Dielectric-line integrated circuit

Abstract: A dielectric-line component (circulator) has a dielectric strip (3a) between a pair of electrically conductive flat-plates (1a, 2a). The component is combined with another dielectric-line component which also has dielectric strips (3b) between a pair of conductive plates (1b, 2b). When these components are assembled, a pair of conductive plates (1a, 1b) of the respective two components opposedly face each other at a first position, while the other pair of conductive plates (2a, 2b) of the respective two components opposedly face each other at a second position. The first and second positions are displaced from each other in the vertical direction in relation to the conductive plates. Further, the opposing faces of the dielectric strips (3a, 3b) of the two components are positioned in an area interposed between the first and second positions. Thus, the overall opposing faces of the two components are formed in a step- like shape. Accordingly, easy and correct positioning of the dielectric strips (3a, 3b) is achieved. Further, the configuration of the end faces of the conductive plates (1a, 2a, 1b, 2b) of the dielectric-line components can be determined independently of the configuration of the dielectric strips (3a, 3b). As a consequence, mass production can be enhanced to achieve a reduction in cost.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric-line integrated circuit formed by a combination of dielectric-line components, each having a dielectric strip between two electrically conductive flat-plates located substantially parallel to each other. 2. Description of the Related Art As the above type of dielectric-line integrated circuit, for example, vehicle-loaded millimetric-wave radar using dielectric lines is formed by a combination of various types of dielectric-line components, such as an oscillator, a circulator, and a mixer. Two examples of conventional vehicle-loaded millimetric-wave radar known e.g. from EP-A-0 700 112 are shown in Figs. 14 and 15. In Fig. 14, the radar includes electrically conductive flat-plates 1a and 2a, which also serve as the radar body, i.e., a casing for dielectric-line components. Hollows indicated by H1, H2 and H3 are formed on the opposing surfaces of the conductive plates 1a and 2a. Reference numerals 10 and 11 respectively indicate an oscillator and a circulator which are respectively fit into the hollows H1 and H2. A mixer (not shown) is fit into the hollow H3. Disposed between the conductive plates 1a and 2a are dielectric strips 6, 7 and 8 and terminating devices 9 and 12. With this arrangement, in operation, an oscillation signal output from the oscillator 10 passes through one port of the circulator 11 and the dielectric strip 6, and radiates from a horn 13 to the exterior. Conversely, electromagnetic waves propagating via the dielectric strip 6 in the direction opposite to the transmitting direction of the oscillation signal do not return to the oscillator 10 but are transmitted to the terminating device 12 connected to another port of the circulator 11. Waves reflected from a subject are received by a horn 14 and input into the mixer via the dielectric strip 8. A coupler is interposed between the dielectric strips 6 and 7 and between the dielectric strips 7 and 8, and a reflection signal indicating the waves reflected from the subject and a local signal are input into the mixer. In another example of the dielectric-line integrated circuit shown in Fig. 15, apertures A1, A2 and A3 are formed on the upper conductive plate 2a, so that the oscillator 10, the circulator 11, and a mixer (unillustrated) can be respectively fit into the apertures A1, A2 and A3 from the exterior in the state in which the two conductive plates 1a and 2a are assembled. The other configurations of this example are similar to the example illustrated in Fig. 14. In the dielectric-line integrated circuits shown in Figs. 14 and 15, the characteristics of the individual dielectric-line components, such as an oscillator and a circulator, can be singly measured and calibrated, and then, the dielectric-line components can be attached to the radar body (i.e., the conductive plates), thereby constructing a single dielectric-line integrated circuit. This type of integrated circuit is more advantageous over a dielectric-line integrated circuit of the type in which all of the dielectric lines are formed between two conductive plates, because the evaluation and adjustment of the overall characteristics can be made simple, and the individual dielectric-line components can be formed into modules. However, the following problem is encountered in aligning the dielectric strips formed in a plurality of dielectric-line components when the components are assembled and integrated into a single circuit. More specifically, referring to Fig. 14, the dimensions of the dielectric-line components are determined so that the heights of the two dielectric strips