JP2005210424A - High-frequency circuit module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-frequency circuit module in which a high-frequency signal leaking to the outside is suppressed. <P>SOLUTION: In the high-frequency circuit module H1, a first base 1 and a second base 2 each having an inside surface facing each other at a distance not more than half of the wavelength of a high-frequency signal are combined, so that a dielectric line 3 and a high-frequency circuit component are disposed between the inside surfaces of the first and second bases 1 and 2. Further, a convex 1a is formed on the first base 1 and a concave 2a is formed on the second base 2 so as to surround the dielectric line 3 and the high-frequency circuit component, and the first and second bases 1 and 2 are mated with each other. Gaps 4a, 4b are provided between the side surface of the convex portion 1a and the side surface of the concave portion 2a. Since a high-frequency signal is hardly incident into the gap 4b, and in addition, the concave 1a and the gap 4a efficiently function as a choke for the high-frequency signal; the high-frequency signal can be prevented from leaking to the outside of the module H1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a high-frequency circuit module using a nonradiative dielectric line used in a high-frequency transceiver module such as a millimeter wave radar module.

  2. Description of the Related Art Conventionally, a technique related to a high-frequency circuit module using a non-radiative dielectric waveguide (hereinafter also referred to as an NRD guide) that transmits a high-frequency signal such as a microwave or a millimeter wave has been proposed. An example of a conventional high-frequency circuit module will be described with reference to FIGS. FIG. 4 is a partially broken perspective view showing a basic configuration of a non-radiative dielectric line, and FIG. 5 is a schematic longitudinal sectional view showing an example of a conventional high-frequency circuit module using a non-radiative dielectric line.

  As shown in FIG. 4, the basic configuration of the non-radiative dielectric line constituting the high-frequency circuit module is a rectangular shape such as a rectangular cross section between parallel plate conductors 11 and 12 arranged in parallel with a predetermined interval a. The dielectric line 13 is arranged such that the interval a is a ≦ λ / 2 with respect to the wavelength λ of the high frequency signal. As a result, the intrusion of noise from the outside to the dielectric line 13 can be eliminated, and the emission of the high frequency signal to the outside can be eliminated, and the high frequency signal can be propagated through the dielectric line 13 with almost no loss. The wavelength λ is the wavelength of the high frequency signal in the air (free space) at the operating frequency. Such a non-radiative dielectric line can be suitably used for transmission of, for example, a millimeter-wave band high-frequency signal of about 70 GHz, and a high-frequency circuit in which various high-frequency circuit components for millimeter-wave band are incorporated therein to form a circuit. Circuit modules have been developed.

  A conventional high-frequency circuit module shown in a longitudinal cross-sectional view in FIG. 5 includes, for example, a metal base 14 having a recess formed as a component corresponding to the parallel plate conductors 11 and 12 shown in FIG. After the dielectric line 13 and the high-frequency circuit component (not shown) are accommodated in the recess of the base 14 using the metal base 15 for forming the parallel plate conductor with the bottom surface of the base, The base 15 is attached to the base 14 so as to cover the attached dielectric line 13 and the high-frequency circuit component.

In such a high-frequency circuit module, in order to prevent a high-frequency signal transmitted to the dielectric line 13 and the high-frequency circuit component from leaking to the outside of the bases 14 and 15 from the gap between the contact portions of the base 14 and the base 15 For example, it is known that a choke structure may be used between the base 14 and the base 15 (see, for example, Patent Document 1).
JP 2003-188601 A

  However, in the conventional high-frequency circuit module, a gap is formed between the base 14 and the base 15 on the extension of the transmission direction of the high-frequency signal because of the structure. Therefore, the gap leaks from the dielectric line 13 or the high-frequency circuit components. Therefore, even if a choke structure is used in this gap, the high-frequency signal leaking from the gap may not be sufficiently blocked, resulting in a decrease in transmission output or leakage of the high-frequency signal in the vicinity. There were problems such as malfunction of the circuit.

  An object of the present invention is to provide a high-frequency circuit module having a dielectric line and a high-frequency circuit component inside, and suppressing leakage of a high-frequency signal transmitted inside to the outside. .

