The walls and ceiling are made of a transparent veil fabric woven from thin wire. The base is a layer of absorbent sheet on top of reflecting foil. For a better idea of the size and shape of the canopy, we invite you to watch the following video.
The implantable lamp is an A3024Y, which has no tuning capacitor or inductor, and is therefore sensitive to all RF frequencies. The white lamp flashes when it is within a few centimeters of our 2.4 GHz wireless router. Inside the the canopy, however, it never turns on unless we stimulate it with our own RF power. We transmit 146-MHz with a half-wave, telescoping antenna driven by a Command Transmitter (A3023CT) with booster amplifier. The booster amplifier delivers 1.6 W to the antenna and is only 10% efficient, so its black heat-sink vanes get hot to the touch.
We hold the A3024Y between thumb and forefinger and move it at random 30 cm from the transmitting antenna. We obtain 100% reliable reception. We move to range 50 cm and obtain 95% reliable reception. If we hold the A3024Y in our hand, enclosing its two-loop receiving antenna, reception at 30 cm drops to 95% and at 50 cm drops to around 80%. We expect that reception from an implanted A3034Y would be somewhere in between these two tests.
We measure the isolation provided by the canopy enclosure with respect to external interference in the 900-930 MHz range, this being the range used by our SCT system. We are hoping to find that interference power drops by a factor of one hundred within the enclosure, but instead we observe a factor of ten or twenty. For more details and discussion see here.
We are gratified to find that the ISL command transmission works just as well inside the enclosure as outside. We will work on improving the isolation the enclosure offers at the SCT data frequency. We might, for example, try adding a layer of absorber to the ceiling.
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