Patent ID: 6985054

Claim:
An electrically controllable/tunable microwave device having a capacitance which depends on applied voltage C(V), the device comprising: a ferroelectric substrate with a variable dielectric permittivity and conducting electrodes arranged on said substrate; at least two sections or parts of the substrate/electrodes for each of which different electrical field strengths are generated upon voltage application, wherein said generated electrical field strengths are controlled by design of the device and/or the voltage application such that a slope (dC(dV) of voltage dependence of the capacitance (C(V)) of the microwave device can be controlled; wherein each section has a thickness and/or an electrode plate area differing from the thickness(es) and/or the plate area(s) of the other section(s), and wherein the dependance of the capacitance on the voltage is controlled by appropriate selection of the thicknesses and the electrode plate areas of the sections; and wherein a same voltage is applied to the different sections and wherein, for the applied voltage, the generated electric field of a section depends on the thickness and the plate area of the section.