CA1230172A - Microwave integrated circuit immune to adverse shielding effects - Google Patents
Microwave integrated circuit immune to adverse shielding effectsInfo
- Publication number
- CA1230172A CA1230172A CA000510869A CA510869A CA1230172A CA 1230172 A CA1230172 A CA 1230172A CA 000510869 A CA000510869 A CA 000510869A CA 510869 A CA510869 A CA 510869A CA 1230172 A CA1230172 A CA 1230172A
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- frequency converter
- microwave frequency
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- conductive
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/552—Protection against radiation, e.g. light or electromagnetic waves
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
- H01L2924/161—Cap
- H01L2924/1615—Shape
- H01L2924/16152—Cap comprising a cavity for hosting the device, e.g. U-shaped cap
- H01L2924/1616—Cavity shape
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- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Electromagnetism (AREA)
- Toxicology (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
Abstract
"Microwave Integrated Circuit Immune to Adverse Shielding Effects"
ABSTRACT
A microwave integrated circuit comprises a shield case having a pair of opposed first and second end walls, a pair of side walls and top and bottom walls, and a dielectric substrate on the bottom wall. First and second interconnected integrated circuit portions are arranged on the substrate between the first and second end walls. An input strip line is arranged on the substrate, the strip line having one end coupled to the input of the first integrated circuit portion and the other end terminating at a position spaced from the first end wall by a distance approximately equal to an integral multiple of the half wavelength of a signal propagating in the shield case. An elongated coupling member is disposed in parallel with the first end wall, the coupling member extending from the other end of the input strip line to an external circuit.
ABSTRACT
A microwave integrated circuit comprises a shield case having a pair of opposed first and second end walls, a pair of side walls and top and bottom walls, and a dielectric substrate on the bottom wall. First and second interconnected integrated circuit portions are arranged on the substrate between the first and second end walls. An input strip line is arranged on the substrate, the strip line having one end coupled to the input of the first integrated circuit portion and the other end terminating at a position spaced from the first end wall by a distance approximately equal to an integral multiple of the half wavelength of a signal propagating in the shield case. An elongated coupling member is disposed in parallel with the first end wall, the coupling member extending from the other end of the input strip line to an external circuit.
Description
12~0~72 TITLE OF THE INVENTION
"Microwave Integrated Circuit Immune to Adverse Shielding Effects"
~ACKGRO~ND OF THE INVENTION
5The present invention relates to a microwave integrated circuit.
In conventional microwave integrated circuits which comprise a plurality of interconnected circuits of different functions, the operating characteristics of the individual circuits are not reflected faithfully in the overall operating characteristic of the integrated circuit due to the shielding effect of a casing in which the circuits are housed, 5pecifically, in a microwave integrated circuit frequency converter which compri~es an amplifier, mixes and local oscillator, the operating characteristics of the individual circuits can be fully exploited if the interconnecting parts of the converter are appropriately designed. Ho~ever, the shielding effect of the casing adversely affects the various operating factors including input VSWR, noise figure, leakage of local oscillator output, image suppression ratio and conversion gain. In a local oscillator having a dielectric resonator, the resonator tends to couple with a particular waveguide resonance mode of the shield case to such a degree that the t23~172 oscillator ceases to generate an output.
SUMMARY OF THE INVENTION
An object of the present invention is therefore to provide a microwave integrated circuit which is immune to adverse effects produced by the shield case in which the individual components of the 'integrated circuit are housed.
