lutful... of ideasPremium
join:2005-06-16
Ottawa, ON Reviews:
 ·TekSavvy DSL
| You can use 2 prisms to build a variable attenuator for 60-90Ghz ... this method was actually invented in the 1890s by microwave/wireless pioneer Jagadish Chandra Bose.
When the prisms are widely separated, total internal reflection takes place and the incident radiation is reflected inside the dielectric. When the 2 prisms touch, radiation propagates unhindered through both prisms. By introducing a small air gap, the combination becomes a variable attenuator to incident radiation;
Bose investigated this prism attenuator experimentally; his results were published in the Proceedings of the Royal Society in November, 1897 [8]. Schaefer and Gross [16] made a theoretical study of the prism combination in 1910; the device has since been described in standard texts.
The higher the dielectric constant of the material (which can be glass, plastic or even styrofoam) the better it will be for high power outdoor radios. |