  In the high-frequency circuit module of the present invention, the first and second bases having inner surfaces facing each other in parallel with an interval of half or less of the wavelength of the high-frequency signal have a dielectric line and a high-frequency circuit component between the inner surfaces. The first and second bases are arranged so as to surround the dielectric line and the high-frequency circuit component, and a convex part is formed on one side and a concave part is formed on the other, and the first and second bases are fitted together. A gap is provided between a side surface of the convex portion and a side surface of the concave portion.

  According to the high frequency circuit module of the present invention, the first and second bases having inner surfaces facing each other in parallel with an interval of half or less of the wavelength of the high frequency signal are provided between the inner surface and the dielectric line and the high frequency circuit. Components are arranged and combined, and the first and second bases are fitted with a convex portion on one side and a concave portion on the other side so as to surround the dielectric line and the high-frequency circuit component. In addition, since a gap is provided between the side surface of the convex portion and the side surface of the concave portion, the gap provided between the side surface of the convex portion and the side surface of the concave portion that fit together is a dielectric line. The leakage mode from the dielectric line or the high-frequency circuit component is difficult to be coupled to this gap, and is provided between the side surface of the convex portion and the side surface of the concave portion. During since effectively functions as a choke for a high-frequency signal, it is possible to effectively suppress the leakage to the outside of the high frequency signal transmitted internally.

  Hereinafter, the high-frequency circuit module of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing a high-frequency circuit module H1 which is an example of an embodiment of a high-frequency circuit module according to the present invention, where (a) is an overall vertical cross-sectional view, and (b) is its main part (A Part) Enlarged vertical sectional view, (c) is a cross-sectional view taken along the line BB 'of Part A. FIG. 2 is a schematic cross-sectional view showing a high-frequency circuit module H2, which is another example of an embodiment of the high-frequency circuit module of the present invention. FIG. 2 (a) is an overall vertical cross-sectional view, and FIG. The principal part (C part) expansion longitudinal cross-sectional view, (c) is the DD 'line horizontal cross-sectional view of C part. FIG. 3 is a schematic longitudinal sectional view showing still another example of the embodiment of the high-frequency circuit module of the present invention.

  1 to 3, 1 is a first substrate, 2 is a second substrate, 3 is a dielectric line, 1a is a protrusion formed on the first substrate 1, and 1b is one of the protrusions 1a. A notch portion 2 a provided in the portion is a recess formed in the second base 2. Reference numerals 4a, 4b, 4c, and 4d denote gaps in the respective portions between the convex portion 1a of the first base 1 and the concave portion 2a of the second base 2, and 4a and 4b of these are the convex portions 1a. It is a gap provided between the side surface and the side surface of the recess 2a.

  The high-frequency circuit module H1 of the example shown in FIG. 1 includes a first substrate 1 and a second substrate 2 having inner surfaces that face each other in parallel with an interval of 1/2 or less of the wavelength of a high-frequency signal such as a millimeter wave signal. A dielectric line 3 and a high-frequency circuit component (not shown) are arranged between the inner surfaces of the first and second substrates 1 and 2 (here, the lower surface of the first substrate 1 and the upper surface of the second substrate 2). The first and second bases 1 and 2 surround the dielectric line 3 and the high-frequency circuit component, and the first base 1 has a convex portion 1a and the second base 2 has a concave portion. 2a is formed and fitted together, and gaps 4a and 4b are provided between the side surface of the convex portion 1a and the side surface of the concave portion 2a. Here, among the gaps between the side surfaces of the convex portion 1a and the concave portion 2a, a gap located inside the module is indicated by 4a, and a gap located outside is indicated by 4b. Further, the gap between the lower surface of the convex portion 1a and the upper surface of the concave portion 2a is 4c, and a gap different from the gap 4c between the lower surface of the convex portion 1a and the upper surface of the concave portion 2a formed in steps is provided. This is indicated by 4d.

  Further, the high-frequency circuit module H1 of the example shown in FIG. 1 has a high-frequency signal transmitted to a non-radiative dielectric line composed of the dielectric line 3 and the first and second bases 1 and 2 in the above configuration. When the wavelength at the center frequency is λ, the width W and the height H of the gap 4a are preferably λ / 4. The gaps 4b, 4c and 4d are preferably as narrow as possible. Note that a part of the convex portion 1a and the concave portion 2a may be in contact with each other without having the gaps 4b, 4c, and 4d.

  In such a configuration, the convex portion 1a and the gap 4a are further separated from the gap 4a by causing the high-frequency signal propagating through the gaps 4b and 4c to resonate at the gap 4a larger than the convex portion 1a and the gaps 4b and 4c. It acts as a choke so as to suppress this high frequency signal from propagating to 4d and leaking to the outside. At this time, the passage of the high-frequency signal having the wavelength λ is almost blocked by the gap 4a, but the high-frequency signal having a wavelength different from λ leaks from the gap 4a to the gap 4d with an intensity corresponding to the wavelength shift. .

  Further, since the gap 4b is not open in the transmission direction of the high-frequency signal transmitted to the dielectric line 3 or the high-frequency circuit component, even if there is a high-frequency signal leaked from the dielectric line 3 or the high-frequency circuit component, Is difficult to enter. That is, the gap 4b provided between the first and second substrates 1 and 2 can be equivalently viewed as an open terminal portion of a waveguide connected to a non-radiative dielectric line. Compared to the case where the open end portion of the waveguide (corresponding to the gap 16) is provided on the extension of the dielectric line 13 of the non-radiative dielectric line as in the conventional example shown in FIG. Dielectric line 3 when the open end portion of the waveguide (corresponding to gap 4b) is provided in a direction perpendicular to the transmission direction of the high-frequency signal transmitted to dielectric line 3 of the dielectric line. Since the loss increases by the amount of bending with respect to the transmission direction of the high-frequency signal leaked from the high-frequency signal, it becomes difficult for the high-frequency signal leaked from the dielectric line 3 or the high-frequency circuit component to be coupled to the gap 4b. Also works to increase the transmission loss of high-frequency signals It becomes.

  Therefore, according to the high frequency circuit module H1 of the example shown in FIG. 1, with the above configuration, the gap 4b provided between the side surface of the convex portion 1a and the side surface of the concave portion 2a opens toward the transmission direction of the high frequency signal. Therefore, the leakage mode from the dielectric line 3 or the high-frequency circuit component is not easily coupled to the gap 4b, and the gap 4a provided between the side surface of the convex portion 1a and the convex portion 1a and the side surface of the concave portion 2a is provided. Since it effectively functions as a choke for the high frequency signal, the high frequency signal leaking to the outside of the high frequency circuit module M1 can be effectively suppressed.

  In the high-frequency circuit module of the present invention, the first base 1 and the second base 2 accommodate a function as a parallel plate conductor, which is a component of the non-radiative dielectric line, and a set of high-frequency circuits inside. The first base body 1 and the second base body 2 have a function as a container for hermetically accommodating the interior thereof, and the first substrate 1 and the second substrate 2 have a high-frequency signal whose interval facing each other is used in the high-frequency circuit. The inner surface has a parallel inner surface that is less than or equal to one-half of the wavelength of the first electrode. The inner surface is electrically conductive, and the width of the inner surface mounts the dielectric line 3 and the high-frequency circuit component between the inner surfaces. It is said to be large enough. For example, for a millimeter wave band high-frequency signal having a frequency of 77 GHz, the interval between the inner surfaces and the width of the inner surfaces may be about 1.8 mm and about several cm square, respectively. Further, the thickness of the first base 1 and the second base 2 may be sufficient to ensure the rigidity required for the module. For example, in a module using a millimeter-wave band high-frequency signal with a frequency of 77 GHz, the thickness of the portion constituting the parallel inner surface may be 1 mm or more.

  The materials of the first substrate 1 and the second substrate 2 are copper, aluminum (Al), iron (Fe), silver (Ag), gold (Au), platinum (Pt), and SUS (stainless steel). Brass (Cu-Zn alloy) or the like may be used. In particular, aluminum (Al) is suitable in terms of workability and durability. Alternatively, a dielectric material such as resin or ceramics may be used, and a metal made of the above material in the form of a film or plate may be attached to the surface of the part that needs to be electrically conductive.

  For the production of the first substrate 1 and the second substrate 2, powder injection molding such as cutting using a so-called NC lathe, die casting, or MIM (metal injection mold) may be used.

  The convex portion 1a provided on the first base body 1 fits with the concave portion 2a provided on the second base body 2, and the high-frequency signal to be transmitted through the convex portion 1a An induced current flows on the surface by an electromagnetic field and acts as an inductance (L) in terms of an electrical equivalent circuit. In order to effectively provide such a function in the high-frequency circuit module of the present invention, the cross-sectional shape of the convex portion 1a is a rectangular shape having a width λ / 4 with respect to the wavelength λ of the high-frequency signal, and the surface thereof is What is necessary is just to be electroconductive.

