Antenna with inherent filtering action

• US 4,008,477 A
• Filed: 06/25/1975
• Issued: 02/15/1977
• Est. Priority Date: 06/25/1975
• Status: Expired due to Term

• Current Assignee: THE GOVERNMENT OF THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF COMMERCE
• Original Assignee: THE GOVERNMENT OF THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF COMMERCE
• Inventors: Bowman, Ronald R., Babij, Tadeusz M., Wacker, Paul F.
• Primary Examiner(s): Smith, Alfred E.
• Assistant Examiner(s): Moore, David K.
• Application Number:
  US05/590,355
• Time in Patent Office: 601 Days
• Field of Search: 343/701, 343/703, 343/802, 343/873, 343/794, 343/792
• US Class Current: 343/701
• CPC Class Codes: H01Q 19/09 wherein the primary active element is coated with or embedded in a dielectric or magnetic material protective material H01Q1/40, varying the electric or magnetic characteristics of refracting or diffracting devices H01Q3/44
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence

Abstract

A novel antenna is disclosed which provides inherent filtering action by ch the frequency response curve of the antenna can be shaped. In the preferred inventive embodiment, the antenna comprises at least one elongated receiving element, and preferably two such elements in the form of a dipole, both elements being constructed, at least in part, of an electrically resistive material. A detector, such as a diode detector, is directly coupled to the receiving elements. The resistance of the receiving element and the capacitances of the receiving element and the detector form a distributed parameter RC filter, the values of which parameters can be carefully controlled so as to provide the desired frequency response curve shaping. In the preferred inventive embodiment, a conductive strip is disposed along the length of and preferably to both sides of each receiving element, with a layer of dielectric material being sandwiched therebetween, whereby the filtering action is enhanced.

Claims

1. An antenna with inherent filtering action for shaping the frequency response curve thereof, said antenna comprising, in combination, at least one elongated receiving element constructed of an electrically-conductive material;

a dielectric sheath surrounding said receiving element;

a resistive shield surrounding said dielectric sheath, and a detector directly coupled to said receiving element;

whereby a distributed parameter RC filter is formed decreasing the low-frequency response of said antenna.