INCONSPICUOUS VEHICLE MOUNTED RADIO ANTENNA

• US 3,742,508 A
• Filed: 06/01/1971
• Issued: 06/26/1973
• Est. Priority Date: 06/01/1971
• Status: Expired due to Term

• Current Assignee: Donald E. Tomaszewski
• Original Assignee: Donald E. Tomaszewski
• Inventors: Tomaszewski, Donald E.
• Primary Examiner(s): Lieberman, Eli
• Application Number:
  US05/148,546
• Time in Patent Office: 756 Days
• Field of Search: 343/711,712,713,716,862
• US Class Current: 343/713
• CPC Class Codes: H01Q 1/3283 side-mounted antennas, e.g. bumper-mounted, door-mounted mounted on windscreens H01Q1/1271

Abstract

A conductive rod is mounted in spaced relationship to the outer body of an automotive vehicle to provide a decorative ornament for the vehicle and to provide an inconspicuous antenna for a radio receiver contained within the vehicle. The capacitance developed between the conductive rod and the vehicle body tunes the rod to act as a quarter wavelength antenna. An adjustable connector assembly couples the conductive rod to the radio receiver so as to match the output impedance of the antenna to the input impedance of the radio receiver.

Claims

1. In an automotive vehicle including a body structure having a contoured outer portion and a radio receiver adapted to receive radio signals in a particular frequency band over a coaxial cable including inner and outer conductors across which an input impedance is developed, the combination comprising:

a conductive antenna rod having a terminal end and an open end, the antenna rod having a physical length less than a quarter wavelength of a desired frequency to provide an antenna which resonates at the desired frequency when mounted to the outer portion of the vehicle body structure, and the antenna rod having a shape generally conforming to the contour of the outer portion of the vehicle body structure to provide a decorative ornament when mounted to the outer portion of the vehicle body structure;

support means for mounting the antenna rod in physically spaced relationship from and in electrically isolated relationship from the outer portion of the vehicle body structure so that the rod exhibits a distributed capacitance along its physical length with respect to the vehicle body structure thereby to increase the electrical length of the rod to approximately a quarter wavelength of the desired frequency to resonate the antenna rod at the desired frequency;

terminal means for electrically connecting the outer conductor of the coaxial cable to the terminal end of the antenna rod so that the rod exhibits a distributed impedance along its length which increases from a low impendance at the terminal end to a high impedance at the open end; and

connector means including a conductive connector rod having a terminal end and an open end, support means for mounting the connector rod in physically spaced relationship from and electrically isolated relationship from the antenna rod adjacent the terminal end, terminal means for connecting the inner conductor of the coaxial cable to the terminal end of the connector rod, and conductor means mounted between the connector rod and the antenna rod for effectively connecting the inner conducTor of the coaxial cable through the connector rod to a tap point on the antenna rod so as to define an output impedance between the tap point and the terminal end of the antenna rod which matches the input impedance developed across the inner and outer conductors of the coaxial cable.