US3308467A - Waveguide antenna with non-resonant slots - Google Patents

Waveguide antenna with non-resonant slots Download PDF

Info

Publication number
US3308467A
US3308467A US218059A US21805951A US3308467A US 3308467 A US3308467 A US 3308467A US 218059 A US218059 A US 218059A US 21805951 A US21805951 A US 21805951A US 3308467 A US3308467 A US 3308467A
Authority
US
United States
Prior art keywords
waveguide
slots
slot
longitudinal axis
radiation
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
US218059A
Inventor
Jr Robert F Morrison
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to US218059A priority Critical patent/US3308467A/en
Application granted granted Critical
Publication of US3308467A publication Critical patent/US3308467A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/0006—Particular feeding systems
    • H01Q21/0037—Particular feeding systems linear waveguide fed arrays
    • H01Q21/0043—Slotted waveguides

Definitions

  • This invention relate-s to waveguide antenna arrays, particularly to waveguide antenna arrays having nonresonant slots and capable of transmitting electromagnetic waves in narrowly defined and highly directional beams.
  • waveguide antennas of rectangular cross section have cut in one of the broad faces of the guide two rows of longitudinally spaced resonant slots.
  • Each slot is spaced from the longitudinal axis of the broad surface with the longitudinal axis of each slot paralleling the longitudinal axis of the broad surface.
  • the amount of radiation from each slot in the row is controlled by varying the spacing between the longitudinal axis of each slot and the longitudinal axis of the broad surface. The more close-1y the longitudinal axis of a slot approaches the longitudinal axis of the broad surface, the lower the amount of radiation therefrom.
  • the directivity of the radiation pattern of slotted waveguide antennas is usually controlled by varying the longitudinal spacing between slots. For example, a spacing of one-half wavelength between resonant slots will result in maximum radiation normal to the longitudinal axis of the waveguide antenna. A spacing greater than one-half wavelength will result in radiation at an angle to one side of the plane normal to the longitudinal axis of the waveguide antenna and a spacing less than one-half wavelength will result in radiation at an angle to the opposite side of the plane normal to the longitudinal axis of the waveguide antenna.
  • a primary object of the invention is a slotted waveguide antenna having great structural strength.
  • Another object of the invention is a microwave antenna array wherein the radiating slots of the waveguide are arranged to prevent overlapping.
  • Another object of the invention is a microwave antan'ce.
  • Another object of the invention is a waveguide antenna having novel means for forming the radiation pattern.
  • Another object of the invention is a novel means for controlling the amount of radiation of a waveguide antenna.
  • Another object of the invention is a waveguide antenna having novel directivity means incorporated therein.
  • Another object of the invention is the elimination of probes adjacent to the slots for controlling the amount of radiated energy of a waveguide antenna.
  • FIGURE 1 is a perspective view showing a section of a conventional waveguide antenna wherein the resonant slots are closely spaced with respect to the longitudinal axis of the waveguide.
  • FIGURE 2 is a plan View of the slotted waveguide antenna of the invention.
  • FIGURE 3 shows the radiation pattern of the waveguide antenna of FIGURE 1, illustrating output in decibels in relation to the antenna axis.
  • FIGURE 4 is a typical plot illustrating the relationship of the slot length to the slot conductance.
  • FIGURE 5 is a perspective view showing four slotted waveguide antennas embodied in the nose of a missile.
  • the desired radiation pattern for the Waveguide antenna of the invention is obtained by choosing a suitable combination of slot dimensions and longitudinal spacing between slots.
  • the slot spacing is given by the following formula:
  • the slot size depends upon the required slot conduc-
  • the required slot conductance is obtained from the following formula:
  • Gn Pn 11-1 ri-k2 PK The manner in which Pn varies with n depends upon the desired radiation pattern. In some cases, Pn is a constant, while in others, Pn is small near the ends of the antenna and large near the center. Once Gn is determined, the slot length is obtained from the curve shown in FIGURE 4.
  • FIGURE 1 of the drawings shows a conventional type of'waveguide radiator in which 1 indicates the waveguide of rectangular cross section.
  • Radiation means comprising slots 3 and 4 are formed in the wall 2 of the waveguide, parallel to the longitudinal axis of the wall.
  • the slots be longitudinally spaced less than one-half wavelength, resulting in the waveguide wall being weakened in the areas between the adjacent ends of the opposing slots of each of the series of slots.
  • the present invention eliminates the possibility of positioning the slots so that overlapping at the axis can occur, for all slots of the array of the invention are well and equidistantly spaced from the longitudinal axis of the waveguide wall.
  • the amount of radiation from each slot is controlled by the length of the slot rather than by its distance from the longitudinal axis of the waveguide wall.
  • FIGURE 3 shows the radiation pattern produced by the slot pattern of the waveguide of FIGURE 2.
  • various radiation patterns can be obtained as may be desired by selected arrangement of slot size and spacing in accordance with the formulas listed above.
  • slotted waveguide antennas may be placed on the surface, or may comprise a portion thereof, of a cylinder or cone to produce a radiation pat-tern which is omnidirectional in the plane perpendicular to the axis of the cone, but highly directional in the plane containing the axis of the cone.
  • the number and distribution of the slotted waveguide antennas depends upon the all-owable variation in beam angle and radiated power as the cone is rotated about its axis.
  • the variation in beam angle is due to the fact that th cone axis and waveguide axis are not parallel.
  • the power variation is due to interference effects and directivity of the individual antennas.
  • FIGURE 5 An embodiment of the foregoing is shown in FIGURE 5 wherein f-our radiating elements 11, 12, 13 and 14 are disposed at equal intervals around the conical nose 15 of a missile 16.
  • the elements 11, 12, 13 and 14 are supplied with microwave energy from a common source such as a transceiver 17 by means of waveguide feeders 18, 19, 20 and 21, respectively.
  • a common source such as a transceiver 17
  • an explosive missi-le having an aerodynamic surface, may be provided with a microwave antenna array conforming to the aerodynamic surface.
  • the antenna array is adapted to produce an omnidirectional radiation pattern in azimuth about the longitudinal axis of the missile and inclined in elevation as desired in respect to the direction of flight of the missile.
  • a microwave antenna array conforming to said aerodynamic surface and producing an omnidirectional radiation pattern in azimuth about the longitudinal axis of said missile and inclined in elevation as desired in respect to the direction of flight of said missile, said array comprising a multiple of waveguide radiators fixed in spaced relationship in the peripheral surface of the nose of said missile, microwave generating means fixed within the said nose, each of said waveguide radiators connected to said generating means by waveguide feeders, each of said waveguide radiators having formed in one wall thereof two rows of microwave radiating means in staggered relation to each other and equidistantly spaced from the longitudinal axis of said wall, said microwav radiating means comprising resonant slots in said wall intermediate the end of said guide and progressively non resonant slots on each side of said resonant slots towards the ends of said guide to form a microwave radiation beam having its major lobe intermediate said ends, the said beam of each waveguide contributing to form said omnidirectional radiation pattern.

