US3868689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Log periodic pole mounted marker beacon antenna
Assignee: Texas Instruments Inc
•
Filing: 1973-07-30
•
Granted: 1975-02-25
•
Expires: 1993-07-30
Abstract
Abstract An ILS marker beacon antenna of the type wherein a pair of parallel conductors form a balanced transmission line and support a plurality of lateral radiators of graded lengths. An unbalanced RF transmission line extends through one of the conductors to the apex feed point of the antenna with one conductor of the unbalanced line connected to one of the pair of conductors and the other conductor of the unbalanced line connected to the other of the pair of conductors for flow of RF current from the feed point along the balanced transmission line to the radiating elements. An electrically small dipole monitor antenna mounted on the parallel conductors terminates the balanced transmission line by short circuit in a region near the back of the log periodic antenna to prevent back radiation and monitor antenna operation.
Inventors
- 👤 Charles C Liu
- 👤 Dean A Hofer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:26
CPC Classifications
H; H01; H01Q; H01Q11/00; H01Q11/02; H01Q11/10; G; G01; G01S; G01S1/00; G01S1/02; H01P; H01P5/00; H01P5/08; H01P5/10
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
100 words
An ILS marker beacon antenna which comprises: a. an antenna having a pair of spaced parallel conductors forming a balanced transmission line and a plurality of radiators of graded lengths extending from said pair of spaced parallel conductors to form a log periodic array, b. an unbalanced RF transmission line connected to feed said antenna at the apex, and c. a dipole monitor antenna structure mounted parallel to said radiators and including structure electrically to terminate said antenna by a short circuit near the bottom of said log periodic antenna to monitor the antenna field while minimizing back radiation thereof.
Claim 2
Dependent Claim
100 words
An ILS marker beacon antenna which comprises: a. an antenna having a pair of spaced parallel conductors forming a balanced transmission line and a plurality of radiators of graded lengths extending from said pair of spaced parallel conductors to form a log periodic array, b. an unbalanced RF transmission line connected to feed said antenna at the apex, and c. a dipole monitor antenna structure mounted parallel to said radiators and including structure electrically to terminate said antenna by a short circuit near the bottom of said log periodic antenna to monitor the antenna field while minimizing back radiation thereof.
Claim 3
Dependent Claim
33 words
The combination of claim 1 wherein said monitor structure is supported between said parallel conductors to monitor a field of log periodic antenna, modify its back radiation pattern and short circuit said conductors.
Claim 4
Dependent Claim
24 words
The combination of claim 1 wherein a pole supports said antenna with said parallel conductors vertical and said feed point at the top thereof.
Claim 5
Dependent Claim
144 words
An ILS marker beacon antenna which comprises: a. a log periodic antenna having a pair of parallel conductors forming a balanced transmission line with a plurality of radiators of graded lengths extending generally in a plane from said pair of parallel conductors, b. an unbalanced RF transmission line extending upward through one of said conductors to an apex feed point of said antenna, c. Means for connecting one conductor of said line to one of said pair of conductors and the other conductor of said line to the other of said pair of conductors for flow of RF current from said feed point downward along said transmission line to said radiators, and d. a dipole monitor structure mounted parallel to said radiators and having support structure connected electrically to terminate said antenna by a short circuit near the bottom of said log periodic antenna.
Claim 6
Dependent Claim
144 words
An ILS marker beacon antenna which comprises: a. a log periodic antenna having a pair of parallel conductors forming a balanced transmission line with a plurality of radiators of graded lengths extending generally in a plane from said pair of parallel conductors, b. an unbalanced RF transmission line extending upward through one of said conductors to an apex feed point of said antenna, c. Means for connecting one conductor of said line to one of said pair of conductors and the other conductor of said line to the other of said pair of conductors for flow of RF current from said feed point downward along said transmission line to said radiators, and d. a dipole monitor structure mounted parallel to said radiators and having support structure connected electrically to terminate said antenna by a short circuit near the bottom of said log periodic antenna.
