Vol. 104

Latest Volume
All Volumes
All Issues
2021-09-07

Wave Propagation in Electric Periodic Structure in Space with Modulation in Time (2D+1)

By Jose Salazar-Arrieta and Peter Halevi
Progress In Electromagnetics Research M, Vol. 104, 145-158, 2021
doi:10.2528/PIERM21061707

Abstract

We studied electromagnetic wave propagation in a system that is periodic in both space and time, namely a discrete 2D transmission line (TL) with capacitors modulated in tandem externally. Kirchhoff's laws lead to an eigenvalue equation whose solutions yield a band structure (BS) for the circular frequency ω as function of the phase advances kxa and kya in the plane of the TL. The surfaces ω(kxa, kya) display exotic behavior like forbidden ω bands, forbidden k bands, both, or neither. Certain critical combinations of the modulation strength mc and the modulation frequency Ω mark transitions from ω stopbands to forbidden k bands, corresponding to phase transitions from no propagation to propagation of waves. Such behavior is found invariably at the high symmetry X and M points of the spatial Brillouin zone (BZ) and at the boundary ω = (1/2)Ω of the temporal BZ. At such boundaries the ω(kxa, kya) surfaces in neighboring BZs assume conical forms that just touch, resembling a South American toy ``diábolo''; the point of contact is thus called a ``diabolic point''. Our investigation reveals interesting interplay among geometry, critical points, and phase transitions.

Citation


Jose Salazar-Arrieta and Peter Halevi, "Wave Propagation in Electric Periodic Structure in Space with Modulation in Time (2D+1)," Progress In Electromagnetics Research M, Vol. 104, 145-158, 2021.
doi:10.2528/PIERM21061707
http://jpier.org/PIERM/pier.php?paper=21061707

References