EP0155761A1 - Antenne mit einem parabolischen und einem ebenen Reflektor und darin eingelassenem Speisehorn - Google Patents

Antenne mit einem parabolischen und einem ebenen Reflektor und darin eingelassenem Speisehorn Download PDF

Info

Publication number
EP0155761A1
EP0155761A1 EP85300961A EP85300961A EP0155761A1 EP 0155761 A1 EP0155761 A1 EP 0155761A1 EP 85300961 A EP85300961 A EP 85300961A EP 85300961 A EP85300961 A EP 85300961A EP 0155761 A1 EP0155761 A1 EP 0155761A1
Authority
EP
European Patent Office
Prior art keywords
antenna
feed horn
dish
reflector
aperture
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.)
Withdrawn
Application number
EP85300961A
Other languages
English (en)
French (fr)
Inventor
Charles M. Knop
Edward L. Ostertag
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.)
Commscope Technologies LLC
Original Assignee
Andrew LLC
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 Andrew LLC filed Critical Andrew LLC
Publication of EP0155761A1 publication Critical patent/EP0155761A1/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • 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
    • H01Q19/10—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 reflecting surfaces
    • H01Q19/18—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 reflecting surfaces having two or more spaced reflecting surfaces
    • 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
    • H01Q19/10—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 reflecting surfaces
    • H01Q19/104—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 reflecting surfaces using a substantially flat reflector for deflecting the radiated beam, e.g. periscopic antennas

Definitions

  • the present invention relates generally to microwave antennas and, more particularly, to planar-parabolic dual-reflector antennas.
  • Offset-reflector antennas are those which have the feed horn longitudinal axis non-coincident with the axis of the paraboloidal antenna dish; whereas axisymmetrical antennas are those which have the longitudinal axis of the feed horn positioned coincident with the paraboloidal axis.
  • this reduction of the aperture-blocking effect in offset-reflector antennas is a very significant advantage.
  • Aperture blocking by a feed horn leads to 1) a decrease in the effective aperture area of the dish which results in a loss of system gain, and 2) the scattering of radiation off the feed horn itself and off the connecting waveguide which results in a general degradation of side lobe suppression.
  • the airwaves are becoming increasingly crowded and, as a result, spurious radiation specifications for antennas have tightened, these aperture-blocking effects are becoming increasingly important.
  • the offset-reflector antenna's ability to reduce the aperture-blocking effect the offset-reflector antenna has been favoured in most applications calling for tight performance specifications.
  • the offset-reflector configuration has several major disadvantages.
  • One of these disadvantages is that it generates a cross-polarized component in the antenna's radiation field. This cross-polarization can be a significant problem when the antenna is required to conform to strict cross-polarization radiation specifications which may increase the mechanical rigidity requirements (and hence cost) of the tower on which the antenna is mounted.
  • the geometry of an offset-reflector configuration can be a major construction problem since it is more expensive to manufacture than an axisymmetrical antenna design.
  • the reflector is chosen as large as practical and the feed horn is thereafter designed for efficient illumination of the reflector surface. Normally the design is for maximum gain or for the maximum reduction of side lobe levels. Because the reflector is large in both axisymmetrical and offset-reflector antenna designs, there inherently is a problem with wind-loading. Expensive mountings often must be provided for the antenna in order to provide the structural integrity required to minimise the bowing of the antenna mast which occurs as a result of the sail-like capturing of the wind by the antenna reflector. If bowing is sufficiently severe, beam tilting and increased cross-polarized radiation can become a significant problem.
  • R PEs superior radiation pattern envelopes
  • an axisymmetrical antenna in the form of a planar-parabolic reflector antenna having a paraboloidal dish reflector and a planar reflector wherein the feed horn illuminating the paraboloidal dish is recessed into the planar reflector so as to reduce aperture blocking caused by the feed horn; preferably, the feed horn is fully recessed into the planar reflector so as to minimise the aperture-blocking effect.
  • the feed horn In its upper frequency band, the feed horn has a vanishing electric field at the edge of its aperture which suppresses edge currents at the mouth of the feed horn and along the planar reflector surface, thereby preventing the flow of ground-plane currents in the planar reflector which would degrade the antenna's performance.
  • the feed horn's choke surrounding the mouth of the feed horn effectively accomplishes the edge current suppression.
  • the reflector is configured as a 45° circular-paraboloidal dish with a focal length-to-diameter ratio of approximately 0.6, so that the recessed feed horn fully illuminates the paraboloidal dish without interference from the planar reflector.
  • the feed horn preferably utilised in connection with the invention has a small aperture which further reduces the aperture-blocking effect.
  • a noncircular-paraboloidal reflector creates unequal horizontal and vertical plane radiation patterns to provide narrower horizontal plane radiation patterns for terrestrial applications of the antenna.
  • the noncircular-paraboloidal reflector has focal length-to-diameter ratios of approximately 0.833 and 0.333 in the vertical and horizontal planes, respectively.
  • planar-parabolic reflector antenna comprising a paraboloidal main reflector dish 10, a primary feed horn 11 connected to and supported by a circular waveguide 12 extending along the axis of the circular dish 10, and a planar reflector 13 positioned along, and at a 45° angle with respect to, the axis of the main dish.
  • the axis of the main dish 10 is vertically positioned and coincident with the longitudinal axis of the waveguide 12 and the feed horn 11.
  • feed as used herein, although having an apparent implication of use in a transmitting mode, will be understood to encompass use in a receiving mode as well, as is conventional in the art.
  • the feed horn 11 receives microwave signals via the circular waveguide 12 and a combiner 14 and launches those signals as spherical waves upwardly onto the paraboloidal main reflector dish 10; the main dish 10 reflects the signals in a generally planar wave downwardly onto the planar reflector 13, which in turn reflects the signals laterally in a planar horizontal wave.
  • the planar reflector 13 is illuminated by an incoming planar horizontal wave and reflects its energy to the main dish 10; the main dish 10 reflects this incoming energy into a spherical wave and directs it into the feed horn 11 for transmission to the receiving equipment via the circular waveguide 12 and the combiner 14.
