US2977552A - Microwave duplexer - Google Patents
Microwave duplexer Download PDFInfo
- Publication number
- US2977552A US2977552A US761224A US76122458A US2977552A US 2977552 A US2977552 A US 2977552A US 761224 A US761224 A US 761224A US 76122458 A US76122458 A US 76122458A US 2977552 A US2977552 A US 2977552A
- Authority
- US
- United States
- Prior art keywords
- waveguide
- duplexer
- microwave
- disposed
- coupling
- 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
Links
- 230000008878 coupling Effects 0.000 description 17
- 238000010168 coupling process Methods 0.000 description 17
- 238000005859 coupling reaction Methods 0.000 description 17
- 239000000523 sample Substances 0.000 description 10
- 230000005540 biological transmission Effects 0.000 description 4
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J17/00—Gas-filled discharge tubes with solid cathode
- H01J17/02—Details
- H01J17/04—Electrodes; Screens
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/03—Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
- G01S7/034—Duplexers
Definitions
- the present invention relates to electromagnetic waveguide apparatus and more particularly to an improved crossed-guide duplexer employed in microwave radar systems.
- Duplexers of the character to be described are generally employed to combine in a unitary structure the T-R and anti T-R functions necessary for operation of a single antenna microwave radar system.
- An example of such a device is shown in US. Patent No. 2,627,573,
- the invention has for its principal object the provision 'of an improved crossed-guide duplexer having a higher efliciency by lowering the VSWR during the receiving cycle of operation.
- a further object is the provision of an improved structure in combination with the directional coupling member of a crossed-guide waveguide duplexer to thereby alter the electrical characteristics, particularly at the low power level cycle of operation.
- the invention attains these objectives simply and efficiently by the provision of an electric field concentrator member within one waveguide member in proximity to the directional coupling iris. Due to the unique electric field configuration found in the crossed-guide duplexer devices, it has been determined empirically that the VSWR is considerably reduced by the placement of a probe type structure in the guide member connected to the transmitter and antenna. With the circular polarization of the field such a probe structure appears to act as a field concentrator to eliminate the prior art disadvantages.
- - Fig. l is a cross-sectional view of the embodiment of the invention.
- Fig. 2 is a top plan view along the line 22 in Fig. 1;
- Fig. 3 is an exploded perspective view of the illustrative embodiment partially cut away to reveal internal structure
- Figs. 4 and 5 are performance charts.
- the crossed-guide duplexer 1 comprises waveguide sections 2 and 3 disposed at right angles to each other to define a common wide wall having a coupling member 4 disposed therein.
- the upper waveguide section 2 is hermetically sealed at the ends thereof by means of dielectric windows 5.
- Another window 6 isiprovided in the upper wide wall of lower waveguide section 3 below the coupling member to provide a vacu um tight chamber 7 within waveguide 2.
- An exhaust tubulation 8 is provided to evacuate chamber 7 and tointroduce a gaseous ionizable atmosphere of hydrogen or argon and a small amount of water vapor at reduced pressure.
- Mounting flanges 9 and 10 are utilized for coupling to the components of the radar system with flange 9 connected to the receiver and flange 10 connected to a dissipative load termination.
- Metallic brackets 11 provide for maintaining the rectangularly disposed crossedguide relationship.
- a conventional ignitor electrode 12 supplies a stream of electrons directed to the coupling member 4.
- Additional mounting flanges 13 are disposed at the ends of waveguide 3 for coupling to the antenna and transmitter.
- the coupling member 4 constructed in accordance with the aforementioned patent is shown in detail in Fig. 2 and comprises a plurality of oppositely disposed extensions 20 formed by slots 21 and 22 each resonant at the middle frequency of the selected hand.
- the crossed slot coupling member 4 is disposed to one side of the longitudinal center line of each waveguide.
- the theory of operation of the complete duplexer arrangement is omitted herein since it is adequately discussed in the aforementioned patent.
- a dome-tipped metallic probe member 23 within waveguide section 3.
- the probe member 23 is secured to the waveguide wall opposite the common wide wall and extends into the guide a distance less than half the overall height.
- the center axis of the probe member was determined empirically to be displaced from the center axis of coupling member 4 to thereby lie closer to nearest narrow wall of waveguide 3 as shown in Figs. 1 and 2.
- the complete duplexer arrangement will be as illustrated in Fig. 3 showing the crossed-guides prior to assembly with the flanges removed for the sake of clarity.
- the appropriate components connected at the ends of the waveguides 2 and 3 are indicated thereon.
- Results are plotted in Figs. 4 and 5 for the VSWR and insertion loss at low level fora typical duplexer operating at X-band frequencies.
- the solid lines 24 and 26 indicate prior art structure while the dotted lines 25 and 27 indicate the improved structure.
- the data shown was obtained with the probe member 23 having its center axis oriented approximately .735 inch from the antenna end of the waveguide and .180 inch from the narrow waveguide wall.
- the overall diameter of the probe member was .250 inch and the height to the tip of the probe from the inside wide wall was .125 inch.
