What do the K and ka frequencies of radar signals mean?

Ka frequency, electromagnetic wave with frequency of 26.5-40GHz, K frequency, electromagnetic wave with frequency of 18-26.5GHz.

Ka band is a part of microwave band of electromagnetic spectrum, and its frequency range is 26.5-40GHz. Ka stands for K-above, in other words, the band is just above the k-band. Ka band, also known as 30/20 GHz band, is usually used for satellite communication.

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The difference between ka-band and ku-band

1, ka frequency is higher, and the antenna beam with the same aperture is narrower and more directional, which means that the antenna receives less interference from neighboring satellites. The popular ka satellites in the world all adopt point beam design, and beam switching is needed under the same satellite. Ku is usually a large beam, so it is not necessary to switch under the same satellite.

2. Different from Ku band, the United States allocated a special Ka frequency for government applications, which enabled the government to establish its own satellite constellation system. The famous broadband global communication satellite communication system (WGS) is the product of this policy.

3. The limitation of 3.Ka band is different from that of Ku band. Although Ka-band can obtain better directivity and gain under the condition of fixed antenna size, it will be offset by higher space loss. In addition, for commercial Ka-band, the off-axis EIRP spectral density (ESD) is more strictly limited, which is very important for mobile application systems.

Baidu encyclopedia -Ka band