Ferroelectric varactors suitable for capacitive shunt switching
First Claim
1. A frequency selective filter, the filter comprising:
- at least two varactor shunt switches, wherein the varactor shunt switch comprises;
a substrate;
a patterned bottom metal layer deposited on said substrate;
a ferroelectric thin film is deposited on said patterned bottom metal layer; and
a top metal electrode deposited on said ferroelectric thin film, wherein said top metal electrode is patterned to form a coplanar waveguide transmission line,wherein the coplanar waveguide transmission lines of the at least two varactor shunt switches are connected in series.
1 Assignment
0 Petitions
Accused Products
Abstract
A ferroelectric varactor suitable for capacitive shunt switching is disclosed. High resistivity silicon with a SiO2 layer and a patterned metallic layer deposited on top is used as the substrate. A ferroelectric thin-film layer deposited on the substrate is used for the implementation of the varactor. A top metal electrode is deposited on the ferroelectric thin-film layer forming a CPW transmission line. By using the capacitance formed by the large area ground conductors in the top metal electrode and bottom metallic layer, a series connection of the ferroelectric varactor with the large capacitor defined by the ground conductors is created. The large capacitor acts as a short to ground, eliminating the need for vias. The varactor shunt switches can be used to create a bandpass filter and a tunable notch filter. The bandpass filter is implemented by cascading the switches, and the bandpass filter implemented through the use of a resonance circuit.
-
Citations
8 Claims
-
1. A frequency selective filter, the filter comprising:
-
at least two varactor shunt switches, wherein the varactor shunt switch comprises; a substrate; a patterned bottom metal layer deposited on said substrate; a ferroelectric thin film is deposited on said patterned bottom metal layer; and a top metal electrode deposited on said ferroelectric thin film, wherein said top metal electrode is patterned to form a coplanar waveguide transmission line, wherein the coplanar waveguide transmission lines of the at least two varactor shunt switches are connected in series. - View Dependent Claims (2, 3)
-
-
4. A notch filter, the notch filter comprising:
-
at least two varactor shunt switches, wherein the varactor shunt switch comprises; a substrate; a patterned bottom metal layer deposited on said substrate; a functionalized polymer thin film is spin coated on said patterned bottom metal layer; and a top metal electrode deposited on said ferroelectric thin film, wherein said top metal electrode is patterned to form a coplanar waveguide transmission line, wherein the coplanar waveguide transmission lines of the at least two varactor shunt switches are connected in series. - View Dependent Claims (5, 6, 7, 8)
-
Specification