Metamaterials have attracted increasing attention in recent years due to their powerful abilities in manipulating electromagnetic (EM) waves. However, most previously reported metamaterials are unable to actively control full-band EM waves. In this paper, we propose a thermo-tunable broadband metamaterial (T-TBM) using paraffin-based composites (PD-Cs) with different phase transition temperatures. Active control of the T-TBM reflection loss peaks from low to high frequency is realized by manipulating the solid–liquid state of the PD-Cs at different phase transition temperatures. The absorption peak bandwidth (where the reflection loss value is less than −30 dB) can be changed, while the broad bandwidth absorption (where the reflection loss value is less than −10 dB) is satisfied by adjusting the temperature of the T-TBM. It is shown that the stagnation of the phase transition temperature of the PD-Cs in the T-TBM provides a time window for actively controlling the EM wave absorption response under different thermal conditions. The device has a broad application prospect in the fields of EM absorption, intelligent metamaterials, multifunctional structural devices, and more.

近年来，由于超材料在操纵电磁 (EM) 波方面的强大能力，它们引起了越来越多的关注。然而，大多数先前报道的超材料无法主动控制全波段电磁波。在本文中，我们提出了一种使用具有不同相变温度的石蜡基复合材料 (PD-Cs) 的热可调宽带超材料 (T-TBM)。通过在不同相变温度下操纵 PD-C 的固-液状态，实现了从低频到高频的 T-TBM 反射损耗峰值的主动控制。可以改变吸收峰带宽（反射损耗值小于-30 dB），而宽带宽吸收（反射损耗值小于-10 dB）通过调整T-TBM的温度来满足. 结果表明，T-TBM 中 PD-C 相变温度的停滞为主动控制不同热条件下的 EM 波吸收响应提供了一个时间窗口。该器件在电磁吸收、智能超材料、多功能结构器件等领域具有广阔的应用前景。