JP2017187379A - Multilayer substrate circuit module, radio communication apparatus and radar equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a module having a millimeter wave antenna, a digital circuit, etc., mixed together, capable of suppressing cost and noise sneaking, and entirely integrated on one multilayer substrate.SOLUTION: A dielectric layer 1 and a dielectric layer 2 consist of a double sided metal-clad substrate; a circuit is subjected to patterning; a planar antenna and a high frequency analog circuit are formed on one surface of the dielectric layer 1; an analog ground covering the entire surface is formed on the other surface; via holes for connecting between the patterns of the one surface and the other surface are formed in the inside; a low frequency analog circuit and a digital circuit are formed on one surface of the dielectric layer 2; analog and digital grounds are formed on the other surface; via holes for connecting between the patterns of the one surface and the other surface are formed in the inside; the analog ground of the dielectric layer 1 is directly connected to the analog ground of the dielectric layer 2 by via holes penetrating the entire layer; and the analog ground of the dielectric layer 1 is connected to the digital ground through the analog ground of the dielectric layer 2 or a noise filter.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a multilayer substrate circuit module, a wireless communication device, and a radar device.

  In the car world, in recent years, millimeter wave radar modules have been rapidly spread for the purpose of collision prevention. As a frequency band of these millimeter wave radar modules, a quasi-millimeter wave band of 24 GHz to a millimeter wave band of 79 GHz is used. The configuration and principle of these millimeter wave radars are already widely known and will be described with reference to FIG.

  The circuit board inside the current in-vehicle radar (millimeter wave radar) is, for example, as shown in the perspective view on page 6 of Non-Patent Document 1. This will be described in detail with reference to FIG. 9. In general, a two-substrate configuration of a first substrate (901) and a second substrate (902) is adopted. There are several reasons why they are separated into two instead of being integrated into one, but the biggest reason is that different materials are used for the first substrate (901) and the second substrate (902). . The first substrate (901) is for millimeter wave analog circuits, and an expensive special substrate of Teflon (registered trademark) or ceramic is used with emphasis on low loss even in the millimeter wave band. The second substrate (902) is a substrate dedicated to a low-frequency circuit, and a glass epoxy substrate is used with an emphasis on low cost.

  In the following, the three terms “millimeter wave analog circuit”, “low frequency analog circuit”, and “digital circuit” will be used in order to easily identify the circuit elements constituting the radar device and the radio communication device in the high frequency band. explain.

  Here, the term “millimeter wave” is used to mean an RF band in a high-frequency device. For example, a millimeter wave band such as 60 GHz is naturally a quasi-millimeter wave band such as 24 GHz to a microwave band such as 12 GHz. Includes up to.

  The term “low frequency” is used to mean a frequency band below the IF band in a high frequency device, and refers to a frequency range from DC to about 2 GHz.

  On the first substrate (901) dedicated to the millimeter wave circuit, the oscillation circuit (963) generates a millimeter wave signal. In order to stabilize the frequency of the millimeter wave signal, a part of the output is fed back through the frequency dividing circuit (969) and the PLL circuit (971). The oscillation output is divided into two by the branching portion (965), and one of the oscillation outputs is radiated from the transmitting antenna (961) via the signal pattern (967). Part of the reflected wave that hits the distant obstacle (925) is picked up by the receiving antenna (962). The mixer circuit (966) compares this received signal with the other distributed signal, and outputs a slight frequency and phase difference as a low frequency signal of about several tens of kHz from the output line (903).

  On the second substrate (902) dedicated to the low-frequency circuit, the low-frequency signal on the output line (903) is first amplified by the operational amplifier (972) that is an analog low-frequency circuit, and the microcomputer (digital circuit) 973). On the second substrate (902), for example, a power circuit (974) and a communication circuit (975) such as USB and CAN are mounted.

  Incidentally, the first substrate (901) dedicated to the millimeter wave circuit is generally designed based on the concept of “antenna integrated multilayer substrate module”. As this concept, FIG. 1 of Patent Document 1 is a representative one. FIG. 7 is an outline drawing of FIG. 1 of Patent Document 1.