- a duplexer comprising first and second. mutually perpendicular rectangular waveguide transmission lines having a common wide wall with a resonant directional coupling element disposed therein, said first transmission line being connected between the receiver and a dissipative load termination, said second transmission line being connected between the transmitter and the antenna,
- an electric field con centrator disposed intermediate the ends of one of said waveguides in the region of the: coupling element; said field concentrator comprising a metallic probe -member secured to the wide wall opposite the common wide wall andextending into said waveguide-toward the coupling element a distance less than half the height of said waveguide, thecenter axis'ofsaid' probe member-"beingdisplaced from the center axis of the coupling element in a direction toward the nearest narrow Wall of said 5 waveguide.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Variable-Direction Aerials And Aerial Arrays (AREA)
Description
March 28, 1961 M. R. HAMILTON 2,977,552
MICROWAVE DUPLEXER Filed Sept. 15, 1958 2 Sheets-Sheet 1 N R I I E I W I L I ON MILTO FIG. 2.
sfak
ATTORNEY March 28, 1961 M. R. HAMILTON 2,977,552
MICROWAVE DUPLEXER Filed Sept. 15, 1958 2 Sheets-Sheet 2 RECEIVER TRANSMITTER ANTENNA L2 .2 32.00 A 10 cc g g 80 2 v o 8 3, L60 1 8 0.6 c O 3 L40 O. 2 25 L20 3 0. q (I) 00 E 0 1 9325 9375 9425 2 9375 425 Frequency MC/SEC Frequency MC/SEC IF IG. 4 IF IG. 5
INVENTOR. MILTON R. HA MILTON BY dg/z" ATTORNEY.
MICROWAVE DUPLEXER Milton R. Hamilton, Beverly, Mass., assignor to Bomac' Laboratories Inc., Beverly, Mass, a corporation of Massachusetts 7 Filed Sept. 15, 1958, Ser. No. 761,224
2 Claims. (Cl. 333-13) The present invention relates to electromagnetic waveguide apparatus and more particularly to an improved crossed-guide duplexer employed in microwave radar systems.
Duplexers of the character to be described are generally employed to combine in a unitary structure the T-R and anti T-R functions necessary for operation of a single antenna microwave radar system. An example of such a device is shown in US. Patent No. 2,627,573,
issued February 3, 1953, wherein parallel waveguide structures are joined together with a coupling element disposed in the common wall formed therebetween. In the use of subject device, particularly over the range of frequencies between 9325 to 9500 megacycles; it has been noted that the amount of insertion loss at low power or during the receiving cycle resulted in a high VSWR (voltage standing wave ratio). As a result a certain amount of received signal power is not coupled into the receiver thereby reducing the usefulness of the device.
The invention has for its principal object the provision 'of an improved crossed-guide duplexer having a higher efliciency by lowering the VSWR during the receiving cycle of operation.
A further object is the provision of an improved structure in combination with the directional coupling member of a crossed-guide waveguide duplexer to thereby alter the electrical characteristics, particularly at the low power level cycle of operation.
The invention attains these objectives simply and efficiently by the provision of an electric field concentrator member within one waveguide member in proximity to the directional coupling iris. Due to the unique electric field configuration found in the crossed-guide duplexer devices, it has been determined empirically that the VSWR is considerably reduced by the placement of a probe type structure in the guide member connected to the transmitter and antenna. With the circular polarization of the field such a probe structure appears to act as a field concentrator to eliminate the prior art disadvantages.
The following detailed description will assist in an understanding of the invention together with its attendant features and advantages, reference being bad to the accompanying drawings, in which:
- Fig. l is a cross-sectional view of the embodiment of the invention;
Fig. 2 is a top plan view along the line 22 in Fig. 1;
Fig. 3 is an exploded perspective view of the illustrative embodiment partially cut away to reveal internal structure; and
Figs. 4 and 5 are performance charts.
Referring to Fig. 1 the crossed-guide duplexer 1 comprises waveguide sections 2 and 3 disposed at right angles to each other to define a common wide wall having a coupling member 4 disposed therein. The upper waveguide section 2 is hermetically sealed at the ends thereof by means of dielectric windows 5. Another window 6 isiprovided in the upper wide wall of lower waveguide section 3 below the coupling member to provide a vacu um tight chamber 7 within waveguide 2. An exhaust tubulation 8 is provided to evacuate chamber 7 and tointroduce a gaseous ionizable atmosphere of hydrogen or argon and a small amount of water vapor at reduced pressure.
For the purpose of this disclosure it will be noted that the crossed slot coupling member 4 is disposed to one side of the longitudinal center line of each waveguide. The theory of operation of the complete duplexer arrangement is omitted herein since it is adequately discussed in the aforementioned patent.
In accordance with the present invention, improvement in the operating characteristics of the embodiment was observed after introduction of a dome-tipped metallic probe member 23 within waveguide section 3. The probe member 23 is secured to the waveguide wall opposite the common wide wall and extends into the guide a distance less than half the overall height. The center axis of the probe member was determined empirically to be displaced from the center axis of coupling member 4 to thereby lie closer to nearest narrow wall of waveguide 3 as shown in Figs. 1 and 2. Hence, the complete duplexer arrangement will be as illustrated in Fig. 3 showing the crossed-guides prior to assembly with the flanges removed for the sake of clarity. The appropriate components connected at the ends of the waveguides 2 and 3 are indicated thereon.
