US3796972A - Simulated antenna - Google Patents

Simulated antenna Download PDF

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Publication number
US3796972A
US3796972A US00253486A US3796972DA US3796972A US 3796972 A US3796972 A US 3796972A US 00253486 A US00253486 A US 00253486A US 3796972D A US3796972D A US 3796972DA US 3796972 A US3796972 A US 3796972A
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US
United States
Prior art keywords
tape
metallic
antenna structure
simulated antenna
housing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00253486A
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English (en)
Inventor
O Snedkerud
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Patelhold Patenverwertungs and Elektro-Holding AG
Original Assignee
Patelhold Patenverwertungs and Elektro-Holding AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Patelhold Patenverwertungs and Elektro-Holding AG filed Critical Patelhold Patenverwertungs and Elektro-Holding AG
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Publication of US3796972A publication Critical patent/US3796972A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/38—Impedance-matching networks
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/40—Means for monitoring or calibrating
    • G01S7/4004—Means for monitoring or calibrating of parts of a radar system
    • G01S7/4008—Means for monitoring or calibrating of parts of a radar system of transmitters

Definitions

  • a simulated antenna structure for use in conjunction with trial or experimental operation of a radiant en- PP NOJ 253,486 ergy transmitter includes a metallic tape extending in a meandering fashion in one or more parallel planes
  • Foreign Application Priority Data over supporting insulators located within a housing Ma 28 1971 Switzerland 7823/71 through which a current of cooling air is passed in y heat transfer relation with the tape.
  • One end of the 4 tape is connectible to the output terminal of the trans- (g1.
  • SIMULATED ANTENNA This invention relates to an improved construction for a simulated antenna for use in conjunction with trial or experimental operations of radiant energy transmitters.
  • simulated antennas consisting of systems of ohmic resistances are being used for this purpose, these being as radiation-free as possible, and which are usually utilized at the same time to measure calorimetrically the transmitter output being supplied.
  • Most simple in design, and thus relatively inexpensive, are aircooled resistances which are suitable for maximum outputs in the medium and long-wave ranges.
  • fabrics made from resistance wire (weft) and asbestos cord (warp) which due to their bifilar characteristic are of low inductance similar to cross-wound resistances.
  • the mismatch should be held below 1.1 for frequencies in the long and medium wave ranges (up to approximately 5 MHz), and the manufacture of such antenna should be possible at low cost.
  • the invention solves this problem by providing a metal tape which runs in a meandering fashion within at least one plane, its beginning to be connected to a transmitter output and its end to the ground terminal of the transmitter, and by connecting capacities from this end to several points which are distributed along the metal tape at substantially equal distances.
  • the advantage offered by the invention is due primarily to the simple and sturdy method of construction which results, in comparison with the known simulated or artificial antennas of the above described type, in a substantially greater durability.
  • the simulated antenna as proposed by the invention has a substantially greater band width, compared with the present state of art, a fact which will become readily apparent from the description given below.
  • FIG. 1 is a front elevational view of one embodiment 'of the improved simulated antenna structure
  • FIG. 2 is a sectional view taken along line X-Y in the direction of the arrow;
  • FIG. 3 shows the equivalent electrical circuit for the anntenna structure illustrated in FIGS. 1 and 2;
  • FIG. 4 is a view of a modified arrangement for the meandering tape and capacitor components of FIGS. 1 and 2;
  • FIG. 5 is a view of another modification for the meandering tape and capacitor components of the antenna.
  • a housing for the simulated antenna components is indicated at I.
  • This housing is provided with cylindrical, or tubular insulators 2 installed between its side walls.
  • flanged openings 3 are provided which serve-for attachment of a fan and duct assembly, not illustrated, which serves to blow air through the simulated antenna structure in a direction parallel with the opposite faces of the metal tape 4.
  • the extent of the lateral openings through which air is blown by the fan through the housing is indicated in FIG. 2 by an interrupted line 3.
  • the front wall of housing 1 is to be considered transparent, so that the windings of the metal tape 4 become visible. In the case of this illustration the metal tape 4 runs within three planes.
  • the metal tape 4 is conducted with the aid of the insulators 2 in a meandering fashion, a fact which is more clearly shown by FIG. 2. More particularly, within each of the three .meander planes, the tape 4 is seen to be constituted by a series of, straight sections 4 c alternating with curved sections 4d such that the straight sections 4c of the tape are supported between upper and lower rows of parallel spaced insulators 2 around and in contact with whichthe curved tape sections 4d lie, and the plane of the meandering path is disposed at a right angle to the plane of the straight tape sections.
  • the beginning 5 of the metal tape 4 is lead through the insulating bushing 6 to the outside of housing 1 and can thus be connected to a transmitter output.
  • capacitors In order to compensate for the inductivity of the metal tape 4, capacities are connected" from its end to points which are distributed at equal distances along the metal tape 4.
  • Commerciallly available capacitors can be used for this purpose, or a special design, as shown diagrammatically in FIGS. 1 and 2, can be employed.
  • Inside the housing 1 there are arranged metal bars 9. Two such metal bars 9 are required for each plane. They are electrically connected with the end 7 of the metal tape 4 and represent one plane of a con denser.
  • a dielectric medium (for example mica) 10 is applied to each metal bar 9.
  • the construction of the condensers is completed by metal plates 11 which are connected by way of stranded wires 12 with the proper points of the metal tape 4.
