Design of Tunable, Thin, and Wide-band Microwave Absorbers.

摘要

Recent development in military and civilian applications requires switchable or tunable radar absorbers, which are very useful in electromagnetic compatibility test facilities, radar camouflage and deception roles, and tagging and asset tracking systems. There are a number of designs for tunable or switchable absorbers available in the literature. Almost all the designs use either liquid crystal materials or diodes to realize the tunability. Unfortunately, the operation bandwidth of most existing tunable absorbers is narrow and the achieved tunable frequency range is very small. Unlike existing tunable absorbers, we realize the tunable absorber through electronically changing its equivalent thickness of the absorber for different frequency bands. The operating principle is verified by theoretical analysis and experiment results. Both simulated and measured results show that this absorber can realize a wide bandwidth and its thickness is less than one-tenth free- space wavelength at the lowest frequency.