The Edward S. Rogers Sr Department of Electrical and Computer Engineering, University of Toronto, 40 Saint George Street, 10 King's College Road, Toronto, Ontario, Canada M5S 2E4.
Nat Commun. 2015 Jan 5;6:5855. doi: 10.1038/ncomms6855.
Leaky-Wave Antennas (LWAs) enable directive and scannable radiation patterns, which are highly desirable attributes at terahertz, infrared and optical frequencies. However, a LWA is generally incapable of continuous beam scanning through broadside, due to an open stopband in its dispersion characteristic. This issue is yet to be addressed at frequencies beyond microwaves, mainly as existing microwave solutions (for example, transmission line metamaterials) are unavailable at these higher frequencies. Here we report leaky-wave radiation from the interface of a photonic crystal (PC) with a Dirac-type dispersion and air. The resulting Dirac LWA (DLWA) can radiate at broadside, chiefly owing to the closed Γ-point bandgap of the Dirac PC. Thus, the DLWA can continuously scan a directive beam over a wide range of angles by varying the frequency. These DLWAs can be designed at microwave as well as terahertz to optical frequencies, with feasible dimensions and low losses.
漏波天线 (LWA) 能够实现定向和可扫描的辐射模式，这在太赫兹、红外和光学频率下是非常理想的特性。然而，由于其色散特性中的开停带，LWA 通常无法在宽角范围内进行连续波束扫描。在微波频率以外的频率下，这个问题尚未得到解决，主要是因为现有的微波解决方案（例如传输线超材料）在这些更高的频率下不可用。在这里，我们报告了在具有狄拉克型色散和空气的光子晶体 (PC) 界面处的漏波辐射。由此产生的狄拉克漏波天线 (DLWA) 可以在宽角处辐射，主要是由于狄拉克光子晶体的 Γ 点带隙是闭合的。因此，DLWA 可以通过改变频率在很宽的角度范围内连续扫描定向波束。这些 DLWA 可以在微波以及太赫兹到光学频率范围内设计，具有可行的尺寸和低损耗。
