US3922684A - Radio antennae encased in dielectric to reduce size - Google Patents
Radio antennae encased in dielectric to reduce size Download PDFInfo
- Publication number
- US3922684A US3922684A US478890A US47889074A US3922684A US 3922684 A US3922684 A US 3922684A US 478890 A US478890 A US 478890A US 47889074 A US47889074 A US 47889074A US 3922684 A US3922684 A US 3922684A
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- United States
- Prior art keywords
- antenna
- titanate
- cylinder
- dielectric
- constituents
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/40—Radiating elements coated with or embedded in protective material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
- H01Q19/06—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using refracting or diffracting devices, e.g. lens
- H01Q19/09—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using refracting or diffracting devices, e.g. lens wherein the primary active element is coated with or embedded in a dielectric or magnetic material
Definitions
- a workable ratio antenna can be made if an electrical conductor is surrounded by low loss. high permittn ity. dielectric material.
- Such an antenna which can be used for either transmission or reception. requires a smaller length of conductor for a given frequency than does an antenna with no dielectric.
- a further adv antage of such an antenna lies in the protection from impact and weather which is afforded to the conductor by the surrounding dielectric.
- a suitable dielectric material was found to be barium titanate.
- the material was prepared in powder form. and was held around the conductor by means of a container. For a conductor of (1.3 cm radius. it was found that an internal container radius of about IO cm was desirable for satisfactory functioning of the antenna.
- a radio antenna comprising an electrical conductor in combination with dielectric material.
- the dielectric material is a body of compacted constituents.
- the material is prepared from barium carbonate, strontium carbonate and titanium dioxide. which are mixed together in or about the proportion of 46012293 l0 parts respectively by weight. Water is added. and the mix is milled for aproximately 1 hour. after which the mix is o ⁇ en dried and sieved. The sieving yields a powder which is pressed into blocks at around 2 tons per square inch. The blocks are then fired at approximately I350C for about 2 hours. During the firing process. the carbonates are converted into the titanates. and carbon dioxide is liberated. After the firing process. the blocks are fragmented by being quenched from I350C into water. The fragments are ground and milled until a substantially uniform powder is obtained. the powder being subsequently dried and sieved.
- This powder is then compacted into rods either hydrostatically or by extrusion.
- the powder In the hydrostatic method. the powder is subjected to a pressure of 33 tons per square inch and fired at [200C In the extrusion method. the powder is mixed with polyvinyl alcohol.
- Rods prepared in this way can be bored to receive a conductor.
- a conductor of radius 0.3 cm. a rod radius of less than It) cm is acceptable.
- FIGS. l4 Various antenna constructions are possible. Four possible constructions are shown in cross section in FIGS. l4 respectively of the accompanying drawings.
- signals are conveyed to or from the antenna by a coaxial cable.
- a coaxial cable comprising a core I and a sleeve 2.
- the core I is joined to a conducting rod 3 of the antenna.
- the rod 3 is located in a central bore of a cylinder 4 of compacted dielectric material. conveniently made in the manner just described.
- the cable sleeve 2 is connected: in FIG. I to a conductive ground plate 5 extending at right angles to the rod 3: in FIG. 2 to a conductive annulus 6 encircling the core I where the core joins the rod 3: and in FIG. 3 by a wire 7 to a conductive band 8 encircling the cylinder 4 near its mid point.
- the cylinder 10 of dielectric material is solid and has a conductive disc at each end as shown at II. I2.
- the cable core I is joined directly to the disc II. and the sleeve 2 is joined by a wire [3 to the disc I2.
- Alternative dielectric materials can be prepared by mixing (a) lanthanum oxide. magnesium carbonate and titanium oxide in or about the proportion of 25:72:25 parts respectively by weight; and (b) calcium oxide. bismuth oxide and titanium oxide in or about the proportion of 23:3l:46 parts respectively by weight. With mixture (at) the constituents of the resulting dielectric material are lanthanum titanate and magnesium titanate; and with mixture (b) calcium titanate and bismuth titanate.
- a radio antenna comprising an electrical conductor in combination with low-loss high permittivity dielectric material formed of a mixture of titanates compacted under pressure to form a rigid structure.
- said dielectric matcrial being a single cylindrical body of uniform diameter with a central hold bored therein to receive the electrical conductor along the length thereof.
- An antenna as claimed in claim I which includes a conductive ground plate extending at right angles to the cylinder at one end of the cylinder.
- An antenna as claimed in claim I which includes a conductive annulus at one end of the cylinder.
- An antenna as claimed in claim I which includes a conductive band encircling the cylinder about the midpoint of the cylinder.
Abstract
A radio antenna in which the length of conductor needed is appreciably reduced by the use of a compacted dielectric material as part of the antenna. Various constructions and various dielectric materials are considered.