Claim 7
Dependent Claim
171 words
An ILS marker beacon antenna which comprises: a. a log periodic antenna having a pair of spaced parallel conductors forming a balanced transmission line with a plurality of parallel radiators of graded lengths extending from said pair of spaced parallel conductors, b. means for supporting said antenna above the earth along an aircraft glide path with the apex vertical and with the radiators extending parallel to said glide path, c. a coaxial RF transmission cable passing upward through one of said conductors, d. means for connecting the inner conductor of said cable to one of said pair of conductors and for connecting the outer conductor of said cable to the other of said pair of conductors for flow of RF current from said feed point downward along said balanced transmission line to said radiating elements, and e. a monitor dipole mounted parallel to said radiators to sense the antenna field and having support structure connected electrically to terminate said antenna by short circuit near the bottom of said log periodic antenna.
Claim 8
Dependent Claim
171 words
An ILS marker beacon antenna which comprises: a. a log periodic antenna having a pair of spaced parallel conductors forming a balanced transmission line with a plurality of parallel radiators of graded lengths extending from said pair of spaced parallel conductors, b. means for supporting said antenna above the earth along an aircraft glide path with the apex vertical and with the radiators extending parallel to said glide path, c. a coaxial RF transmission cable passing upward through one of said conductors, d. means for connecting the inner conductor of said cable to one of said pair of conductors and for connecting the outer conductor of said cable to the other of said pair of conductors for flow of RF current from said feed point downward along said balanced transmission line to said radiating elements, and e. a monitor dipole mounted parallel to said radiators to sense the antenna field and having support structure connected electrically to terminate said antenna by short circuit near the bottom of said log periodic antenna.
Claim 9
Dependent Claim
107 words
Means to provide an electromagnetic field as a marker beacon along an airport glide path which comprises: a log periodic antenna pole mounted above the earth below said path with the apex up and radiating elements thereof parallel to said path, source means to excite said antenna at beacon frequency at said apex, means to short circuit said antenna near the back thereof, and means including a monitor antenna housing mounted in the region of said short circuit to provide a monitor signal dependent upon the existence of an electromagnetic field from said log periodic antenna and to null the back radiation from said log periodic antenna.
Claim 10
Dependent Claim
107 words
Means to provide an electromagnetic field as a marker beacon along an airport glide path which comprises: a log periodic antenna pole mounted above the earth below said path with the apex up and radiating elements thereof parallel to said path, source means to excite said antenna at beacon frequency at said apex, means to short circuit said antenna near the back thereof, and means including a monitor antenna housing mounted in the region of said short circuit to provide a monitor signal dependent upon the existence of an electromagnetic field from said log periodic antenna and to null the back radiation from said log periodic antenna.
Claim 11
Dependent Claim
28 words
The combination set forth in claim 6 in which said monitor antenna is supported by conductive means, which conductive means contacts said antenna to establish said short circuit.
Claim 12
Dependent Claim
24 words
The combination set forth in claim 6 in which coupling structure connects said source means to said antenna for balanced transmission line operation thereof.
Claim 13
Dependent Claim
43 words
The combination set forth in claim 7 in which an unbalanced transmission line feeds excitation current to said apex through one of two transmission line elements of said antenna and a balanced feed connecting structure connects said unbalanced line to said antenna apex.
Claim 14
Dependent Claim
52 words
The combination set forth in claim 9 in which said transmission line is a coaxial cable insulated from one element and wherein coupling means connects the shield of said coaxial cable to said one element and the center conductor of said cable to the other of said two elements at said apex.
Claim 15
Dependent Claim
85 words
The combination set forth in claim 9 in which: said two elements are electrically short circuited by said housing near the back of said log periodic antenna, an insulator couples said elements in spaced apart relation at said apex, two conductors on said insulator are each connected to one of said two elements, and an excitation source including a coaxial cable extends through one of said elements and terminates at said two conductors for balanced excitation of said log periodic antenna from the apex thereof.
Claim 16
Independent Claim
62 words
The method of establishing an electromagnetic field as a marker beacon along an airport glide path which comprises: exciting a pole mounted log periodic antenna with radiating elements parallel to said path with the apex of said antenna directed upward, and shorting said antenna near the back thereof with monitor antenna strucTure to null the back radiation while establishing a monitor signal.
Claim 17
Independent Claim
62 words
The method of establishing an electromagnetic field as a marker beacon along an airport glide path which comprises: exciting a pole mounted log periodic antenna with radiating elements parallel to said path with the apex of said antenna directed upward, and shorting said antenna near the back thereof with monitor antenna strucTure to null the back radiation while establishing a monitor signal.
Claim 18
Dependent Claim
29 words
The method of claim 12 in which excitation current is fed to said apex through an element of said antenna for balanced feed of said antenna at said apex.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |