TL theory extended to 2D (or 3D) [9] [10]. Assuming that the electrical size of the unit
cell is small enough (p<<λg) and defining the series and shunt resonances respectively,
by, The phase constant β vary depending on whether the radicand is positive or
negative. It can be purely real or purely imaginary, respectively. When it is purely real,
a stop band occurs as shown in Fig.2(c) since γ=α. This stop band is the unique
characteristic of the CRLH TL.
A particularly interesting situation occurs when the series and shunt resonances are
equal, as shown below:
