PHYSICALLY SMALL COMBINED LOOP AND DIPOLE ALL CHANNEL TELEVISION ANTENNA SYSTEM

• US 3,721,990 A
• Filed: 12/27/1971
• Issued: 03/20/1973
• Est. Priority Date: 12/27/1971
• Status: Expired due to Term

• Current Assignee: RCA Corporation (General Electric Company)
• Original Assignee: Donald William Peterson, John James Gibson
• Inventors: Gibson, John James, Peterson, Donald William
• Primary Examiner(s): Lieberman, Eli
• Application Number:
  US05/212,431
• Time in Patent Office: 449 Days
• Field of Search: 343/726,727,728,740,744,795,853
• US Class Current: 343/726
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

A low cost, physically small, all channel television antenna system is provided for reception in high signal strength areas. The antenna is characterized by a loop having a pair of separated gaps, one of which is a feed gap and the other an impedance termination gap for operating as a directional reception antenna at the low and high VHF television frequency bands. Inboard the loop is placed a television band UHF dipole antenna. The input terminals of the dipole antenna and the feed terminal of the loop antenna are each coupled to a combiner with a single output from the combiner.

Claims

1. An antenna system for operation in the very high frequency band and in the ultra high frequency band comprising:

a conductive loop having a pair of gaps at opposite points along said loops, a first of said gaps forming a pair of feed terminals adapted to be coupled to a first transmission line, a predominantly resistive impedance serially connected in said loop and across the second of said pair of gaps located directly opposite the first of said pair of gaps, the linear dimension of said loop between diametrically opposed points on said loop midway between the pair of gaps being less than a half of an operating very high frequency wave such that said loop has a maximum response to said signals in the direction of said first gap and a lesser response in the opposite direction, an ultra high frequency dipole element fixed substantially inboard said loop and having a total length to act as a half wavelength dipole element for a frequency within the ultra high frequency band, said dipole element having terminal means adapted to be coupled to a second transmission line.

2. The combination claimed in claim 1, wherein said dipole element is a bow tie antenna element adapted to provide reception over the entire television ultra high frequency band.

3. The combination claimed in claim 1, wherein the feed terminals of said loop are aligned with the feed terminals of said dipole element.

4. The combination claimed in claim 3, including a thin metal strip fixed rearward of said dipole relative to the terminals of the feed of said loop element.

5. The combination claimed in claim 4, including a pair of colinear thin metal strips forward of said dipole element between the dipole element and said loop element feed.

6. The combination claimed in claim 3, including a combiner, said combiner having a pair of input terminals and an output terminal, said combiner including between a first of said pair of input terminals and said output terminal, a relatively low pass filter for providing low loss coupling of signals within the very high frequency band and for presenting a high reactance to signals within the ultra high frequency band, said combiner including between a second of said pair of input terminals and said output terminal a relatively high pass filter for providing low loss coupling of signals within the ultra high frequency band for presenting a high reflective reactance to signals within the very high frequency bands, said first transmission line being coupled between said first input terminal of said combiner and said feed terminals of said conductive loop elements, said second transmission line being coupled between said second input terminal and said feed terminals of said ultra high frequency dipole element.

7. The combination claimed in claim 1, wherein said loop has slots therein with at least one slot being a given distance from the first feed terminal of said loop and at least one other slot being said given distance from the second feed terminal of said loop.

8. The combination claimed in claim 7, wherein said given distance is at least a quarter wavelength at a frequency within said ultra high frequency band.

9. The combination claimed in claim 1, wherein said conductive loop is just slightly larger in diameter than the length of said dipole element.

10. The combination claimed in claim 1, wherein said very high frequency band includes said low and high very high frequency television frequency bands and the circumference of the loop is less than a half of an operating wave at the low very high frequency television band.

11. The combination claimed in claim 10, wherein said dipole element is fixed inboard the loop element with the plane of the dipole element spaced less than a half a television ultra high frequency band wavelength from the plane of the loop.

12. The combination claimed in claim 11, wherein said dipole element is fixed in the plane of the loop.