According to a feature of the invention, a microwave integrated circuit comprises a shield case having a pair of opposed first and second end walls, a pair of side walls and top and bottom walls, and a dielectric substrate on the bottom wall. First and second interconnected integrated circuit portions are arranged on the substrate between the first and second end walls. An input strip line located on the substrate has first and second ends respectively coupled to the input of the first integrated circuit portion and terminates at a position spaced from the first end wall by a distance approximately equal to an integral multiple of a half wavelength of a signal propagating in the shield case. An elongated coupling member disposed parallel with first end wall extends from the other end of the input strip line to an external circuit, A connection of the input strip line and the elongated coupling member at the half-wavelength point 25 eliminates the effect of the shield case on the input 017~
impedance of ~he first integrated circuit portion, eliminating the need to take the shield casing into account in the design of the integrated circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in further detail with reference to the accompanying drawings, in which:
Fig. la is a cross-sectional view of a microwave integrated circuit as seen from above and Fig. lb is a cross-sectional view taken along the line lb-lb of Fig. la;
Fig. 2 is an illustration of an alternative embodiment of the invention;
Fig. 3a is a cross-sectional view of a lS modified embodiment of the invention, and Fig. 3b is a cross-sectional view taken along the line 3b-3b of Fig. 3a;
Figs. 4a and 4b are illustrations of a further modified embodiment of the invention;
Figs. 5a and Sb are illustrations of a specific form of the embodiment of Figs. 4a, 4b;
Fig. 6a and 6b are illustrations of a further modification of the present invention;
~ig. 7a and 7b are illustrations of a modified form of the embodiment oÇ Figs. 6a, 6b;
Fig. B is a cross-sectional view of another 123~72 embodiment of the invention in which the integrated circuit is shown separated from the lower waveguide section;
Fig, 9 is a perspecti~e view of the shield casing of Fig. 8; and Fig~ 10 is a sectional vàew of an interconnecting strip line having a DC decoupling section.
D~TAILED DESCRIPTION
In Figs. la and lb, a microwave integrated-circuit frequency con~erter according to the present invention lQ comprises a super high frequency amplifier 1, a frequency mixer 2 and a local oscillator 3 all of which are mounted on a common dielectric substrate 4 formed of a material such as alumina or Teflon ~ glass fibers and are connected in series with a common shield case 5. An input strip line 6 is located in an unoccupied area of the dielectric substrate 4. First and second ends of the strip line 6 are respectively connected to the input to SHF amplifier 1 and to a coupling element 7 which extends downward through the subs~rate 4 into a waveguide ~, which is located below th~
integrated circuit, to couple an input microwa~e signal to amplifier 1. The coupling element 7 is located in a position spaced a distance "L" from an adjacent end wall 5a of the shield case 5, the distance L being approximately equal to an integral multiple of the half wavelength of the signal propagating through the case 5 or an integral multiple of the half wavelength of the signal generated by the local oscillator 3.
The above noted half-wavelength spacing has an important advantage in that the input impedance of the SHF
amplifier 1 is rendered constant regardless of whether the case 5 is provided or not. This eliminates the need to take the case 5 into consideration when the input impedance is calculated. As a result, the design of the SHF
amplifier 1 is simplified and the operating characteristics of the individual constituents of the integrated circuit can be reflected faithfully in the overall operating characteristic of the integrated circuit.
At the same time the amount of undesired spurious emission from the local oscillator 3 to the waveguide 8 is also reduced.
The parallel arrangement of the waveguide 8 and the integrated circuit allows the microwave frequency converter to have a relatively small longitudinal dimension and enables the waveguide portion to be longer to achieve a small transmission loss.
In a further alternative embodiment, the coupling element 7 is connected to an end of a coaxial cable to receive input microwave signals.
The coupling el~ment 7 may alternatively be formed by a se~ment 7' which is disposed on the unoccupied area of 7~
the dielectric substrate 4 and through an extension of the substrate 4, as shown in Fig. 2, and extends to the waveguide 8' which is provided on a lateral side of the case 5.
Figs. 3a and 3b are illustrations of another embodiment of the invention in which parts corresponding to those in Figs. la and lb are marked with like numerals.