  • the extended leg of the metal L-shaped bracket 8 can also function as a metal bar 9, If the housing 1 is made of metal with a sufficiently level surface, the metal bars 9 can be omitted by applying the dielectric medium 10 directly at the inner wall of the housing 1.
  • the metal tape 4 preferably has a thickness of approximately 0.2 mm and a width of to cm. It can consist, for example, of a copper alloy, but any other materials which are electrically conductive and are sufficiently stable under mechanical and thermal stresses can also be used. At a thickness of 0.2 mm, a skin effect-will begin to appear only at approximately 10 MHz and will therefore not interefere. Important however is the maximum electrical carrying capacity per unit area (that is wattlcm which is related to the material and can be computed from the allowable running temperature and the thermal dissipation at a specific cooling-air velocity and temperature.
  • the maximum allowable operating temperature of the metal tape 4 will give the maximum carrying capacity per unit area (watt/cm).
  • the maximum allowable resistance per unit of length ohm/cm. Since the d.c. resistance of the simulated antenna is determined by the transmitter (for example 60 ohm), the required total length of the metal tape 4 can thus be computed.
  • the metal tape 4 is divided into sections similar to a lattice network.
  • FIG. 3 shows some of these sections in the form of an equivalent circuit.
  • AL and AR denote the inductance and the ohmic resistance respectively of one section, and AC represents the capacitance assigned to the specific section.
  • the wave impedance Z of the simulated antenna (also called its characteristic impedance) is computed according to the formula:
  • the wave impedance Z is to be equal to the d.c. resistance so that the required capacitances AC can be computed by use of the formula above (AL is known).
  • each section also possesses a low-pass filter characteristic; therefore the wave impedance Z can be determined by the above formula only in the case of frequencies which are sufficiently below the resonant frequency.
  • the inducance L of the simulated antenna is greater than the inductance of a simulated antenna using resistance wire mats, such antennas representing the present state of art, the division into a multitude of sections will result in such small values AL and AC, that the resonant freqency will be much higher.
  • FIG. 4 shows, in a simplified manner, a second embodiment of the invention.
  • the metal tape 4 is seen to run in a meandering fashion, in like manner as shown in FIGS. 1 and 2, but tubular insulators 21 are provided here which carry tubular metal linings 22 at their inner surfaces. These metal linings 22 are electrically connected with the end 7 of the metal tape 4, and function, in conjunction with the surfaces of the metal tape 4 in contact with the outer surfaces of the tubular insulators 21, as capacitances. Since such cylindrical or tubular insulators are needed in any event for the purpose of guiding the metal tape 4, and since the metal linings 22 can be attached without any difficulties, the second embodiment of the invention, shown diagrammatically in FIG. 4, does represent an advantageous and simplified development of a simulated antenna. In order to obtain the required capacity value AC, it is only necessary to design the tubular insulators 21 in such manner that their walls have the appropriate thickness.
  • FIG. 5 A third embodiment of the invention is shown in FIG. 5, likewise in a simplified manner.
  • the metal tape 4 is guided along a meandering path inside the housing 1 by the insulators 2 in the same manner as shown by FIGS. 1 and 2.
  • Metal plates 13 project into the loops formed by the metal tape 4 and are electrically connected to the end 7 of the metal tape 4. If the housing 1 consists of metal, the electrical connection is ensured automatically.
  • the areas of the metal plates 13 which are disposed opposite the metal tape 4 willfunction as capacities. In this manner there is produced a capacity cover, distributed nearly uniformly over the entire metal tape 4 (with the exception of'the tape-bending areas if the housing l is non-metallic).
  • the values AL, AR and AC are replaced by incrementally small values dL, dR and dC, From these extremely small incremental values, there will result a still greater increase in the band width.
  • the wave impedance Z in case of this embodiment can be computed approximately by. use of the equation 2 60 lo 2.55 D/b,
  • a simulated antenna structure for use in conjunction with trial or experimental operation of a radiant energy transmitter comprising a metallic tape extending in a meandering path comprising a series of straight sections alternating with curved sections, said meandering path being arranged within atleast one plane which is located at a right angle to the plane of said straight section, one end of said tape being connectible to the output terminal of the transmitter and the other end thereof being grounded, and capacities connected respectively between the grounded end of said tape and substantially equally spaced points along said tape.
  • a simulated antenna structure as defined in claim 1 wherein the meandering path of said metallic tape is arranged within a plurality of parallel planes and wherein the portion of the tape located in one plane passes to the portion of the tape located in an adjacent plane by means of slanting straight section of the tape.
  • a simulated antenna structure as defined in claim 1 including tubular insulators said curved sections of supporting said meandering tape at substantially equally spaced locations therealong and wherein said spaced capacities are established by metallic linings within said tubular insulators and which are electrically connected to the grounded end of said tape.
  • a simulated antenna structure as defined in claim 1 including insulators supporting said curved sections of said meandering tape at substantially equally spaced locations therealong and wherein said spaced capacities are established by metallic plates projecting into the spaces formed between adjacent straight sections of said tape and which are electrically connected to the grounded end of said tape.
  • a simulated antenna structure as defined in claim 1 including tubular insulators supporting said curved sections of said meandering tape at substantially equally spaced locations therealong, andwherein said spaced capacities are established in part by metallic linings within said tubular insulators and also in part by metallic plates projecting into the spaces formed between adjacent straight sections of said tape, said metallic linings and said metallic plates being electrically connected to the grounded end of said tape.