can be equal to each other in the state in which the bottom surface of the mounting component is placed on the bottom surface of the hollow formed in the dielectric-line body. The dimensional precision of the respective components should be extremely high, which would otherwise change the characteristics of the components due to a displacement of the dielectric strips. Moreover, in known dielectric-line components, for example, in a circulator, upper and lower dielectric plates 2b and 1b are configured, as illustrated in Fig. 16, to match the end faces of three-port dielectric strips, thereby inevitably forming the overall circulator generally in a regular triangle shape, and forming the mating hollows and apertures of the dielectric-line body in the same shape as well. However, conductive plates having such flat end faces or having hollows and apertures with internal flat surfaces are difficult to fabricate and also occupy a large area of a resulting dielectric-line integrated circuit. In contrast, the end faces of dielectric strips are desirably flat to be easily manufactured. Thus, for example, if the shape of a dielectric strip 3b remains unchanged (i.e., flat), and the upper and lower conductive plates 1b and 2b are formed in a disc-like shape, the following inconveniences are generated. If the end face of the dielectric strip 3b disposed in the circulator is located not to project from the end face of the conductive plate, as illustrated in Fig. 17A, a clearance is disadvantageously formed between the end face of the dielectric strip 3b and the end face of a mating dielectric strip 3a. Conversely, if the end face of the dielectric strip 3b formed in the circulator projects to reach the end face of the mating dielectric strip 3a, as shown in Fig. 17B, the dielectric-line component having the dielectric strip 3b is too tight to fit into the aperture A2 shown in Fig. 15, since the edge of the strip 3b tightly hits the internal surface of the aperture A2. Or, the component having the dielectric strip 3b is forced into the aperture A2, resulting in damaging the edge of the dielectric strip 3b. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a dielectric-line integrated circuit which exhibits stable characteristics by performing easy and correct alignment of dielectric strips used in the dielectric-line integrated circuit. It is another object of the present invention to provide a dielectric-line integrated circuit in which mass production is enhanced to achieve a reduction in cost by separately determining the configuration of end faces of electrically conductive flat-plates used in dielectric- line components and the configuration of end faces of dielectric strips used in the components. In order to achieve the above objects, according to a broad aspect of present invention, there is provided a dielectric-line integrated circuit comprising a plurality of dielectric-line components, each including two electrically conductive flat-plates located substantially parallel to each other and a dielectric strip interposed between the conductive plates, wherein one of the two conductive plates provided for one dielectric-line component and one of the two conductive plates provided for another dielectric-line component opposedly face each other at a first position, while the other conductive plates of the dielectric-line components opposedly face each other at a second position, the first and second positions being displaced from each other in the vertical direction in relation to the conductive plates, and the dielectric strips of the dielectric-line components opposedly face each other at a position in an area interposed between the first and second positions. In the foregoing dielectric-line integrated circuit, grooves may be respectively formed in the conductive plates, and the dielectric strips may be fit into the grooves. Alternatively, engaging portions may be formed at end faces of the dielectric strips of the two dielectric-line components so that the dielectric strips may be engaged with each other. Theses and other objects, features and advantages of the invention will become more apparent by referring to the following detailed description in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a partial perspective view illustrating two dielectric-line components used in a dielectric-line integrated circuit; Fig. 2 is a sectional view of the two dielectric-line components shown in Fig. 1: Fig. 2A illustrates the dielectric-line components before assembly; and Fig. 2B illustrates the dielectric-line components after assembly; Fig. 3 is a partial perspective view illustrating two dielectric-line components; Fig. 4 is a sectional view of the dielectric-line components shown in Fig. 3; Fig. 4A illustrates the dielectric-line components before assembly; and Fig. 4B illustrates the dielectric-line components after assembly; Fig. 5 is a partial perspective view illustrating two dielectric-line