  • the paraboloidal main dish 10 has a diameter D and, as is required in dual-reflector antennas of this type, the focal point F of the paraboloidal surface of the main reflector is located at the phase centre of the feed horn 11 (usually at the mouth of the feed horn).
  • the planar reflector 13 has a central opening which allows the feed horn 11 to illuminate the main dish 10 without interference from the surface of the planar reflector.
  • the planar reflector 13 is positioned to intercept substantially all of the radiation launched from the feed horn 11 after it is reflected from the main dish 10 (in the transmitting mode). Since the aperture of the main dish 10 is circular, the planar reflector 13 has an elliptical shape because of its angled position with respect to the axis of the main dish. The planar reflector's position of 45° with respect to the axis of the main reflector dish 10 causes the vertically travelling radiation from the main dish lO to be redirected to a horizontal path. In the receiving mode, the planar reflector 13 redirects incoming horizontal radiation to a vertical path which illuminates the main dish 10.
  • a cylindrical housing 15 is provided.
  • the antenna's cylindrical housing 15 has an opening 16 to allow radiation to enter the cylindrical housing and illuminate the planar reflector 13. Because of the 45° angle of the planar reflector with respect to the axis of the paraboloidal main dish 10, radiation which best illuminates the main dish 10 travels along a horizontal beam path whose direction of propagation is orthogonal to the axis of the main dish.
  • an absorber-lined cylindrical shield 30 which serves to reduce incoming radiation which is off-axis from the main horizontal beam path.
  • the shield 30 is preferably constructed of a continuous metal or fibreglass projection in an annular shape whose inner and outer walls are substantially parallel to the direction of propagation of the main horizontal radiation beam path.
  • Conventional microwave absorbing material 27 having a pyramidal, flat or convoluted surface, or even "hair” absorber, can be used on the inside surface of the shield.
  • a frame consisting of a pair of vertical beams 18 and 19 and a pair of horizontal beams 20 and 21 surround the cylindrical housing 15.
  • a vertical mast beam 22 is coupled to the horizontal beam 21 by way of a perpendicular beam 23.
  • an L-bracket 24 joins the back of the dish 10 to the vertical mast beam 22.
  • a pair of diagonal beams 25 and 26 are provided at the ends of the reflector.
  • absorber material 27 is located around the periphery of the dish 10 as well as on the inner wall of the shield 30.
  • the feed horn 11 preferably comprises two straight circular waveguide sections 40 and 41 interconnected by a conical circular waveguide section 42.
  • This particular feed horn 11 produces substantially equal E-plane and H-plane patterns in two different frequency bands. This is accomplished by selecting the diameter of the horn mouth to be approximately equal to one wavelength in the lower frequency band and then selecting the slope B of the conical wall to cancel the radial electric field at the edge of the horn's aperture (having an inner diameter D 1 ) in the upper frequency band.
  • the one-wavelength diameter of the lower frequency band produces substantially equal patterns in the E and H-planes for the lower frequency signals, while the cancellation of the electric field of the higher frequency signals at the inside wall of the horn aperture produces substantially equal patterns in the E and H-planes for the higher frequency signals.
  • the horn is both small and inexpensive to fabricate, and yet it simultaneously produces equal main beam patterns in both the E and H-planes in each of two frequency bands.
  • the small size of the horn minimises horn blockage caused by the presence of the horn at the centre of the planar reflector 13.
  • Section 40 of the illustrative feed horn 11 is a conventional smooth-wall TEll mode horn at the low frequency (e.g., 3.95 GHz) with an inside diameter Dl approximately equal to one wavelength at the centre frequency (e.g., 3.95 GHz) of the lower frequency band.
  • the second cylindrical section 41 of the feed horn has a smaller inside diameter D2, and the two cylindrical sections 40 and 41 are joined by the uniformly tapered conical section 42 to generate (at the junction of sections 40 and 42) and propagate the TM 11 mode in the upper frequency band (e.g., 6 GHz).
  • the conical section 42 generates (at the junction of sections 40 and 42) a TM 11 mode from the TEll mode propagating from bottom to top in the smaller cylindrical section 41 and in the section 42.
  • the freshly generated TM 11 mode leads the TEll mode by about 90° in phase.
  • the slope S of the conical section 42 determines the amplitude of the TM 11 mode signal, while the length L of the larger cylindrical section 40 determines the phase relationship between the two modes at the aperture of the feed horn.
  • the open end of the horn is surrounded by a quarter-wave choke 46 comprising a short conductive cylinder 47, concentric with the horn 11, and a shorting ring 48.