Description
United States Patent :wi
Wright 1 Nov. 25, I975 l 'l RADIO AN'l'l'lNN/ili ENCASED IN [)ll'lLlLtlRlC TO REDUCE. SIZE Hubert Charles Wright. Bliswurth, England [75] lnvcntm.
Plesse Handel und Investments A.(;.. lissex, England 221 Filed: June 12, 1974 21; Appl No 478,890
17 ii Asslgneei [3U] Foreign Application Priority Data Aug 3t) 1971 tinned Kingdom 408lU/73 2.6M 1.869 9/l952 Willoughhy. .7 343/873 2,748,386 5/!956 Polydoroft 343/787 1769170 l()/l956 Clogston .7 343/873 35181183 6/!970 Jones. H. 341/873 177L157 ll/l973 Slang H lit/7R7 Primary Examiner-Eli Lieberman Attorney, Agenr, nr FirmScrivencr Parker Scrivener & Clarke I ABSTRACT A radio antenna in which the length of conductor needed is appreciably reduced by the use of a compacted dielectric material as part of the antenna. Various constructions and various dielectric materials are considered.
7 Claims, 4 Drawing Figures US. Patent Nov. 25, 1975 3,922,684
F/G.3. F a l RADIO ANTENNAE ENCASIZI) IN DIELECTRIC TO REDUCE SIZE This invention relates to radio antennae and their manufacture.
It has been found. for example in British patent specification No. 27097/73 dated June 6. I973. that a workable ratio antenna can be made if an electrical conductor is surrounded by low loss. high permittn ity. dielectric material. Such an antenna. which can be used for either transmission or reception. requires a smaller length of conductor for a given frequency than does an antenna with no dielectric. A further adv antage of such an antenna lies in the protection from impact and weather which is afforded to the conductor by the surrounding dielectric.
A suitable dielectric material was found to be barium titanate. The material was prepared in powder form. and was held around the conductor by means of a container. For a conductor of (1.3 cm radius. it was found that an internal container radius of about IO cm was desirable for satisfactory functioning of the antenna.
According to the invention there is provided a radio antenna comprising an electrical conductor in combination with dielectric material. in which the dielectric material is a body of compacted constituents.
The material is prepared from barium carbonate, strontium carbonate and titanium dioxide. which are mixed together in or about the proportion of 46012293 l0 parts respectively by weight. Water is added. and the mix is milled for aproximately 1 hour. after which the mix is o\ en dried and sieved. The sieving yields a powder which is pressed into blocks at around 2 tons per square inch. The blocks are then fired at approximately I350C for about 2 hours. During the firing process. the carbonates are converted into the titanates. and carbon dioxide is liberated. After the firing process. the blocks are fragmented by being quenched from I350C into water. The fragments are ground and milled until a substantially uniform powder is obtained. the powder being subsequently dried and sieved. This powder is then compacted into rods either hydrostatically or by extrusion. In the hydrostatic method. the powder is subjected to a pressure of 33 tons per square inch and fired at [200C In the extrusion method. the powder is mixed with polyvinyl alcohol.
Rods prepared in this way can be bored to receive a conductor. For a conductor of radius 0.3 cm. a rod radius of less than It) cm is acceptable.
Various antenna constructions are possible. Four possible constructions are shown in cross section in FIGS. l4 respectively of the accompanying drawings.
In each example signals are conveyed to or from the antenna by a coaxial cable. comprising a core I and a sleeve 2. In FIGS. I. 2, 3 the core I is joined to a conducting rod 3 of the antenna. The rod 3 is located in a central bore of a cylinder 4 of compacted dielectric material. conveniently made in the manner just described. The cable sleeve 2 is connected: in FIG. I to a conductive ground plate 5 extending at right angles to the rod 3: in FIG. 2 to a conductive annulus 6 encircling the core I where the core joins the rod 3: and in FIG. 3 by a wire 7 to a conductive band 8 encircling the cylinder 4 near its mid point. In the embodiment of FIG. 4, the cylinder 10 of dielectric material is solid and has a conductive disc at each end as shown at II. I2. The cable core I is joined directly to the disc II. and the sleeve 2 is joined by a wire [3 to the disc I2.
Using a compacted mixture of barium strontium titanate as a dielectric in a reception antenna. it has been found possible to make the length ofthe rod 3 equal to one eighth of the length required for an antenna with no dielectric. the frequency employed being (183MHz. At a frequency of 90MH2. the fraction was one fifth.
When used as for transmitting in the band 400-500MH2. a conductive rod surrounded by dielectric showed a gain of Sdb compared with a rod of equal length having no dielectric.
Alternative dielectric materials can be prepared by mixing (a) lanthanum oxide. magnesium carbonate and titanium oxide in or about the proportion of 25:72:25 parts respectively by weight; and (b) calcium oxide. bismuth oxide and titanium oxide in or about the proportion of 23:3l:46 parts respectively by weight. With mixture (at) the constituents of the resulting dielectric material are lanthanum titanate and magnesium titanate; and with mixture (b) calcium titanate and bismuth titanate.
