Research progress of low-frequency radar absorbents

With the large-scale application of meter-wave and decimeter-wave low-frequency radars in the military field, aircraft, especially long-range strategic bombers, are facing increasing air threats. In order to improve their survive capabilities, low-frequency radars are used to absorb microwave except the external design. To overcome this difficult point, long-wave microwave absorption materials are one of the key measures for its stealth effectiveness. This article discusses the low-frequency absorbing mechanism, summarizes the applications of traditional absorbing materials at low frequencies, including ferrites, composites, magnetic metal powders, then analyzes various factors that affect low-frequency absorbing performance. Finally, the current development of absorbing materials is explored, and the future development direction of low-frequency absorbent is prospected.