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  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Details Of Aerials (AREA)
  • Support Of Aerials (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Arrangements For Transmission Of Measured Signals (AREA)
  • Monitoring And Testing Of Transmission In General (AREA)
US00253486A 1971-05-28 1972-05-15 Simulated antenna Expired - Lifetime US3796972A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH782371A CH531813A (de) 1971-05-28 1971-05-28 Künstliche Antenne

Publications (1)

Publication Number Publication Date
US3796972A true US3796972A (en) 1974-03-12

Family

ID=4330977

Family Applications (1)

Application Number Title Priority Date Filing Date
US00253486A Expired - Lifetime US3796972A (en) 1971-05-28 1972-05-15 Simulated antenna

Country Status (9)

Country Link
US (1) US3796972A (enExample)
CH (1) CH531813A (enExample)
DE (2) DE2130015A1 (enExample)
ES (1) ES403215A1 (enExample)
FR (1) FR2140145B3 (enExample)
GB (1) GB1383542A (enExample)
NL (1) NL7207100A (enExample)
NO (1) NO130615C (enExample)
SE (1) SE371731B (enExample)

Also Published As

Publication number Publication date
NL7207100A (enExample) 1972-11-30
NO130615C (enExample) 1975-01-08
CH531813A (de) 1972-12-15
ES403215A1 (es) 1975-05-01
FR2140145B3 (enExample) 1975-08-08
DE2130015A1 (de) 1972-12-07
DE7123314U (de) 1973-06-28
NO130615B (enExample) 1974-09-30
SE371731B (enExample) 1974-11-25
FR2140145A1 (enExample) 1973-01-12
GB1383542A (en) 1974-02-12

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