components; Fig. 6 is a sectional view of the dielectric-line components shown in Fig. 5: Fig. 6A illustrates the dielectric-line components before assembly; and Fig. 6B illustrates the dielectric-line components after assembly; Fig. 7A is a partial perspective view of a dielectric-line component used in a dielectric-line integrated circuit; Fig. 7B is a fragmentary plan view of a dielectric strip used in the dielectric-line component shown in Fig. 7A; Figs. 8A and 8B are fragmentary plan views illustrating various configurations of the end faces of dielectric strips used in a dielectric-line integrated circuit; Fig. 9, which is comprised of Figs. 9A and 9B, is a perspective view illustrating a dielectric-line integrated circuit according to a first embodiment of the present invention; Fig. 10, which is comprised of Figs. 10A and 10B, is a perspective view illustrating a circulator used in a dielectric-line integrated circuit according to a second embodiment of the present invention; Fig. 11 is a perspective view illustrating the circulator shown in Fig. 10 being fit into another dielectric-line component; Fig. 12, which is comprised of Figs. 12A and 12B, is a sectional view illustrating the dielectric-line integrated circuit shown in Fig. 11; Fig. 13, which is comprised of Figs. 13A and 13B, is a sectional view illustrating a modification made to the dielectric-line integrated circuit shown in Figs. 11 and 12; Fig. 14 is an exploded perspective view illustrating an example of conventional dielectric-line integrated circuits; Fig. 15 is a perspective view cutaway in part illustrating another example of conventional dielectric-line integrated circuits; Fig. 16 is a perspective view illustrating a conventional circulator; and Fig. 17, which is comprised of Figs. 17A and 17B, illustrates the configurations of end faces of a conductive plate and a dielectric strip. DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, according to the present invention, there is provided a dielectric-line integrated circuit comprising a plurality of dielectric-line components, each including two electrically conductive flat-plates located substantially parallel to each other and a dielectric strip interposed between the conductive plates, wherein one of the two conductive plates provided for one dielectric-line component and one of the two conductive plates provided for another dielectric-line component opposedly face each other at a first position, while the other conductive plates of the dielectric-line components opposedly face each other at a second position, the first and second positions being displaced from each other in the vertical direction in relation to the conductive plates, and the dielectric strips of the dielectric-line components opposedly face each other at a position in an area interposed between the first and second positions. The above broad aspect of the present invention can be implemented by the following example. It will now be assumed that two dielectric-line components illustrated in Fig. 1 be combined with each other. One dielectric-line component is formed by disposing a dielectric strip 3a between two electrically conductive flat-plates 1a and 2a which are located parallel to each other, while the other component is formed by providing a dielectric strip 3b between two electrically conductive flat-plates 1b and 2b which are positioned parallel to each other. Fig. 2 is a sectional view illustrating the dielectric-line components shown in Fig. 1: Fig. 2A illustrates the components before they are combined; and Fig. 2B illustrates the components after they are combined. Fig. 2B reveals that one pair of conductive plates 1a and 1b of the respective components opposedly face each other at a facing position F1, while the other pair of conductive plates 2a and 2b opposedly face each other at a facing position F2, the facing positions F1 and F2 being displaced from each other in the vertical direction in relation to the conductive plates. In this example, the opposing faces of the dielectric strips 3a and 3b are located at the position F2. In this manner, the two dielectric-line components are assembled so that the opposing faces of the components are formed in a step-like shape. Accordingly, the conductive plate 1a and the dielectric strip 3b abut against each other at a section indicated by S1. This makes it possible to correctly position the dielectric strips 3a and 3b in the vertical direction (i.e., in a direction along the height of the strips 3a and 3b in Fig. 2) in relation to the conductive plates. In the example of the dielectric-line components shown in Figs. 3 and 4, a pair of dielectric plates 1a and 1b of the respective components opposedly face each other at a facing position F1, while the other pair of dielectric plates 2a and 2b opposedly face each other at a facing position F2. Further, in this example, the position at which the dielectric strips 3a and 3b opposedly face each other is