The MY-70A radio altimeter is a solid-state C-band radio altimeter system based on frequency-modulated continuous wave (FMCW) technology, featuring constant beat frequency and closed-loop tracking measurement. It maintains a constant beat frequency by servo-controlling the slope of the sawtooth wave that modulates the microwave oscillator, thereby achieving automatic altitude tracking. Under the condition of a constant beat frequency, the measured altitude is proportional to the modulation period; thus, altitude information can be acquired by measuring the modulation period, and the system then converts this information into an altitude voltage for output. The MY-70A altimeter boasts excellent anti-jamming performance, thanks to its adoption of a narrow-band receiver (with gain adjustable according to altitude), as well as technologies including equivalent spectrum front-end detection, weighted frequency identification, and automatic servo tracking. Additionally, the altimeter’s high-frequency components are implemented with microwave integration, while its low-frequency components utilize a modular design—these measures collectively enhance the product’s reliability, anti-interference capability, and electromagnetic compatibility.