US2981947A - Coupling device for slot antenna - Google Patents

Coupling device for slot antenna Download PDF

Info

Publication number
US2981947A
US2981947A US685920A US68592057A US2981947A US 2981947 A US2981947 A US 2981947A US 685920 A US685920 A US 685920A US 68592057 A US68592057 A US 68592057A US 2981947 A US2981947 A US 2981947A
Authority
US
United States
Prior art keywords
slot
transmission line
length
coupler
coupling device
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
US685920A
Inventor
Steven J Bazan
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.)
RCA Corp
Original Assignee
RCA Corp
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 RCA Corp filed Critical RCA Corp
Priority to US685920A priority Critical patent/US2981947A/en
Application granted granted Critical
Publication of US2981947A publication Critical patent/US2981947A/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
    • H01Q21/0062—Slotted waveguides the slots being disposed around the feeding waveguide

Definitions

  • the invention relates to a'coupling device, and particular'ly to a coupling device for'slot antennas or for slotted transmission lines.
  • An object of the invention is to provide. an improved coupling device for use with a slot antenna. Another object-of the invention is to provide an im- Uni sd S a s Patent proved coupling device for use 'with slotted transmission lines.
  • the coupling device is designed to be used with a hollow 6r coaxial transmission line having a slot in its wall, and provides improved means for coupling radio frequencyenergy between the interior of the transmission line and the surrounding space; Such a transmission line is frequently used as a 'slot' antenna
  • the coupling device comprises 'a cylindrically shaped rod-like metallic couplerfas'te'ne'd to the inner surface of the wall of the transmission'linei The coupler is positioned adja- ⁇ cent one edge of the slot so, that its long dimension is substantially parallel to thato'ne edge.
  • thepresence of the coupler disturbs the exciting field within the transmissionline so as to provide a radiating fieldacross the slot to the surrounding space.
  • the coupler can a t he used to provide a field within the transmissionline that the transmission line can be used'to receive rad1o frequency energy from the surrounding space.
  • the length of the coupler is made to approach the length of the slot so that for a total amountof radiating field through or across the slot, excess disturbance to the ex- Citing field is avoided.
  • FIGS 1 and 1a show longitudinal views of slotted coaxial transmission line radiators orantennasutilizing the invention
  • Figure 2 shows a transverse cross-sectional view taken along the lines 2-2 in Figure l; j Figure 3 shows a perspective view of the'coupler shown in Figures l, 1a and 2; j p I Figure 4 shows .a transverse. cross-sectional view of a slotted hollow transmission line radiator or antenna utilizing the invention, and Figures 5 and 5a show modificationsof the arrangement shown in Figures 1', 1a and 2.'
  • a slotted coaxial transmission line 10 comprises a hollow cylindrical: outer conductor 12 and a concentric inner conductor 14 positioned within the outer conductor 12.
  • the dominantmode for the coaxial transmission line 10 is the TEMinode, and radio frequency energy propagated through the transmission line ltl has"- atransversefelectricfield in radialdirections.”
  • the slot 16 may be oriented in other positions, such as with its longer edges positioned at some angle with respect to the longitudinal axis of the transmission line 10.
  • the slot 16 is indicated, illustratively, ters of a wave length longitudinally.
  • a voltage or radiating field may be developed across the slot 16 by means of. an elongated, cylindrically shaped, metallic coupler 18.
  • the coupler-18 is shown having a circular cross-sectiomit may alsohave as being three quara polygonal or non-circular curved cross-section. '.
  • coupler 18 is located within the transmission line 10, and is fastened to the inner surface of the outer conductor 12 adjacent one of the longer edges of the slot 16.
  • coupler 18 is positioned so that its longitudinal axisis substantially parallel to' the one edge of the slot 16.
  • the arrangement ofthe coupler 18 in the transmission line It) is also shown in Figure 2.
  • a perspective view of the coupler 18 is shown in Figure 3. V
