This thesis presents the work of using magnetic responsive particles as a method to manipulate the surface impedance reactance of a microstrip line containing uniform capacitive gaps and cavities containing the particles. In order to determine the transmission line’s surface impedances created by each gap and particle containing cavities, a sub-unit cell that centers the gap and cavities was used. Shown in simulation, the magnetic responsive particles can then be manipulated to increase or decrease the reactance of the surface impedance based on the strength of the magnetic field present. The sub-unit cell with the greatest reactance change was then implemented into a unit cell, which is a cascade of sub-unit cells. This unit cell design was simulated, milled and tested to determine the response a unit cell should see based on extreme states of the particles represented by copper vias and open air cavities.