Variable z0 antenna device design system and method

Abstract

A variable Z 0 impedance method (“Variable Z 0 ”) for designing and/or optimizing antenna systems. The method provides that the value of an antenna's feed system characteristic impedance or apparatus internal impedance (Z 0 ) changes as a true variable quantity during the antenna system design or optimization methodology. The value is allowed to be determined by the methodology, because different values of Z 0 result in different antenna system performance. It is applied to any set of performance objectives on any antenna system wherein apparatus internal or transmission line characteristic impedance is an explicit or implicit parameter. Variable Z 0 is applied to any design or optimization methodology. Structures include Yagi-Uda arrays, Meander Monopoles, and transmission line Multi-Stub Matching Networks, and can incorporate Central Force Optimization or Biogeography Based Optimization or other optimization algorithms.

I claim: 
     
         1 . A method of designing an antenna connected to a feed system including a radio frequency source, the method comprising:
 using an iterative antenna design algorithm on a computer where one or more antenna design parameters and a feed system characteristic impedance value are variables to achieve one or more antenna performance objectives;   varying said one or more antenna design parameters while varying said feed system characteristic impedance value until said one or more antenna performance objectives are achieved using said iterative antenna design algorithm; and   determining a feed system characteristic impedance value from the varied feed system characteristic impedance values which results in said one or more antenna performance objectives.   
     
     
         2 . The method of  claim 1  further including:
 designing the feed system such that said feed system exhibits said determined feed system characteristic impedance value or an approximation of the determined feed system characteristic impedance value; 
 determining one or more antenna design parameters which results in said antenna performance objectives; and 
 designing the antenna according to said one or more determined antenna design parameters to achieve said one or more antenna performance objectives. 
 
     
     
         3 . The method of  claim 1  in which said one or more antenna design parameters include one or more of antenna element length, diameter, and/or spacing; and/or helix diameter, turn pitch, wire gauge, and/or the number of turns. 
     
     
         4 . The method of  claim 1  in which varying the one or more antenna design parameters includes varying the one or more antenna design parameters between maximum and minimum values. 
     
     
         5 . The method of  claim 1  in which said one or more antenna performance objectives are input into the iterative antenna design algorithm. 
     
     
         6 . The method of  claim 1  in which said iterative antenna design algorithm includes Central Force Optimization, Dominating Cone Line Search, Particle Swarm Optimization, a Genetic Algorithm, Ant Colony Optimization, and/or Differential Evolution. 
     
     
         7 . The method of  claim 2  in which the feed system further includes a transmission line and/or a matching network and designing the feed system includes choosing a transmission line and/or matching network such as that the feed system exhibits said determined feed system characteristic impedance value. 
     
     
         8 . The method of  claim 1  in which said antenna performance objectives include voltage standing wave ratio, gain, and/or Front-to-Back ratio. 
     
     
         9 . A method of designing an antenna connected to a feed system including a radio frequency source, the method comprising:
 choosing minimum and maximum feed system characteristic impedance values;   using an iterative antenna design algorithm on a computer where one or more antenna design parameters and a feed system characteristic impedance value are variables to achieve one or more antenna performance objectives;   varying said one or more antenna design parameters while varying feed system characteristic impedance values between the minimum and maximum feed system characteristic impedance values until said one or more antenna performance objectives are achieved using said iterative antenna design algorithm; and   determining a feed system characteristic impedance value from the varied feed system characteristic impedance values which results in said one or more antenna performance objectives.   
     
     
         10 . The method of  claim 9  further including:
 designing the feed system such that said feed system exhibits said determined feed system characteristic impedance value or an approximation of the determined feed system characteristic impedance value; 
 determining which one or more antenna design parameters result in said one or more antenna performance objectives; and 
 designing the antenna according to said one or more determined antenna design parameters to achieve said one or more antenna performance objectives. 
 
     
     
         11 . The method of  claim 9  in which said one or more antenna design parameters include antenna element length, diameter, and/or spacing; and/or helix diameter, turn pitch, wire gauge, and/or the number of turns. 
     
     
         12 . The method of  claim 9  in which varying the one or more antenna design parameters include varying the antenna design parameters between maximum and minimum values. 
     
     
         13 . The method of  claim 9  in which said one or more antenna performance objectives are input into the iterative antenna design algorithm. 
     
     
         14 . The method of  claim 9  in which said iterative antenna design algorithm includes Central Force Optimization, Dominating Cone Line Search, Particle Swarm Optimization, a Genetic Algorithm, Ant Colony Optimization, and/or Differential Evolution. 
     
     
         15 . The method of  claim 10  in which the feed system further includes a transmission line and/or a matching network and designing the feed system includes choosing a transmission line and/or matching network such as that the feed system exhibits said determined feed system characteristic impedance value. 
     
     
         16 . The method of  claim 9  in which said antenna performance objectives include voltage standing wave ratio, gain, and/or Front-to-Back ratio. 
     
     
         17 . The method of  claim 9  in which the determined feed system characteristic impedance value is within a factor of three of a standard fixed antenna feed system characteristic impedance value. 
     
     
         18 . A computer program for designing an antenna connected to a feed system including a radio frequency source, the computer program comprising:
 an iterative antenna design algorithm configured so one or more antenna design parameters and a feed system characteristic impedance value are variables to achieve one or more antenna performance objectives;   said antenna design parameters are varied in said design algorithm while varying the feed system characteristic impedance value until said one or more antenna performance objectives are achieved; and   a feed system characteristic impedance value determined by said algorithm which results in said one or more antenna performance objectives.   
     
     
         19 . The computer program of  claim 18  in which said antenna design parameters include antenna element length, diameter, and/or spacing; and/or helix diameter, turn pitch, wire gauge, and/or the number of turns. 
     
     
         20 . The computer program of  claim 18  in which the interactive design algorithm is configured to accept as inputs minimum and maximum feed system characteristic impedance values and to vary the feed system characteristic impedance value between said minimum and maximum values. 
     
     
         21 . The computer program of  claim 18  in which said iterative antenna design algorithm includes Central Force Optimization, Dominating Cone Line Search, Particle Swarm Optimization, a Genetic Algorithm, Ant Colony Optimization, and/or Differential Evolution. 
     
     
         22 . The computer program of  claim 18  in which said antenna performance objectives include voltage standing wave ratio, gain, and/or Front-to-Back ratio. 
     
     
         23 . An antenna connected to a feed system designed by a method comprising:
 choosing minimum and maximum feed system characteristic impedance values;   using an iterative antenna design algorithm on a computer where antenna design parameters and a feed system characteristic impedance value are variables to achieve one or more antenna performance objectives;   varying said antenna design parameters while varying feed system characteristic impedance values between the minimum and maximum feed system characteristic impedance values until said one or more antenna performance objectives are achieved using said iterative antenna design algorithm;   determining a feed system characteristic impedance value from the varied feed system characteristic impedance values which results in said one or more antenna performance objectives;   designing the feed system such that said feed system exhibits said determined feed system characteristic impedance value or an approximation of the determined feed system characteristic impedance value;   determining which antenna design parameters result in said antenna performance objectives; and   
       designing the antenna according to said determined antenna design parameters to achieve said one or more antenna performance objectives.