  As shown in FIG. 7, the “antenna integrated multilayer substrate module” is formed by integrally bonding a first dielectric layer (711) and a second dielectric layer (712) with an adhesive layer (713) sandwiched therebetween. It has a multi-layered substrate structure. Since the two dielectric layers (711 to 712) before bonding are double-sided copper-clad substrates, a total of four metal pattern layers (721 to 724) are formed by patterning them. A millimeter-wave antenna (761 to 762) is configured on one side of the multilayer substrate, and a millimeter-wave circuit (732) is configured on the opposite side, and a through VIA hole (715) is connected between the two. ing.

  In FIG. 7, the millimeter wave antennas (761 to 762) and the millimeter wave circuit (732) are separated on different substrate surfaces with a common ground (730) hidden in the multilayer substrate interposed therebetween. In FIG. 7, such a structure is intended to reduce the substrate size and cope with the problem of signal interference.

  In general, in order to improve the sensitivity of the antennas (761 to 762), for example, FIG. 3 and FIG. In many cases, the area of the substrate increases as shown in FIG. Therefore, in FIG. 7, the circuit (732) other than the antenna is arranged on the back surface of the substrate on which the antenna is mounted, thereby realizing downsizing as a whole.

  As for signal interference, for example, the output of a local oscillator (eg, 963 in FIG. 9) with particularly high power leaks out of the millimeter wave circuit (732), and is mixed with the original transmission signal and spuriously radiated into the air. In FIG. 7, the common ground layer (730) is used to shield the antennas (761 to 762) to prevent signal interference.

  FIG. 8 shows a circuit block diagram in the case where the concept of FIG. 7 is applied to the first substrate (901) dedicated to the millimeter wave circuit of the millimeter wave radar shown in FIG. The four dotted line portions (821 to 824) in FIG. 8 correspond to the four metal pattern layers (721 to 724) in FIG. The first metal pattern layer (821) is a pattern layer dedicated to the millimeter wave antennas (861 to 862), and the second metal pattern layer (822) is a pattern layer dedicated to the common ground (830). The third metal pattern layer (823) is a pattern layer dedicated to power supply wiring. Since the power supply wiring layer is not related to the solution of the problem described below, the description of other figures is omitted. The fourth metal pattern layer (824) is a pattern layer dedicated to the millimeter wave circuit (732), and between the pattern layer dedicated to the millimeter wave circuit (732) and the pattern layer dedicated to the millimeter wave antenna (861 to 862), As described above, it is connected to the electrical connection by the through VIA hole (815).

Japanese Patent No. 2840493

Maria S. Greco, “Automatic Radar”, 2012 IEEE Radar Conference, May 7-11, Atlanta, Internet <URL: http://www.iet.unipi.it/m.greco/esami_lab/Radar/automotive_radar.pdf> Martin Schneider, “Automotive Radar-Status and Trends”, GeMiC 2005, Internet <URL: https://duepublico.uni-duisburg-essen.de/servlets/DerivateServlet/Derivate-14581/Paper/5_3.pdf>

  By the way, in recent years, especially in the world of the automobile radar in the 24 GHz band, two changes are progressing. The first change currently in progress is the rapid integration of one chip on the millimeter wave circuit (732) on the first substrate (901) dedicated to the millimeter wave circuit, which reduces the area occupied. Is. Therefore, in FIG. 7, the area of the antennas (761 to 762) on one side (721) is remarkably large, whereas the area of the millimeter wave circuit (732) on the other side (724) is remarkably small. Dead space has arisen and is not optimal.

  The second change that is currently in progress is that prices have fallen sharply and, for example, 24 GHz radar has become available for around 1 to 30,000 yen. On the other hand, FIG. 7 can contribute to lowering the cost of the first substrate (901) dedicated to the millimeter wave circuit locally, but lacks the viewpoint of cost reduction that overlooks the entire apparatus of FIG. And there was a limit.

  Here, considering that the two-substrate configuration of FIG. 9 is integrated on one substrate, the cross-sectional structure is as shown in FIG. As shown in FIG. 5, a low frequency analog circuit (542) and a digital circuit (552) are mixedly mounted so as to fill a dead space on the millimeter wave analog circuit (532) side. FIG. 6 is a circuit block diagram of FIG. 5. On the fourth metal pattern layer (624), an operational amplifier (672) that is a low-frequency analog circuit, a microcomputer (673) that is a digital circuit, and a communication circuit. (675), the number of power supply circuits (674) is increasing.

