JP2017121077A - High frequency module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high frequency module that can facilitate the design of a cavity resonator.SOLUTION: A high frequency module includes a module housing, a coaxial line path which penetrates through the module housing and has an inner conductor and a dielectric body, a substrate which is housed in the module housing and transmits a high frequency signal amplified by an amplifier, a gold ribbon for connecting the coaxial line path and the substrate, and plural cavity resonators which are arranged in alignment with one another along the coaxial line path at one portion in a direction along the coaxial line path at a portion around the coaxial line path in the module housing and connected to one another through the coaxial line path, and have mutually different resonance frequencies. Each of the plural cavity resonators is substantially rectangular when viewed in a cross-section perpendicular to the coaxial line path. An inner conductor and a dielectric body of the coaxial line path are included in each cavity of the plural cavity resonators, and the dielectric body is in contact with the bottom surface of each cavity.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a high frequency module.

  In general, a microwave amplifier generates harmonics in addition to a fundamental wave to be amplified. For this reason, in order to connect between the circuit including the microwave amplifier and the circuit using the amplified fundamental wave signal, a filter for suppressing unnecessary harmonics is required.

  In Patent Document 1, in a high-frequency circuit, an input matching circuit is connected to an input terminal of a semiconductor element, and an output matching circuit and one end of a line having a length of 1/4 of the fundamental wavelength are connected to an output terminal of the semiconductor element. In addition, it is described that the other end of the line is grounded via a capacitor. Thus, according to Patent Document 1, when viewed from the output terminal of the semiconductor element, one end of the line is in an open state with respect to the fundamental wave, and for a double wave having a wavelength twice that of the fundamental wave. Since it is in a short state, it is said that the second harmonic (harmonic) can be suppressed without affecting the fundamental wave.

  In Patent Document 2, a power amplifier includes a second harmonic resonator having one end grounded and having a length of ¼ of the wavelength of the second harmonic in parallel with a constant interval along the transmission line of the output of the amplifier. And a third harmonic resonator having one end grounded and a quarter length of the wavelength of the third harmonic is described. Thus, according to Patent Document 2, the second harmonic and the third harmonic are reflected to the amplifier by the short-circuit impedance of the second harmonic resonator and the short-circuit impedance of the third harmonic resonator, respectively. Therefore, it is said that a harmonic processing circuit having no influence on the fundamental wave of the amplifier output can be obtained.

  In Patent Document 3, in a high-frequency module, one end of a dielectric and an inner conductor of a coaxial connector protrudes from an outer conductor and penetrates a metal plate and a module housing, and the inner conductor is disposed between the metal plate and the outer surface of the module housing. It is described that a disk-shaped digging having a radius of a quarter of a harmonic (for example, a second harmonic) at the center is formed. Thus, according to Patent Document 3, a harmonic signal that is radiated from the output end of the microwave amplifier into the housing space and propagates in the housing space as a waveguide mode is reflected back into the module housing, and the high-frequency module It is said that the harmonic signal leaking outside can be suppressed.

Japanese Patent Laid-Open No. 2001-53510 JP-A-8-139535 JP 2009-252794 A

  Patent Documents 1 and 2 both describe only suppression of harmonics propagating through the transmission line, and do not describe at all how to suppress harmonics propagating in the enclosure space. Absent.

  However, if the amplifier is installed in a metal enclosure, some of the harmonics will be radiated into the enclosure space and propagate in the waveguide mode. The harmonics that have propagated in the enclosure space may be coupled to the output connector of the module and leak out of the enclosure through the connector.

  On the other hand, Patent Document 3 describes a digging (cavity resonator) in a module housing as a configuration for suppressing harmonics propagating in the enclosure space.

  However, since the technique described in Patent Document 3 forms a disk-shaped digging (cavity resonator), it is difficult to determine the dimensional relationship of the cavity resonator. That is, the interference principle of the cavity resonator described in Patent Document 3 is resonance by electromagnetic waves in the waveguide mode in the cavity, but even if a cavity resonator having a radius of 1/4 of the harmonic is designed, Resonance tends to be difficult at the expected frequency. This makes it difficult to design a cavity resonator.

  Moreover, since the cavity resonator described in Patent Document 3 has a narrow band, there is a possibility that a margin for processing accuracy may be reduced.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a high-frequency module capable of easily designing a cavity resonator.