It is to be understood that the foregoing description of specific examples of this invention is made by way of example only and is not to be considered as a limitation in its scope.
What is claimed is:
l. A radio antenna comprising an electrical conductor in combination with low-loss high permittivity dielectric material formed of a mixture of titanates compacted under pressure to form a rigid structure. said dielectric matcrial being a single cylindrical body of uniform diameter with a central hold bored therein to receive the electrical conductor along the length thereof.
2. An antenna as claimed in claim I in which the constituents are barium titanate and strontium titanate.
3. An antenna claimed in claim I in which the constituents are lanthanum titanate and magnesium titanate.
4. An antenna as claimed in claim I in which the constituents are calcium titanate and bismuth titanate.
5. An antenna as claimed in claim I which includes a conductive ground plate extending at right angles to the cylinder at one end of the cylinder.
6. An antenna as claimed in claim I which includes a conductive annulus at one end of the cylinder.
7. An antenna as claimed in claim I which includes a conductive band encircling the cylinder about the midpoint of the cylinder.
Claims (7)
1. A radio antenna comprising an electrical conductor in combination with low-loss high permittivity dielectric material formed of a mixture of titanates compacted under pressure to form a rigid structure, said dielectric material being a single cylindrical body of uniform diameter with a central hold bored therein to receive the electrical conductor along the length thereof.
2. An antenna as claimed in claim 1 in which the constituents are barium titanate and strontium titanate.
3. An antenna as claimed in claim 1 in which the constituents are lanthanum titanate and magnesium titanate.
4. An antenna as claimed in claim 1 in which the constituents are calcium titanate and bismuth titanate.
5. An antenna as claimed in claim 1 which includes a conductive ground plate extending at right angles to the cylinder at one end of the cylinder.
6. An antenna as claimed in claim 1 which includes a conductive annulus at one end of the cylinder.
7. An antenna as claimed in claim 1 which includes a conductive band encircling the cylinder about the mid-point of the cylinder.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB4081073 | 1973-08-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3922684A true US3922684A (en) | 1975-11-25 |
Family
ID=10416736
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US478890A Expired - Lifetime US3922684A (en) | 1973-08-30 | 1974-06-12 | Radio antennae encased in dielectric to reduce size |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3922684A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4223317A (en) * | 1977-12-27 | 1980-09-16 | Monogram Industries, Inc | Dual polarization antenna couplets |
| US5293174A (en) * | 1987-05-21 | 1994-03-08 | Kropielnicki Jerzy J | Vehicle antenna |
| US5394164A (en) * | 1992-07-16 | 1995-02-28 | The Narda Microwave Corp. | Human-equivalent antenna for electromagnetic fields |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2567260A (en) * | 1947-09-12 | 1951-09-11 | Carl A Wiley | Antenna with dielectric casing |
| US2611869A (en) * | 1944-04-21 | 1952-09-23 | Int Standard Electric Corp | Aerial system |
| US2748386A (en) * | 1951-12-04 | 1956-05-29 | Wladimir J Polydoroff | Antenna systems |
| US2769170A (en) * | 1952-05-29 | 1956-10-30 | Bell Telephone Labor Inc | Composite antenna structure |
| US3518683A (en) * | 1967-11-09 | 1970-06-30 | Us Army | Dielectric-loaded antenna with matching window |
| US3771157A (en) * | 1972-07-03 | 1973-11-06 | Lockheed Aircraft Corp | Ferrite broadband semi-notch antenna |
-
1974
- 1974-06-12 US US478890A patent/US3922684A/en not_active Expired - Lifetime
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2611869A (en) * | 1944-04-21 | 1952-09-23 | Int Standard Electric Corp | Aerial system |
| US2567260A (en) * | 1947-09-12 | 1951-09-11 | Carl A Wiley | Antenna with dielectric casing |
| US2748386A (en) * | 1951-12-04 | 1956-05-29 | Wladimir J Polydoroff | Antenna systems |
| US2769170A (en) * | 1952-05-29 | 1956-10-30 | Bell Telephone Labor Inc | Composite antenna structure |
| US3518683A (en) * | 1967-11-09 | 1970-06-30 | Us Army | Dielectric-loaded antenna with matching window |
| US3771157A (en) * | 1972-07-03 | 1973-11-06 | Lockheed Aircraft Corp | Ferrite broadband semi-notch antenna |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4223317A (en) * | 1977-12-27 | 1980-09-16 | Monogram Industries, Inc | Dual polarization antenna couplets |
| US5293174A (en) * | 1987-05-21 | 1994-03-08 | Kropielnicki Jerzy J | Vehicle antenna |
| US5394164A (en) * | 1992-07-16 | 1995-02-28 | The Narda Microwave Corp. | Human-equivalent antenna for electromagnetic fields |
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