  • the coupler '18 creates a disturbance in the field of this radio frequency energy so that a voltage or radiating field appears across the slot 16.
  • the, length of the coupler11l8 be in the order of 50% to of the length ofjthe slot 16, so that the disturbance to-be exciting field along the length of the transmission line 10 may be held to a minimum.
  • the length of the member 18 is indicated, illustratively, .as being one half wave length
  • the coupler 18 extracts the total amount of radiating field across the slot 16 along a greater length from the feeding transmission line 10 than prior art devices, such as a probe, thus avoiding a point loading.
  • the heavy energy concentration present at a point loading will not only result in a voltage breakdown and hence limited power rating but, in the case of a plurality of slots extending longitudinally along the 7 transmission line 10, will also cause unwanted disturbance in adjacent slots. 7 V
  • Figure 4 shows a transverse cross-sectional view of a hollow cylindrically shaped transmission line 20 utilizing the invention.
  • the transmission line 20 is provided with an elongated slot 22 similar in shape to the slot 16 shown in Figures 1 and 2.
  • a cylindrically shaped metallic coupler 18 is fastened to the inner surface of the wallet the transmission line 20 adjacent the slot 22, and is positioned with its longitudinal axis substantially parallel to the one edge of the slot 22.
  • the operation ofthe transmission line shown in Figure 4 is coaxial transmission 1ine'10 While the invention has been described in connection with-hollow and coaxial cylindrically shaped transmission lines," the invention can also be used with other i" transmission li'nes,such-as a slotted rectangular wave,- g ,7
  • cylindrical slot antennas which are designed to radiate radio frequency energy through a plurality of slots. These slots may be positioned in various configurations around the circumference of the antenna as shown in Figure 5, and, above one another in various arrays as shown in Figures 1a and 5.
  • Figure 5a shows a transverse crosssectional view of the arrangement of Figure 5, on the line 5a-5b of Figure 5.
  • the dimensions of the coupler and slot will provide interdependent amplitude and phase controls; If the antenna is provided with a plurality' of slots along its length, different slots may be provided with difiierent diameter and length couplers. Also, if. a plurality of slots are provided at the same level in the antenna, different size and dimensioned couplersmay be used with the different slots to shape the radiated pattern, so as to ,favor one direction over another.
  • the'invention can
  • the couplers provide a means for radiating energy from the exciting field over a greater length than previous devices,
  • An antenna comprising a coaxial transmission line -having cylindrical inner and outer conductors was constructed in accordance with the invention with the following specifications:
  • Frequency 629 megacycles 0uter conductor: 12.820 inches inside diameter Inner conductor: 8.268 inches outside diameter Couplers: Solid aluminum, M2 long and 0.5-1.6 inches.
  • said apparatus comprising an elongated conductive member fastened to the inner wall of said outer coaxial member at one side of the said elongated slot opening with one side of said members long dimension substantially parallel to and substantially registered with said one side of said elongated slot, said conductive member having a length of the order of A/ 2, where A is the RF wave length.
  • Apparatus for translating radio frequency energy through an elongated slot opening in the outer member of two coaxial members said members being capable of presenting a transverse electric field in radial directions upon excitation by radio frequency energy, said elongated slot having a length not to materially exceed 3M4, said apparatus comprising an elongated conductive member positioned with respect to the inner wall of said outer coaxial member to cooperate with one side of the said elongated slot opening and with one side of said members long dimension substantially parallel to and substantially registered with said one side of said elongated slot whereby to create a disturbance in said field so that a radiating field appears. across said slot, said conductive member having a length of the order of M2, where A is the RF wave length.

Landscapes

  • Waveguide Aerials (AREA)