Results are plotted in Figs. 4 and 5 for the VSWR and insertion loss at low level fora typical duplexer operating at X-band frequencies. The solid lines 24 and 26 indicate prior art structure while the dotted lines 25 and 27 indicate the improved structure. The data shown was obtained with the probe member 23 having its center axis oriented approximately .735 inch from the antenna end of the waveguide and .180 inch from the narrow waveguide wall. The overall diameter of the probe member was .250 inch and the height to the tip of the probe from the inside wide wall was .125 inch.
There is thus disclosed an improved structure for enhancing the electrical characteristics of microwave duplexers in single antenna radar systems.
What is claimed is:
1. In a single antenna microwave frequency radio system, a duplexer comprising first and second. mutually perpendicular rectangular waveguide transmission lines having a common wide wall with a resonant directional coupling element disposed therein, said first transmission line being connected between the receiver and a dissipative load termination, said second transmission line being connected between the transmitter and the antenna,
Patented Mar. 28, 1961 a its center axis disposed" between the center axis of the coupling element and the nearest narrow wall' of said second transmission line.
2., In a microwave frequency duplexerhaving a pair of mutually. perpendicular rectangular Waveguides defining a'common wide wallwith a resonant directional coupling elementdisposed'therein, an electric" field con: centrator disposed intermediate the ends of one of said waveguides in the region of the: coupling element; said field concentrator comprising a metallic probe -member secured to the wide wall opposite the common wide wall andextending into said waveguide-toward the coupling element a distance less than half the height of said waveguide, thecenter axis'ofsaid' probe member-"beingdisplaced from the center axis of the coupling element in a direction toward the nearest narrow Wall of said 5 waveguide.
References Cited in. thefile of this patent UNITED STATES PATENTS
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US761224A US2977552A (en) | 1958-09-15 | 1958-09-15 | Microwave duplexer |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US761224A US2977552A (en) | 1958-09-15 | 1958-09-15 | Microwave duplexer |
Publications (1)
Publication Number | Publication Date |
---|---|
US2977552A true US2977552A (en) | 1961-03-28 |
Family
ID=25061555
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US761224A Expired - Lifetime US2977552A (en) | 1958-09-15 | 1958-09-15 | Microwave duplexer |
Country Status (1)
Country | Link |
---|---|
US (1) | US2977552A (en) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2627573A (en) * | 1948-04-28 | 1953-02-03 | Raytheon Mfg Co | Wave guide duplexer |
US2647952A (en) * | 1945-08-02 | 1953-08-04 | Us Navy | High power transmit-receive box |
US2770779A (en) * | 1951-02-08 | 1956-11-13 | Sierra Electronic Corp | Directional coupler |
-
1958
- 1958-09-15 US US761224A patent/US2977552A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2647952A (en) * | 1945-08-02 | 1953-08-04 | Us Navy | High power transmit-receive box |
US2627573A (en) * | 1948-04-28 | 1953-02-03 | Raytheon Mfg Co | Wave guide duplexer |
US2770779A (en) * | 1951-02-08 | 1956-11-13 | Sierra Electronic Corp | Directional coupler |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2422190A (en) | Ultra high frequency coupling device and system | |
US2402184A (en) | Ultra high frequency electronic device contained within wave guides | |
US2454761A (en) | Ultra high frequency device | |
US2524268A (en) | Ultra high frequency resonator | |
US2412446A (en) | Ultra high frequency system | |
US2627573A (en) | Wave guide duplexer | |
US3212034A (en) | Electromagnetic wave energy filtering | |
US2745984A (en) | Microwave oscillator | |
US3223882A (en) | Traveling wave electric discharge oscillator with directional coupling connections to a traveling wave structure wherein the number of coupling connections times the phase shift between adjacent connections equal an integral number of wavelengths | |
US2531122A (en) | Frequency responsive protective arrangement for ultra high frequency systems | |
US2710932A (en) | Broad-band transmit-receive tube for duplexers | |
US2977552A (en) | Microwave duplexer | |
US2510288A (en) | Microwave band reflection filter | |
JPH0810801B2 (en) | Ultra shortwave waveguide window | |
US2922124A (en) | Microwave transmission control device | |
US2660667A (en) | Ultrahigh frequency resonator | |
US2745910A (en) | High frequency electric discharge device coupling apparatus | |
US2895110A (en) | High frequency apparatus | |
US3209285A (en) | Folded cylinder gaseous discharge device | |
US3104340A (en) | Broadband klystron | |
US2922131A (en) | Folded cylinder gaseous discharge device | |
US2724090A (en) | Electron discharge device output coupler | |
US3521197A (en) | High frequency power limiter device for a waveguide | |
US3085213A (en) | Circular waveguide mode filter and breakdown switch device, utilizing resonant iris | |
US2625668A (en) | Ultrahigh-frequency switch tube |