  Further, the concave portion 2a provided in the second base 2 is fitted with the convex portion 1a provided in the first base 1, and for a high-frequency signal that attempts to transmit the fit, The gap 4a formed inside the fit works as a capacitance (C) in terms of an electrical equivalent circuit. In order to effectively provide such a function in the high-frequency circuit module of the present invention, the recess 2a has a width W with respect to the wavelength λ of the high-frequency signal so that the cross-sectional shape of the gap 4a formed inside the fitting is Is λ / 4 and the height H is λ / 4, and the surface thereof may be made conductive.

  Then, when the convex portion 1a and the concave portion 2a are fitted together, the dielectric line 3 and the high-frequency circuit component are accommodated in the container constituted by the first base body 1 and the second base body 2, and are airtight. The high-frequency circuit module H1 in which the high-frequency signal having a frequency close to the resonance frequency of the LC resonance is less likely to leak from the inside of the container to the outside because the convex portion 1a and the concave portion 2a, which are excellent in performance, are LC-resonated. Composed. In order to make the resonance frequency of this LC resonance correspond to the frequency of a high-frequency signal that is intended to prevent (choke) leakage, the dimensions of the convex portions 1a and the concave portions 2a may be appropriately adjusted in accordance with the frequencies.

Dielectric waveguide 3 is for transmitting a high frequency signal, the material, tetrafluoroethylene resin such as polystyrene or a low dielectric constant of the _{cordierite, (2MgO · 2Al 2 O 3} · 5SiO 2 ) Ceramics such as ceramics, alumina (Al ₂ O ₃ ) ceramics, and glass ceramics are preferable, and these have low loss in the millimeter wave band. In addition, the cross-sectional shape of the dielectric line 3 is basically a rectangular shape, but may be a shape with rounded corners of the rectangular shape, and various cross-sectional shapes used for high-frequency signal transmission are used. can do. In addition, the dielectric line 3 transmits a high-frequency signal in a millimeter wave band with a frequency of 77 GHz, for example, and when a cordierite ceramic having a relative dielectric constant of 4.8 is used as a material, the width is about 0.8 mm. A rectangular shape having a height of about 1.8 mm may be used.

  The high-frequency circuit component is connected to the dielectric line 3 to form a high-frequency circuit and functions as an individual high-frequency circuit element. Specific components include an oscillator that generates a high-frequency signal, a high-frequency signal, Modulator for modulation, mixer for mixing multiple high-frequency signals, coupler for branching high-frequency signals, three or more input / output terminals arranged on the outer periphery, and one input / output terminal in the clockwise or counterclockwise direction A circulator that outputs an input high-frequency signal from another adjacent input / output terminal, one input terminal, and one output terminal. The high-frequency signal input from the input terminal is output to the output terminal. Has an isolator that does not output high-frequency signals, a resonator that resonates high-frequency signals, a phase shifter that changes the phase of high-frequency signals, and an open termination. There are radiators or the like for emitting a high-frequency signal from the open end of perilla.

  The high-frequency circuit module H1 of the present invention configured as described above transmits, for example, a high-frequency signal, receives the high-frequency signal reflected back from the target, and receives the distance to the target. It can be used as a radar that measures the frequency of a low frequency signal or a transceiver that transmits and receives the low frequency signal using a high frequency signal superimposed with a low frequency signal having a frequency equal to or less than half the frequency of the high frequency signal.

  Next, the high-frequency circuit module H2 in the example shown in FIG. 2 has the same configuration as the high-frequency circuit module H1, and the height of the gap 4a so that the convex portion 1a penetrates the convex portion 1a inward and outward in a part of the convex portion 1a. A notch 1b having a height similar to H and a predetermined length D is formed. In this configuration, the notch 1b preferably has a length along the gap 4b formed so as to surround the dielectric line 3 and the high-frequency circuit component between the side surface of the convex portion 1a and the side surface of the concave portion 2a. It is preferable that D is a length of λ / 4, the interval between the notches 1b is also λ / 4, and is provided over the entire circumference of the gap 4b or partially. Thus, by forming the notch 1b with respect to the convex portion 1a, an annular formed between the convex portion 1a and the concave portion 2a that are fitted so as to surround the dielectric line 3 and the high-frequency circuit component. With respect to the gap 4b, a resonance mode that circulates around the gap 4b with respect to the high-frequency signal can be suppressed, and leakage of the high-frequency signal to the outside of the high-frequency circuit module H2 can be further effectively suppressed. Become.