  In order to solve the above-described problems and achieve the object, a high-frequency module according to one aspect of the present invention includes a module housing, a coaxial line that penetrates the module housing and includes an inner conductor and a dielectric, A substrate that is housed in the module housing and transmits a high-frequency signal amplified by an amplifier, a gold ribbon that connects the coaxial line and the substrate, and the coaxial in a portion around the coaxial line in the module housing A plurality of cavity resonators that are arranged side by side along the coaxial line in a part of the direction along the line, and are connected to each other via the coaxial line and have different resonance frequencies; Each of the plurality of cavity resonators has a substantially rectangular shape when viewed in a cross section perpendicular to the coaxial line, and the cavity of each of the plurality of cavity resonators includes the coaxial line. Together include conductor and the dielectric, wherein the dielectric is in contact with the bottom surface of each of said cavities.

  According to the present invention, since the cavity resonator is substantially rectangular when viewed in a cross section perpendicular to the coaxial line, the dimensional relationship of the cavity resonator can be uniquely determined. This facilitates the design of the cavity resonator.

The figure which shows the structure of the high frequency module concerning Embodiment 1. The figure which shows the structure of the cavity resonator in Embodiment 1. FIG. The figure which shows the structure of the cavity resonator in Embodiment 1. FIG. The figure which shows operation | movement of the cavity resonator in Embodiment 1. The figure which shows the structure of the cavity resonator in the modification of Embodiment 1. FIG.

  Embodiments of a high-frequency module according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
A high-frequency module 100 according to the first embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view showing the configuration of the high-frequency module 100.

  The high-frequency module 100 includes a module housing 1, an amplifier 9, a gold ribbon 42, a substrate 2, a carrier 3, a gold ribbon 41, a coaxial line 5, and a plurality of cavity resonators 13 and 14.

  The module housing 1 is configured, for example, in the form of a dielectric package in which a dielectric multilayer substrate is laminated and metal plating is applied to the surface to form a box shape, or a package made up of a metal casing in which metal is formed in a box shape. Is done. The module housing 1 has a housing space 1a inside thereof. The module housing 1 mainly accommodates the amplifier 9, the substrate 2, and the carrier 3 in the housing space 1a. Further, a concave structure to be the cavity 11 is formed on the outer wall surface 1 b on the coaxial line 5 side in the module housing 1. A cavity 12 is formed in the module housing 1.

  The amplifier 9 is configured in the form of, for example, an MIC (microwave integrated circuit) or an MMIC (monolithic microwave integrated circuit) formed of semiconductor elements such as a field effect transistor or a high electron mobility transistor. The amplifier 9 receives the high frequency signal, amplifies the high frequency signal, and outputs the amplified high frequency signal from the output terminal 9b. The high frequency signal is, for example, a signal in a microwave band or a millimeter wave band. The high-frequency signal amplified by the amplifier 9 includes a fundamental wave component having a desired frequency and a harmonic (for example, second harmonic) component with respect to the fundamental wave.

  The gold ribbon 42 electrically connects the output terminal 9 b of the amplifier 9 and the input terminal 21 a of the substrate 2.

  The substrate 2 receives the high-frequency signal output from the amplifier 9 via the gold ribbon 42. The substrate 2 transmits and outputs a high frequency signal.

  Specifically, the substrate 2 has a transmission line 21. For example, one end 21 a and the other end 21 b of the transmission line 21 are exposed on the surface 2 a of the substrate 2, and a main portion 21 c between the one end 21 a and the other end 21 b extends in the substrate 2. The transmission line 21 transmits a high-frequency signal received at one end 21a as an input terminal via the main part 21c and outputs the other end 21b as an output terminal.

  The carrier 3 is disposed between the substrate 2 and the module housing 1. The carrier 3 supports the substrate 2 and fixes the substrate 2 to the module housing 1.

  The gold ribbon 41 electrically connects the output terminal 21 b of the substrate 2 and the input terminal 51 a of the coaxial line 5.

  The coaxial line 5 penetrates the module housing 1 so as to go from the outside of the module housing 1 into the housing space 1a. The coaxial line 5 receives a high-frequency signal output from the substrate 2 via the gold ribbon 41. The coaxial line 5 transmits and outputs a high frequency signal.

  Specifically, the coaxial line 5 includes an inner conductor 51, a dielectric 52, an outer conductor 53, and a conductor plate 54. The inner conductor 51 extends from the outside of the module housing 1 into the housing space 1a and extends through the module housing 1 so that one end 51a thereof is located in the housing space 1a. The inner conductor 51 transmits a high frequency signal received at one end 51a as an input terminal and outputs the other end 51b as an output terminal.

