Uniplanar Compact Electromagnetic Bandgap Structure Research Articles

Curvature-Adaptive Compact Triple-Band Metamaterial Uniplanar Compact Electromagnetic Bandgap-Based Printed Antenna for Wearable Wireless and Medical Body Area Network Applications

A novel, compact, monopole apple-shaped, triple-band metamaterial-printed wearable antenna backed by a uniplanar compact electromagnetic bandgap (UC-EBG) structure is introduced in this paper for wearable wireless and medical body area network (WBAN/MBAN) applications. A tri-band UC-EBG structure has been utilized as a ground plane to minimize the impact of antenna radiation on the human body and improve antenna performance for the proposed wearable antenna. Metamaterial triangular complementary split ring resonators (TCSRRs) are incorporated into the antenna and UC-EBG structure, resulting in a compact UC-EBG-backed antenna with an overall size of 39 × 39 × 2.84 mm3 (0.41 λg × 0.41 λg × 0.029 λg). The printed textile antenna operates at 2.45 GHz for the wireless local area network (WLAN), 3.5 GHz for 5G new radio (NR), and 5.8 GHz for the industrial, scientific, and medical (ISM) bands with improved gain and high-efficiency values. Furthermore, the performance of the antenna is analyzed on the human body, where three models of curved body parts are considered: a child’s arm (worst case) with a 40 mm radius, an adult’s arm with a 60 mm radius, and an adult’s leg with a 70 mm radius. The results demonstrate that the proposed antenna is an attractive candidate for wearable healthcare and fitness monitoring devices and other WBAN/MBAN applications due to its compact size, high performance, and low SAR values.

Ultrawide-band Wearable Antenna with Uniplanar Compact Electromagnetic Band Gap

Ultrawide-band technology, commonly known as UWB, sends data over a wide frequency range for many applications. WBAN applications use wearable antennas because they have flexible materials and are suitable for telemedicine technology and have many advantages such as small size, lightweight, able to work at a wide enough frequency, easy fabrications, and affordable costs. In this research, the hexagonal patch ultrawide-band monopole planar wearable antenna was designed using Cordura Delinova 2000 textile material for the substrate and copper tape for the groundplane and patch. The Uniplanar Compact Electromagnetic Band Gap (UC-EBG) as a metamaterial was added to the design of the monopole planar antenna in this final project which aims to improve antenna parameters, increase efficiency, and reduce the effects of radiation on the body. From the measurement results on the antenna with the addition of the UC-EBG structure at the bottom of the patch, it produces a 6% fractional bandwidth increase and able to work in the frequency range of 3-10 GHz off-body conditions and 2-11 GHz on-body conditions. In the SAR test at 45 mm, it was found that the value decreased from previously 1.535 W/Kg to 1.31 W/Kg at a frequency of 3.5 GHz and previously from 1.421 to 1.267 W/Kg at a frequency of 5 GHz on a wrist phantom object which is a good value for SAR. The resulting increase in antenna gain after the addition of the UC-EBG structure. The radiation pattern on the antenna is bidirectional.

ENHANCING WEARABLE AND MEDICAL CONNECTIVITY: A NOVEL PRINTED TRIPLE-BAND METAMATERIAL ANTENNA FOR WBAN/MBAN APPLICATIONS

This paper presents a novel, compact, monopole apple-shaped, and triple-band metamaterial printed antenna for wireless body area network (WBAN) and medical body area network (MBAN) applications. The antenna is backed by a tri-band uniplanar compact electromagnetic bandgap (UC-EBG) structure that acts as a ground plane and incorporates metamaterial triangular complementary splitring resonators (TCSRRs). The proposed printed textile antenna operates at 2.45 GHz for wireless local area network (WLAN), 3.5 GHz for 5G new radio (NR), and 5.8 GHz for industrial, scientific, and medical bands. Implementing the UC-EBG structure resulted in a 99% decrease in the specific absorption rate (SAR) values over 1 g and 10 g of tissues and achieved gains of 5.45, 6.09, and 7.63 dBi at 2.45, 3.5, and 5.8 GHz, respectively. Due to its high performance, low SAR values, and compact size of 39 × 39 × 2.84 mm<sup>3</sup> (0.41 λ<sub>g</sub> × 0.41 λ<sub>g</sub> × 0.029 λ<sub>g</sub> ), the proposed antenna is an attractive candidate for wearable healthcare, fitness monitoring devices, and other WBAN/MBAN applications.