Landscapes

  • Waveguide Aerials (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)

Description

M r h 7, 1967 R. F. MORRISON, JR 3,303,467
WAVEGUIDE ANTENNA WITH NON-RESONANT SLOTS Filed March 28, 1951 v 6] 6 d H Q, [j z m INVENTOR. \9 Q Ruherfi: FlMurm'ann,Jr. 2 BY ATTOR NEYs United States Patent 3,308,467 WAVEGUIDE ANTENSNA WITH N ON-RESONANT LOTS This invention relate-s to waveguide antenna arrays, particularly to waveguide antenna arrays having nonresonant slots and capable of transmitting electromagnetic waves in narrowly defined and highly directional beams.
Normally, waveguide antennas of rectangular cross section have cut in one of the broad faces of the guide two rows of longitudinally spaced resonant slots. Each slot is spaced from the longitudinal axis of the broad surface with the longitudinal axis of each slot paralleling the longitudinal axis of the broad surface. The amount of radiation from each slot in the row is controlled by varying the spacing between the longitudinal axis of each slot and the longitudinal axis of the broad surface. The more close-1y the longitudinal axis of a slot approaches the longitudinal axis of the broad surface, the lower the amount of radiation therefrom. Since the slots are arranged in two rows and staggered relative to each other, an overlapping or intersection of slots may occur when both rows are placed at Dr extremely close to the longitudinal axis of the broad face to obtain minimum radiation. The use of pins or stubs adjacent to the slots on the inner wall of the wave-guide has also been employed in the past as a means to control the amount of radiation from the slots. This method has proven to be time consuming and costly in mass production.
The directivity of the radiation pattern of slotted waveguide antennas is usually controlled by varying the longitudinal spacing between slots. For example, a spacing of one-half wavelength between resonant slots will result in maximum radiation normal to the longitudinal axis of the waveguide antenna. A spacing greater than one-half wavelength will result in radiation at an angle to one side of the plane normal to the longitudinal axis of the waveguide antenna and a spacing less than one-half wavelength will result in radiation at an angle to the opposite side of the plane normal to the longitudinal axis of the waveguide antenna.
A primary object of the invention is a slotted waveguide antenna having great structural strength.
Another object of the invention is a microwave antenna array wherein the radiating slots of the waveguide are arranged to prevent overlapping.
Another object of the invention is a microwave antan'ce.
tenna array wherein the staggered slots in the elements of the array are arranged to avoid intersection of each other.
Another object of the invention is a waveguide antenna having novel means for forming the radiation pattern.
Another object of the invention is a novel means for controlling the amount of radiation of a waveguide antenna.
Another object of the invention is a waveguide antenna having novel directivity means incorporated therein.
Another object of the invention is the elimination of probes adjacent to the slots for controlling the amount of radiated energy of a waveguide antenna.
The specific nature of the invention as well as other objects and advantages thereof Will clearly appear from the following description and accompanying drawings in which:
FIGURE 1 is a perspective view showing a section of a conventional waveguide antenna wherein the resonant slots are closely spaced with respect to the longitudinal axis of the waveguide.
FIGURE 2 is a plan View of the slotted waveguide antenna of the invention.
FIGURE 3 shows the radiation pattern of the waveguide antenna of FIGURE 1, illustrating output in decibels in relation to the antenna axis.
FIGURE 4 is a typical plot illustrating the relationship of the slot length to the slot conductance; and
FIGURE 5 is a perspective view showing four slotted waveguide antennas embodied in the nose of a missile.
The desired radiation pattern for the Waveguide antenna of the invention is obtained by choosing a suitable combination of slot dimensions and longitudinal spacing between slots. The slot spacing is given by the following formula:
where d=longitudinal spacing between slot centers. \=free space wavelength.
Ag=wavelength in the guide.
0=angle of the major lobe.
The slot size depends upon the required slot conduc- The required slot conductance is obtained from the following formula:
