NANOSTRUCTURED BARIUM STRONTIUM TITANATE (BST) THIN-FILM VARACTORS ON SAPPHIRE
First Claim
1. A varactor shunt switch for microwave applications, the varactor shunt switch comprising:
- a sapphire substrate;
a bottom metal layer stack deposited on the sapphire substrate;
a tunable nanostructured thin-film dielectric layer on the bottom metal layer; and
a top metal layer stack on said tunable thin-film dielectric layer, wherein said top metal layer defines a coplanar waveguide transmission line.
1 Assignment
0 Petitions
Accused Products
Abstract
Varactor shunt switches based on a nonlinear dielectric tunability of BaxSr(1−x)TiO3 (BST) thin-film on a sapphire substrates are presented. Nanostructured BST thin-films with dielectric tunability as high as 4.3:1 can be obtained on sapphire substrates, with very low loss-tangents below 0.025 at zero-bias and 20 GHz. The large capacitance of the varactor at zero bias can shunt the input signal to ground isolating the output port, resulting in the OFF state. When applying a bias voltage of approximately 10 V (a dc electric field of ˜250 kV/cm), the varactor'"'"'s capacitance can be reduced to a minimum, allowing maximum transmission to the output resulting in the ON state. The microwave switching performance of the varactor shunt switch can be compared with the RF MEMS switches for potential applications at microwave and millimeterwave frequencies. Other applications of such BST varactors include tunable filters, phase shifter circuits and impedance matching circuits
43 Citations
16 Claims
-
1. A varactor shunt switch for microwave applications, the varactor shunt switch comprising:
-
a sapphire substrate; a bottom metal layer stack deposited on the sapphire substrate; a tunable nanostructured thin-film dielectric layer on the bottom metal layer; and a top metal layer stack on said tunable thin-film dielectric layer, wherein said top metal layer defines a coplanar waveguide transmission line. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. A varactor shunt switch for microwave applications, the varactor shunt switch comprising:
-
a sapphire substrate; a bottom metal layer on the sapphire substrate; a tunable barium strontium titanate thin-film dielectric layer on the bottom metal layer; and a top metal layer on the tunable thin-film dielectric layer, wherein said top metal layer defines a coplanar waveguide transmission line.
-
-
16. A varactor shunt switch for microwave applications, the varactor shunt switch comprising:
-
a sapphire substrate; a bottom metal layer on the sapphire substrate; a tunable nanostructured barium strontium titanate thin-film dielectric layer on the bottom metal layer; and a top metal layer on the tunable nanostructured thin-film dielectric layer, wherein said top metal layer defines a coplanar waveguide transmission line.
-
Specification