  • the inner surface of the cylinder 47 is spaced away from the outer surface of the horn 11 along a length of the horn about equal to a quarter wavelength (at the lower end of the low band) from the end of the horn, and then the cylinder 47 is shorted to the horn 11 by the ring 48 to form a quarter-wave coaxial choke which suppresses current flow on the outer surface of the horn.
  • the ratio of the mode powers W TM 11 and W TE 11 must be: where the guide wavelength of the TM 11 mode is The guide wavelength of the TEll mode is and
  • Equating equations (1) and (5) yields:
  • Equation (5) can then be solved for ⁇ :
  • This value of S results, at the high band, in cancellation of the electric field at the aperture boundary, which in turn results in approximately equal E and H-patterns of the main beam radiated from the horn in the high frequency band.
  • the diameter D1 must be such that the value of C, which is defined by equation (4) as , is above the Eigen value of 3.83 for the TM 11 mode in H the high frequency band.
  • the diameter Dl must be such that the value of C is below the Eigen value of 5.33 for the TE 12 mode in the high frequency band.
  • the value of C must be within the range of from about 3.83 to about 5.33.
  • equation (4) gives: and, therefore, the ratio ⁇ L/ ⁇ H must be within the range of from about 3.83/ ⁇ to about 5.33/ ⁇ , which is 1.22 to 1.61.
  • the two frequency bands must be selected to satisfy the above criteria.
  • One suitable pair of frequency bands is 4GHz and 6GHz, because ⁇ L and Dl are 2.953 inches, ⁇ H is 1.969 inches, and ⁇ L / ⁇ H is 1.5. This value of the ratio ⁇ L / ⁇ H is, of course, within the prescribed range of 1.22 to 1.61.
  • a feed horn of the type shown in Fig. 3 had an inner diameter of 2.125 inches in its smaller cylindrical section 40 and 2.810 inches in its larger cylindrical section 41.
  • the conical section 42 connecting the two cylindrical sections had a half flare angle fl (via equation (9)) of 30° with respect to the axis of the feed horn.
  • the axial length of the conical section was 0.593 inches.
  • the lengths of the two cylindrical sections 41 and 40 were 1.0 inches and 4.531 inches, respectively.
  • the working example described above produced the E-plane and H-plane power patterns shown in Figs. 4 and 6 at 3.95 GHz and 6.175 GHz, respectively.
  • the power patterns in Figs. 4 and 6 represent amplitude in decibels along an arc length of a circle whose centre is coincident with the position of the centre of the aperture of the antenna and whose radius is 11 inches or more.
  • This same feed horn produced the E-plane and H-plane phase patterns shown in Figs. 5 and 7 at 3.95 GHz and 6.175 GHz, respectively. From Figs.
  • the feed horn 11 is recessed into the planar reflector 13 such that the aperture-blocking effect of the feed horn is minimised, and currents in the planar reflector, as a result of the planar reflector functioning as a ground plane for the feed horn, are avoided because of the insignificant amount of edge current at the feed horn aperture.
  • the antenna produces substantially equal E and H-plane patterns and very low horizontal plane radiation (i.e. 90° radiation is transmitted directly from the feed horn without reflection).
  • Other feed horns may also be used in connection with the invention.
  • a corrugated feed horn may also provide low edge currents at the feed horn aperture and equal E and H-plane radiation patterns. But, because of its small aperture, the feed horn in Fig. 3 provides the smallest amount of aperture blocking and, therefore, is preferred.
  • the feed horn 11 In its fully recessed position, the feed horn 11, or a flared corrugated feed horn, is positioned such that the phase centre of the feed horn's open end is located 1) coincident with the focal point F of the paraboloidal dish, and 2) at a distance from the surface of the planar reflector 13, as measured along the axis of the paraboloidal dish 10, approximately equal to the radius r of the feed horn at its open end.
  • the radius r of the feed horn's open end is defined as the distance of the outermost surface of the feed horn from the centre of the feed horn's open end.
  • the antenna of this invention displays greatly improved RPEs, and a relatively low wind-loading factor, in comparison to prior axisymmetrical antenna designs.
  • the mounting structure for this antenna can be much less costly than the equivalent mounting for other types of antenna designs.
  • Figs. 8-11 illustrate the radiation patterns for a planar-parabolic reflector antenna according to the invention at a 3.95 GHz frequency.
  • a 7.098 scaled version of the antenna was constructed. Specifically, to simulate the performance of a full-size antenna with a lO-foot diameter paraboloidal dish, and to predict the patterns at 3.95 GHz (shown by Figs. 8-11), a 17-inch diameter dish antenna was constructed and measured using a scaled frequency (i.e., 7.058 times 3.95 GHz or 27.88 GHz). Accordingly, a 7.098 scaled version of the feed horn 11 which produced the patterns in Figs. 4-7 was used in combination with the 17-inch diameter dish antenna.
  • a scaled frequency i.e., 7.058 times 3.95 GHz or 27.88 GHz
  • the patterns A in Figs. 8 and 9 were obtained. They indicate a superior performance by the antenna in comparison to a radiation pattern envelope (RPE) B at 3.95 GHz for a shielded axisymmetrical single-reflector paraboloidal dish antenna.
  • Measured E and H-plane RPEs C in Figs. 8 and 9, respectively, are for an offset-reflector antenna at 3.95 GHz.
  • the planar-parabolic reflector antenna according to the invention performs substantially as well as an offset configuration (RPEs C).
