Title of Invention

"A GUNN DIODE OSCILLATOR IN SUSPENDED STRIPLINE CONFIGURATION WITH EVANESCENT GUIDE TERMINATION".

Abstract A novel Gunn diode oscillator, particularly a millimeter wave Gunn diode oscillator, more particularly a Gunn diode oscillator in suspended stripline configuration, even more particularly a Gunn diode oscillator in suspended stripline configuration with evanescent mode waveguide termination has been developed. The newly developed oscillator is economical and simple to fabricate, provides convenience of biasing and is amenable for integration with various planar circuits. The oscillator has minimum circuit losses with easy tunability. The suspended stripline is terminated in an evanescent mode waveguide section on one end with a low pass filter connected directly for the application of dc bias on other end. The Gunn diode is shunt mounted into the suspended stripline towards the end connected to the evanescent mode waveguide section. A dielectric screw is inserted from the side opposite to the Gunn diode and an additional screw is provided in the evanescent guide section to facilitate the tuning. The output can be obtained from the third end either through a coaxial connector or through a rectangular waveguide. The disclosed oscillator simultaneously provides dual advantages of low loss property of suspended stripline and of inductive property of the evanescent mode guide for mechanical tuning.
Full Text The present invention is by Dr. Bharathi Bhat and Dr. Shiban Kishen Koul, both Professors of Centre for Applied Research in Electronics (CARE), Indian Institute of Technology Delhi, (IITD),Hauz Khas, New Delhi-110016, India, both Indian Nationals.
FIELD OF THE INVENTION :
The present invention relates to a Gunn diode oscillator, particularly to a millimeter wave Gunn diode oscillator, more particularly to a Gunn diode oscillator in suspended stripline configuration, even more particularly to a Gunn diode oscillator in suspended stripline configuration with evanescent guide termination.
BACKGROUND OF THE INVENTION :
Millimeter wave oscillators in millimeter-wave integrated circuits, herein after referred to as MIC, offer advantages in terms of small size and ease of integration with other planar circuits. But the limitation of such devices is that they have not been completely successful. Since an oscillator forms an essential part of a millimeter wave receiver front end, its development leading to simplicity of fabrication with minimum dimensions and size thereof, and lower circuit losses while retaining the advantages of the MIC form of fabrication is of considerable importance.
The mechanically tunable milimeter wave oscillators known in the prior art generally comprise of microstrip configuration. The oscillators in microstrip configuration, as known in the prior art are expensive and have higher circuit losses.
Oscillators for applications not requiring electronic tuning, an arrangement of microstrip oscillator employing evanescent mode resonator offers cost effective solution.
The drawback of such an arrangement as known in the prior art, is that, the diode is mounted in the evanescent mode guide and biasing the diode requires bonding of a wire to the anode, which complicates the fabrication. It is well known in the art, that in the millimeter wave band, the microstrip tends to be excessively lossy.
The oscillators employing rectangular waveguide are generally difficult to fabricate and uneconomical for commercialisation.
Further disadvantage of such arrangements is that, the waveguide adds to the size and weight of the device.
NEED OF THE INVENTION :
Therefore, there is a need to have an oscillator, particularly a Gunn diode oscillator which can overcome the limitations and disadvantages of the oscillators known in the prior art for the said purpose.
OBJECTS OF THE INVENTION :
This is the main object of the present invention to propose for an oscillator, particularly a Gunn diode oscillator, which can overcome the limitations and drawbacks, as described herein above, of such oscillators as known in the prior art.
This is further an object of the present invention to propose for a Gunn diode oscillator, which comprises of simple configuration, particularly single pattern only on one side of the substrate.
This is still an object of the present invention to propose for a Gunn diode oscillator, which does not comprise of any additional components in-addition to the minimum existing components.
Still further an object of the present invention to propose for a Gunn diode oscillator, which can be conveniently fabricated at the most economical price for commercial purpose.
Yet another object of this invention is to make a complete disclosure of a Gunn diode oscillator, which can provide dual advantages of low loss property and of inductive property providing for mechanical tuning.