Gn Pn 11-1 ri-k2 PK The manner in which Pn varies with n depends upon the desired radiation pattern. In some cases, Pn is a constant, while in others, Pn is small near the ends of the antenna and large near the center. Once Gn is determined, the slot length is obtained from the curve shown in FIGURE 4.
FIGURE 1 of the drawings shows a conventional type of'waveguide radiator in which 1 indicates the waveguide of rectangular cross section. Radiation means comprising slots 3 and 4 are formed in the wall 2 of the waveguide, parallel to the longitudinal axis of the wall. For certain directivity characteristics and radiation power, it is necessary that the slots be longitudinally spaced less than one-half wavelength, resulting in the waveguide wall being weakened in the areas between the adjacent ends of the opposing slots of each of the series of slots.
The present invention eliminates the possibility of positioning the slots so that overlapping at the axis can occur, for all slots of the array of the invention are well and equidistantly spaced from the longitudinal axis of the waveguide wall. The amount of radiation from each slot is controlled by the length of the slot rather than by its distance from the longitudinal axis of the waveguide wall.
Referring now to FIGURE 2, wherein there is shown one embodiment of the waveguide array of the invention FIGURE 3 shows the radiation pattern produced by the slot pattern of the waveguide of FIGURE 2. However, it is to be noted that various radiation patterns can be obtained as may be desired by selected arrangement of slot size and spacing in accordance with the formulas listed above.
Several of the slotted waveguide antennas may be placed on the surface, or may comprise a portion thereof, of a cylinder or cone to produce a radiation pat-tern which is omnidirectional in the plane perpendicular to the axis of the cone, but highly directional in the plane containing the axis of the cone. The number and distribution of the slotted waveguide antennas depends upon the all-owable variation in beam angle and radiated power as the cone is rotated about its axis. The variation in beam angle is due to the fact that th cone axis and waveguide axis are not parallel. The power variation is due to interference effects and directivity of the individual antennas. An embodiment of the foregoing is shown in FIGURE 5 wherein f-our radiating elements 11, 12, 13 and 14 are disposed at equal intervals around the conical nose 15 of a missile 16. The elements 11, 12, 13 and 14 are supplied with microwave energy from a common source such as a transceiver 17 by means of waveguide feeders 18, 19, 20 and 21, respectively. Accordingly, an explosive missi-le, having an aerodynamic surface, may be provided with a microwave antenna array conforming to the aerodynamic surface. Obviously, the antenna array is adapted to produce an omnidirectional radiation pattern in azimuth about the longitudinal axis of the missile and inclined in elevation as desired in respect to the direction of flight of the missile.
I claim:
In an explosive missile having an aerodynamic surface, a microwave antenna array conforming to said aerodynamic surface and producing an omnidirectional radiation pattern in azimuth about the longitudinal axis of said missile and inclined in elevation as desired in respect to the direction of flight of said missile, said array comprising a multiple of waveguide radiators fixed in spaced relationship in the peripheral surface of the nose of said missile, microwave generating means fixed within the said nose, each of said waveguide radiators connected to said generating means by waveguide feeders, each of said waveguide radiators having formed in one wall thereof two rows of microwave radiating means in staggered relation to each other and equidistantly spaced from the longitudinal axis of said wall, said microwav radiating means comprising resonant slots in said wall intermediate the end of said guide and progressively non resonant slots on each side of said resonant slots towards the ends of said guide to form a microwave radiation beam having its major lobe intermediate said ends, the said beam of each waveguide contributing to form said omnidirectional radiation pattern.
References Cited by the Examiner UNITED STATES PATENTS 2,574,433 11/1951 Clapp 343-771 2,648,839 8/1953 Ford et al 343-771 ELI LIEBERMAN, Primary Examiner.
NORMAN H. EVANS, Examiner.
R. E. BERGER, Assistant Examiner.
US218059A 1951-03-28 1951-03-28 Waveguide antenna with non-resonant slots Expired - Lifetime US3308467A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US218059A US3308467A (en) 1951-03-28 1951-03-28 Waveguide antenna with non-resonant slots