  • Figs. 10 and 11 The full 360 0 E and H-plane radiation patterns A at 3.95 GHz for an antenna according to the invention are shown in Figs. 10 and 11, respectively. These patterns were also measured using the 7.098 scaled antenna. For comparison, Figs. 10 and 11 also include the full 360° E and H-plane radiation pattern envelopes B and C for the shielded single-reflector paraboloidal dish antenna and the offset-reflector antenna, respectively, measured at 3.95 GHz.
  • the patterns in Figs. 8-11 indicate, the patterns of the planar-parabolic reflector antenna according to the invention are superior to the axisymmetrical single-reflector antenna RPEs B and virtually equivalent in overall performance to the offset-reflector antenna RPEs C. Predictions of the performance of the antenna according to the invention at a 6 GHz frequency band indicate the antenna should have radiation patterns similar or superior to the 3.95 GHz patterns.
  • an alternative embodiment of the invention utilises a noncircular-paraboloidal reflector 50 in place of the circular-paraboloidal reflector 10 in Figs. 1 and 2.
  • the width of an antenna's horizontal plane radiation pattern is of greater importance than the width of the antenna's vertical plane radiation pattern. This is so since interference between adjacent terrestrial antennas is of greatest concern along the earth's surface (i.e., horizontal plane), thus making the width of the vertical plane of lesser concern.
  • the predicted radiation patterns for the planar-parabolic reflector antenna of Figs. 12 and 13, utilising a noncircular-paraboloidal reflector 50 (Fig. 14) and the feed horn in Fig. 3, are superior to the predicted radiation patterns for the planar-parabolic reflector antenna of Figs. 1 and 2 which utilises a 10-foot circular-paraboloidal reflector.
  • the non- circular-paraboloidal reflector 50 results. It has a focal length-to-diameter ratio of 5/15 or 1/3 (i.e., 0.333) in the horizontal plane and a ratio of 5/6 (i.e., 0.833) in the vertical plane (this is in contrast to the single focal length-to-diameter ratio of 0.6036 of the reflector 10 in Figs. 1 and 2).
  • the ratio between the 10-foot diameter of the circular paraboloid and the 15-foot horizontal dimension of the noncircular paraboloid is inversely proportional to the ratio between the 3 decibel (db) beam width of the horizontal plane of the circular paraboloid and the 3db beam width of the horizontal plane radiation pattern of the noncircular paraboloid; correspondingly, the ratio between the 10-foot diameter of the circular paraboloid and the 6-foot vertical dimension of the noncircular paraboloid is inversely proportional to the ratio between the 3db of the beam width radiation pattern vertical plane of the circular paraboloid and the 3db of the beam width vertical plane of the non- circular paraboloid.
  • the surface areas of the two reflectors should be approximately equal. Accordingly, by selecting a horizontal dimension of 15 feet and a vertical dimension of 6 feet for the noncircular-paraboloidal reflector 50, the antenna maintains about the same gain as that of a 10-foot diameter circular-paraboloidal reflector.
  • the mountings and support structures are the same for both the noncircular-paraboloidal antenna and the circular-paraboloidal antenna, they must be re-sized to conform to the shape of the noncircular-paraboloidal reflector.
  • the X-axis dimensions of the mounting and support structures in Fig. 12 must be longer than the analogous dimensions in Fig. 1 to accommodate the lengthening of the paraboloidal reflector along the X-axis from 10 feet to 15 feet and the associated increase in the subtended angle W D ;
  • the Y-axis dimensions of the mounting and support structures in Fig. 13 must be shorter than the analogous dimensions in Fig. 2 to accommodate the shortening of the paraboloidal reflector along the Y-axis from 10 feet to 6 feet.
  • the generally oval shape of the noncircular-paraboloidal reflector 50 in Fig. 14 is illustrative only. It will be appreciated that the noncircular-paraboloidal reflector 50 may have non-circular shapes other than that of Fig. 14.
  • the paraboloidal reflector may have an elliptical shape with its major axis being about 15 feet in length and its minor axis being about 6 feet in length.
  • the planar-parabolic reflector antenna according to the invention in Figs. 12 and 13 utilises the feed horn 11 in Fig. 3, other feed horns may also be used.
  • a flared corrugated feed horn is one example. Because of the non- circular shape of the paraboloidal reflector 50, feed horns having non-circular apertures may be desirable (e.g., an elliptical or rectangular aperture) to improve gain.
  • a planar-parabolic reflector antenna with its feed horn recessed into the planar reflector minimises the degradation of the performance of an axisymmetrical antenna caused by the feed horn's aperture-blocking effect.
  • the recessed feed horn does not generate significant ground currents in the planar reflector.
  • the aperture opening for the feed horn in planar reflector 13 is small, thereby allowing a further reduction of aperture blocking.
  • the feed horn's contribution to the horizontal plane radiation of the antenna is the radiation 90° off the feed horn's axis. Therefore its contribution is quite low. Accordingly, an inexpensive axisymmetrical antenna is realised which has superior radiation patterns and a low wind-loading factor.