Further an object of the present invention is to provide a Gunn diode oscillator, which does not comprise of any electronically tunable component but comprises of the mechanically tunable component.
BRIEF DESCRIPTION OF THE INVENTION :
Accordingly, the present invention relates to an oscillator, particularly to a Gunn diode oscillator, more particularly to a millimeter wave Gunn diode oscillator, even more particularly to a Gunn diode oscillator in suspended stripline configuration, still more particularly to a Gunn diode oscillator in suspended stripline configuration with evanescent guide termination.
In accordance to the present invention, a new Gunn diode oscillator, particularly a millimeter wave Gunn diode oscillator, more particularly a Gunn diode oscillator in suspended stripline configuration, even more particularly a Gunn diode oscillator in suspended stripline configuration with evanescent mode waveguide termination is proposed.
The presently disclosed Gunn diode oscillator, as stated herein above is economical and simple to fabricate, which provides convenience of biasing and is amenable for integration with various planar circuits.
The Gunn diode oscillator, as disclosed herein this description, has minimum circuit losses and easy mechanical tunability.
Further, in accordance to one of the preferred embodiments of this invention the suspended stripline is terminated in an evanescent mode waveguide section on one end with a low pass filter connected directly for the application of dc bias on other end. The Gunn diode is mounted onto the suspended stripline towards the end connected to the evanescent mode waveguide section. A dielectric screw is inserted from the side opposite to the Gunn diode and an additional screw is provided in the evanescent guide section to facilitate the tuning. The output can be obtained from the third end either through a coaxial connector or through a rectangular waveguide.
The presently disclosed Gunn diode oscillator simultaneously provides dual advantages of low loss property of suspended stripline and of inductive property of the evanescent mode guide for providing easy mechanical tuning.
The Gunn diode oscillator, as disclosed in the present invention further includes an housing made to accommodate the Gunn diode oscillator circuit after it is fabricated having the configuration in accordance to the preferred embodiments of this invention as described herein this description.
The nature of the presently disclosed Gunn diode oscillator will be more apparent from the accompanying drawings and the following description, which are not intended to limit the scope of the present invention.
DESCRIPTION OF THE FIGURES :
Figure-1 shows the top surface of the Gunn diode oscillator in suspended stripline configuration with evanescent guide termination in accordance to one of the preferred embodiment of the present invention.
Figure-2a and 2b shows the top/inner surfaces of the blocks of the housing of the presently disclosed Gunn diode oscillator in accordance to one of the preferred embodiment of the present invention.
Figure-2c shows the schematic view of the assembeled blocks of the housing of the presently disclosed Gunn diode oscillator in accordance to one of the preferred embodiment of the present invention (the internal structure not shown).
DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS OF THE INVENTION :
Accordingly, an oscillator, particularly a Gunn diode oscillator, more particularly a millimeter wave Gunn diode oscillator, even more particularly a Gunn diode oscillator in suspended stripline configuration, still more particularly a Gunn diode oscillator in suspended stripline configuration with evanescent guide termination is disclosed in the present invention.
In accordance to the preferred embodiments of this invention and referring to accompanying figures, a Gunn diode oscillator, comprises of a Gunn diode oscillator circuit (1), which in-turn comprises of a substrate (2) metallised (3) only on one side, including a Gunn diode 14 (figure-1), and of a housing, which in-turn comprises of two blocks 17a (figure-2a) and 17b (figure-2b). The Gunn diode circuit (1) has three ends (4,5,6) and three arms (8,9,10). The arm 9 joins the arms 8 and 10 forming the junction 7 and the Gunn diode oscillator circuit (1) thus obtained is of L shape.
In accordance to the preferred embodiment of this invention, the arm 9 employs the low pass filter 11 printed as part of the suspended stripline circuit, and arm 8 employs the suspended stripline 12. The end 4 is provided with the short inductive line 13 in the suspended stripline 12. The short inductive line 13 is provided with a Gunn diode 14: which is shunt mounted through the upper block of the housing (explained below) [figure-2a]. The end 4 terminates into the evanescent mode waveguide 15. A tuning screw 16