  However, this structure has three problems. The first problem is material cost. In FIG. 5, since the millimeter wave antennas (561 to 562) and the millimeter wave analog circuit (532) are mounted, both the first dielectric layer (511) and the second dielectric layer (512) are used. Even in the millimeter wave band, low loss Teflon and ceramic expensive substrates must be used. As a result, although the operational amplifier (672), the microcomputer (673), the power supply circuit (674), and the communication circuit (675) are not necessarily required, they are all mounted on an expensive millimeter wave circuit board. In terms of material cost, the design is extremely useless.

  The second problem is performance degradation due to noise wraparound. The “millimeter wave analog circuit”, “low frequency analog circuit”, and “digital circuit” are mutually noise sources. It is well known that the typical noise wraparound route is a ground pattern. However, in the “antenna integrated (multilayer substrate) module” structure described in Patent Document 1, only noise due to the “millimeter wave analog circuit” is considered, and therefore an unstable common ground (630) is included in the substrate. ) Is shared by all the metal pattern layers (621-624) through the through VIA hole (615). Therefore, noise wraparound cannot be effectively prevented.

  The third problem is the low degree of freedom of wiring due to the use of only through VIA holes. The through-via hole (615) penetrating all layers is exposed to a layer unrelated to the layer to be wired although the manufacturing cost is low. For this reason, the antennas (561 to 562, 661 to 662) occupying a wide space can hardly be formed. However, in a general millimeter wave radar apparatus, the antenna (561 to 562, 661 to 662) is large enough to occupy almost one side of the substrate, and as a result, the entire multilayer substrate structure (FIG. 5) is obtained. Then, only a few through VIA holes (515, 615) can be formed. It is extremely difficult to repeat wiring of all the components (532, 542, 552) with such a small number of through VIA holes (515, 615).

  Therefore, the present invention has been made in view of the above problems, and in a module in which a millimeter wave antenna, a millimeter wave analog circuit, a low frequency analog circuit, and a digital circuit are mixed, while suppressing material cost and manufacturing cost, noise can be reduced. A multilayer substrate circuit module that suppresses wraparound and integrates all on a single multilayer substrate is provided.

  Form 1; One or more embodiments of the present invention comprise a first dielectric layer, a second dielectric layer, and the first dielectric layer and the second dielectric layer bonded together. The first dielectric layer and the second dielectric layer are each made of a double-sided metal-clad substrate, a circuit is formed by patterning, and the air of the first dielectric layer is formed. A planar antenna and a high-frequency first analog circuit are formed on the side surface, and a first analog ground covering the entire surface is formed on the surface of the first dielectric layer on the adhesive layer side, A blind VIA hole is formed in the first dielectric layer to electrically connect the patterns on the air-side surface and the adhesive layer-side surface, and on the air side of the second dielectric layer. On the surface, a low-frequency second analog circuit and a digital circuit are formed, and the second dielectric circuit is formed. A second analog ground and a digital ground are formed on the surface of the adhesive layer side of the layer, and a pattern of the air side surface and the surface of the adhesive layer side is formed inside the second dielectric layer. A blind VIA hole is formed to electrically connect the first analog ground, and the first analog ground is electrically connected directly to the second analog ground by a penetrating VIA hole penetrating all layers. A multi-layer circuit board module is proposed in which the ground is connected to the digital ground via the second analog ground or a noise filter.

  Mode 2; In one or more embodiments of the present invention, the first dielectric layer is made of a Teflon or ceramic base material, and the second dielectric layer is made of a glass epoxy base material. A module is proposed.

  Mode 3 One or more embodiments of the present invention propose a multilayer substrate circuit module comprising a multilayer substrate structure in which the second dielectric layer is further subdivided into a plurality of portions.

  Mode 4: In one or more embodiments of the present invention, a metal shield case covering the first analog circuit excluding the planar antenna is provided, and the metal shield case is electrically connected to the first analog ground VIA. A multilayer board circuit module connected through holes is proposed.

  Mode 5: In one or more embodiments of the present invention, the first analog circuit includes a millimeter wave oscillation circuit, and the metal shield case is provided so as to cover the millimeter wave oscillation circuit Has proposed.

  Mode 6: One or more embodiments of the present invention propose a wireless communication apparatus including the multilayer substrate circuit module of mode 5.

