At frequencies of hundreds and thousands of MHz where lumped elements are hard to realize, the use of sections
of transmission line as reactive elements may be more convenient.
The turns in the wire of the inductor have small distributed capacitors.
As the frequency increases, the capacitance begins to play a role in the response of the circuit and beyond the
resonant frequency, the capacitance predominates the response. That is the inductance coil effectively behaves like a capacitor.
Similarly, for a capacitance, there exist lead inductance. As the frequency increases, the lead inductance starts dominating over the capacitance and beyond the resonant frequency of the LC combination, the capacitor effectively behaves like an inductor.
So, it is clear that at high frequencies, realization of reactive element is not that simple.
On the other hand at high frequencies, the wavelength and the length of the transmission line section reduces and becomes more manageable.
