US3165748A - Series fed log periodic antenna with coplanar conductor pairs - Google Patents
Series fed log periodic antenna with coplanar conductor pairs Download PDFInfo
- Publication number
- US3165748A US3165748A US180483A US18048362A US3165748A US 3165748 A US3165748 A US 3165748A US 180483 A US180483 A US 180483A US 18048362 A US18048362 A US 18048362A US 3165748 A US3165748 A US 3165748A
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- US
- United States
- Prior art keywords
- conductor
- pair
- pairs
- aerial
- conductor pairs
- 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
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q11/00—Electrically-long antennas having dimensions more than twice the shortest operating wavelength and consisting of conductive active radiating elements
- H01Q11/02—Non-resonant antennas, e.g. travelling-wave antenna
- H01Q11/10—Logperiodic antennas
Definitions
- This invention relates to directional aerial systems and has for its object to provide improved directional aerial systems of relatively cheap and simple construction suitable for use for high frequency communication and simil lar purposes and which can be constructed to be of large bandwidth, good impedance matching qualities and low side lobe level, i.e., such that the polar diagram of radiation exhibits only small side lobes adjacent the lobe corresponding to the main intended direction of radiation or reception.
- Aerial systems according -to this invention may be used equally well for transmission and reception.
- a directional aerial system comprises a plurality of conductor pairs of progressively dilfering lengths, the conductors of each pair being of substantially the same length, close together, and connected together at one end, and a plurality of series connecting substantially co-linear connectors of progressively different lengths and extending substantially at right angles to the conductors of the conductor pairs, each connector connecting the free end of one conductor of one pair to the free end of one conductor of the next pair, the ratio of the electrical length of each conductor pair to the electrical length of the connector connecting it to the next conductor pair of smaller length being substantially the same in all cases and the ratio of the electrical length of each conductor pair to that of the next conductor pair of smaller length being also substantially the same in all cases.
- the system is thus a series array and feeder means in association therewith are arranged at the end where the conductor pair of smallest length is situated.
- the various parts of the aerial system are so dimensioned that, at any particular given frequency within the intended working frequency range, one of the conductor pairs is electrically a quarter of a wavelength long and the connector connecting it to the adjacent smaller conductor pair is of an electrical length chosen to be at some value between one-twentieth and one-quarter of a wavelength. At this particular frequency this conductor pair will be the resonant part of the system.
- balanced feeder means is employed with the two wires oi a balanced feeder connected to the adjacent connectors at the smaller end of the whole system.
- Such abalanced aerial system will, of course, have a plane of polarisation dependent on the common plane oi the conductor pairs-vertical if the common plane is vertical and horizontal if the common plane is horizontal.
- the invention is not limited to plane polarised aerials.
- circular polarisation can be obtained by employing two component aerial systems each in accordance with this invention and each having alternate conductor pairs at right angles to the ⁇ other pairs, arranged with their connectors close together so that corresponding alternate conductor pairs of both component systems are in ⁇ one common plane and the remaining conductor pairs are ⁇ in a second common plane at right angles to the rst.
- This embodiment is again a balanced system and is also employed in conjunction with a balanced feeder.
- a director system of the Yagi type comprises parallel elements arranged in manner corresponding to that of the conductor pairs of the aerial system with which it is employed and extending from a backbone conductor substantially in line with the connectors of said aerial system.
- the director elements are unbalanced the director elements all extend parallel to one another on the same side of the backbone conductor, the said elements and the conductor pairs of the aerial system being in a common plane.
- each director element is symmetrical with respect to the backbone conductor and again in a common plane with the conductor pairs of the aerial system.
- each director element is symmetrical with respect to the backbone conductor and alternate director elements are in one plane and the remaining director elements are in a plane perpendicular thereto, alternate director elements which are co-planar with one another being also co-planar with alternate conductor pairs in the balanced circularly polarised balanced aerial system.
