Broadband and High-Efficiency Microwave Absorbers Based on Pyramid Structure

Abstract

Microwave-absorbing materials with wide bandwidth and high absorptivity are increasingly playing an important role in overthe-air (OTA) testing. In this work, a kind of pyramid absorbing material was prepared using flame-retardant absorbers as the filler. In addition, a coating was used to further improve the flame-retardant properties of the microwave-absorbing material. To obtain excellent microwave absorption performance (MWAP), a high-frequency structure simulator (HFSS) was adopted to design structural materials. Here, the total height, the base height, the decapitation height of the pyramid tip, the distance between the pyramids, and other parameters were analyzed; then, the actual processing and molding were realized. The MWAP of −30 dB was achieved at 2.7−18 GHz, and the MWAP of −10 dB was also met at 2−18 GHz. In particular, the study also investigated the MWAP of large angle, which can meet the MWAP of −10 dB at 2−18 GHz and MWAP of −30 dB at 4−18 GHz. Most importantly, the absorption mechanism of the pyramid structure was explored. The influence of the tip was proved by the distribution of the electromagnetic field in the pyramid. It can be regarded as a multilayer microwave-absorbing material due to the impedance gradient of the pyramid, which can provide an effective research idea and method for future engineering applications.

Boosting the performance of low‐cost eco‐friendly pyramidal absorbers with a Salisbury screen

“…Furthermore, novel approaches have been undertaken to enhance the absorption level of absorbers. One such approach involves shaping the absorber in a specific pattern [20] and conducting a thorough investigation of the material and shape of the absorber [21]. However, these innovative methods of fabricating absorbers with improved absorption capabilities are not able to improve low-cost eco-friendly pyramidal absorbers.…”

Establishing a unified paradigm of microwave absorption inspired by the merging of traditional microwave absorbing materials and metamaterials

“…While attempts at discretizing continuous MAMs have been made, efficiently expanding bandwidth, achieving optimal outcomes has remained challenging. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] The advent of metamaterial absorbers (MMAs), initiated by Landy's perfect MMA in 2008, 30 introduced a new avenue. Early metal-based MMAs relied on single-order resonance of subwavelength structures, displaying narrowband performances.…”