Corporate Research & Development Center

Narrowband Tunable Superconducting Filter

Precise weather observation using a 9 GHz-band weather radar network is expected to mitigate disasters caused by sudden torrential rains in urban areas. To simplify the deployment of a weather radar network, weather radars having a frequency-tuning function are required to suppress radio wave interference between weather radars and make it possible to adjust the radar frequency for easy installation in any location.

In response to this requirement, Toshiba has developed a narrowband tunable superconducting filter for weather radar applications, which has a narrowband characteristic to suppress radio wave interference from adjacent radar frequency channels as well as a wide frequency tuning range exceeding the allocated weather radar frequency band.

The proprietary tunable filter with a coupled microstrip line resonator and dielectric trimmer structure provides an outstanding low-loss property and thus a bandwidth 1/50th as narrow as that attainable with the conventional technology. It was commonly thought that a frequencytuning function with low loss and constant bandwidth would be difficult to realize with conventional technology. However, our innovative technique has achieved a ratio of the tuning range to the bandwidth more than five times higher than the conventional method.

Structure and measured characteristics of narrowband tunable superconducting filter

Structure and measured characteristics of narrowband tunable superconducting filter

Structure and measured characteristics of narrowband tunable superconducting filter