- FIGURE 1 shows one embodiment which is of the unbalanced type
- FIGURE la shows a detail modification of the embodiment of FIG- URE 1
- FIGURE 2 shows, in conventional graphical manner, polar radiation diagrams obtainable from an aerial system as represented in FIGURE l
- FIGURE 3 shows a system of the nature of that of FIGURE 1 with an associated director array of the Yagi type
- FIGURE -4 shows a plane polarised balanced aerial system in accordance with the invention
- FIGURE shows a system of the nature of that of FIGURE 4 with an associated Yagi-type director array
- FIGURE 6 shows acircularly polarised balanced aerial system in accordance with the invention
- FIGURE 7 shows a system of the nature of that of FIGURE 6 employed with an associated Yagitype director array.
- Like references denote like parts throughout. n
- the aerial system therein shown comprises a plurality of (in the particular case illustrated eleven) conductor pairs referenced Pl to PII inclusive each consisting of ⁇ two conductors referenced I and 2 in all cases. These conductors are all vertical and the conductors of each pair are connected together at their upper ends by connections which are very short since the said conductors of each pair are close together.
- the conductor pairs are connected together in series to form a series array by co-linear conductors referenced C2 to CII inclusive.
- the ratio of the electrical length (height) of each conductor pair to the electrical length of the connector connecting it to the next, smaller, conductor pair is constant throughout the system and the electrical lengths of the conductor pairs increase logarithmically from the shortest pair P1 to the longest pair P11.
- H1, H2, H3 H11 are the electrical lengths of the conductor pairs P1, P2 Pil respectively, then and so on, where k is a constant.
- the reciprocal of k, i.e., 1/ k may be referred 4to as the taper of the system.
- the co-linear connectors C2 to CII are close to the ground plane G so that radiation therefrom is very small. There will also be negligible small radiation from the horizontal connections between the conductors of each pair, since these connections are of negligible length.
- a feeder shown as a screened cable F is connected to the system at the smaller end.
- the resonant conductor pair being that pair which has an electrical length of a quarter of a wavelength at the particular frequency considered.
- the resonant pair is spaced from the next smaller pair by a distance which is from 1/0 to 1A of a wavelength at the frequency considered, the optimum distance depending on the taper, the value of which determines the gain of the array.
- the limits of bandwidth of the system are set by the dimensions of the longest and shortest conductor pairs and it is possible to design a single aerial system to cover the whole high frequency band.
- the aerial system is not only structurally simple in itself, but it can be supported by a single mast which need only be a little over a quarter of a wavelength high at the lowest frequecny in the band for which the system is designed.
- a mast is represented in FIG- URE 1 by the broken line M, the conductor pairs being supported as conventionally indicated from a stay or guy S leading down at an angle from the top of the mast.
- the connectors C2 to CII inclusive may be and prefer-l ably are constituted by short lengths of screened co-axial cable. This is illustrated in FIGURE la which shows a modification of this nature, the said ligure showing this modification (to a larger scale) for the ringed round portion of FIGURE l.
- FIGURE 2 shows in conventional manner horizontal and vertical polar radiation diagrams which have been obtained from an experimental system as shown in FIG- URE l.
- the full line curve HPD is the horizontal plane polar diagram
- the chain line curve VPD is the vertical plane polar radiation diagram in the direction X which corresponds to the direction X of maximum radiation-endwise-shown in FIGURE l.
- FIGURE 3 shows an arrangement of the nature of that of FIGURE 1 combined with a Yagi-type director consisting of vertical director elements D.
- These elements hl may be regarded as extending from a backbone conductor, although in fact, in FIGURE 3 because the elements D are vertical, there is no separately provided backbone conductor, the ground plane itself serving as the backbone conductor.
- FIGURES l and la show unbalanced systems with associated unbalanced feeders.
- FIGURE 4 shows a balanced system. As will be seen, it consists in effect of two component systems, each of the general nature of that of FIGURE l in mirror image arrangement with the connectors close together and parallel.
- references corresponding to those used in FIGURE 1 are applied to one component system and similar but primed references are applied to the other component system.
