Feed network for quadrifilar helix antenna

• US 5,872,549 A
• Filed: 04/30/1996
• Issued: 02/16/1999
• Est. Priority Date: 04/30/1996
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: TRW Inc. (Northrop Grumman Corporation)
• Inventors: Chen, Chun-Hong, Mc Laren, Jack S., Huynh, Son H., Briscoe, Donnie H.
• Primary Examiner(s): Hajec, Donald T.
• Assistant Examiner(s): PHAN, THO GIA
• Application Number:
  US08/640,325
• Time in Patent Office: 1,022 Days
• Field of Search: 343/872, 343/702, 343/865, 343/895, 343/858, 343/850, 343/891, 343/830, 333/26
• US Class Current: 343/895
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 11/08 Helical antennas

Abstract

An antenna and antenna feed assembly for a communication handset is constructed as a unitary assembly in which each of the antenna and antenna feed, suitably a balun, conform to a cylindrical geometry and is small enough in size for handset applications.

Claims

1. A unitary antenna and antenna feed assembly for a handset communication device comprising:

a small diameter elongate cylindrical envelope, said cylindrical envelope containing;

a first balanced quadrifilar helix antenna; and

a first balun for coupling microwave energy between said first balanced quadrifilar helix antenna and an external microwave transmission line, each of said first balanced quadrifilar helix antenna and said first balun being of a shape that conforms to said cylindrical envelope;

said balanced quadrifilar helix antenna including first, second, third and fourth antenna chords; and

wherein said first balun comprises;

a first meandering closed line, said first meandering closed line being closed upon itself and defining in appearance an outline of the English letter "H";

a second meandering closed line, said second meandering closed line being closed upon itself and defining in appearance an outline of the English capital letter "H";

said first and second meandering closed lines being substantially identical in size and being positioned in spaced side by side relationship;

a ground plane member;

first resistor means;

first lead means connected to a first predetermined position on said first meandering line;

said second resistor means connected between an end of said first lead means and said ground plane member;

second resistor means;

second lead means connected to a first predetermined position on said second meandering line;

said second resistor means connected between an end of said second lead means and said ground plane member;

first coupling lead means connected to a second predetermined position on said first meandering line for providing an electrical path to a first chord of said quadrifilar antenna and second coupling lead means connected to a third predetermined position on said first meandering line for providing an electrical path to a second chord of said quadrifilar antenna;

third coupling lead means connected to a second predetermined position on said second meandering line for providing an electrical path to a third chord of said quadrifilar antenna and fourth coupling lead means connected to a third predetermined position on said second meandering line for providing an electrical path to a fourth chord of said quadrifilar antenna;

a third meandering closed line, said third meandering closed line being closed upon itself;

said third meandering closed line being positioned adjacent and axially spaced from said first and second meandering lines;

first coupling lead means connected to a first predetermined position on said third meandering closed line for coupling said third meandering closed line to an external transmission line;

third resistor means;

third lead means connected to a second predetermined position on said third meandering closed line;

said third resistor means connected between an end of said third lead means and said ground plane member;

first bridging lead means for bridging a fourth predetermined position on said first meandering closed line and a third predetermined position on said third meandering closed line; and

second bridging lead means for bridging a fourth predetermined position on said second meandering line and a fourth predetermined position on said third meandering line.

2. The invention as defined in claim 1, wherein said third meandering closed line further comprises in appearance an outline of two copies of the English capital letter "H" that are connected together by a bridge.