Bound states can be supported on the surface of a periodically corrugated perfect conductor known as spoof surface plasmon polaritons with their dispersion curves reside below the light line. Here we show that bound states in the continuum (BICs) can also be achieved in such systems. Two types of grating structures are proposed to suppress the radiation leakage and hence generate bound states. The first one is a simple grating with broad grooves in which multiple cavity modes are accommodated. Due to the symmetry incompatibility and the destructive interaction mainly from the TM₀ and TM₁ modes, BICs at the Γ point and at off-Γ points are both realized. The second one is a dimerized grating with two grooves in each unit cell. The destructive interaction between the modes in the two grooves can suppresses the radiation and BICs at the Γ point are observed. The Q factors of the whole bands can be further tuned by the dimerization strength effectively. This work may offer new opportunity for the applications of metallic grating in the low frequency bands.

束缚态可以支持在周期性波纹完美导体的表面上，称为欺骗表面等离子体激元，其色散曲线位于光线下方。在这里，我们表明在这样的系统中也可以实现连续统 (BIC) 中的束缚态。提出了两种类型的光栅结构来抑制辐射泄漏并因此产生束缚态。第一个是带有宽槽的简单光栅，其中可容纳多种腔模式。由于对称性不相容性和破坏性相互作用主要来自 TM ₀和 TM ₁模式，Γ点和 off- Γ处的 BIC点都实现了。第二个是在每个晶胞中有两个凹槽的二聚化光栅。两个凹槽中模式之间的破坏性相互作用可以抑制辐射，并在Γ点观察到BIC 。整个波段的Q因子可以通过二聚化强度进一步调整。这项工作可能为金属光栅在低频段的应用提供新的机会。