Description

April 25, 1961 s. J. BAZAN 2,981,947 COUPLING DEVICE FOR SLOT ANTENNA Filed Sept 24, 1957 INVEN TOR. ST EVE-N J. BAZAN F'. Bymdflzgm J 7' Tana Er 2,981,947 r COUPLING DEVICE FOR SLOT ANTENNA Qteven J. Bazan, Philadelphia, Pa., assignor to Radio Corporation ofAmerica, a corporation of Delaware I Filed Sept. 24, 19s7,'ser.No.6ss,92o
' ZClaims. or. 343-767 j j The invention relates to a'coupling device, and particular'ly to a coupling device for'slot antennas or for slotted transmission lines. a
An object of the invention is to provide. an improved coupling device for use with a slot antenna. Another object-of the invention is to provide an im- Uni sd S a s Patent proved coupling device for use 'with slotted transmission lines.
Another object ofthe inventionis to provide an ultrahigh frequency (UHF) antenna system capable of handling large amounts of power, for'example, in the order of a plurality of megawatts of eifectiveradiated power. The coupling device is designed to be used with a hollow 6r coaxial transmission line having a slot in its wall, and provides improved means for coupling radio frequencyenergy between the interior of the transmission line and the surrounding space; Such a transmission line is frequently used as a 'slot' antenna Briefly, the coupling device comprises 'a cylindrically shaped rod-like metallic couplerfas'te'ne'd to the inner surface of the wall of the transmission'linei The coupler is positioned adja- {cent one edge of the slot so, that its long dimension is substantially parallel to thato'ne edge. If the transmission line is to be used to radiate radio frequency energy t to the surrounding space, thepresence of the coupler disturbs the exciting field within the transmissionline so as to provide a radiating fieldacross the slot to the surrounding space. In a like manner, the coupler can a t he used to provide a field within the transmissionline that the transmission line can be used'to receive rad1o frequency energy from the surrounding space. The length of the coupler is made to approach the length of the slot so that for a total amountof radiating field through or across the slot, excess disturbance to the ex- Citing field is avoided. p j
The invention is explained in detail in connection with the accompanying drawing in which;
Figures 1 and 1a show longitudinal views of slotted coaxial transmission line radiators orantennasutilizing the invention;
Figure 2 shows a transverse cross-sectional view taken along the lines 2-2 in Figure l; j Figure 3 shows a perspective view of the'coupler shown in Figures l, 1a and 2; j p I Figure 4 shows .a transverse. cross-sectional view of a slotted hollow transmission line radiator or antenna utilizing the invention, and Figures 5 and 5a show modificationsof the arrangement shown in Figures 1', 1a and 2.'
In Figure 1 a slotted coaxial transmission line 10 comprises a hollow cylindrical: outer conductor 12 and a concentric inner conductor 14 positioned within the outer conductor 12. The dominantmode for the coaxial transmission line 10 is the TEMinode, and radio frequency energy propagated through the transmission line ltl has"- atransversefelectricfield in radialdirections." An clon [gated or 'rectangnlarly shaped slot -16'is' provided in the outergconductotr 12, :and is positionedwithitsfllonger longitudinally.
edges substantially parallel to the longitudinal axis of the transmission line 10. However, the slot 16 may be oriented in other positions, such as with its longer edges positioned at some angle with respect to the longitudinal axis of the transmission line 10. the slot 16 is indicated, illustratively, ters of a wave length longitudinally.
Practically no voltage will be developed across the slot 16 of the transmission line 10, as described so far, in response to the presence of radio frequency energy in the TEM mode within the transmission line 10. Consequently, no radio frequency energy will be coupled between the interior of the transmission line 10 and the surrounding space. However, in accordance with the invention, a voltage or radiating field may be developed across the slot 16 by means of. an elongated, cylindrically shaped, metallic coupler 18. Although the coupler-18 is shown having a circular cross-sectiomit may alsohave as being three quara polygonal or non-circular curved cross-section. '.The
coupler 18 is located within the transmission line 10, and is fastened to the inner surface of the outer conductor 12 adjacent one of the longer edges of the slot 16. The
coupler 18 is positioned so that its longitudinal axisis substantially parallel to' the one edge of the slot 16. The arrangement ofthe coupler 18 in the transmission line It) is also shown in Figure 2. A perspective view of the coupler 18 is shown in Figure 3. V
When radio frequency energyis propagated through the transmission line 10, the coupler '18 creates a disturbance in the field of this radio frequency energy so that a voltage or radiating field appears across the slot 16. It is preferred that the, length of the coupler11l8 be in the order of 50% to of the length ofjthe slot 16, so that the disturbance to-be exciting field along the length of the transmission line 10 may be held to a minimum. In Fig. 1 the length of the member 18 is indicated, illustratively, .as being one half wave length In other words, the coupler 18 extracts the total amount of radiating field across the slot 16 along a greater length from the feeding transmission line 10 than prior art devices, such as a probe, thus avoiding a point loading. The heavy energy concentration present at a point loading will not only result in a voltage breakdown and hence limited power rating but, in the case of a plurality of slots extending longitudinally along the 7 transmission line 10, will also cause unwanted disturbance in adjacent slots. 7 V