Design and Modeling of Hybrid Uniplanar Electromagnetic Bandgap Power Planes for Wide-Band Noise Suppression on Printed Circuit Boards

In this paper, a hybrid uniplanar compact electromagnetic bandgap (UC-EBG) design is proposed with a wide-band noise suppression in power planes of printed circuit boards (PCBs). To achieve wide-band noise suppression, the proposed hybrid UC-EBG design employs a combination of various uniplanar EBG unit cells with different sizes which have different frequency ranges of noise suppression corresponding to the size of the cells. In addition, an analytic model of the EBG unit cell composed of cavity resonant model and meander line inductance is proposed and validated by 3-dimensional field simulation and measurement. To demonstrate the proposed design, a heterogeneous group of unit cells with different sizes was selected and the noise transfer function was compared with that of a conventional UC-EBG structure. The proposed hybrid UC-EBG design is experimentally verified by noise transfer function measurement with a significant expansion of the stopband up to 478 % in comparison to the conventional uniplanar EBG designs with the same area occupation.

Isolation Enhancement in Patch Antenna Array With Fractal UC-EBG Structure and Cross Slot

A compact patch antenna array with high isolation by using two decoupling structures including a row of fractal uniplanar compact electromagnetic bandgap (UC-EBG) structure and three cross slots is proposed. Simulated results show that significant improvement in interelement isolation of 13 dB is obtained by placing the proposed fractal UC-EBG structure between the two radiating patches. Moreover, three cross slots etched on the ground plane are introduced to further suppress the mutual coupling. The design is easy to be manufactured without the implementation of metal vias, and a more compact array with the edge-to-edge distance of 0.22 λ0 can be facilitated by a row of fractal UC-EBG, which can be well applied in the patch antenna array.

A NOVEL UNI-PLANAR COMPACT EBG STRUCTURE

The radiation and propagation characteristic can be improved by the microstrip structure of the electromagnetic band-gap, which is becoming miniaturized today. In order to reduce the in∞uence to the width of the band-gap brought by the miniaturization of the UC-EBG structure, a novel UC-EBG structure is brought out. The band-gap width is guaranteed, meanwhile, the unit length is reduced to 0:1‚g. Results of measurement indicate that this structure is efiectively miniaturized, has an excellent performance, and can be used in the antenna or microwave circuit flelds. The advancement in the wireless communication technology demands highly e-cient and portable devices. So, for the wireless devices, compactness is an attractive feature. But in a compact device a very small space is required to share by various radiation sources. In the planar antenna and circuit technology, mutual coupling between these sources increases. Also, noise level of the system increases, and electromagnetic interferences (EMI) become signiflcant. These efiects degrade the system performances. Excitation of surface wave inside the substrate material of planar circuits afiects the system negatively. To speed up any devices, mutual coupling reduction and suppression of unwanted noises are very important. Electromagnetic band-gap (EBG) structure, which is a periodic structure composed of metal and medium. EBG can show band rejection characteristics when propagating electromagnetic wave. Results of previous researches indicate that the EBG structure can improve the performance of telecommunication systems in many aspects (1{9). A novel Uni-planar Compact EBG (UC-EBG) structure is designed in this letter. This structure is small in size and suitable for portable and compact telecommunication systems. The results of simulation and actual measurement indicate that this UC-EGB structure has a good band-gap characteristic, with a much smaller size than other UC-EGB structures.

