Tunable microwave devices with auto-adjusting matching circuit

Abstract

A variable impedance circuit includes a matching network for coupling to a tunable device, where the matching network has a first port and a second port, where the tunable device is coupled to one of the first port or the second port, and where the matching network has one or more variable dielectric capacitors. The one or more variable dielectric capacitors can be operable to receive a first of one or more variable voltage signals to cause the one or more variable dielectric capacitors to change a first impedance of the matching network. The tunable device can be operable to receive a second of one or more variable voltage signals to cause a change in a second impedance of the tunable device.

1 . A variable impedance circuit, comprising:
 a matching network for coupling to a tunable device;   wherein the matching network comprises a first port and a second port;   wherein the tunable device is coupled to one of the first port or the second port;   wherein the matching network comprises one or more variable dielectric capacitors;   wherein the one or more variable dielectric capacitors are operable to receive a first of one or more variable voltage signals to cause the one or more variable dielectric capacitors to change a first impedance of the matching network; and   wherein the tunable device is operable to receive a second of one or more variable voltage signals to cause a change in a second impedance of the tunable device.   
     
     
         2 . The variable impedance circuit of  claim 1 , wherein at least one of the change in the first impedance of the matching network, or the change in the second impedance of the tunable device, or both causes an increase in power transferred from the first port to the second port or from the second port to the first port. 
     
     
         3 . The variable impedance circuit of  claim 1 , wherein each of the one or more variable dielectric capacitors comprises a tunable dielectric material comprising a composition of barium strontium titanate. 
     
     
         4 . The variable impedance circuit of  claim 1 , wherein the tunable device comprises a tunable dielectric material. 
     
     
         5 . The variable impedance circuit of  claim 4 , wherein the second of the one or more variable voltages is coupled to the tunable dielectric material to cause the change in the second impedance of the tunable device. 
     
     
         6 . The variable impedance circuit of  claim 1 , wherein the tunable device is a tunable antenna. 
     
     
         7 . The variable impedance circuit of  claim 1 , wherein at least one of the one or more variable dielectric capacitors comprises:
 a first conductor coupled to one of the first port or the second port;   a second conductor;   a tunable dielectric material positioned between the first conductor and the second conductor; and   wherein at least one of the first conductor or the second conductor, or both are adapted to receive the first of the one or more variable voltage signals to cause the change in the first impedance of the matching network.   
     
     
         8 . An variable impedance circuit, comprising:
 a matching network for coupling to an antenna, wherein the antenna comprises a component that makes the antenna tunable;   wherein the matching network comprises a first port and a second port;   wherein the antenna is coupled to one of the first port or the second port;   wherein the matching network comprises one or more variable reactive elements;   wherein the one or more variable reactive elements are operable to receive a first of one or more variable voltage signals to cause the one or more variable reactive elements to change a first impedance of the matching network; and   wherein the component of the antenna is operable to receive a second of one or more variable voltage signals to cause the component to change a second impedance of the antenna.   
     
     
         9 . The variable impedance circuit of  claim 1 , wherein at least one of the change in the first impedance of the matching network, or the change in the second impedance of the antenna, or both causes a change in power transferred from the first port to the second port or from the second port to the first port. 
     
     
         10 . The variable impedance circuit of  claim 8 , wherein each of the one or more variable reactive elements comprises one or more variable dielectric capacitors, and wherein each of the one or more variable dielectric capacitors comprises a tunable dielectric material. 
     
     
         11 . The variable impedance circuit of  claim 10 , wherein the tunable dielectric material comprises a composition of barium strontium titanate. 
     
     
         12 . The variable impedance circuit of  claim 8 , wherein the component comprises a tunable dielectric material. 
     
     
         13 . The variable impedance circuit of  claim 12 , wherein the second of the one or more variable voltages is coupled to the tunable dielectric material to cause the change in the second impedance of the antenna. 
     
     
         14 . The variable impedance circuit of  claim 8 , wherein at least one of the one or more variable reactive elements comprises a tunable dielectric material. 
     
     
         15 . The variable impedance circuit of  claim 14 , wherein the tunable dielectric material comprises a composition of barium strontium titanate. 
     
     
         16 . A variable impedance circuit, comprising:
 an antenna; and   wherein the antenna comprises a tunable component;   wherein the tunable component is operable to receive a variable voltage signal to cause the tunable component to change an impedance of the antenna.   
     
     
         17 . The variable impedance circuit of  claim 16 , wherein the change in the impedance of the antenna causes a change in power transferred by the antenna. 
     
     
         18 . The variable impedance circuit of  claim 16 , wherein the tunable component comprises a variable reactive device. 
     
     
         19 . The variable impedance circuit of  claim 18 , wherein the variable voltage signal is coupled to the variable reactive device to cause the change in the impedance of the antenna. 
     
     
         20 . The variable impedance circuit of  claim 19 , wherein the variable reactive device comprises a tunable dielectric material.