  Mode 7: One or more embodiments of the present invention propose a multilayer substrate circuit module in which the first analog circuit excluding the planar antenna is electrically open to the air.

  Mode 8: One or more embodiments of the present invention propose a radar apparatus including the multilayer substrate circuit module of Mode 7.

  According to one or more embodiments of the present invention, in a module including a millimeter-wave antenna, a millimeter-wave analog circuit, a low-frequency analog circuit, and a digital circuit, suppression of noise is suppressed while suppressing material cost and manufacturing cost. Thus, there is an effect that all can be integrated on a single multilayer substrate.

It is a cross-sectional structure schematic diagram of the multilayer substrate circuit module which concerns on embodiment of this invention. It is a circuit block schematic diagram of a multilayer substrate circuit module according to an embodiment of the present invention. It is a plane schematic diagram of each layer in the multilayer substrate of the multilayer substrate circuit module according to the embodiment of the present invention. It is a manufacturing process schematic diagram in the multilayer substrate of the multilayer substrate circuit module concerning the embodiment of the present invention. It is a cross-sectional schematic diagram for demonstrating the problem of related technology. It is a circuit block schematic diagram of FIG. It is a cross-sectional schematic diagram of related technology. It is a circuit block schematic diagram of FIG. It is a circuit block schematic diagram of a general radar apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Note that the constituent elements in the present embodiment can be appropriately replaced with existing constituent elements and the like, and various variations including combinations with other existing constituent elements are possible. Therefore, the description of the present embodiment does not limit the contents of the invention described in the claims.

<Embodiment>
The embodiment of the present invention will be described with reference to FIGS. In the following, a case where the multilayer substrate circuit module according to this embodiment is applied to a millimeter wave radar will be described as an example.

  As shown in FIG. 1, the multilayer substrate of the multilayer substrate circuit module according to the present embodiment includes a first dielectric layer (111), a second dielectric layer (112), and a first dielectric layer ( 111) and a second dielectric layer (112) are laminated to form an adhesive layer (113).

  Each of the first dielectric layer (111) and the second dielectric layer (112) is made of a double-sided metal-clad substrate, and a circuit is formed by patterning. A planar antenna and a high-frequency first analog circuit are formed on the air side surface (121) of the first dielectric layer (111).

  A first analog ground covering the entire surface is formed on the adhesive layer side surface (122) of the first dielectric layer (111), and an air side surface is formed inside the first dielectric layer (111). Blind VIA holes for electrically connecting the patterns of the surface (121) and the surface (122) on the adhesive layer side are appropriately formed.

  A low-frequency second analog circuit and digital circuit are formed on the air side surface (124) of the second dielectric layer, and the adhesive layer side surface (123) of the second dielectric layer is A second analog ground and a digital ground are formed, and the second dielectric layer (112) is electrically connected between the patterns of the air side surface (124) and the adhesive layer side surface (123). Blind VIA holes for connecting to are appropriately formed.

  The first analog ground (131) is electrically directly connected to the second analog ground (141) by a through VIA hole (115A) penetrating all layers, and the first analog ground (131) is connected to the second analog ground (131). It is connected to the digital ground (151) through the ground (141) or the noise filter (114).

  The first dielectric layer (111) is made of a low-loss Teflon-based or ceramic-based substrate such as a ceramic wave, and the second dielectric layer (112) is made of a low-cost glass-epoxy-based substrate. It is a double-sided copper-clad substrate having two metal pattern layers (121 to 124) as shown in FIG.

  The two dielectric layers (111, 112) are first subjected to a VIA hole (114) formation process and a pattern formation process separately as shown in FIG. 4B. Specifically, the metal pattern layer (121) on one side of the first dielectric layer (111) is subjected to a pattern forming process including the millimeter wave antennas (161 to 162), and the VIA hole (114) is formed into the millimeter wave antenna. It is formed in a dead space where (161 to 162) is not formed.

  Next, as shown in FIG. 4C, they are laminated together through an adhesive layer (113) to form an integrated multilayer. As a result, a total of four metal pattern layers (121 to 124) are formed in the multilayer substrate, and the VIA hole (114) is shielded by the adhesive layer (113), so that the non-penetrating blind VIA hole (114) is formed. And change.