referred to as additional screw, is provided through a hole 26 (figure-2b) in the lower block (17b) of the housing (explained below) [figure-2b]. The additional screw 16 is provided in the evanescent guide section to facilitate the tuning, hence referred to as tunning screw. The evanescent guide section comprises of parts 15, 29a, 29b and 26.
In accordance to the preferred embodiment of the present invention, the end 5 is easily provided with a dc bias through the low pass filter 11 printed as part of the suspended stripline circuit. The suspended stripline circuit comprises of parts 8, 9, 10, 12, 13, 4 and 5. The end 6, referred to as third end serves as output end. In accordance to the preferred embodiment of this invention, the output can be obtained from the said third end 6 either through a coaxial connector or through a rectangular waveguide (not shown in the figure). The extended part 6a of the end 6 acts as a output probe, when the output has to be drawn through a rectangular waveguide. Such an end 6a is absent when the output has to be drawn through a coaxial connector.
In accordance to one of the preferred embodiments of this invention the arm 8 is longer than arm 9, which inturn is longer than the arm 10. However, the present invention is not restricted by relative length of the arms 8, 9 and 10.
The housing comprises of two blocks, one upper 17a (figure-2a) and one lower 17b (figure-2b) each having a surface 18. (The marks 'a1 and b' are used to indicate the same components of both the blocks. The mark "a1 is for upper block 17a and mark 'b1 is for lower block 17b. The parts of the housing are referred to as upper and lower blocks merely for the convenience of understanding and such markings are not intended to restrict the scope of the invention.) Each block (17a/17b) is provided with a channel (19a/19b) having three ends 20a/20b, 21 a/21 b and 22a/22b, and three arms 20a720b', 21a721b' and 22a722b' in the similar configuration as that of the Gunn diode oscillator circuit (1). The end 22a/22b opens into the another channel 23a/23b, wherein the output end 6 sits.
In accordance to one of the preferred embodiments of this invention, the channel 23a/23b extends upto the edges of the blocks 17a/17b. Through one end of the channel 23a/23b a moving shorting plunger is connected and through another end the oscillator power output is taken, when the output is drawn through a waveguide, as described herein above. The 'one end' and the 'another end', as referred herein above can be any end of the channel 23a/23b. When the output is drawn through a coaxial connector, then the central pin of the coaxial connector (not shown in figure) is directly connected to the end 6 of the arm 10. Under such conditions the extended end 6a is absent, as described herein above and the channel 23a/23b does not exist.
The end 21 a/21 b extends upto the edge of the blocks17a/17b. The end 20a/20b ends before the edge of the blocks 17a/17b. The arms 20a720b' and 21a'/21b'of the channel 19a/19b form a junction 24a/24b. The channel 19a of the upper block (17a) is provided with a hole 25a to insert the Gunn diode 14, which in-turn sits onto the short inductive line 13 of the suspended stripline 12. In accordance to this invention the hole 25a is provided towards the end 20a and it aligns with the part 13 of the Gunn diode oscillator circuit (1). The Gunn dioide 14 is inserted, through a hole 25a provided in the said upper block 17a of the housing with the help of a screw, referred to as diode mounting screw 14a (shown in the figure-2c). A dielectric screw 14b (shown in the figure-2c) is inserted from opposite side to the Gunn diode 14, through a hole 25b provided in the said lower block 17b of the housing, to enable firm contact of the short inductive line 13 with the Gunn diode 14. The side of the Gunn diode 14, which makes contact with the inductive line 13 acts as anode and the opposite side of the Gunn diode 14 acts as cathode.
The channel 19b of the lower block (17b) is provided with a hole 26 to accommodate the tuning screw 16 in the evanescent guide 15. The channel 19b of the lower block (17b) is provided with an under cut 28 to accommodate the substrate carrying the oscillator pattern, referred to as Gunn diode oscillator circuit (1). In accordance to the preferred embodiment of this invention the part 29a/29b of the channel 19a/19b forms the evanescent mode waveguide 15.
In accordance to the present invention the parts 'a' and 'b' of blocks 17a and 17b combine together and form the closed channels.
The present invention has been explained with the help of the accompanying figures, which are not intended to limit the scope of the present invention. It is obvious to those, having knowledge of the field, that various modifications are possible in the configuration of the Gunn diode oscillator circuit and its housing, which may fall within the scope of the present invention.