  In the high-frequency circuit module of the present invention, the high-frequency signal leaked from the dielectric line 3 or the high-frequency circuit component is between the dielectric line 3 or the high-frequency circuit component and the side wall of the first base 1 that faces the side. In some cases, a standing wave of the electric field may be generated due to the leakage mode. For this, as shown in FIG. 3, the high frequency circuit module H <b> 3 showing still another example of the embodiment of the high frequency circuit module of the present invention, the inside of the convex portion 1 a with respect to the side wall 1 c of the first base 1. It is preferable that the convex portion 1a is formed so that the side surface is located inside the module so that the opening of the gap 4b is located at a place where the electric field of the standing wave due to the leakage mode of the high frequency signal is weak. With such a configuration, a high-frequency signal leaked from the dielectric line 3 or the high-frequency circuit component becomes more difficult to be coupled to the gap 4b, and the high-frequency circuit module works to increase the transmission loss of the high-frequency signal through the gap 4b. A high-frequency signal leaking to the outside of H3 can be more effectively suppressed.

  In the high-frequency circuit modules H1, H2, and H3 of the present invention as described above, when providing a contact surface between the convex portion 1a of the first base 1 and the concave portion 2a of the second base 2, the convex portion 1a. May be provided in a portion where the gap 4c or the gap 4d is formed between the lower surface of the recess and the upper surface of the recess 2a. In this case, even if the gaps 4c and 4d are opened in part of the contact surface due to the processing accuracy of the contact surface, the protrusions 1a and the side surfaces of the protrusions 1a and the side surfaces of the recesses 2a are provided. Since the gap 4a functions as a choke with respect to the high-frequency signal, the high-frequency signal leaked to the outside of the high-frequency circuit modules H1, H2, and H3 is satisfactorily suppressed.

  Thus, according to the present invention, it is possible to provide a high-frequency circuit module having a dielectric line and a high-frequency circuit component inside, and suppressing leakage of a high-frequency signal transmitted inside to the outside. It becomes.

  It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, each of the first base body 1 and the second base body 2 is provided with a plurality of convex portions 1a and a plurality of concave portions 2a in an annular shape or multiple annular shapes, and the width W or the height H of the gap 4a is set to the plurality of them. It is good also as a different setting between the side surface of the convex part 1a and the side surface of the recessed part 2a. In this case, leakage to the outside of the high-frequency circuit module can be more effectively suppressed even for a high-frequency signal whose wavelength at the center frequency is different from λ.

It is typical sectional drawing which shows the high frequency circuit module H1 which is an example of embodiment of the high frequency circuit module of this invention, (a) is a whole longitudinal cross-sectional view, (b) is the principal part (A part) expansion. A longitudinal cross-sectional view, (c) is a cross-sectional view taken along line BB ′ of A part. It is typical sectional drawing which shows the high frequency circuit module H2 which is the other example of embodiment of the high frequency circuit module of this invention, (a) is a whole longitudinal cross-sectional view, (b) is the principal part (C part) ) Enlarged vertical cross-sectional view, (c) is a cross-sectional view taken along the line DD 'of section C. It is a typical longitudinal section showing other examples of an embodiment of a high frequency circuit module of the present invention. It is a partially broken perspective view which shows the basic composition of a non-radioactive dielectric track | line. It is a typical longitudinal section showing an example of the conventional high frequency circuit module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: 1st base | substrate 1a: Convex part 1b: Notch part 1c: Side wall 2: 2nd base | substrate 2a: Concave part 3: Dielectric line | wire 4a, 4b, 4c, 4d: Gap H1, H2, H3: High frequency circuit module

Claims (1)

First and second bases having inner surfaces facing each other in parallel with an interval equal to or less than a half of the wavelength of the high-frequency signal are combined with a dielectric line and a high-frequency circuit component disposed between the inner surfaces, The first and second bases are fitted with a convex portion formed on one side and a concave portion formed on the other so as to surround the dielectric line and the high-frequency circuit component, and a side surface of the convex portion and the concave portion A high frequency circuit module characterized in that a gap is provided between the side surfaces of the high frequency circuit module.

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