Landscapes

  • Aerials With Secondary Devices (AREA)
  • Waveguide Aerials (AREA)
EP85300961A 1984-02-13 1985-02-13 Antenne mit einem parabolischen und einem ebenen Reflektor und darin eingelassenem Speisehorn Withdrawn EP0155761A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US57939284A 1984-02-13 1984-02-13
US579392 1984-02-13

Publications (1)

Publication Number Publication Date
EP0155761A1 true EP0155761A1 (de) 1985-09-25

Family

ID=24316718

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85300961A Withdrawn EP0155761A1 (de) 1984-02-13 1985-02-13 Antenne mit einem parabolischen und einem ebenen Reflektor und darin eingelassenem Speisehorn

Country Status (3)

Country Link
EP (1) EP0155761A1 (de)
JP (1) JPS60186102A (de)
AU (1) AU3852885A (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0235932A1 (de) * 1986-02-13 1987-09-09 THORN EMI Electronics Limited Radarsystem mit zwei Funktionen
US4829315A (en) * 1987-01-21 1989-05-09 Cookman William T Dual frequency feed apparatus
EP0732766A1 (de) * 1995-03-17 1996-09-18 Hughes Aircraft Company Antennensystem mit gesteuerter Ablenkung
TWI384775B (zh) * 2008-02-21 2013-02-01 Qualcomm Inc 用於正交分頻多重存取系統的訊號品質估計
US11069973B1 (en) * 2020-05-13 2021-07-20 Amazon Technologies, Inc. Mechanically steered antenna with improved efficiency

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1099429A (en) * 1965-12-03 1968-01-17 Mini Of Technology Improvements in or relating to microwave aerial assemblies
US3633209A (en) * 1968-09-06 1972-01-04 Mostafa S Afifi Offset paraboloid-plane reflector antenna
US3763493A (en) * 1970-10-17 1973-10-02 Nippon Telegraph & Telephone Antenna device applicable for two different frequency bands
GB2056181A (en) * 1979-07-30 1981-03-11 Siemens Ag Electro-magnetic wave horn radiators
GB1603657A (en) * 1977-09-13 1981-11-25 Marconi Co Ltd Systems for the transmission and/or reception of electromagnetic waves
FR2531276A3 (fr) * 1982-07-28 1984-02-03 Europ Agence Spatiale Antenne du type cassegrain a source primaire excentree