This embodiment differs from the previous embodiment in that the SHF amplifier 1 and frequency mixer 2 are spatially separated by a conducti~e partition 9 and the SHF
amplifier 1 comprises a first, preamplifier stage la and a second, next amplifier stage lb to provide a higher ampli-fication gain. These successive amplifier stages are spatially divided from each other by a conductive partition 10. The partition 9 effectively eliminates a leakage path which otherwise exists between the local oscillator 3 output and the waveguide 8 to thereby further reduce the undesired spurious emission. The partition 9, on the other hand, effectively stabilizes the operation of amplifier 1 by cutting off a feedback path which otherwise may exist from the output of the second amplifier stage lb to the input of the first stage la~
Figs. ~a and 4b are illustrations of a further modification of the present invention which is generally similar to that shown in Figs. 3a and 3b except ~3(~L7~
that it includes emission absorbing blocks 11, 12 and 13 formed of ferrite rubber or the like~ The block 11 is located in a chamber 14 which subsists between wall 5a and partition 10 and is shared ~ith the first amplifier stage la. Block 11 is adjacent one sicLe wall of the case 5 remote from the signal trave;ling path. In chamber 15 which is defined between partitions 9 and 10, are located block 12 and the second amplifier stage lb. 810ck 12 is likewise located in a position adjacent one side wall of the shield case 5 remote from the signal travelling path.
In chamber 16, defined between the partition 4 and an end wall 5b of case 5, are third emission absorbing block 13 and local oscillator 3.
In addition to the advantages provided by the previous embodiments, the emission absorbing blocks 11, 12 and 13 absorb undesired emissions which are generated in the respective chambers due to the provision of the shield partitions 9 and 10. Emission absorbing blocks 11-13 stabilize the input VSWR and the gain versus frequency 2Q characteristic of the SHF amplifier 1 and the conversion-loss and image signal suppression ratio versus frequency characteristics of the frequency mixer 2 and eliminate undersirable resonance characteristics, while at ~5 ~3~
the same time ensuring that the local oscillator 3 supplies a sufficient amount of energy to the frequency mlxer 2. The emission absorbing blocks 11 and 12 further reduce the amount of undesirable spurious emissions from the local oscillator 3 to the waveguide 8.
Figs, 5a and 5b are illustrations of a practical form of the embodiment of Figs. 4a and 4b. ~he local oscillator 3 is formed by a GaAs ~ield-effect transistor 22 and a dielectric resonator 23 located adjacent theretol and the mixer 2 comprises an image signal rejection filter 27 formed by a set of three open-ended stubs 26 and a mixer diode 28. The emission absorbing block 13 is secured to an inner side wall of the case S proximate the ends of stubs 26 to suppress a particular waveguide mode of the case 5 which would otherwise couple with the rejection filter 27.
The proximate location of the absorbing block 13 to the rejection filter 27 has further advantageous effects of suppressing the coupling of the waveguide mode of the case with the rejection filter 27 and ~inimizing the unde~ired 2Q effects of the case 5 on the conversion ioss characteristic of the mixer 2 and on the image suppression performance of the filter 27. 5ince the absorbing block 13 is located remote from the di~lectric resonator 23, the latter is not affected by the absorption effect of the block 13.
Undesired coupling of the waveguide mode with the ~Z30~72 _ 9 dielectric resonator 23 can be eliminated with the use of a metal block 25 located in proximity to the rejection filter 26. The metal block 25 extends between the dielectric substrate 4 and the top wall of the case 5. With the chamber 16 meas~ring 60 mm x 30 mm x 9 mm and the dielectric resonator 23 being located approximately 14 mm from the lower right corner of the chamber 16, the metal block 25 has dimensions of 8 mm x 6 mm x 2 mm as measured in the vertical, transverse and longitudinal directions of lQ the case and is located a distance of approximately 17 mm from the upper left corner of the chamber so that it projects from the side wall of the case. This ensures normal operation of the local oscillator 3; it has been confirmed that the current flowing through the mixer diode 28 is at a normal level.