  Finally, a penetrating VIA hole (115B) penetrating all the layers (111 to 113) including the adhesive layer (113) is similarly formed in the dead space between the millimeter wave antennas (161 to 162) and is located on both surfaces. Two metal pattern layers (121, 124) are electrically connected.

  Thus, the digital circuit (152) and the low-frequency analog circuit (142) can be provided in the second dielectric layer (112). Therefore, the first dielectric layer (111) made of the low loss base material is a layer dedicated to the millimeter wave circuit, and the millimeter wave band circuit can be completed only by the metal pattern layers (121 to 122) on both sides. it can.

  As shown in the plan view of FIG. 3A, the air-side surface layer (121) can occupy almost the entire surface by the millimeter wave antennas (161 to 162) as in the conventional case, and the degree of freedom in design is high. On this surface, for example, a very small number of millimeter-wave ICs (132) are also mounted, but the area occupied is small due to the recent trend toward one chip.

  Further, since the transmitting antenna (161) and the receiving antenna (162) constituting the millimeter wave antennas (161 to 162) must be laid out at a distance from each other in order to avoid electromagnetic interference, FIG. Thus, if the millimeter wave IC (132) is disposed in the gap between the two, it is possible to suppress the occurrence of dead space.

  The internal circuit of the millimeter wave IC (132) is an oscillation circuit (263), a frequency dividing circuit (269), a mixer circuit (266), and the like. The millimeter wave analog ground (131) required by these circuits is an adhesive layer. A wide area is formed on the metal pattern layer (122) of the first dielectric layer (111) on the (113) side, and is electrically connected to the low-frequency analog ground (141) through the VIA holes (114 to 115B).

  At this time, as apparent from the manufacturing process of FIG. 4, since the blind VIA hole (114) can be freely set in terms of space, even if the VIA hole is arranged in a relatively favorite place, the electrons arranged in other layers are arranged. Since there is no risk of interference with parts, the degree of freedom in design is high.

  On the other hand, the second dielectric layer (112) made of a low-cost substrate is a layer dedicated to the low-frequency analog circuit (142) and the digital circuit (152), and only the metal pattern layers (123 to 124) on both sides are low. High frequency analog and digital circuits are complete.

  Specifically, the internal circuit of the low frequency analog circuit (142) and the digital circuit (152) includes an operational amplifier (272), a PLL circuit (271), a microcomputer (273), a digital communication circuit (275), a power supply circuit ( 274) and the like, but the low frequency analog ground (141) and digital ground (151) required by them, and the inner auxiliary wiring (136) often required are provided on the second dielectric layer (112). The metal pattern layer (123) is formed on the same plane and electrically connected to the digital circuit (152) or the low-frequency analog circuit (142) through the VIA holes (114 to 115B).

  At this time, as is apparent from the manufacturing process of FIG. 4, since the blind VIA hole (114) can be freely arranged, even if the VIA hole is arranged in a relatively favorite place, it interferes with electronic components arranged in other layers. Since there is no risk of causing any problems, the degree of freedom in design is high.

  In addition, it is known that low frequency analog ground (141) and digital ground (151) are particularly susceptible to noise. For this reason, in consideration of the layout, it is common to selectively connect to each other in only a few places, or to connect to each other via a noise filter (114) therebetween.

  In the present embodiment, these two types of grounds are arranged on the same plane (123), but it goes without saying that the same noise countermeasures can be taken up to now. Needless to say, it can be implemented in parallel with other types of noise reduction technologies. In the plan view of FIG. 3C, such noise countermeasures are omitted for simplification.

  From the above, in the present embodiment, the first dielectric layer (111) in which the millimeter wave circuit unit (132) is formed, the digital circuit unit (152), and the low frequency analog circuit unit (142) are formed. The two dielectric layers (112) are connected by only a relatively small number of through VIA holes (115A). This is effective in electrically separating the two and preventing noise from entering.

  Further, in the present embodiment, the electrical connection between the millimeter wave analog ground (131) and the low frequency analog ground (141) is realized by a part of the through VIA hole (115). The millimeter wave analog ground (131) and the digital ground (151) are not directly connected, but are connected only via the low frequency analog ground (141) or the noise filter (114).

  As described above, according to this embodiment, in the module in which the millimeter wave antenna, the millimeter wave analog circuit, the low frequency analog circuit, and the digital circuit are mixed, noise wraparound is suppressed while suppressing material cost and manufacturing cost. All can be integrated on a single multilayer substrate.

