14 DAY TRIAL // Weather radars are extremely important, due to the fact that they can provide critical weather information for ships, airplanes, etc., thus preparing their crews for what lies ahead. However, these things are typically very large and this is the reason why the people over at Toshiba have announced that the company has developed and delivered the world's first operational weather radar system that replaces electron tubes in the transmitter with a high-power semiconductor module.
The new radar is only one sixth the size of conventional equipment (but it's still rather large, with a minimum installation size of 2 x 2 meters) but offers comparable output power (200 W), along with improved waveband efficiency and enhanced features. The first unit of the new system has been installed at the Hydrospheric Atmospheric Research Center at Nagoya University, Japan. The Nagoya radar operates in the 9GHz frequency band (X-band) and is the first solid-state weather radar to go into practical operation.
While the new weather radar is much more compact and offers much higher performance than conventional systems, it maintains the same level of output power by adopting a combination of gallium nitride (GaN) power field effect transistors (FET) and pulse compression technology, which strengthens peak output power. Implementation of fully digital data processing suppresses the spurious level, allowing the frequency separation required for interference suppression to be shortened to one fourth. This contributes to efficient use of crowded radio frequencies.
The new radar reinforces performance by adding innovative features: dual polarization observation enhances the precision of rainfall estimation by capturing the shape and size of raindrops and cloud; clear-air turbulence observation detects very low levels of signal scattering, enabling to observe air conditions including wind speed even in clear weather, a very difficult task for most weather radars, at distances of up to 64 kilometers.
The new system has a modular structure for the antenna, transmitter and received signal processor, which supports more flexible physical system layout depending on the installation site and operation. As the new radar does not use electron tubes, which have to be periodically replaced and disposed of, it reduces environmental loads, meeting Toshiba's goal of maximizing the eco-efficiency of its products and systems.
Because of the limitation of bandwidth availability with increasing use of radio wave frequency resources, steady demand for solid-state radars is expected, as they can contribute to more efficient use of frequencies. Toshiba will market the new high-power semiconductor-based weather radar in both 9GHz band (X-band) and 5GHz band (C-band) versions, both in Japan and overseas, including sales of individual modules that build the system, but has provided no information on just how expensive its very innovative weather radar will actually be.