A further modific~tion of the present invention illustrated in Figs. 6a and 6b is similar to the embodiment of Figs. 4a, 4b except that a conductive block 17 replaces emission absorbing block 11 in the chamber 14; block 17 occupies a lateral portion of chamber 14 to reduce the effective width of the chamber. The reduction of the transverse dimension of the SHF first amplifier stage la shifts the undesirable resonance frequency to a point outside the bandwidth of the MIC frequency converter to eliminate undesirable effects on the input VSWR and gain 7~
versus frequency characteristics and prevents a reduction in the noise figure of the frequency converter. It has been confirmed that a 7-mm wide metal block 17 in a shield case operating in the range between 11.7 GHz and 12.5 GHz with dimensions 30 mm wide, 9 mm high and 23.5 mm long, caused an undesirable resonance point shift from 12.5 GHz to 12.9 GHz and a noise figure reduction from 0.1 to 0.2 dB.
A metal block 18 ~ay also be provided in t~e chamber 15, as shown in Figs. 7a and 7b, instead of the emission lQ absorbing block 12 of Figs. 6a, 6b to shift the undesirable resonance peak to a point outside the bandwidth of the MIC frequency converter. This diminishes the effect of the resonance which would adversely affect the operating performance of the converter including the input VSWR and frequency response and the noise figure versus frequency characteristic.
A specific version of the embodiment of Figs. 7a, 7b is shown in Figs. 8 and 9 The waveguide 8 has a top wall 19 which also serves as a bottom wall of the shield case 5.
The case 5 is a one-piece unit 20, secured to the top wall 19 of the waveguide 8. In Fig. 9, the shield partitions 9 and 10 are formed with recesses 9' and 10', respectively, to allow the interstage section of the strip line oi the integrated circuit to pass therethrough. Each of these recesses has a width greater than approximately twice the ~3~
width of the interstage strip-line sect'~on and has a depth approximately three times greater than its thickness~
This construction facilitates assemblage of MIC frequency converters and pro~ides uniformity in manufacture.
In a further preferred embodiment, each interstage section of the strip line includes a DC decoupler 31, in Fig. 10. A strip-line section 32 extending from the previous stage output terminates with a quarter wavelength coupling portion 33. A strip-line coupling portion 34 extending from the input of the next stage likewise terminates with a quarter wavelength portion 35; the q~arter wavelength portions 33 and 35 being disposed in an inter-digital configuration. Each of the coupling portions 33 and 35 has a quarter wavelength of the signal that travels along the strip-line sections 32 and 34~ The interdigital configuration causes the characteristic impedance of the strip-line sections to be less influenced by the shielding effect of the partitions 9 and 10
"Microwave Integrated Circuit Immune to Adverse Shielding Effects"
~ACKGRO~ND OF THE INVENTION
5The present invention relates to a microwave integrated circuit.
In conventional microwave integrated circuits which comprise a plurality of interconnected circuits of different functions, the operating characteristics of the individual circuits are not reflected faithfully in the overall operating characteristic of the integrated circuit due to the shielding effect of a casing in which the circuits are housed, 5pecifically, in a microwave integrated circuit frequency converter which compri~es an amplifier, mixes and local oscillator, the operating characteristics of the individual circuits can be fully exploited if the interconnecting parts of the converter are appropriately designed. Ho~ever, the shielding effect of the casing adversely affects the various operating factors including input VSWR, noise figure, leakage of local oscillator output, image suppression ratio and conversion gain. In a local oscillator having a dielectric resonator, the resonator tends to couple with a particular waveguide resonance mode of the shield case to such a degree that the t23~172 oscillator ceases to generate an output.
SUMMARY OF THE INVENTION
An object of the present invention is therefore to provide a microwave integrated circuit which is immune to adverse effects produced by the shield case in which the individual components of the 'integrated circuit are housed.