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1099429A (en) * 1965-12-03 1968-01-17 Mini Of Technology Improvements in or relating to microwave aerial assemblies
US3633209A (en) * 1968-09-06 1972-01-04 Mostafa S Afifi Offset paraboloid-plane reflector antenna
US3763493A (en) * 1970-10-17 1973-10-02 Nippon Telegraph & Telephone Antenna device applicable for two different frequency bands
GB1603657A (en) * 1977-09-13 1981-11-25 Marconi Co Ltd Systems for the transmission and/or reception of electromagnetic waves
GB2056181A (en) * 1979-07-30 1981-03-11 Siemens Ag Electro-magnetic wave horn radiators
FR2531276A3 (fr) * 1982-07-28 1984-02-03 Europ Agence Spatiale Antenne du type cassegrain a source primaire excentree

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, vol. MTT-28, no. 3, March 1980, New York, USA;M.A. STUCHLY et al. "Diathermy Applicators with Circular Aperture and Corrugated Flange", pages 267-271 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0235932A1 (de) * 1986-02-13 1987-09-09 THORN EMI Electronics Limited Radarsystem mit zwei Funktionen
US4829315A (en) * 1987-01-21 1989-05-09 Cookman William T Dual frequency feed apparatus
EP0732766A1 (de) * 1995-03-17 1996-09-18 Hughes Aircraft Company Antennensystem mit gesteuerter Ablenkung
TWI384775B (zh) * 2008-02-21 2013-02-01 Qualcomm Inc 用於正交分頻多重存取系統的訊號品質估計
US11069973B1 (en) * 2020-05-13 2021-07-20 Amazon Technologies, Inc. Mechanically steered antenna with improved efficiency

Also Published As

Publication number Publication date
AU3852885A (en) 1985-08-22
JPS60186102A (ja) 1985-09-21

Similar Documents

Publication Publication Date Title
US4626863A (en) Low side lobe Gregorian antenna
EP0136818A1 (de) Zweimoden Hornstrahler für zwei oder mehr Wellenbereiche
EP0102846A1 (de) Mikrowellenantenne mit Haupt- und Hilfsreflektor
US4604627A (en) Flared microwave feed horns and waveguide transitions
US5959590A (en) Low sidelobe reflector antenna system employing a corrugated subreflector
US6137449A (en) Reflector antenna with a self-supported feed
US6020859A (en) Reflector antenna with a self-supported feed
EP0859427B1 (de) Doppelreflektormikrowellenantenne
CN106785469B (zh) 双频同轴馈源及具有其的天线
EP1004151B1 (de) Verbesserte reflektorantenne mit selbsttragendem speiseelement
EP0005487A1 (de) Antenne mit Parabolreflektor und optimaler Strahlungscharakteristik
EP0066455B1 (de) Mikrowellenantennen vom Reflektortyp mit einem Absorber bedeckten Erreger
EP0403894B1 (de) Ineinandergeschachtelte Anordnung von Hornstrahlern
US4423422A (en) Diagonal-conical horn-reflector antenna
US4982198A (en) High performance dipole feed for reflector antennas
EP0155761A1 (de) Antenne mit einem parabolischen und einem ebenen Reflektor und darin eingelassenem Speisehorn
US5903241A (en) Waveguide horn with restricted-length septums
CN109411870B (zh) 一种双频共用的抛物面天线馈源
US4521783A (en) Offset microwave feed horn for producing focused beam having reduced sidelobe radiation
EP0136817A1 (de) Gregory Antenne mit unterdrückten Nebenkeulen
KR101032190B1 (ko) 유전체 장하혼 및 이를 이용한 이중 반사판 안테나
US5187491A (en) Low sidelobes antenna
EP0140598B1 (de) Mikrowellen-Reflektorantenne deren Speisehornstrahler mit Absorbermaterial bedeckt ist
US4689633A (en) Flared microwave feed horns and waveguide transitions
US4343003A (en) Directional antenna for microwave transmissions

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR GB IT NL

17P Request for examination filed

Effective date: 19860109

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19870319

RIN1 Information on inventor provided before grant (corrected)

Inventor name: KNOP, CHARLES M.

Inventor name: OSTERTAG, EDWARD L.