- FIGURE 5 is largely self-explanatory. It shows an aerial system of the nature of that illustrated by FIGURE 4 used as a launcher in association with a Yagi director system Vcomprising director elements D extending from a backbone conductor referenced BC. In FIGURE 5 there is an extension BCE of the backbone conductor back between the connectors of the launching aerial system. This back-extension is, of course, not necessary, but its provision is preferred.
- FIGURE 6 shows another balanced aerial system which is, however, circularly polarised.
- the system of FIG- URE 6 differs from that of FIGURE 4 in that all the conductor pairs are not co-planar but alternate pairs are in one plane and the remaining pairs in a second plane perpendicular to the first.
- the odd numbered pairs PI, PI; P3, P3 P13, P13 are in a vertical plane and the even numbered pairs P2, P2', P4, P4 Pll21, P12" are in a horizontal plane.
- the even numbered pairs look inclined in FIGURE 6, but this is only in order to represent, in perspective manner, that the even numbered pairs are as stated, at right angles to the odd numbered pairs.
- All the conductor pairs are at right angles to the line of the substantially co-linear connectors which are, of course, crossed over between the pairs PI, PI and P2, P2', the pairs P3, P3 and P4, P4 PII, Pill. and P12, P12 as indicated.
- FIGURE 7 shows a system of the nature of that of FIGURE 6 employed with a Yagi director arrangement.
- FIGURE 7 is largely self-explanatory.
- the Yagi comprises a backbone conductor BC substantially co-linear with the line of connectors of the launching aerial system and director elements DE and DO, of which the alternate elements DE are vertical and the remaining elements DO are horizontal.
- a series array directional aerial system comprising a plurality of conductor pairs of progressively differing lengths, the conductors of each pair being of substantially the same length, close together, and connected together at one end, and a plurality of series connecting substantially co-linear connectors of progressively different lengths and extending substantially at right angles to the conductors of the conductor pairs, each connector connecting the free end of one conductor of one pair to the free end of one conductor of the next pair, the ratio of the electrical length of each conductor pair to the electrical length of the connector connecting it to the next conductor pair of smaller length being substantially the same in all cases and the ratio of the electrical length of each conductor pair to that of the next conductor pair of smaller length being also substantially the same in all cases.
- An aerial system as claimed in claim 1 wherein the parts of said aerial system are so dimensioned that, at a selected frequency within the intended Working frequency range, one of the conductor pairs is electrically a quarter of a wavelength long and the connector connecting said one conductor pair to the adjacent smaller conductor pair is of an electrical length of between one twentieth and one quarter of a wavelength.
- a balanced plane polarised aerial system comprising two component aerial systems each as claimed in claim 1 arranged with their connectors close together and all the pairs of conductors of both component systems in a common plane, one component system being the mirror image of the other.
- a balanced circularly polarised aerial system coniprising two component aerial systems each as claimed in claim 1 and each having alternate conductor pairs at right angles to the other pairs, the connectors between alternate conductor pairs and the connectors between the other pairs being close together, so that corresponding alternate conductor pairs of both component systems are in one common plane and the remaining conductor pairs are in a second common plane at right angles to the said one common plane.
- a director system of the Yagi type comprising parallel director elements arranged in a manner corresponding to that of the conductor pairs of said aerial system and extending from a backbone conductor substantially in line with the connectors of said aerial system.
- a director system of the Yagi type comprising parallel director elements arranged in a manner corresponding to that of the conductor pairs of said aerial systems and extending from a backbone conductor substantially in line with the connectors of said aerial systems, each director element being symmetrical with respect to the backbone conductor and being in a common plane with the conductor pairs of the aerial systems.
- a combination as claimed in claim 10 wherein the backbone conductor has an extension lying midway between and parallel to the two lines of connectors of the two component aerial systems of the balanced system.
- a director system of the Yagi type comprising parallel director elements arranged in a manner corresponding to that of the conductor pairs of said aerial systems and extending from a backbone conductor substantially in line with the connectors of said aerial systems, each director element being symmetrical with respect to the backbone conductor, alternate director elements being in one plane and the remaining director elements in a plane perpendicular thereto, the alternate director elements which are co-planar with one another also being co-planar with alternate conductor pairs in the balanced circularly polarised aerial system.