According to a feature of the invention, a microwave integrated circuit comprises a shield case having a pair of opposed first and second end walls, a pair of side walls and top and bottom walls, and a dielectric substrate on the bottom wall. First and second interconnected integrated circuit portions are arranged on the substrate between the first and second end walls. An input strip line located on the substrate has first and second ends respectively coupled to the input of the first integrated circuit portion and terminates at a position spaced from the first end wall by a distance approximately equal to an integral multiple of a half wavelength of a signal propagating in the shield case. An elongated coupling member disposed parallel with first end wall extends from the other end of the input strip line to an external circuit, A connection of the input strip line and the elongated coupling member at the half-wavelength point 25 eliminates the effect of the shield case on the input 017~
impedance of ~he first integrated circuit portion, eliminating the need to take the shield casing into account in the design of the integrated circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in further detail with reference to the accompanying drawings, in which:
Fig. la is a cross-sectional view of a microwave integrated circuit as seen from above and Fig. lb is a cross-sectional view taken along the line lb-lb of Fig. la;
Fig. 2 is an illustration of an alternative embodiment of the invention;
Fig. 3a is a cross-sectional view of a lS modified embodiment of the invention, and Fig. 3b is a cross-sectional view taken along the line 3b-3b of Fig. 3a;
Figs. 4a and 4b are illustrations of a further modified embodiment of the invention;
Figs. 5a and Sb are illustrations of a specific form of the embodiment of Figs. 4a, 4b;
Fig. 6a and 6b are illustrations of a further modification of the present invention;
~ig. 7a and 7b are illustrations of a modified form of the embodiment oÇ Figs. 6a, 6b;
Fig. B is a cross-sectional view of another 123~72 embodiment of the invention in which the integrated circuit is shown separated from the lower waveguide section;
Fig, 9 is a perspecti~e view of the shield casing of Fig. 8; and Fig~ 10 is a sectional vàew of an interconnecting strip line having a DC decoupling section.
D~TAILED DESCRIPTION
In Figs. la and lb, a microwave integrated-circuit frequency con~erter according to the present invention lQ comprises a super high frequency amplifier 1, a frequency mixer 2 and a local oscillator 3 all of which are mounted on a common dielectric substrate 4 formed of a material such as alumina or Teflon ~ glass fibers and are connected in series with a common shield case 5. An input strip line 6 is located in an unoccupied area of the dielectric substrate 4. First and second ends of the strip line 6 are respectively connected to the input to SHF amplifier 1 and to a coupling element 7 which extends downward through the subs~rate 4 into a waveguide ~, which is located below th~
integrated circuit, to couple an input microwa~e signal to amplifier 1. The coupling element 7 is located in a position spaced a distance "L" from an adjacent end wall 5a of the shield case 5, the distance L being approximately equal to an integral multiple of the half wavelength of the signal propagating through the case 5 or an integral multiple of the half wavelength of the signal generated by the local oscillator 3.
The above noted half-wavelength spacing has an important advantage in that the input impedance of the SHF
amplifier 1 is rendered constant regardless of whether the case 5 is provided or not. This eliminates the need to take the case 5 into consideration when the input impedance is calculated. As a result, the design of the SHF
amplifier 1 is simplified and the operating characteristics of the individual constituents of the integrated circuit can be reflected faithfully in the overall operating characteristic of the integrated circuit.
At the same time the amount of undesired spurious emission from the local oscillator 3 to the waveguide 8 is also reduced.
The parallel arrangement of the waveguide 8 and the integrated circuit allows the microwave frequency converter to have a relatively small longitudinal dimension and enables the waveguide portion to be longer to achieve a small transmission loss.
In a further alternative embodiment, the coupling element 7 is connected to an end of a coaxial cable to receive input microwave signals.
The coupling el~ment 7 may alternatively be formed by a se~ment 7' which is disposed on the unoccupied area of 7~
the dielectric substrate 4 and through an extension of the substrate 4, as shown in Fig. 2, and extends to the waveguide 8' which is provided on a lateral side of the case 5.
Figs. 3a and 3b are illustrations of another embodiment of the invention in which parts corresponding to those in Figs. la and lb are marked with like numerals.