In contrast to this, the coupler 18 of this invention,
while extracting the same total amount of energy, but
'Figure 4 shows a transverse cross-sectional view of a hollow cylindrically shaped transmission line 20 utilizing the invention. The transmission line 20 is provided with an elongated slot 22 similar in shape to the slot 16 shown in Figures 1 and 2.
A cylindrically shaped metallic coupler 18 is fastened to the inner surface of the wallet the transmission line 20 adjacent the slot 22, and is positioned with its longitudinal axis substantially parallel to the one edge of the slot 22. The operation ofthe transmission line shown in Figure 4 is coaxial transmission 1ine'10 While the invention has been described in connection with-hollow and coaxial cylindrically shaped transmission lines," the invention can also be used with other i" transmission li'nes,such-as a slotted rectangular wave,- g ,7
The coirlplifis Of the lli ventiqnjis (mit fi d i i connection with high frequency or ultra-high frequency i InFig. 1 the length of similar to that of the shown in'Figur'es 1 and 2.
cylindrical slot antennas which are designed to radiate radio frequency energy through a plurality of slots. These slots may be positioned in various configurations around the circumference of the antenna as shown in Figure 5, and, above one another in various arrays as shown in Figures 1a and 5. Figure 5a shows a transverse crosssectional view of the arrangement of Figure 5, on the line 5a-5b of Figure 5. With a proper selection of conpler diameter and associated slot length, an independent amplitude control or an independent phase control of the radiated energy may be obtained. -Some antennas may utilize one of the controls. However, in a more general case, the dimensions of the coupler and slot will provide interdependent amplitude and phase controls; If the antenna is provided with a plurality' of slots along its length, different slots may be provided with difiierent diameter and length couplers. Also, if. a plurality of slots are provided at the same level in the antenna, different size and dimensioned couplersmay be used with the different slots to shape the radiated pattern, so as to ,favor one direction over another. Thus, the'invention,can
provide any desired amplitude and phase of the energy radiated from any of the slots. In addition, since the couplers provide a means for radiating energy from the exciting field over a greater length than previous devices,
their power handling capacity is limited only to the extent of the power handling capacity of the transmission line itself.
An antenna comprising a coaxial transmission line -having cylindrical inner and outer conductors was constructed in accordance with the invention with the following specifications:
Frequency: 629 megacycles 0uter conductor: 12.820 inches inside diameter Inner conductor: 8.268 inches outside diameter Couplers: Solid aluminum, M2 long and 0.5-1.6 inches.
in diameter effective radiated power of one megawatt when excited by a transmitter delivering a rated power of 25 kilowatts.
What is claimed is:
1. Apparatus for translating radio frequency energy through an elongated slot opening in the outer member of two coaxial members, said elongated slot having a length not to materially exceed 3M 4, said apparatus comprising an elongated conductive member fastened to the inner wall of said outer coaxial member at one side of the said elongated slot opening with one side of said members long dimension substantially parallel to and substantially registered with said one side of said elongated slot, said conductive member having a length of the order of A/ 2, where A is the RF wave length.
2. Apparatus for translating radio frequency energy through an elongated slot opening in the outer member of two coaxial members, said members being capable of presenting a transverse electric field in radial directions upon excitation by radio frequency energy, said elongated slot having a length not to materially exceed 3M4, said apparatus comprising an elongated conductive member positioned with respect to the inner wall of said outer coaxial member to cooperate with one side of the said elongated slot opening and with one side of said members long dimension substantially parallel to and substantially registered with said one side of said elongated slot whereby to create a disturbance in said field so that a radiating field appears. across said slot, said conductive member having a length of the order of M2, where A is the RF wave length.
References Cited in the file of this patent UNITED STATES PATENTS 2,477,510 Chu July 26, 1949 2,574,433 Clapp Nov. 6, 1951 2,600,179 Alford June 10, 1952 2,658,143 Fiet et al. Nov. 3, 1953 2,724,774 Fiet Nov. 22, 1955 2,803,008 Lindenblad Aug. 13, 1957 2,818,565 Ajioka et al. Dec. 31. 1957
US685920A 1957-09-24 1957-09-24 Coupling device for slot antenna Expired - Lifetime US2981947A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US685920A US2981947A (en) 1957-09-24 1957-09-24 Coupling device for slot antenna