  The dielectric 52 extends from the outside of the module housing 1 into the housing space 1a, and extends through the module housing 1 to a position where one end thereof is in front of the one end 51a of the inner conductor 51 and faces the housing space 1a. ing. The dielectric 52 has, for example, a substantially cylindrical shape that is coaxial with the inner conductor 51. For example, the dielectric 52 covers the inner conductor 51 so as to surround the section when viewed in a cross section perpendicular to the inner conductor 51 (see FIG. 3).

  The outer conductor 53 extends from the outside of the module housing 1 into the housing space 1 a and extends to a position where it is connected to the conductor plate 54. The outer conductor 53 has, for example, a substantially cylindrical shape that is coaxial with the inner conductor 51 and the dielectric 52. The outer conductor 53 covers, for example, the inner conductor 51 and the dielectric 52 when viewed in a cross section perpendicular to the inner conductor 51.

  The conductor plate 54 covers the outer wall surface 1 b on the coaxial line 5 side in the module housing 1 so as to close the cavity 11. The conductor plate 54 is connected to the outer conductor 53 and is connected to the outer wall surface 1 b on the opposite side of the outer conductor 53. The conductor plate 54 has a through hole 54a on the inner side thereof, and is penetrated by the inner conductor 51 and the dielectric 52 through the through hole 54a.

  The plurality of cavity resonators 13 and 14 are respectively arranged in a part of the portion 10 around the coaxial line 5 in the module housing 1 in the direction along the coaxial line 5. For example, the cavity resonator 13 includes the cavity 11 formed by closing the concave structure of the outer wall surface 1 b with the conductor plate 54. The cavity resonator 14 includes a cavity 12 formed in the module housing 1. The cavity resonators 13 and 14 include, for example, substantially rectangular cavities 11 and 12 when viewed in a cross section perpendicular to the coaxial line 5 (see FIG. 3).

  The plurality of cavity resonators 13 and 14 are respectively arranged in the portion 10 around the coaxial line 5 in the module housing 1 and are connected to each other via the coaxial line 5. The plurality of cavity resonators 13 and 14 are arranged along the coaxial line 5 so as to be separated from each other in the direction along the coaxial line 5 in the portion 10 around the coaxial line 5 in the module housing 1. . As a result, when the high frequency signal is transmitted through the inner conductor 51 of the coaxial line 5, the plurality of cavity resonators 13 and 14 transmits the harmonic component (for example, second harmonic) included in the high frequency signal to the amplifier 9 side. The fundamental wave component included in the high-frequency signal is selectively transmitted through the inner conductor 51. Further, when the plurality of cavity resonators 13 and 14 receive a high-frequency signal that is radiated from the output terminal 9b of the amplifier 9 to the housing space 1a and propagates in the waveguide mode, harmonics included in the high-frequency signal (for example, The second harmonic wave component is reflected to the amplifier 9 side, and the fundamental wave component included in the high frequency signal is selectively guided into the inner conductor 51.

  The plurality of cavity resonators 13 and 14 have different resonance frequencies. Specifically, the plurality of cavity resonators 13 and 14 have a configuration as shown in FIGS. FIG. 2 is a perspective perspective view showing the configuration of the cavity resonators 13 and 14. FIG. 3 is a cross-sectional view taken along the outer wall surface 1 b on the coaxial line 5 side in the module housing 1, and is a cross-sectional view illustrating the configuration of the cavity resonators 13 and 14.

The cavity resonator 13 includes a substantially rectangular cavity 11 when viewed in a cross section perpendicular to the coaxial line 5. When viewed in a cross section perpendicular to the coaxial line 5, the cavity 11 includes an inner conductor 51 and a dielectric 52 of the coaxial line 5. For example, the dielectric 52 is in contact with the bottom surface 11 b of the cavity 11. At this time, for example, when one length of the long side and the short side of the cavity 11 is a ₁ and the other length is b ₁ , the resonance wavelength λ _c1 corresponding to the resonance frequency of the cavity resonator 13 is It is designed to satisfy Equation 1 below.
λ _c1 = 1 / √ ((1 / (2a ₁ )) ² + (1 / (2b ₁ )) ² ) Equation 1