determined to be a facing position F3, which is a middle point interposed between the facing positions F1 and F2. In this manner, the two dielectric-line components are assembled so that the opposing faces of the components are formed in a step-like shape. Accordingly, the conductive plate 1a and the dielectric strip 3b abut against each other at a section indicated by S1, while the conductive plate 2b and the dielectric strip 3a abut against each other at a section indicated by S2. As a result, accurate positioning of the dielectric strips 3a and 3b in the vertical direction in relation to the conductive plates can be performed. Further, the foregoing dielectric-line integrated circuit may be modified in the following manner. The conductive plates shown in Figs. 1 through 4 are grooved, and the dielectric strips are fit into the grooves. For example, as shown in Fig. 5, grooves g, g are respectively formed on the internal surfaces of the conductive plates 1a and 2a, into which the dielectric strip 3a is fit. Moreover, grooves g, g are formed on the internal surfaces of the conductive plates 1b and 2b, into which the dielectric strip 3b is inserted. When the two dielectric- line components are assembled, as indicated in the sectional view of Fig. 6, the dielectric strip 3b is fit into the groove g formed in the conductive plate 1a, while the groove g formed in the conductive plate 2b covers part of the dielectric strip 3a. With this arrangement, the dielectric strips 3a and 3b can be correctly located in a direction parallel to the conductive plates and perpendicular to the direction in which electromagnetic waves propagate in the dielectric strips 3a and 3b, as well as in the vertical direction in relation to the conductive plates. Moreover, engaging portions are respectively provided on their opposing end faces for the engagement of the two dielectric strips. For example, as illustrated in Fig. 7, a depressed engaging portion is formed at the end face of the dielectric strip 3a, while a projecting engaging portion is formed at the end face of the mating dielectric strip 3b. Thus, the dielectric strips 3a and 3b can be engaged with each other, as is seen from the plan view of Fig. 7B. It is thus possible to correctly position the dielectric strips 3a and 3b in a direction parallel to the conductive plates and perpendicular to the direction in which electromagnetic waves propagate in the dielectric strips 3a and 3b, as well as in the vertical direction to the conductive plates. The shapes of the foregoing pair of engaging portions are not restricted to a depression and a projection. A pair of engaging portions may be configured, as shown in Fig. 8A, as a wedge and "V" shape, or may be curved, as illustrated in Fig. 8B. A dielectric-line integrated circuit constructed in accordance with a first embodiment of the present invention will now be described while referring to Fig. 9. The oscillator shown in Fig. 9A can be substituted for, for example, the oscillator 10 illustrated in Fig. 14. In this oscillator, which is also designated by 10, grooves g are respectively formed in the internal surfaces of the upper and lower electrically conductive flat-plates 1b and 2b which are disposed parallel to each other. A dielectric strip 3b is located between the conductive plates 1b and 2b, and certain circuits are also formed therebetween. Two end faces E21 and E22 of the conductive plate 2b respectively project farther than two end faces E11 and E12 of the conductive plate 1b, and an end face of the dielectric strip 3b is positioned at a middle point between the end faces E11 and E21 of the conductive plates 1b and 2b. The above-described oscillator 10, which is used as a dielectric-line component, is reversed upside down and fits into a hollow H formed in a mating dielectric-line component, as shown in Fig. 9B. A dielectric strip 3a is provided on the mating dielectric- line component in which the hollow H is formed, and the end face of the strip 3a is located at a position farther inward from the end face (internal wall) of the hollow H (in other words, at a position farther outward, as viewed from the hollow H). The foregoing oscillator 10 is placed in the hollow H formed in the conductive plate 1a, so that the lower conductive plate 1b of the oscillator 10 fits into the hollow H, and the end face of the dielectric strip 3b fits into the groove g of the conductive plate 1a. Further, the groove g formed in the conductive plate 2b covers part of the dielectric strip 3a. With this arrangement, the dielectric strips 3a and 3b are positioned both in the vertical and horizontal directions in relation to the conductive plates. An explanation will now be given of a dielectric-line integrated circuit constructed in accordance with a second embodiment of the present invention while referring to Figs. 10 through 13. Fig. 10 is a perspective view of a circulator: Fig. 10A illustrates the circulator without having its upper