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US218059A US3308467A (en) 1951-03-28 1951-03-28 Waveguide antenna with non-resonant slots

Publications (1)

Publication Number Publication Date
US3308467A true US3308467A (en) 1967-03-07

Family

ID=22813567

Family Applications (1)

Application Number Title Priority Date Filing Date
US218059A Expired - Lifetime US3308467A (en) 1951-03-28 1951-03-28 Waveguide antenna with non-resonant slots

Country Status (1)

Country Link
US (1) US3308467A (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3364489A (en) * 1964-09-17 1968-01-16 Melpar Inc Traveling wave antenna having radiator elements with doubly periodic spacing
US3389393A (en) * 1966-02-18 1968-06-18 Lockheed Aircraft Corp Low profile broadband microwave antenna system
US3581038A (en) * 1969-05-02 1971-05-25 Varian Associates Microwave applicator employing a broadside radiator in a conductive enclosure
US3829862A (en) * 1973-04-20 1974-08-13 D Young Ridge scan antenna
US4032917A (en) * 1975-08-21 1977-06-28 The Singer Company Synthesis technique for constructing cylindrical and spherical shaped wave guide arrays to form pencil beams
EP0047684A1 (en) * 1980-09-05 1982-03-17 Thomson-Csf Missile antenna and missile provided with such an antenna
DE3310043A1 (en) * 1983-03-19 1984-09-20 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Sector antenna consisting of a slotted waveguide
US4658261A (en) * 1985-01-25 1987-04-14 The United States Of America As Represented By The Secretary Of The Navy Circumferential slotted ridged waveguide array antenna
WO1988002934A1 (en) * 1986-10-17 1988-04-21 Hughes Aircraft Company Array beam position control using compound slots
US4985708A (en) * 1990-02-08 1991-01-15 Hughes Aircraft Company Array antenna with slot radiators offset by inclination to eliminate grating lobes
JP2014053735A (en) * 2012-09-06 2014-03-20 Sumitomo Electric Ind Ltd Horizontal polarization omnidirectional antenna

