HY-70A radio altimeter is a solid-state C-band, frequency modulated continuous wave, constant beat, closed-loop tracking measurement system of radio altimeter. By servo controlling the slope of sawtooth wave modulated by the microwave oscillator, the beat frequency can be kept constant, so as to realize the automatic height tracking. Under the condition of constant beat, the measured height is proportional to the modulation period. The height information can be obtained by measuring and modulating the period, and the height voltage can be converted to output.
HY-70A altimeter has good anti-jamming performance because it adopts narrow-band receiver, its gain can be controlled with altitude, and adopts equivalent spectrum front detection, weighted frequency identification and automatic servo tracking technology. The high-frequency components of the altimeter realize microwave integration, and the low-frequency components realize modular design, which improves the reliability, anti-interference and electromagnetic compatibility of the product.