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US685920A US2981947A (en) 1957-09-24 1957-09-24 Coupling device for slot antenna

Publications (1)

Publication Number Publication Date
US2981947A true US2981947A (en) 1961-04-25

Family

ID=24754205

Family Applications (1)

Application Number Title Priority Date Filing Date
US685920A Expired - Lifetime US2981947A (en) 1957-09-24 1957-09-24 Coupling device for slot antenna

Country Status (1)

Country Link
US (1) US2981947A (en)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3127609A (en) * 1960-03-30 1964-03-31 Frederick L Wentworth Antenna having ring waveguide two wavelengths long for feeding two slots in diametrically opposed portions thereof
US3149336A (en) * 1961-02-17 1964-09-15 Rca Corp Slot radiator in wall of coaxial feed having mode coupling means at slot
US3164834A (en) * 1960-11-25 1965-01-05 Rca Corp Waveguide tower with stacked slot radiators
US3657652A (en) * 1969-12-17 1972-04-18 Itt Inter-compartment coupling device
US3870977A (en) * 1973-09-25 1975-03-11 Times Wire And Cable Companay Radiating coaxial cable
US4583098A (en) * 1984-08-31 1986-04-15 Rca Corporation Circularly polarized antenna using axial slot and slanted parasitic radiators
US4590480A (en) * 1984-08-31 1986-05-20 Rca Corporation Broadcast antenna which radiates horizontal polarization towards distant locations and circular polarization towards nearby locations
US4590479A (en) * 1984-03-29 1986-05-20 Rca Corporation Broadcast antenna system with high power aural/visual self-diplexing capability
US4907008A (en) * 1988-04-01 1990-03-06 Andrew Corporation Antenna for transmitting circularly polarized television signals
US5929821A (en) * 1998-04-03 1999-07-27 Harris Corporation Slot antenna
US6373444B1 (en) * 2001-03-08 2002-04-16 General Signal Corporation Common aperture UHF/VHF high band slotted coaxial antenna
DE10126469A1 (en) * 2001-05-31 2002-12-12 Eads Deutschland Gmbh Slot radiating element
US20050146474A1 (en) * 2003-12-30 2005-07-07 Bannon Walter W. Apparatus and method to increase apparent resonant slot length in a slotted coaxial antenna
US11069981B2 (en) * 2017-03-27 2021-07-20 Nokia Shanghai Bell Co., Ltd. Radiating cable and method of manufacturing a radiating cable with an inner and outer conductor, each having openings

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2477510A (en) * 1944-01-31 1949-07-26 Chu Lan Jen Slotted wave guide antenna
US2574433A (en) * 1943-10-01 1951-11-06 Roger E Clapp System for directional interchange of energy between wave guides and free space
US2600179A (en) * 1946-02-18 1952-06-10 Alford Andrew Split cylinder antenna
US2658143A (en) * 1950-03-16 1953-11-03 Rca Corp Ultrahigh-frequency broadcast antenna system
US2724774A (en) * 1952-06-03 1955-11-22 Rca Corp Slotted cylinder antenna
US2803008A (en) * 1953-12-28 1957-08-13 Rca Corp Slotted cylindrical antenna systems
US2818565A (en) * 1956-09-05 1957-12-31 James S Ajioka Slab excited continuous slot antenna

Patent Citations (7)