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2574433A (en) * 1943-10-01 1951-11-06 Roger E Clapp System for directional interchange of energy between wave guides and free space
US2648839A (en) * 1950-10-02 1953-08-11 Rca Corp Direction finding antenna system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2574433A (en) * 1943-10-01 1951-11-06 Roger E Clapp System for directional interchange of energy between wave guides and free space
US2648839A (en) * 1950-10-02 1953-08-11 Rca Corp Direction finding antenna system

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3364489A (en) * 1964-09-17 1968-01-16 Melpar Inc Traveling wave antenna having radiator elements with doubly periodic spacing
US3389393A (en) * 1966-02-18 1968-06-18 Lockheed Aircraft Corp Low profile broadband microwave antenna system
US3581038A (en) * 1969-05-02 1971-05-25 Varian Associates Microwave applicator employing a broadside radiator in a conductive enclosure
US3829862A (en) * 1973-04-20 1974-08-13 D Young Ridge scan antenna
US4032917A (en) * 1975-08-21 1977-06-28 The Singer Company Synthesis technique for constructing cylindrical and spherical shaped wave guide arrays to form pencil beams
EP0047684A1 (en) * 1980-09-05 1982-03-17 Thomson-Csf Missile antenna and missile provided with such an antenna
DE3310043A1 (en) * 1983-03-19 1984-09-20 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Sector antenna consisting of a slotted waveguide
US4658261A (en) * 1985-01-25 1987-04-14 The United States Of America As Represented By The Secretary Of The Navy Circumferential slotted ridged waveguide array antenna
WO1988002934A1 (en) * 1986-10-17 1988-04-21 Hughes Aircraft Company Array beam position control using compound slots
JPH01501194A (en) * 1986-10-17 1989-04-20 ヒユーズ・エアクラフト・カンパニー traveling wave array antenna
JPH0552081B2 (en) * 1986-10-17 1993-08-04 Hughes Aircraft Co
US4985708A (en) * 1990-02-08 1991-01-15 Hughes Aircraft Company Array antenna with slot radiators offset by inclination to eliminate grating lobes
JP2014053735A (en) * 2012-09-06 2014-03-20 Sumitomo Electric Ind Ltd Horizontal polarization omnidirectional antenna

Similar Documents

Publication Publication Date Title
US3755815A (en) Phased array fed lens antenna
US3500422A (en) Sub-array horn assembly for phased array application
US3623114A (en) Conical reflector antenna
US3308467A (en) Waveguide antenna with non-resonant slots
US4783665A (en) Hybrid mode horn antennas
US2840818A (en) Slotted antenna
US3987454A (en) Log-periodic longitudinal slot antenna array excited by a waveguide with a conductive ridge
US3990079A (en) Log-periodic longitudinal slot antenna array excited by a waveguide with a conductive ridge
US3742513A (en) Optimized reflector antenna
US4499474A (en) Slot antenna with face mounted baffle
US3096520A (en) Endfire array
US4305078A (en) Multifrequency series-fed edge slot antenna
US4477816A (en) Corrugated antenna feed horn with means for radiation pattern control
US2453414A (en) System for directing radio waves
US5233356A (en) Low sidelobe solid state array antenna apparatus and process for configuring an array antenna aperture
RU2435263C1 (en) Dual-band antenna
US3078463A (en) Parallel plate waveguide with slotted array and multiple feeds
US3864679A (en) Antenna system for radiating doppler coded pattern using multiple beam antenna
US3218645A (en) Endfire array having vertically and horizontally spaced parasitic arrays
CN108682968B (en) Single-feed three-beam low-RCS super-surface included angle reflector antenna
US2929064A (en) Pencil beam slot antenna
WO1988001106A1 (en) Low sidelobe solid state array antenna apparatus and process for configuring an array antenna aperture
US4423421A (en) Slot array antenna with amplitude taper across a small circular aperture
US3995274A (en) Cylindrically shaped leaky wave antenna
US3435458A (en) Stepped dielectric constant end fire antenna