A novel broadband EBG using cascaded mushroom‐like structure

Abstract

In order to test the influence of the drop channel to its adjacent channels, we input three adjacent channels which satisfy the specification of the 100 GHz DWDM system. Figure 7 shows three channels in the tunable range (1543-1546 nm) without drop any one. Then we drop the middle of the three channels, and the Figure 8 shows the measured spectrum.From the Figure 8 we can see that the drop channel has not any damnification to the adjacent channels, and the adjacent channel isolation degree N is more than 35-dB. CONCLUSIONSIn this article, we have developed a novel stack of 100 GHz DWDM four cavities interference narrowband thin film angletuned filter and a novel three-port tunable filter. It has a simple structure, stable transmission characteristics, simple light path and it is easy to be fabricated. As the novel stack is optimized, the tunable filter has eliminated the phenomenon of polarization light central wavelength separation and its polarization dependent loss is very low (Ͻ0.1-dB). The experiments demonstrate that its insertion loss is very low (Ͻ2-dB), its adjacent channel isolation degree is very high (Ͼ35-dB), and its effective tunable range of 26 nm. This device has a bright application opportunity for its flexibility, low cost, and wide tunable range. INTRODUCTIONThe electromagnetic band-gap (EBG) structures are periodical cells composed of metallic or dielectric elements. One of the most important properties of EBG structure is to prohibit the propagation of surface wave [1, 2]. Practical applications of EBG structure usually have difficulty in accommodating its physical size, because the period of EBG lattices has to be a half-wavelength at the band-gap frequency. This problem had not been solved until the mushroom-like EBG was proposed by Sievenpiper et al. [3]. Later on, several other novel EBG structures were presented such as uniplanar compact EBG (UC-EBG) [4] and fork-like EBG [5]. These structures have several advantages, such as compact size, low loss, and so on. They can be integrated with antenna to enhance the gain and reduce the backward radiation by suppressing surface wave and improving efficiency [6]. Alternatively, radiating element can be mounted above the EBG structure to form high impedance ground plane (HIP) [7]. However, because of their resonant nature, all of those structures are narrow band, which restricts them to be used in broadband application. The challenge is to produce an EBG structure with wide bandwidth.In this article, two kinds of mushroom-like EBG unit with different radius of via are cascaded to form a novel broadband structure. The effects of the radius of via and unit number on the band-gap are considered using direct transmission method [8]. The simulation and experimental results show that the band-gap of the broadband structure covers the stop-band of the two different uniform configurations with the radius of via changed. The bandgap is enlarged greatly which achieves almost 70%. MUSHROOM-LIKE EBG THEORY AND DIRECT TRANSMISSION METHODThe mushroom-like E...

Experimental Study of the Behavior of an Ebg-Based Patch Antenna Subjected to Mechanical Deformations

“…Then, the antenna radiating elements have to be closer from each other and thus, reducing their mutual coupling arises from such a design constraint. A solution can consist in using metamaterial structures to reduce electromagnetic interactions between the antenna radiating elements, such as EBG structures [1][2][3][4][5][6], Complementary Split Ring Resonator (CSRR) structures [7,9] and/or the planar MTM surfaces [8].…”

“…Then, two open boundaries are set at the two port locations. Figure 2(d) depicts the reflection coefficient S 11 and transmission coefficient S 21 associated with the computed HIS using the method described in [5,6] in the 4-8 GHz frequency range. It shows that the bandgap of the MTM matrix (where the entire surface waves are reflected) is included between 4.7 GHz and 6.3 GHz.…”

“…In this kind of new multi-frequencies antennas, some radiating elements might be close to each other, and an unwanted coupling effects might arise if there is not a suitable distance separating two successive radiating elements. These undesired coupling can be reduced using metamaterial (MTM) structures, such as EBG structures [1][2][3][4][5][6] and/or planar MTM surfaces such as Complementary Split Ring Resonator (CSRR) structures [7][8][9]. Commonly, this kind of EBG (electromagnetic bandgap) structures is used for planar antennal structures but is not optimally designed when deformed due to mechanical loads (except the theoretically study of [4]).…”

Development of Electromagnetic Band Gap Structures in the Perspective of Microstrip Antenna Design

“…As depicted in Figure 3(c), the frequency range with attenuation losses of less than −10 dB or −20 dB is usually considered as the band gap [29]. The other one, directive transmission method, consider a finite number of unit cell into a two port TEM waveguide with periodicity along the main direction of propagation, and transmission result is calculated [32].…”

A Novel Design Approach for Dual-Band Electromagnetic Band-Gap Structure

“…A multi-band structure by utilizing for S-shaped corrugated arms or spiral arms connected to the edge of a square patch was presented in [12] and a dual-band 1-D EBG was analyzed in [13]. Recently, cascaded structure with different radius of via was presented to enlarge the bandwidth of the stopband [14].…”