electrically conductive flat-plate 1b; Fig. 10B illustrates the circulator 11 with its upper electrically conductive flat-plate 1b. Upper and lower conductive plates 1b and 2b are aluminum disc-like plates. Formed in the internal surface of each of the conductive plates 1b and 2b are three grooves into which dielectric strips 3b, 4b and 5b are inserted. Further, two upper and lower ferrite plates 15 are disposed at the center of the disc- like plates 1b and 2b. The external diameter of the lower conductive plate 2b is set to be greater than that of the upper conductive plate 1b, and the end faces of the three dielectric strips 3b, 4b and 5b are each positioned at a midpoint between the end faces of the conductive plates 1b and 2b. Fig. 11 is a perspective view illustrating the circulator shown in Fig. 10 to be inserted into a mating dielectric-line component. The mating dielectric-line component provided for the dielectric-line body has dielectric strips 3a and 5a formed between the conductive plates 1a and 2a, and an aperture is formed in each of the conductive plates 1a and 2a. The internal diameters of the apertures are formed to be slightly larger than the external diameters of the conductive plates 1b and 2b of the circulator 11. With this arrangement, the circulator 11 is fit into the aperture, so that the end face of the dielectric strip 5b illustrated in Fig. 10 opposedly faces the end face of the dielectric strip 5a provided for the dielectric-line body without substantially producing a clearance therebetween. Fig. 12 is a sectional view of the dielectric-line integrated circuit shown in Fig. 11: Fig. 12A illustrates the integrated circuit before the circulator is attached to a mating dielectric-line component; and Fig. 12B illustrates the integrated circuit after the circulator is attached to the mating component. Fig. 12B shows that the edge portions of the dielectric strips 4b and 3b formed in the circulator 11 fit into the groove formed in the conductive plate 1a of the dielectric-line body, and that the grooves of the conductive plate 2b of the circulator accommodate the top surfaces of part of the dielectric strips 4a and 3a formed on the dielectric-line body. Thus, the dielectric strips 4b and 3b of the circulator 11 can be respectively aligned with the dielectric strips 4a and 3a both in the vertical direction in relation to the conductive plates and in the direction of planar rotation. Fig. 13 is a sectional view illustrating a modification made to the dielectric-line integrated circuit shown in Fig. 12. In this modification, unlike the configuration of the circuit shown in Fig. 12, the circulator 11 is fit into the lower conductive plate 1a, and then, the upper conductive plate 2a covers the lower plate 1b to complete an assembly. As has been discussed in the second embodiment, the dielectric plates of a dielectric-line component to be inserted into the dielectric-line body are formed into a disc-like shape, and mating hollows or apertures formed in the dielectric-line body to receive the above component are also formed to be circular. Thus, the conductive plates and hollows or apertures can be readily formed by means such as milling.

Claims: A dielectric-line integrated circuit comprising a plurality of dielectric-line components, each including two electrically conductive flat-plates (1a, 2a, 1b, 2b) located substantially parallel to each other and a dielectric strip (3a, 3b) interposed between said electrically conductive flat-plates (1a, 2a, 1b, 2b), characterised in that one of the two electrically conductive flat-plates (1a) provided for one dielectric-line component and one of the two electrically conductive flat-plates (1b) provided for another dielectric-line component opposedly face each other at a first position, while the other electrically conductive flat-plates (2a, 2b) of the dielectric-line components opposedly face each other at a second position, said first and second positions being displaced from each other in the vertical direction in relation to the conductive plates (1a, 2a, 1b, 2b), and the dielectric strips (3a, 3b) of the dielectric-line components opposedly face each other at a position in an area interposed between said first and second positions. A dielectric-line integrated circuit according to claim 1, wherein grooves (g) are respectively formed in said electrically conductive flat-plates (1a, 2a, 1b, 2b), and said dielectric strips (3a, 3b) are fit into said grooves (g). A dielectric-line integrated circuit according to claim 1 or 2, wherein engaging portions are formed at end faces of the dielectric strips (3a, 3b) of said two dielectric-line components so that said dielectric strips (3a, 3b) are engaged with each other.

Inventors: TAGUCHI YOSHINORI, TANIZAKI TORU, TAGUCHI, YOSHINORI, TANIZAKI, TORU
Applicants: MURATA MANUFACTURING CO, MURATA MANUFACTURING CO., LTD.
Application year: 1997
Main classification: H01P1
IPC codes: H01P3, H01P5, H01P1