Superconductor Devices

Filters are an important ingredient in radio bandwidth quality�"the Q of the filter has
a direct impact on received C/I and transmit energy purity (keeping transmit energy
out of other users’ transmit and receive bands). Superconductor filters deliver very
substantial performance gains in terms of selectivity with relatively little insertion loss.
Practical implementation issues (doubts about the mechanical reliability of cooling
engines) have prevented their widespread deployment to date.
Superconductors can also be used to produce very low noise amplifiers. However,
in practical networks, thermal considerations may limit their application. In parallel,
conventional filter design continues to improve. Better mechanical design and
improvements in materials, including the use of silver plating and other passive techniques
for improving conductivity, deliver year-on-year performance gains.
Network operators are, by nature, quite conservative and are very sensitive to lifecost
liabilities. This prudence tends to prevent aggressive adoption of new technologies,
even when those technologies (on paper) offer substantial performance advantage�"a
protective technology adoption inertia. Superconductors, therefore, rather like smart
antennas, are an educational sell. The customer needs to be convinced of the long-term
cost and performance advantage of a new technology, technique, or process. Products
that are an educational sell suffer from dwell time. Adoption is slow because operators
cannot make up their minds on the technology.
Usually, there are also competing flavors involved�"adaptive or switched beam
antennas, thin or thick film superconductors�"and the customer hears competing and
conflicting claims from different vendors. If a customer has too many choices, he or she
will often make a positive choice: not to choose any of the choices. When benefits
remain unproven, the safest choice is not to make a choice.