claim:
A Gunn diode Oscillators in inspended stripline configration with evanescent guide terminate on
comprising a substrate metallised on one side having a

gunn diode mounted on a suspended stripline enclosed is a housing the suspended stripline terminated on one end in an avanescent mode wave guide, with a low pass filter connected on the other end for application of dc bias, the said evanescent mode wave guide being provided with a short inductive line at the said end, the evanescent guide provided with a tuning screw for mechanical tuning.
2. A Gunn diode oscillator as claimed in claim 1, wherein siad metallised substrate
is metallised only on one side.
3. A Gunn diode oscillator as claimed in claims 1 to 2, wherein said Gunn diode
oscillator circuit (1) has three ends (4,5,6) and three arms (8,9,10) and arm 9 joins the
arms 8 and 10.
4. A Gunn diode oscillator as claimed in claims 1 to 3, wherein said Gunn diode
oscillator circuit (1) is of L shape.
5. A Gunn diode oscillator as claimed in claims 1 to 4, wherein said arm 9 employs
the printed low pass filter 11 and arm 8 employs the suspended stripline 12.
6. A Gunn diode oscillator as claimed in claims 1 to 5 wherein said end 4 is
provided with the short inductive line 13.
7. A Gunn diode oscillator as claimed in claims 1 to 6 wherein said end 4 terminates
into said evanescent mode waveguide 15.
8. A Gunn diode oscillator as claimed in claims 1 to 7, wherein said short inductive
line 13 is provided with said Gunn diode 14.
9. A Gunn diode oscillator as claimed in claims 1 to 8, wherein said Gunn diode 14
is shunt mounted through said upper block of said housing.
10. A Gunn diode oscillator as claimed in claims 1 to 9, wherein a tuning screw 16,
is provided through a hole 26 in said lower block of said housing.
11. A Gunn diode oscillator as claimed in claims 1 to 10, wherein an additional
screw 16 is provided in the evanescent guide section.
12. A Gunn diode oscillator as claimed in claims 1 to 11, wherein said evanescent
guide section comprises of said parts 15, 29a, 29b and 26.
13. A Gunn diode oscillator as claimed in claims 1 to 12, wherein said suspended
stripline circuit comprises of said parts 8, 9, 10, 12, 13, 4 and 5.
14. A Gunn diode oscillator as claimed in claims 1 to 13, wherein said third end 6
serves as output end for said Gunn diode oscillator.
15. A Gunn diode oscillator as claimed in claims 1 to 14, wherein an extended part
6a of said third end 6 acts as an output probe.
16. A Gunn diode oscillator as claimed in claim 1, wherein said housing comprises
of two blocks, one upper 17a and one lower block 17b.
17. A Gunn diode oscillator as claimed in preceeding claims, wherein siad blocks
(17a/17b) are provided with a channel (19a/19b) having three ends'20a/20b, 21a/21b and
22a/22b, and three arms 20a'/20b', 21a'/21b' and 22a'/22b' in the similar configuration
as that of said Gunn diode oscillator circuit (1).
18. A Gunn diode oscillator as claimed in preceeding claims, wherien said end
22a/22b opens into another channel 23a/23b.
19. A Gunn diode oscillator as claimed in preceeding claims, wherein said output end
6 sits in the said channel 23a/23b.
20. A Gunn diode oscillator as claimed in preceeding claims, wherein said channel
231/23b extends upto edges of said block 17/a/17b.
21. A Gunn diode oscillator as claimed in preceeding claims, wherein said end
21a/21b extends upto edges of said blocks 17a/17b.
22. A Gunn diode oscillator as claimed in preceeding claims, wherein said end
20a/20b ends before edge of said blocks 17a/17b.
23. A Gunn diode oscillator as claimed in preceeding claims, wherein said channel
19a of said upper block (17a) is provided with a hole 2 5 a.
24. A Gunn diode oscillator as claimed in preceeding claims, wherein said hole 25a
is provided towards end 20a of chanel 19a/19b.
25. A Gunn diode oscillator as claimed in preceeding claims, wherein said Gunn
diode 14 is enserted with the help of said mounting screw 14a.
26. A Gunn diode oscillator as claimed in preceeding claims, wherein said dielectric
screw 14b is inserted from opposite side to said Gunn diode 14 and said mounting screw
14a, through a hole 25b provided in said lower block 17b.
27. A Gunn diode oscillator as claimed in preceeding claims, wherein said channel
19b of said lower block (17B) is provided with a hole 26.
28. A Gunn diode oscillator as claimed in preceeding claims, wherein said channel
19b of said lower block (17B) is porived with an under cut 28.
29. A Gunn diode oscillator as claimed in preceeding claims, wherein said part
29a/29b of said channel 19a/19b forms said evanescent mode waveguide 15.
30. A Gunn diode oscillator as claimed in preceeding claims and described herein
above with the help of the accompanying figures.


Documents:

1579-del-1997-abstract.pdf

1579-del-1997-claims.pdf

1579-del-1997-correspondence-others.pdf

1579-del-1997-correspondence-po.pdf

1579-del-1997-description (complete).pdf

1579-del-1997-drawings.pdf

1579-del-1997-form-1.pdf

1579-del-1997-form-13.pdf

1579-del-1997-form-19.pdf

1579-del-1997-form-2.pdf

1579-del-1997-form-26.pdf

1579-del-1997-form-3.pdf

1579-del-1997-form-5.pdf

1579-del-1997-form-6.pdf

1589-DEL-1997-Correspondence Others-(21-09-2011).pdf

1589-DEL-1997-GPA-(21-09-2011).pdf


Patent Number 215114
Indian Patent Application Number 1579/DEL/1997
PG Journal Number 10/2008
Publication Date 07-Mar-2008
Grant Date 21-Feb-2008
Date of Filing 13-Jun-1997
Name of Patentee DEAN, INDUSTRIAL RESEARCH AND DEVELOPMENT, INDIAN INSTITUTE OF TECHNOLOGY DELHI (IITD),
Applicant Address HAUZ KHAS, NEW DELHI-110016, INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 DR. BHARATHI BHAT CENTRE FOR APPLIED RESEARCH IN ELECTRONICS, INDIAN INSTITUTE OF TECHNOLOGY, DELHI, (IITD), HAUZ KHAS, NEW DELHI-110016, INDIA.
2 DR. SHIBAN KISHEN KOUL CENTRE FOR APPIIED RESEARCH IN ELECTRONICS, INDIAN INSTITUTE OF TECHNOLOGY, DELHI, (IITD), HAUZ KHAS, NEW DELHI-110016, INDIA.
PCT International Classification Number H03B 9/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA