Electromagnetic wave absorption characteristics of H-shaped fractal antenna for dual-band microbolometer and study on the influence of bias line resistivity on microbolometer characteristics

A dual-band microbolometer coupled with an H-shaped fractal antenna, which can detect both infrared (IR) and THz waves simultaneously is proposed. Firstly, the H-shaped fractal antenna for 125 and 500 μm dual-bands is proposed by using the dipole antenna formula and finite element method (FEM) simulation. On the basis of simulation results, the H-shaped fractal antenna for the microbolometer is fabricated and the electromagnetic wave absorption characteristics of it are measured. Transmission measurement successfully confirmed the absorption peaks near the aimed for two wavelengths in the IR and THz regions, respectively. It showed that the proposed microbolometer coupled with the H-shaped fractal antenna is considered as a useful tool for widely separated multi-band detection. Moreover, for the microbolometer design, the influence of bias line resistivity on microbolometer characteristics with two different bias line materials by the FEM simulation is studied. It is observed that the electromagnetic wave absorption characteristics of the microbolometer are affected by the resistivity of the bias line material, especially when the parallel polarised incident wave to the bias line formation direction is irradiated.