Tunable microwave devices with auto-adjusting matching circuit

Abstract

An impedance matching circuit includes a conductor line having an input port and an output port, a ground conductor, a tunable dielectric material positioned between a first section of the conductor line and the ground conductor, a non-tunable dielectric material positioned between a second section of the conductor line and the ground conductor, and means for applying a DC voltage between the conductor line and the ground conductor. The impedance matching circuit may alternatively include a first planar ground conductor, a second planar ground conductor, a strip conductor having an input port and an output port, and positioned between the first and second planar ground conductors to define first and second gaps, the first gap being positioned between the strip conductor and the first planar ground conductor and the second gap being positioned between the strip conductor and the second planar ground conductor. A non-tunable dielectric material supports the first and second planar ground conductors and the strip conductor in the same plane. A connection is provided for applying a DC voltage between the strip conductor and the first and second planar ground conductors. A plurality of tunable dielectric layer sections are positioned between the strip conductor and the first and second planar ground conductors so as to bridge the gaps between the said first and second planar ground conductors and the strip conductor at a plurality of locations, leaving non-bridged sections in between, defining a plurality of alternating bridged and non-bridged co-planar waveguide sections.

1 . An impedance matching circuit comprising: 
 a conductor line having an input port and an output port;    a ground conductor;    a tunable dielectric material positioned between a first section of said conductor line and said ground conductor;    a non-tunable dielectric material positioned between a second section of said conductor line and said ground conductor; and    means for applying a DC voltage between said conductor line and said ground conductor.    
   
   
       2 . The impedance matching circuit of  claim 1 , wherein: 
 the conductor line comprises a conducting strip line;    the ground conductor comprises a ground plane; and    said conducting strip, tunable dielectric or non-tunable dielectric and ground plane together form a microstrip transmission line.    
   
   
       3 . The impedance matching circuit of  claim 2 , wherein: 
 the microstrip line has a first section deposited on the said tunable dielectric;    the microstrip line has a second section deposited on a non-tunable dielectric; and    the first and second microstrip sections are connected in series to form a tunable microstrip impedance transformer with an entry point that abuts the non-tunable dielectric substrate and an exit point that abuts the tunable dielectric substrate.    
   
   
       4 . A power amplifier, comprising: 
 tunable impedance matching circuit including a plurality of tunable dielectric varactors; and    a DC voltage source interface capable of providing voltage to said plurality of saud tunable dielectric varactors.    
   
   
       5 . An auto-adjusting matching circuit, comprising: 
 a conducting matching network supported by a non-tunable dielectric substrate, said non-tunable dielectric substrate supported by a first ground conductor;    at least one conducting partial-stage supported by a voltage-tunable dielectric layer, said voltage-tunable dielectric layer is supported by a second ground conductor; and    a biasing electrode capable of connection to an external variable DC voltage source.    
   
   
       6 . The auto-adjusting matching circuit of  claim 5 , wherein said biasing electrode is connected to said auto-adjusting matching circuit by way of a microwave choke.  
   
   
       7 . An apparatus, comprising: 
 a phase shifter; and    a matching network coupled to said phase shifter, said matching network including a plurality of voltage tunable dielectric varactors.    
   
   
       8 . The apparatus of  claim 7 , wherein said phase shifter is a tunable phase shifter.  
   
   
       9 . The apparatus of  claim 8 , further comprising a voltage source supplied to said phase shifter and said matching network.  
   
   
       10 . The apparatus of  claim 9 , wherein said voltage source supplying said phase shifter and wherein said voltage source supplying said matching network is controlled by two differene external DC voltage sources.  
   
   
       11 . The apparatus of  claim 7 , further comprising a load coupled to said phase shifter, wherein the impedance of said matching network changes to maximize power transfer to and from said phase shifter.  
   
   
       12 . An apparatus, comprising: 
 a power amplifier; and    a matching network coupled to said power amplifer, said matching network including a plurality of voltage tunable dielectric varactors.    
   
   
       13 . The apparatus of  claim 12 , wherein said power amplifier is a tunable power amplifier.  
   
   
       14 . The apparatus of  claim 13 , further comprising a voltage source supplied to said power amplifier and said matching network.  
   
   
       15 . The apparatus of  claim 14 , wherein said voltage source supplying said power amplifier and wherein said voltage source supplying said matching network is controlled by two differene externarl DC voltage sources.  
   
   
       16 . The apparatus of  claim 12 , further comprising a load coupled to said power amplifier, whrein the impedance of said matching network changes to maximize power transfer to and from said power amplifier.  
   
   
       17 . An apparatus, comprising: 
 a delay line; and    a matching network coupled to said delay line, said matching network including a plurality of voltage tunable dielectric varactors.    
   
   
       18 . The apparatus of  claim 17 , wherein said delay line is a tunable delay line.  
   
   
       19 . The apparatus of  claim 18 , further comprising a voltage source supplied to said delay line and said matching network.  
   
   
       20 . The apparatus of  claim 17 , wherein said voltage source supplying said delay line and wherein said voltage source supplying said matching network is controlled by two different externarl DC voltage sources.  
   
   
       21 . The apparatus of  claim 12 , further comprising a load coupled to said delay line, whrein the impedance of said matching network changes to maximize power transfer to and from said delay line.  
   
   
       22 . An apparatus, comprising: 
 a filter; and    a matching network coupled to said filter, said matching network including a plurality of voltage tunable dielectric varactors.    
   
   
       23 . The apparatus of  claim 22 , wherein said filter is a tunable filter.  
   
   
       24 . The apparatus of  claim 23 , further comprising a voltage source supplied to said phase shifter and said matching network.  
   
   
       25 . The apparatus of  claim 24 , wherein said voltage source supplying said phase shifter and wherein said voltage source supplying said matching network is controlled by two differene externarl DC voltage sources.  
   
   
       26 . The apparatus of  claim 12 , further comprising a load coupled to said phase shifter, whrein the impedance of said matching network changes to maximize power transfer to and from said phase shifter.  
   
   
       27 . An apparatus, comprising: 
 an antenna; and    a matching network coupled to said antenna, said matching network including a plurality of voltage tunable dielectric varactors.    
   
   
       28 . The apparatus of  claim 27  wherein said antenna is an RF antenna.  
   
   
       29 . The apparatus of  claim 27 , wherein said matching network is an auto-adjusting matching circuit capable of contributing to the tunable range of said apparatus.  
   
   
       30 . The apparatus of  claim 27 , wherein said apparatus is a microwave device.  
   
   
       31 . The apparatus of  claim 28 , matching network is a multi-stage impedance matching circuit that includes both non-tunable and tunable dielectric material.  
   
   
       32 . The apparatus of  claim 27 , wherein said matching network facilitates the capability of operation by said apparatus in the frequency range between 500 MHz to 40 GHz.  
   
   
       33 . The apparatus of  claim 31 , wherein said matching circuit has minimal reflection loss and reduced insertion loss over the tuning range of said apparatus.  
   
   
       34 . A method of impedance matching in a device, comprising: 
 interposing a multi-stage impedance matching circuit between a conductor line and an entry point of said device, wherein the multi-stage impedance matching circuit reduces the signal reflection of a signal propagating through a tunable impedance transformer into said device, by matching the wave impedance of a signal at said entry point, to the source impedance.    
   
   
       35 . The method of  claim 34 , wherein the device is a microwave device and said signal is a microwave signal.  
   
   
       36 . The method of  claim 34 , wherein said device is a handset and said source impedance is provided by an antenna coupled to said handset.