| 摘要 |
<p>A panel of microwave absorbent material comprises at least one layer of a ferrite substrate, a backing reflector capable of reflecting incident radiation, and means for applying a magnetic field to the substrate. The applied field changes the ferromagnetic resonance behaviour of the ferrite and hence the absorption characteristics of the substrate can be changed. It is possible to produce materials switchable or biasable to negate the absorbent effect of the ferrite layer, enabling the device to switch from an essentially absorbent to an essentially reflective state.</p> |
