Compact ground-plane antenna

• US 20050174297A1
• Filed: 01/06/2005
• Published: 08/11/2005
• Est. Priority Date: 02/09/2004
• Status: Abandoned Application

• Current Assignee: Hans Kloepfer
• Original Assignee: Hans Kloepfer
• Inventors: Cake, Brian Victor
• Application Number:
  US11/030,411
• Publication Number:
  US 20050174297A1
• Time in Patent Office: Days
• US Class Current: 343/834
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 19/32 the primary active element being end-fed and elongated
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence

Abstract

Compact ground-plane antennas having a plurality of sub-elements disposed in a radially symmetric pattern above a ground-plane. Each sub-element is similarly shaped and has a total lenght of approximately one-quarter wavelength at the corresponding operating frequency. The present antennas exhibit a significant reduction in size and improved current sharing to permit better control of the antenna characteristics; in particular the antenna patterns and drive point impedance.

Claims

1. A ground-plane antenna, comprising:

a plurality of sub-elements, each sub-element having a total length of approximately one-quarter wavelength at a corresponding operating frequency and comprising sequential first, second, and third sections;

said first section extending vertically upward from a horizontal ground-plane;

said second section being perpendicular to the first section, whereby the second section is substantially parallel to the ground-plane;

said third section extending vertically downward toward the ground-plane, whereby the third section is substantially parallel to the first section;

an end of the third section forming a gap with the ground-plane a first fraction of the wavelength in length;

wherein a first sub-element of said plurality of sub-elements has a radio frequency source connected in series to a feed-point located on the first section proximate to the ground-plane; and

said plurality of sub-elements forming a radially symmetric pattern wherein said first sections of each sub-element are positioned in parallel towards a center of the radial pattern and spaced a second fraction of a wavelength apart;

said second sections being equally-spaced and extending outward from the center, whereby the third sections are equally-spaced and vertically parallel along the outside of the radial pattern.

2. The ground-plane antenna according to claim 1, wherein the first sections of said plurality of sub-elements are connected together at a location proximate to the second sections.

3. The ground-plane antenna according to claim 1, wherein said second sections are comprised of sequential first and second sub-sections;

the second sub-sections being bent at a predetermined angle in the horizontal plane from the first sub-sections.

4. The ground-plane antenna according to claim 1, wherein the plurality of sub-elements are conductors of wire, rod, tubing or printed circuit trace.

5. The ground-plane antenna according to claim 1, wherein said ground-plane is a multi-wire radial system of conductors, each having a length of not more than one-quarter wavelength.

6. A ground-plane antenna, comprising:

a plurality of sub-elements, each sub-element having a total length of approximately one-quarter wavelength at a corresponding operating frequency and comprising sequential first and second sections;

said first section extending vertically upwards from a horizontal ground-plane;

said second section comprising a plurality of serially connected sub-sections forming a meander pattern at a predetermined angle from the first section;

wherein a first sub-element of said plurality of sub-elements has a radio frequency source connected in series to a feed-point located on the first section proximate to the ground-plane; and

said plurality of sub-elements forming a radially symmetric pattern wherein said first sections of each sub-element are positioned in parallel towards a center of the radial pattern and spaced a first fraction of a wavelength apart;

said second sections being equally spaced and extending outward from the center.

7. The ground-plane antenna according to claim 6, wherein said plurality of serially connected sub-sections form a horizontal meander pattern perpendicular to the first section, whereby the second section is substantially parallel to the ground-plane;

8. The ground-plane antenna according to claim 6, wherein the first sections of said plurality of sub-elements are connected together at a location proximate to the second sections.

9. The ground-plane antenna according to claim 6, wherein the plurality of sub-elements are conductors of wire, rod, tubing or printed circuit trace.

10. The ground-plane antenna according to claim 6, wherein said ground-plane is a multi-wire radial system of conductors, each having a length of not more than one-quarter wavelength.