This embodiment differs from the previous embodiment in that the SHF amplifier 1 and frequency mixer 2 are spatially separated by a conducti~e partition 9 and the SHF
amplifier 1 comprises a first, preamplifier stage la and a second, next amplifier stage lb to provide a higher ampli-fication gain. These successive amplifier stages are spatially divided from each other by a conductive partition 10. The partition 9 effectively eliminates a leakage path which otherwise exists between the local oscillator 3 output and the waveguide 8 to thereby further reduce the undesired spurious emission. The partition 9, on the other hand, effectively stabilizes the operation of amplifier 1 by cutting off a feedback path which otherwise may exist from the output of the second amplifier stage lb to the input of the first stage la~
Figs. ~a and 4b are illustrations of a further modification of the present invention which is generally similar to that shown in Figs. 3a and 3b except ~3(~L7~
that it includes emission absorbing blocks 11, 12 and 13 formed of ferrite rubber or the like~ The block 11 is located in a chamber 14 which subsists between wall 5a and partition 10 and is shared ~ith the first amplifier stage la. Block 11 is adjacent one sicLe wall of the case 5 remote from the signal trave;ling path. In chamber 15 which is defined between partitions 9 and 10, are located block 12 and the second amplifier stage lb. 810ck 12 is likewise located in a position adjacent one side wall of the shield case 5 remote from the signal travelling path.
In chamber 16, defined between the partition 4 and an end wall 5b of case 5, are third emission absorbing block 13 and local oscillator 3.
In addition to the advantages provided by the previous embodiments, the emission absorbing blocks 11, 12 and 13 absorb undesired emissions which are generated in the respective chambers due to the provision of the shield partitions 9 and 10. Emission absorbing blocks 11-13 stabilize the input VSWR and the gain versus frequency 2Q characteristic of the SHF amplifier 1 and the conversion-loss and image signal suppression ratio versus frequency characteristics of the frequency mixer 2 and eliminate undersirable resonance characteristics, while at ~5 ~3~
the same time ensuring that the local oscillator 3 supplies a sufficient amount of energy to the frequency mlxer 2. The emission absorbing blocks 11 and 12 further reduce the amount of undesirable spurious emissions from the local oscillator 3 to the waveguide 8.
Figs, 5a and 5b are illustrations of a practical form of the embodiment of Figs. 4a and 4b. ~he local oscillator 3 is formed by a GaAs ~ield-effect transistor 22 and a dielectric resonator 23 located adjacent theretol and the mixer 2 comprises an image signal rejection filter 27 formed by a set of three open-ended stubs 26 and a mixer diode 28. The emission absorbing block 13 is secured to an inner side wall of the case S proximate the ends of stubs 26 to suppress a particular waveguide mode of the case 5 which would otherwise couple with the rejection filter 27.
The proximate location of the absorbing block 13 to the rejection filter 27 has further advantageous effects of suppressing the coupling of the waveguide mode of the case with the rejection filter 27 and ~inimizing the unde~ired 2Q effects of the case 5 on the conversion ioss characteristic of the mixer 2 and on the image suppression performance of the filter 27. 5ince the absorbing block 13 is located remote from the di~lectric resonator 23, the latter is not affected by the absorption effect of the block 13.
Undesired coupling of the waveguide mode with the ~Z30~72 _ 9 dielectric resonator 23 can be eliminated with the use of a metal block 25 located in proximity to the rejection filter 26. The metal block 25 extends between the dielectric substrate 4 and the top wall of the case 5. With the chamber 16 meas~ring 60 mm x 30 mm x 9 mm and the dielectric resonator 23 being located approximately 14 mm from the lower right corner of the chamber 16, the metal block 25 has dimensions of 8 mm x 6 mm x 2 mm as measured in the vertical, transverse and longitudinal directions of lQ the case and is located a distance of approximately 17 mm from the upper left corner of the chamber so that it projects from the side wall of the case. This ensures normal operation of the local oscillator 3; it has been confirmed that the current flowing through the mixer diode 28 is at a normal level.
