A new microwave absorber based on antimony-doped tin oxide and ferrite composite with excellent electromagnetic match

Antimony-doped tin oxide (Sn0.9Sb0.1O2, ATO) and W-type barium ferrite (Ba0.9Gd0.1(Zn0.3Co0.7)2Fe16O27) were synthesized by coprecipitation method and polymer adsorbent combustion method, respectively. The microstructures were studied using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the pure ATO with spherical morphology and the pure W-type barium ferrite with hexagonal flake shape were prepared. The complex permittivity and complex permeability of ATO, ferrite and ATO/ferrite composites were analyzed by Agilent 8722ET. It was indicated that ATO had strong dielectric property and ferrite showed superior magnetic performance. An appropriate electromagnetic match was established when the composite microwave absorber contained 50 wt% ATO and 50 wt% ferrite. For the optimized microwave absorber, the maximum reflection loss (RL) was about −19.4 dB at 14.8 GHz. Moreover, the absorption bandwidth reached 3.6 GHz when RL was −10 dB in the measured frequency range of Ku-band.

Research highlights▶ W-type barium ferrite is synthesized by polymer adsorbent combustion method. ▶ Antimony-doped tin oxide is compounded with W-type barium ferrite. ▶ The composite absorber exhibits excellent microwave absorbing properties.