For example, when the cavity resonator 13 is designed so that the resonance wavelength λ _c1 of the cavity resonator 13 is close to twice the wavelength of the fundamental wave, the cavity resonator 13 has transmission / reflection characteristics as shown in FIG. Show. In FIG. 4, when the frequency corresponding to the wavelength of the fundamental wave is 10 GHz and the frequency of the double wave is 20 GHz, the transmission characteristic is indicated by a solid line and the reflection characteristic is indicated by a broken line. As shown in FIG. 4, the harmonic (second harmonic) component is substantially totally reflected from the high-frequency signal transmitted in the inner conductor 51 and the high-frequency signal propagated through the housing space 1a. It is difficult to output to the outside of the module, and it can be seen that the fundamental wave component is easily output to the outside of the module while maintaining very good transmission characteristics.

The cavity resonator 14 includes a substantially rectangular cavity 12 when viewed in a cross section perpendicular to the coaxial line 5. When viewed in a cross section perpendicular to the coaxial line 5, the cavity 12 includes an inner conductor 51 and a dielectric 52 of the coaxial line 5. For example, the dielectric 52 is in contact with the bottom surface 12 b of the cavity 12. At this time, for example, when one length of the long side and the short side of the cavity 12 is a ₂ and the other length is b ₂ , the resonance wavelength λ _c2 corresponding to the resonance frequency of the cavity resonator 14 is: It is designed to satisfy Equation 2 below.
λ _c2 = 1 / √ ((1 / (2a ₂ )) ² + (1 / (2b ₂ )) ² ) Equation 2

For example, when the cavity resonator 14 is designed so that the resonance wavelength λ _c2 of the cavity resonator 14 is close to three times the wavelength of the fundamental wave, the cavity resonator 14 has the same transmission / reflection as that shown in FIG. Show the characteristics. That is, with respect to the high-frequency signal transmitted in the inner conductor 51 and the high-frequency signal propagated through the housing space 1a, the harmonic (third harmonic) component is almost totally reflected and hardly output to the outside of the module. Therefore, the fundamental wave component is easily output outside the module while maintaining very good transmission characteristics.

Here, the plurality of cavity resonators 13 and 14 can be configured to satisfy the following expression 5 by designing so that at least one of the following expression 3 and expression 4 is satisfied.
a ₁ ≠ a ₂ ... Formula 3
b ₁ ≠ b ₂ ... Formula 4
λ _c1 ≠ λ _c2 Equation 5
Note that FIG. 3 exemplarily shows the configuration of the plurality of cavity resonators 13 and 14 in the case where both the above Equation 3 and Equation 4 are satisfied.

  Here, suppose a case where harmonics are suppressed by a harmonic suppression circuit in which an open stub or a short stub is electrically connected to a planar circuit. In this case, when receiving a high frequency signal radiated from the output terminal 9b of the amplifier 9 to the housing space 1a and propagating in the waveguide mode, the harmonic suppression circuit has a harmonic suppression function for the high frequency signal. I can't show it. As a result, harmonics tend to be output outside the module.

  On the other hand, in the first embodiment, when the plurality of cavity resonators 13 and 14 receive a high-frequency signal that is radiated from the output terminal 9b of the amplifier 9 to the housing space 1a and propagates in the waveguide mode, The harmonic component included in the signal is reflected to the amplifier 9 side, and the fundamental component included in the high-frequency signal is selectively guided into the inner conductor 51. Thereby, not only the high frequency signal transmitted through the transmission line but also the high frequency signal propagating in the waveguide mode can be suppressed.

  Alternatively, suppose that each of the cavity resonators 13 and 14 has a disk shape surrounding the inner conductor 51 and the dielectric 52 in a cross-sectional view perpendicular to the coaxial line 5. In this case, it is difficult to determine the dimensional relationship between the cavity resonators 13 and 14. That is, even if each of the cavity resonators 13 and 14 is designed to have a radius that is ¼ of the wavelength of the harmonic to be suppressed with the inner conductor 51 as the center, resonance tends to be difficult at the expected frequency. For this reason, it is difficult to design the cavity resonators 13 and 14.