Wideband uniplanar compact electromagnetic bandgap structure with diagonal connecting elements

A wideband uniplanar compact electromagnetic bandgap structure with diagonal connecting elements (UC-DEBG) is proposed. Compared with a conventional uniplanar compact electromagnetic bandgap (UC-EBG) structure of similar dimensions with horizontal and vertical connecting elements, the UC-DEBG structure significantly increases the equivalent inductance while decreases the equivalent capacitance, resulting in a much wider bandgap. Dispersion diagram method was used to calculate and compare bandgaps of both structures. Bandstop filters using each structure were simulated and fabricated to demonstrate the effectiveness of the proposed structure. Larger bandgap (31%) was achieved from the UC-DEBG structure over the conventional UC-EBG structure. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:979–983, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26736

Partial EBG Structure with DeCap for Ultra-wideband Suppression of Simultaneous Switching Noise in a High-Speed System

To supply a power distribution network with stable power in a high-speed mixed mode system, simultaneous switching noise caused at the multilayer PCB and package structures needs to be sufficiently suppressed. The uniplanar compact electromagnetic bandgap (UC-EBG) structure is well known as a promising solution to suppress the power noise and isolate noise-sensitive analog/RF circuits from a noisy digital circuit. However, a typical UC-EBG structure has several severe problems, such as a limitation in the stop band's lower cutoff frequency and signal quality degradation. To make up for the defects of a conventional EBG structure, a partially located EBG structure with decoupling capacitors is proposed in this paper as a means of both suppressing the power noise propagation and minimizing the effects of the perforated reference plane on the signal quality. The proposed structure is validated and investigated through simulation and measurement in both frequency and time domains.

Mutual Coupling Reduction in Patch Antenna Arrays Using a UC-EBG Superstrate

Reducing mutual coupling between elements of an antenna array is one of the main topics in array designs. The use of electromagnetic band-gap (EBG) structures built by microstrip technology is an attractive way to mitigate the mutual coupling problem. This letter describes a novel configuration of uniplanar compact electromagnetic band-gap (UC-EBG) structures to reduce mutual coupling between the radiating elements. The idea is to use the UC-EBG structures placed on top of the antenna layer. The main objective is to reduce both the element separation and the mutual coupling between the patch antennas, which in turn increases antenna directivity. The proposed configuration eliminates drawbacks of similar structures presented in previous works.

Compact Ultra-Wideband Bandpass Filter With EBG Structure

Two bandpass filters (BPFs) for ultra-wideband (UWB) applications are proposed using the uniplanar compact- electromagnetic bandgap (UC-EBG) and the foliated UC-EBG (FUC-EBG) structures for size reduction. The sizes of the proposed UWB BPFs are reduced by 20 ~ 22% compared to the conventional one with the microstrip multiple-mode resonator (MMR). Both EBG structures are shown to cause a slow-wave effect, which is required for compactness and the characteristic impedance Z <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</i> close to 50 Omega, which is needed for wideband match.

Enhanced bandwidth uniplanar compact electromagnetic bandgap structure with coplanar meander line inductance

A novel compact electromagnetic bandgap structure is presented. The coplanar meander line inductance is adopted to increase the surface equivalent inductance in order to improve the bandwidth of the bandgap and reduce unit cell size. The measured results show that 54.1% relative bandwidth and 25.2% reduction in resonant frequency could be obtained.

Spatial power amplifier using a passive and active TEM waveguide concept

A new spatial power amplifier is presented in which power is spatially combined within a TEM waveguide using a low-loss transition array of E-plane integrated finlines to microstrip lines. The TEM-mode waveguide is implemented using a periodically patterned surface called a uniplanar compact electromagnetic bandgap (UC-EBG) structure. Our designed Ku-band back-to-back transition array demonstrates a maximum return loss of 17.5 dB and a maximum insertion loss of 0.65 dB. The TEM waveguide is found to have a 1-GHz bandwidth centered at 14.5 GHz. Tuning of the center frequency may be accomplished via an active UC-EBG structure that incorporates varactor diodes. The use of the UC-EBG surface allows more power cards to be inserted within the TEM waveguide since the amplifier cells saturate uniformly. The spatial power combiner is used to combine the output powers of 12 20-mW monolithic-microwave integrated-circuit amplifier chips. The designed power module yields an output power of 23.15 dBm and a combining efficiency of 86%. A comparison between the passive and active UC-EGB surfaces is experimentally demonstrated.