* 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
US2477510A (en) * 1944-01-31 1949-07-26 Chu Lan Jen Slotted wave guide antenna
US2600179A (en) * 1946-02-18 1952-06-10 Alford Andrew Split cylinder antenna
US2658143A (en) * 1950-03-16 1953-11-03 Rca Corp Ultrahigh-frequency broadcast antenna system
US2724774A (en) * 1952-06-03 1955-11-22 Rca Corp Slotted cylinder antenna
US2803008A (en) * 1953-12-28 1957-08-13 Rca Corp Slotted cylindrical antenna systems
US2818565A (en) * 1956-09-05 1957-12-31 James S Ajioka Slab excited continuous slot antenna

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3127609A (en) * 1960-03-30 1964-03-31 Frederick L Wentworth Antenna having ring waveguide two wavelengths long for feeding two slots in diametrically opposed portions thereof
US3164834A (en) * 1960-11-25 1965-01-05 Rca Corp Waveguide tower with stacked slot radiators
US3149336A (en) * 1961-02-17 1964-09-15 Rca Corp Slot radiator in wall of coaxial feed having mode coupling means at slot
US3657652A (en) * 1969-12-17 1972-04-18 Itt Inter-compartment coupling device
US3870977A (en) * 1973-09-25 1975-03-11 Times Wire And Cable Companay Radiating coaxial cable
US4590479A (en) * 1984-03-29 1986-05-20 Rca Corporation Broadcast antenna system with high power aural/visual self-diplexing capability
US4590480A (en) * 1984-08-31 1986-05-20 Rca Corporation Broadcast antenna which radiates horizontal polarization towards distant locations and circular polarization towards nearby locations
US4583098A (en) * 1984-08-31 1986-04-15 Rca Corporation Circularly polarized antenna using axial slot and slanted parasitic radiators
US4907008A (en) * 1988-04-01 1990-03-06 Andrew Corporation Antenna for transmitting circularly polarized television signals
US5929821A (en) * 1998-04-03 1999-07-27 Harris Corporation Slot antenna
US6373444B1 (en) * 2001-03-08 2002-04-16 General Signal Corporation Common aperture UHF/VHF high band slotted coaxial antenna
DE10126469A1 (en) * 2001-05-31 2002-12-12 Eads Deutschland Gmbh Slot radiating element
US20050146474A1 (en) * 2003-12-30 2005-07-07 Bannon Walter W. Apparatus and method to increase apparent resonant slot length in a slotted coaxial antenna
US7091919B2 (en) * 2003-12-30 2006-08-15 Spx Corporation Apparatus and method to increase apparent resonant slot length in a slotted coaxial antenna
US11069981B2 (en) * 2017-03-27 2021-07-20 Nokia Shanghai Bell Co., Ltd. Radiating cable and method of manufacturing a radiating cable with an inner and outer conductor, each having openings

Similar Documents

Publication Publication Date Title
US2981947A (en) Coupling device for slot antenna
US2556094A (en) High-frequency apparatus
US2914766A (en) Three conductor planar antenna
US2742612A (en) Mode transformer
US2412320A (en) Antenna system
US3106713A (en) Slot antenna having short radiating slots and long nonradiating distributed capacitance tuning slot
US2877429A (en) High frequency wave translating device
US3340534A (en) Elliptically or circularly polarized antenna
US2611867A (en) Slotted winged cylindrical antenna
US6292072B1 (en) Radiating coaxial cable having groups of spaced apertures for generating a surface wave at a low frequencies and a combination of surface and radiated waves at higher frequencies
US4040061A (en) Broadband corrugated horn antenna
US2597144A (en) Electromagnetic wave control structure
US3364489A (en) Traveling wave antenna having radiator elements with doubly periodic spacing
US3375474A (en) Microwave waveguide to coax coupling system
US2726388A (en) Antenna system combinations and arrays
US2724774A (en) Slotted cylinder antenna
US4558290A (en) Compact broadband rectangular to coaxial waveguide junction
GB1090040A (en) High frequency electron discharge devices of travelling wave type and slow wave circuits
US3189908A (en) Ridged waveguide slot antenna
US2803008A (en) Slotted cylindrical antenna systems
US3103011A (en) Inductively loaded folded antenna
US2759156A (en) Waveguide mode filter
JP5622881B2 (en) Leaky coaxial cable
US4011566A (en) In-line coax-to waveguide transition using dipole
US2635189A (en) Wave guide antenna with bisectional radiator