No. 336: A superconducting receive filter to be built in a weather radar system (October 26, 2011)

Toshiba developed a superconducting receive filter to be built in a weather radar system for the observation of torrential downpours. The new filter increased the utilization efficiency by dividing the band frequency into less than one tenth as compared with copper filter. The weather radar system transmits radio waves of a certain frequency to the air and receives signals that reflect on the raindrops and return to the system. Thesystem can monitor an area of about 250 square meters in about one minute by examining the size and figure of raindrops.

The company employed a superconducting material of the yttrium family for the new receive filter. Besides narrowing the bandwidth of the frequency from 40 MHz to 3 MHz, the new system reduced the power loss to one fourth with the help of the resonance circuit set up that used the superconducting material. Although it is necessary to cool down the circuit to minus 200 degrees centigrade by the accessory freezer, the capacity of the new filter is 10 liters, 65% smaller than the capacity of the existing copper filter. Because of the increased frequency of torrential downpours, it is desired to increase the operation of the weather radar system.