A further modific~tion of the present invention illustrated in Figs. 6a and 6b is similar to the embodiment of Figs. 4a, 4b except that a conductive block 17 replaces emission absorbing block 11 in the chamber 14; block 17 occupies a lateral portion of chamber 14 to reduce the effective width of the chamber. The reduction of the transverse dimension of the SHF first amplifier stage la shifts the undesirable resonance frequency to a point outside the bandwidth of the MIC frequency converter to eliminate undesirable effects on the input VSWR and gain 7~
versus frequency characteristics and prevents a reduction in the noise figure of the frequency converter. It has been confirmed that a 7-mm wide metal block 17 in a shield case operating in the range between 11.7 GHz and 12.5 GHz with dimensions 30 mm wide, 9 mm high and 23.5 mm long, caused an undesirable resonance point shift from 12.5 GHz to 12.9 GHz and a noise figure reduction from 0.1 to 0.2 dB.
A metal block 18 ~ay also be provided in t~e chamber 15, as shown in Figs. 7a and 7b, instead of the emission lQ absorbing block 12 of Figs. 6a, 6b to shift the undesirable resonance peak to a point outside the bandwidth of the MIC frequency converter. This diminishes the effect of the resonance which would adversely affect the operating performance of the converter including the input VSWR and frequency response and the noise figure versus frequency characteristic.
A specific version of the embodiment of Figs. 7a, 7b is shown in Figs. 8 and 9 The waveguide 8 has a top wall 19 which also serves as a bottom wall of the shield case 5.
The case 5 is a one-piece unit 20, secured to the top wall 19 of the waveguide 8. In Fig. 9, the shield partitions 9 and 10 are formed with recesses 9' and 10', respectively, to allow the interstage section of the strip line oi the integrated circuit to pass therethrough. Each of these recesses has a width greater than approximately twice the ~3~
width of the interstage strip-line sect'~on and has a depth approximately three times greater than its thickness~
This construction facilitates assemblage of MIC frequency converters and pro~ides uniformity in manufacture.
In a further preferred embodiment, each interstage section of the strip line includes a DC decoupler 31, in Fig. 10. A strip-line section 32 extending from the previous stage output terminates with a quarter wavelength coupling portion 33. A strip-line coupling portion 34 extending from the input of the next stage likewise terminates with a quarter wavelength portion 35; the q~arter wavelength portions 33 and 35 being disposed in an inter-digital configuration. Each of the coupling portions 33 and 35 has a quarter wavelength of the signal that travels along the strip-line sections 32 and 34~ The interdigital configuration causes the characteristic impedance of the strip-line sections to be less influenced by the shielding effect of the partitions 9 and 10
2~
Claims (14)
1. A microwave frequency converter comprising:
a shield casing;
a dielectric substrate in said shield casing;
a super high frequency amplifier having first and second successive stages, a mixer and a local oscillator all of which are connected and arranged in the order named on said dielectric substrate between first and second end walls of said shield casing;
a first conductive partition disposed in said casing between said first and second amplifier stages; and a second conductive partition disposed in said casing between said amplifier and said mixer.
a shield casing;
a dielectric substrate in said shield casing;
a super high frequency amplifier having first and second successive stages, a mixer and a local oscillator all of which are connected and arranged in the order named on said dielectric substrate between first and second end walls of said shield casing;
a first conductive partition disposed in said casing between said first and second amplifier stages; and a second conductive partition disposed in said casing between said amplifier and said mixer.
2. A microwave frequency converter as claimed in claim 1, further comprising a block of a material absorptive of electromagnetic radiation located in the space in which said first amplifier stage is disposed to absorb undesired electromagnetic radiation.
3. A microwave frequency converter as claimed in claim 1, further comprising a block of a material absorptive of electromagnetic radiation located in the space in which said second amplifier stage is disposed to absorb undesired electromagnetic radiation.