  On the other hand, in the first embodiment, each of the cavity resonators 13 and 14 has a substantially rectangular shape when viewed in a cross section perpendicular to the coaxial line 5. Thereby, the dimensional relationship between the cavity resonators 13 and 14 can be uniquely determined. That is, by designing the cavity resonators 13 and 14 so as to satisfy the above formulas 1 and 2, it is possible to resonate at an expected frequency (see FIG. 4). For example, according to a substantially rectangular cavity resonator, the resonance peak can be sharpened and unnecessary harmonic components can be reliably cut off, compared to a disk-shaped cavity resonator. The fundamental wave can maintain very good transmission characteristics. For this reason, the cavity resonators 13 and 14 can be easily designed.

  In the first embodiment, the plurality of cavity resonators 13 and 14 have different resonance frequencies and are connected to each other via the coaxial line 5. Thereby, as a whole of the plurality of cavity resonators 13 and 14, harmonics are suppressed in a wide band with respect to the high-frequency signal transmitted in the inner conductor 51 and the high-frequency signal transmitted through the housing space 1a. Can do. Furthermore, since the cut-off frequency can be widened, unnecessary harmonics can be suppressed even when individual differences in electrical characteristics occur.

  In the first embodiment, the cavity resonators 13 and 14 are arranged in a part of the portion 10 around the coaxial line 5 in the module housing 1 in the direction along the coaxial line 5. The plurality of cavity resonators 13 and 14 are arranged along the coaxial line 5. Thereby, since the above-mentioned function can be achieved by processing the module housing 1 without mounting new parts or the like, the function of the high-frequency module 100 can be improved without increasing the size of the high-frequency module 100. .

  In the first embodiment, the case where the high-frequency module 100 includes a plurality of cavity resonators 13 and 14 is exemplarily described. However, the high-frequency module 100 may include one cavity resonator. . Even in this case, when the cavity resonator is substantially rectangular when viewed in a cross section perpendicular to the coaxial line 5, the cavity resonator can be easily designed.

  Alternatively, in the high frequency module 100i, as shown in FIG. 5, the dielectric 52 may not be in contact with the bottom surface 11b of the cavities 11i and 12i included in the respective cavity resonators 13i and 14i. That is, when viewed in a cross section perpendicular to the coaxial line 5, the dielectric 52 may be included inside the cavities 11 i and 12 i. Even in this case, the plurality of cavity resonators 13i and 14i can be designed to have different resonance frequencies.

For example, when one length of the long side and the short side of the cavity 11i is c ₁ and the other length is d ₁ , the resonance wavelength λ _c1i corresponding to the resonance frequency of the cavity resonator 13 _i is expressed by the following formula 6: Designed to meet.
λ _c1i = 1 / √ ((1 / (2c ₁ )) ² + (1 / (2d ₁ )) ² ) Equation 6

For example, the long sides and one of the length of the short side of the cavity 12i and c _2, when the other length and d _2, the resonance wavelength lambda _c2i corresponding to the resonant frequency of the cavity resonator 14i is the following equation 7 Designed to meet.
λ _c2i = 1 / √ ((1 / (2c ₂ )) ² + (1 / (2d ₂ )) ² ) Equation 7

Here, by designing so that at least one of the following Equation 8 and Equation 9 is satisfied, the plurality of cavity resonators 13i and 14i can be configured to satisfy the following Equation 10.
c ₁ ≠ c ₂ ... Formula 8
d ₁ ≠ d ₂ ... Equation 9
λ _c1i ≠ λ _c2i Expression 10

  1 module housing, 2 substrate, 3 carrier, 5 coaxial line, 9 amplifier, 10 peripheral part, 11, 11i cavity, 12, 12i cavity, 13, 13i cavity resonator, 14, 14i cavity resonator, 21 transmission line , 41 gold ribbon, 42 gold ribbon, 51 inner conductor, 52 dielectric, 53 outer conductor, 54 conductor plate, 100, 100i high frequency module.

Claims (1)

A module housing;
A coaxial line passing through the module housing and having an inner conductor and a dielectric;
A substrate that is housed in the module housing and transmits a high-frequency signal amplified by an amplifier;
A gold ribbon connecting the coaxial line and the substrate;
In a part of the module casing around the coaxial line, a part of the direction along the coaxial line is arranged side by side along the coaxial line, connected to each other through the coaxial line, and mutually A plurality of cavity resonators having different resonance frequencies,
Each of the plurality of cavity resonators has a substantially rectangular shape when viewed in a cross section perpendicular to the coaxial line, and the cavity of each of the plurality of cavity resonators includes the inner conductor and the coaxial line. A high frequency module comprising: a dielectric, wherein the dielectric is in contact with a bottom surface of each of the cavities.

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