<Application form>
The multilayer substrate circuit module according to the above embodiment can be used not only for millimeter wave radar devices but also for wireless communication devices.

  The greatest difference between the radar circuit and the wireless communication circuit is whether or not the signal radiated from the antenna (161 to 162) is the same as the output signal of the oscillation circuit (263). In the radar circuit, the two signals are the same. Therefore, as described in the above embodiment, it is not necessary to pay much attention to the electromagnetic shield of the oscillation circuit (263). However, in the wireless communication circuit, since the two signals are different, electromagnetic leakage from the oscillation circuit (263) is a big problem, and it is generally necessary to cover the electromagnetic shield.

  When the multilayer substrate circuit module according to the above embodiment is used for a wireless communication circuit, a metal shield case may be put on the dotted line portion (381) in the plan view of FIG. The edge of the metal shield case is provided with a small opening at the part that contacts the signal line on the board to prevent short circuit, and the other part is added with a blind VIA hole (114) on the board to add a millimeter wave analog ground. It is desirable to stabilize the potential by grounding at (131).

  The embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiments, and includes designs and the like that do not depart from the gist of the present invention.

111; first dielectric layer 112; second dielectric layer 113; adhesive layer 114; blind VIA hole 115A; penetrating VIA hole 115B; penetrating VIA hole 121; metal pattern layer 122; metal pattern layer 123; metal pattern layer 124; Metal pattern layer 131, 331; Millimeter wave analog ground 132; Millimeter wave IC
136; Auxiliary wiring pattern 141; Low frequency analog ground 142; Low frequency analog electronic component 151; Digital ground 152; Digital electronic component 161; Millimeter wave antenna 162; Millimeter wave antenna 225; Obstacle 263; Oscillation circuit 264; Branch circuit 266; mixer circuit 269; frequency divider circuit 271; PLL circuit 272; operational amplifier 273; microcomputer 274; power circuit 275; communication circuit 331; millimeter wave analog ground 371; PLL circuit 372; operational amplifier 373; 375; Communication circuit 381; Shield case

Claims (8)

A first dielectric layer;
A second dielectric layer;
An adhesive layer for laminating and multilayering the first dielectric layer and the second dielectric layer;
With
Each of the first dielectric layer and the second dielectric layer comprises a double-sided metal-clad substrate, and a circuit is formed by patterning.
A planar antenna and a high frequency first analog circuit are formed on the air side surface of the first dielectric layer,
A first analog ground covering the entire surface is formed on the surface of the first dielectric layer on the adhesive layer side,
A blind VIA hole is formed in the first dielectric layer to electrically connect the patterns on the air side surface and the adhesive layer side surface,
On the air side surface of the second dielectric layer, a low frequency second analog circuit and a digital circuit are formed,
A second analog ground and a digital ground are formed on the surface of the second dielectric layer on the adhesive layer side,
A blind VIA hole is formed in the second dielectric layer to electrically connect the air side surface and the adhesive layer side surface pattern,
The first analog ground is electrically connected directly to the second analog ground by a through VIA hole penetrating all layers,
The multilayer substrate circuit module, wherein the first analog ground is connected to the digital ground via the second analog ground or a noise filter.   2. The multilayer substrate circuit module according to claim 1, wherein the first dielectric layer is made of a Teflon-based or ceramic-based substrate, and the second dielectric layer is made of a glass-epoxy-based substrate.   3. The multilayer substrate circuit module according to claim 1, wherein the second dielectric layer further includes a multilayer substrate structure divided into a plurality of portions therein. A metal shield case is provided to cover the first analog circuit excluding the planar antenna;
4. The multilayer board circuit module according to claim 1, wherein the metal shield case is electrically connected to the first analog ground via a VIA hole.   The multilayer substrate circuit module according to claim 4, wherein the first analog circuit includes a millimeter wave oscillation circuit, and the metal shield case is provided so as to cover the millimeter wave oscillation circuit.   A wireless communication device comprising the multilayer substrate circuit module according to claim 5.   4. The multilayer substrate circuit module according to claim 1, wherein the first analog circuit excluding the planar antenna is electrically opened toward the air. 5.   A radar apparatus comprising the multilayer substrate circuit module according to claim 7.

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