4. A microwave frequency converter as claimed in claim 2, wherein said mixer includes an image signal rejection filter, further comprising a block of a material absorptive of electromagnetic radiation located adjacent said rejection filter.
5. A microwave frequency converter as claimed in claim 1, further comprising a block of a material absorptive of electromagnetic radiation located in the space in which said second amplifier stage is disposed to absorb undesired electromagnetic radiation.
6. A microwave frequency converter as claimed in claim 5, wherein said mixer includes an image signal rejection filter, further comprising a block of a material absorptive of electromagnetic radiation located adjacent said rejection filter.
7. A microwave frequency converter as claimed in claim 1, further comprising a block of conductive material extending between said first end wall and said first conductive partition adjacent to one of said side walls, the transverse dimension of the space in which said first amplifier stage is located being smaller than the transverse dimension of the space in which said local oscillator is disposed.
8. A microwave frequency converter as claimed in claim 7, further comprising a block of conductive material extending between said first and second conductive partitions adjacent to one of said side walls, the transverse dimension of the space in which said second amplifier stage is located being smaller than the transverse dimension of the space in which said local oscillator is disposed.
9. A microwave frequency converter as claimed in claim 1, further comprising a block of conductive material extending between said first and second conductive partitions adjacent to one of said side walls, the transverse dimension of the space in which said second amplifier stage is located being smaller than the transverse dimension of the space in which said local oscillator is disposed.
10. A microwave frequency converter as claimed in claim 2, further comprising a block of conductive material located adjacent said rejection filter to suppress the amount of coupling between said local oscillator and a resonance mode of said shield casing.
11. A microwave frequency converter as claimed in claim 6, further comprising a block of conductive material located adjacent said rejection filter to suppress the amount of coupling between said local oscillator and a resonance mode of said shield casing.
12. A microwave frequency converter as claimed in claim 1, wherein said end walls, side walls, top wall and said first and second conductive partitions are formed into a one-piece construction.
13. A microwave frequency converter as claimed in claim 9, wherein said end walls, side walls, top wall, said first and second conductive partitions, and said conductive blocks are formed into a one-piece construction.
14. A microwave frequency converter as claimed in claim 1, wherein said first and second amplifier stages are connected by a first strip line having a DC decoupling portion extending through said first partition, and said second amplifier stage and said mixer is connected by a second strip line havng a DC decoupling portion extending through said second partition, each of said DC decoupling portions comprising a pair of interdigitally disposed sections each having a dimension substantially equal to the quarter wavelength of a signal propagating on said first and second strip lines.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000510869A CA1230172A (en) | 1983-05-31 | 1986-06-04 | Microwave integrated circuit immune to adverse shielding effects |
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58-97097 | 1983-05-31 | ||
| JP58097097A JPS59221102A (en) | 1983-05-31 | 1983-05-31 | Microwave integrated circuit |
| JP58-97096 | 1983-05-31 | ||
| JP58097096A JPS59221101A (en) | 1983-05-31 | 1983-05-31 | Microwave integrated circuit |
| CA000455442A CA1218713A (en) | 1983-05-31 | 1984-05-30 | Microwave integrated circuit immune to adverse shielding effects |
| CA000510869A CA1230172A (en) | 1983-05-31 | 1986-06-04 | Microwave integrated circuit immune to adverse shielding effects |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000455442A Division CA1218713A (en) | 1983-05-31 | 1984-05-30 | Microwave integrated circuit immune to adverse shielding effects |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1230172A true CA1230172A (en) | 1987-12-08 |
Family
ID=27167444
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000510869A Expired CA1230172A (en) | 1983-05-31 | 1986-06-04 | Microwave integrated circuit immune to adverse shielding effects |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1230172A (en) |
-
1986
- 1986-06-04 CA CA000510869A patent/CA1230172A/en not_active Expired
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| MKEX | Expiry |