is established using transmission-line sections to precisely predict the lower and upper bound cutoff frequencies. Based on the 1-D model, a physical mechanism is found to explain why the interleaved EBG structure can reduce the size and broaden the stopband. As an example, the bandgap of the interleaved EBG structure is in the range from 1.9 to 4.54 GHz. The electrical size, which is normalized to the wavelength in the substrate, and relative bandwidth are 0.071 λ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">gL</i> and 139%, respectively. Unlike other works with tradeoff between size and bandwidth, the interleaved EBG structure can simultaneously achieve substantial improvements on the bandwidth of 51.1% and on the miniaturization of 61.2% compared with the conventional mushroom-like EBG structure.

Bandwidth Enhancement Based on Optimized Via Location for Multiple Vias EBG Power/Ground Planes

The ground surface perturbation lattice (GSPL) structure is investigated to suppress power noise in the power distribution network of mixed signal circuits. In order to enhance the bandwidth of the noise suppression, the GSPL structure is implemented by using multiple vias in the mushroom-like electromagnetic bandgap structure. Under the concept of multiple vias, the lower and upper bound cutoff frequencies of the bandgap are influenced by the position of the vias. An optimum position for the vias is found to achieve maximum stopband bandwidth. In this paper, the stopband mechanism of GSPL structure is investigated and the corresponding equivalent circuit model is proposed to quickly predict the lower and upper bound cutoff frequencies. Suitable test boards are fabricated and measured to demonstrate the accuracy of the design concept. The result shows that there is a good consistency between simulated, modeled, and measured results.

RCS Reduction of Patch Array Antenna by Electromagnetic Band-Gap Structure

In this letter, electromagnetic band-gap (EBG) structure is used to reduce the radar cross section (RCS) of the patch array antenna. The proposition of this method is based on the high impedance characteristic of the mushroom-like EBG structure. The basic patch array antenna is designed with a central frequency of 5.0 GHz while replacing the substrate of the array with the mushroom-like EBG structure. The frequency band in which RCS of the patch array antenna reduced significantly can be adjusted by parameters of the EBG. The backward RCS of the patch array antenna with EBG can be reduced as much as 10 dB compared to that of the conventional array antenna, and the degradation of the antenna performance is not significant.

A Novel Tri-Band Circular Slot Patch Antenna with an Ebg Structure for Wlan/WiMAX Applications

In this paper, an electromagnetic band-gap (EBG) structure is proposed to achieve tri-band operation for a novel circular slot patch antenna, which is suitable for WLAN and WiMAX applications. The proposed antenna consists of a rectangular radiation patch with an etched circular slot, a circular ring, and a mushroom-like EBG structure, all of which are printed on the top side of the substrate. By embedding a circular ring in the circular slot, the antenna can generate two impedance bandwidths. With the use of EBG structure, the proposed antenna can operate in three separate bands. Simulation results are compared with the measurements, and a good agreement is obtained. The measured results show that the 10 dB return loss bandwidths of the proposed antenna are 530 MHz (2.28–2.81 GHz), 470 MHz (3.29–3.76 GHz) and 1250 MHz (4.87–6.12 GHz), which can cover all the 2.4/5.2/5.8 GHz WLAN bands and 2.5/3.5/5.5 GHz WiMAX bands. In addition, a design evolution and a parametric study of the proposed antenna are presented to provide information for designing, modifying, and optimizing such an antenna. At last, good omnidirectional radiation patterns with appreciable gain are obtained over the operating bands.

MINIATURE ELECTROMAGNETIC BAND-GAP STRUCTURE USING SPIRAL GROUND PLANE

An important application of electromagnetic band-gap (EBG) structures is reducing the mutual coupling and eliminating the scan blindness for array antennas. However, some array antennas have small element spacing, and traditional mushroom-like EBG materials are too large. Under this condition, miniature EBG structures are desired for these array antennas. In this paper, a novel method using spiral ground plane is proposed to reduce EBG structure sizes. A low frequency band-gap can be obtained by adjusting the width and length of the spiral arms. An experimental prototype is fabricated to validate the analysis. The measurement results show a good agreement with the simulation data. Compared with traditional mushroom-like EBG structures, the proposed EBG achieves more than 77% size diminution.

STUDY THE EFFECTS OF ELECTROMAGNETIC BAND-GAP (EBG) SUBSTRATE ON TWO PATCH MICROSTRIP ANTENNA

Utilization of electromagnetic band-gap (EBG) structures is becoming attractive in the electromagnetic and antenna community. In this paper, the effects of a two-dimensional electromagnetic band- gap (EBG) Structures on the performance of microstrip patch antenna arrays are investigated using the Ansoft High Frequency Selective Simulator (HFSS TM ). A mushroom-like EBG structure is compared with 2-DEBG Structures. HFSS TM is employed to determine the effects of different Structures on two element microstrip patch antennas array. Two element microstrip patch antenna array on a uniform substrate suffer from strong mutual coupling due to the pronounced surface waves. Therefore, diverse forms of 2-DEBG Structures like: little number of holes, large number of holes, defect mode and different number of mushroom-patches columns structure are discussed. The two element microstrip patch antennas array placed on a defect in the electromagnetic (EBG) substrate that localizes the energy under the antennas. The excitation frequency of the two element microstrip patch antennas array near the resonance frequency of the defect mode can be used to control the coupling between antennas that are placed in an array. The mutual coupling improved by using large number of mushroom-patches columns structure.