Landscapes
- Variable-Direction Aerials And Aerial Arrays (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB11499/61A GB953805A (en) | 1961-03-29 | 1961-03-29 | Improvements in or relating to directional aerial systems |
Publications (1)
Publication Number | Publication Date |
---|---|
US3165748A true US3165748A (en) | 1965-01-12 |
Family
ID=9987380
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US180483A Expired - Lifetime US3165748A (en) | 1961-03-29 | 1962-03-19 | Series fed log periodic antenna with coplanar conductor pairs |
Country Status (4)
Country | Link |
---|---|
US (1) | US3165748A (xx) |
GB (1) | GB953805A (xx) |
NL (1) | NL276499A (xx) |
SE (1) | SE312591B (xx) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3271775A (en) * | 1963-07-25 | 1966-09-06 | Andrew Corp | Vertically polarized log-periodic antenna |
US3276027A (en) * | 1962-08-07 | 1966-09-27 | Granger Associates | Logarithmic periodic antenna |
US3369243A (en) * | 1965-01-18 | 1968-02-13 | Univ Illinois | Log-periodic antenna structure |
US3454950A (en) * | 1964-12-01 | 1969-07-08 | Jfd Electronics Corp | Multiple mode operational antennas employing reactive elements |
US4468675A (en) * | 1981-11-04 | 1984-08-28 | Robinson Lawrence P | Shortened antenna with coaxial telescoping cylinders |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1291803B (de) * | 1965-01-04 | 1969-04-03 | Blankenburg Antennen | Logarithmisch-periodische Dipolantenne |
DE1960076C3 (de) * | 1969-11-29 | 1982-02-11 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | Monopolar ausgebildete logarithmischperiodische Kurzwellenantenne |
DE2006510C2 (de) * | 1970-02-13 | 1982-07-22 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | Logarithmisch-periodische Kurzwellenantenne |
AU731954B2 (en) * | 1996-07-03 | 2001-04-05 | Radio Frequency Systems Inc. | Log periodic dipole antenna having a microstrip feedline |
US6243050B1 (en) * | 1997-02-28 | 2001-06-05 | Radio Frequency Systems, Inc. | Double-stacked hourglass log periodic dipole antenna |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2192532A (en) * | 1936-02-03 | 1940-03-05 | Rca Corp | Directive antenna |
US3086206A (en) * | 1960-10-19 | 1963-04-16 | Channel Master Corp | End fire planar dipole array with line transposition between dipoles and impedance increase towards feed |
-
0
- NL NL276499D patent/NL276499A/xx unknown
-
1961
- 1961-03-29 GB GB11499/61A patent/GB953805A/en not_active Expired
-
1962
- 1962-03-19 US US180483A patent/US3165748A/en not_active Expired - Lifetime
- 1962-03-21 SE SE3168/62A patent/SE312591B/xx unknown
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2192532A (en) * | 1936-02-03 | 1940-03-05 | Rca Corp | Directive antenna |
US3086206A (en) * | 1960-10-19 | 1963-04-16 | Channel Master Corp | End fire planar dipole array with line transposition between dipoles and impedance increase towards feed |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3276027A (en) * | 1962-08-07 | 1966-09-27 | Granger Associates | Logarithmic periodic antenna |
US3271775A (en) * | 1963-07-25 | 1966-09-06 | Andrew Corp | Vertically polarized log-periodic antenna |
US3454950A (en) * | 1964-12-01 | 1969-07-08 | Jfd Electronics Corp | Multiple mode operational antennas employing reactive elements |
US3369243A (en) * | 1965-01-18 | 1968-02-13 | Univ Illinois | Log-periodic antenna structure |
US4468675A (en) * | 1981-11-04 | 1984-08-28 | Robinson Lawrence P | Shortened antenna with coaxial telescoping cylinders |
Also Published As
Publication number | Publication date |
---|---|
SE312591B (xx) | 1969-07-21 |
GB953805A (en) | 1964-04-02 |
NL276499A (xx) |
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