skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Broadband and Tunable Microwave Absorption Properties from Large Magnetic Loss in Ni–Zn Ferrite
Abstract Highly effective electromagnetic (EM) wave absorber materials with strong reflection loss (RL) and a wide absorption bandwidth (EBW) in gigahertz (GHz) frequencies are crucial for advanced wireless applications and portable electronics. Traditional microwave absorbers lack magnetic loss and struggle with impedance matching, while ferrites are stable, exhibit excellent magnetic and dielectric losses, and offer better impedance matching. However, achieving the desired EBW in ferrites remains a challenge, necessitating further composition design. In this study, impedance matching is successfully enhanced and EBW in Ni–Zn ferrite is broadened by successive doping with Mn and Co , without incorporation of any polymer filler. It is found that Ni0.4Co0.1Zn0.5Fe1.9Mn0.1O4material exhibits exceptional EM wave absorption, with a maximum RL of −48.7 dB. It also featured a significant EBW of 10.8 GHz, maintaining a 90% absorption rate (RL < −10 dB) for a thickness of 4.5 mm. These outstanding properties result from substantial magnetic losses and favorable impedance matching. These findings represent a significant step forward in the development of microwave absorber materials, addressing EM wave pollution concerns within GHz frequencies, including the frequency band used in popular 5G technology.  more » « less
Award ID(s):
1916707
PAR ID:
10496054
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Advanced Materials Technologies
Volume:
9
Issue:
6
ISSN:
2365-709X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; (, Advanced Materials Interfaces)
    Abstract Organic metal halide hybrids have attracted tremendous research interests owing to their outstanding optical and electronic properties suitable for various applications, including photovoltaics, light‐emitting diodes, and photodetectors. Recently, the multifunctionality of this class of materials has been further explored beyond their optical and electronic properties. Here, for the first time the microwave electromagnetic properties of a 1D organic metal halide hybrid, (C6H13N4)3Pb2Br7, a single crystalline bulk assembly of organic metal halide nanotubes, are reported. Good microwave absorption performance with a large reflection loss value of −18.5 dB and a threshold bandwidth of 1.0 GHz is discovered for this material, suggesting its potential as a new microwave absorber. This work reveals a new functionality of organic metal halide hybrids and provides a new material class for microwave absorption application studies. 
    more » « less
  2. ; (, IEEE SoutheastCon 2021)
    A microwave absorber is designed with a given absorbing material whose relative permittivity and permeability are known. In this design process, impedance matching between absorber and free space is achieved by circular metal patches of predesigned shape printed periodically on absorbing material. Designed microwave absorber along with predesigned designed metal strip is modeled in 3D electromagnetic simulation software HFSS. Simulated frequency response of reflection coefficient verifies impedance matching and absorption at design frequency. 
    more » « less
  3. ; (, IEEE Southeastcon 2022)
    A theoretical analysis is conducted to understand the role of dielectric loss component in the design process of a microwave absorber. The analysis starts with the determination of input impedance of the absorber and equating this to free space impedance in order to develop the impedance matching equation. The result of analysis showed that absorbing material must have some amount of loss component for impedance matching at a certain frequency and for perfect impedance matching a specific value of loss factor is required along with specific value of dielectric constant and material thickness. 
    more » « less
  4. ; ; ; ; ; ; ; ; ; (, Scientific Reports)
    Abstract This work is on the design, fabrication and characterization of a hexagonal ferrite band-pass filter that can be tuned either with a magnetic field or an electric field. The filter operation is based on a straight-edge Y-type hexagonal ferrite resonator symmetrically coupled to the input and output microstrip transmission lines. The Zn2Yfilter demonstrated magnetic field tunability in the 8–12 GHz frequency range by applying an in-plane bias magnetic fieldH0provided by a built-in permanent magnet. The insertion loss and 3 dB bandwidth within this band were 8.6 ± 0.4 dB and 350 ± 40 MHz, respectively. The electric fieldEtunability of the pass-band of the device was facilitated by the nonlinear magnetoelectric effect (NLME) in the ferrite. TheE-tuning of the center frequency of the filter by (1150 ± 90) MHz was obtained for an input DC electric power of 200 mW. With efforts directed at a significant reduction in the insertion loss, the compact and power efficient magnetic and electric field tunable Zn2Y band-pass filter has the potential for use in novel reconfigurable RF/microwave devices and communication systems. 
    more » « less
  5. ; ; ; ; (, IEEE Access)
    This paper introduces a novel design methodology for a dual-band branch-line coupler (DBBLC) that, for the first time, facilitates practically unlimited band ratio, enhanced flexibility in power division, and arbitrary port termination impedance concurrently. This approach ensures precise power distribution, matching, and isolation requirements by utilizing a generalized coupler core paired with an L-section impedance-matching network. This paper details an innovative and comprehensive analytical strategy for DBBLC design, which overcomes the limitations noted in prior research by deriving a generalized formula for the power division ratio (k) and simplifying the design equations to decrease complexity. This method enables the simultaneous realization of varied power division ratios, frequency ratios (r), and port impedances ( Zp ), thus offering remarkable design versatility. The effectiveness of this new analytical design methodology is corroborated through several design examples. Moreover, two prototype models operating at 1 GHz/2.5 GHz ( r=2.5,k=0 dB) and 1 GHz/2 GHz ( r=2,k=4.77 dB) frequencies, constructed on Rogers’ RO4003C substrate, exhibit >22 dB return loss, <0.64 dB amplitude imbalance as well as <1° phase imbalance of the transmission parameters and >25 dB isolation at all the targeted frequencies. Therefore, the development and validation of this new DBBLC structure, as demonstrated by the strong correlation between our simulated and experimental findings, not only surpasses the capabilities of existing models, but also broadens the applicability of dual-band couplers in modern wireless communication systems. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email