Pyramidal metamaterial absorber for mode damping in microwave resonant structures

Abstract

In many resonant structures the damping of parasitic or higher order modes is indispensable to guarantee a correct and stable performance. This is particularly true in the microwave region in case of cavities or other resonant systems operating in accelerating structures, where the mitigation of spurious resonance effects is mandatory to achieve high quality particle beams. We present the results on the mode suppression in a real pillbox cavity by inserting a properly designed pyramidal metamaterial that acts as light, small volume damper for specific resonances in the range 3–4 GHz, only slightly perturbing other intrinsic modes. Measurements of the cavity response without and with the metamaterial absorber are presented and compared with full wave simulations. Field distribution for the pillbox intrinsic modes under scrutiny is also presented, showing that damping induced by the metamaterial critically depends on its relative position inside the cavity.

Broadband and High-Efficiency Microwave Absorbers Based on Pyramid Structure

“…However, the low-frequency wavelength is longer, and it is basically not affected by the pyramid tip. The above analysis shows that the high-frequency MWAP and low-frequency MWAP are determined by the pyramid and base, respectively …”

“…To explain the MWAP of pyramid materials, the distribution of electromagnetic fields can clearly show the effects of different frequencies. , Mostly, the local electromagnetic field density can not only reflect the frequency displacement of the absorber but also affect the overall damping, thereby changing the MWAP. Since the pyramid structure with h = 100 mm, a = 20 mm, b = 10 mm, and c = 2 mm is the size in this work, the electromagnetic field distribution of other sizes will not be analyzed.…”

Advancements in 3D-printed architectures for electromagnetic interference shields

“…Typical 3D printing technologies include fused deposition modeling (FDM), 47 digital light processing (DLP), 48 selective laser sintering (SLS) 49 and so on. 3D printing technology can print complex and precise meta structures [50][51][52][53][54][55][56][57] such as honeycomb, [58][59][60][61][62] pyramid, [63][64][65][66][67] and lattice cubes structures. [68][69][70][71][72] These structures combine material characteristics with structural considerations, thereby substantively elevating the electromagnetic shielding performance.…”

Polarization-Insensitive Ultra-wideband Metamaterial Absorber for C-, X- and Ku-bands

“…Metamaterial Absorbers can, broadly, be categorized into single band, multiband [44] and wideband resonant absorbers in microwave, terahertz and optical spectrum [45,46]. Wideband absorbers can be made using multilayered metasurface structures like wedge or pyramidal type meta surfaces [47], frequency selective surfaces (FSS) and fractal structures [48,49]. Each of these has merits and demerits of their own like intricate and laborious fabrication process for multilayered MMAs.…”