JP2002280748A - High frequency substrate structure - Google Patents

Abstract

(57) [Problem] To provide a structure of a high-frequency substrate capable of efficiently miniaturizing while maintaining good characteristics. A DC circuit and an RF circuit are provided on a common substrate.
Is formed, and the inner layer pattern 1 is formed only on the portion of the substrate 10 where the DC circuit 3 is formed. The size of the DC circuit 3 is reduced by forming the inner layer pattern 1. In the portion where the RF circuit 4 is formed, the inner layer pattern 1 is formed.
Is formed, the microstrip line 7 is formed.
By transmitting a high-frequency signal through the microstrip line 7, the size of the RF circuit 4 can be reduced. Further, R is formed on one surface of the substrate 10 through the through hole 5.
A ground plane 6 connected to the F circuit 4 was formed so that a good ground could be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in the structure of a substrate used in a particularly high frequency band such as a microwave band communication device or a millimeter wave band communication device.

[0002]

2. Description of the Related Art In recent years, the signal band in wireless communication has tended to be widened, and the frequency of a carrier wave has been accordingly increased. Special consideration is required for communication equipment used in such a high frequency band. In particular, a DC circuit in which a power supply unit and the like are formed (hereinafter referred to as a DC circuit)
And a radio circuit (hereinafter referred to as R
The formation of the F circuit) requires some contrivance.

[0003] Both the DC circuit and the RF circuit are formed on a substrate such as a dielectric. In the conventional high-frequency board structure, a configuration in which a DC circuit and an RF circuit are formed on separate boards, respectively, and these are connected via a connector has been mainly used. However, the higher the frequency of the signal, the greater the influence of the impedance component and the inductance component of the wiring, and the more likely it is that impedance mismatching occurs when connecting via a connector. Further, since connectors and wiring materials are required, it is disadvantageous in terms of size reduction.

On the other hand, a high-frequency circuit structure in which the RF circuit has a multi-layer substrate structure in order to reduce the size is known. However, in such a structure, measures such as arranging a ground in the inner layer and crossing the substrate are required.
For this reason, there are problems that the ground becomes insufficient and the cost increases.

As another measure for reducing the size,
There is a double-sided board structure. However, even with this type of structure, there are many disadvantages particularly in terms of component mounting, wiring, or processing of the case in the DC circuit, and the area of the substrate as a whole may be rather large.

[0006]

As described above, the conventional high-frequency board structure has a disadvantage that it is difficult to reduce the size when the high-frequency circuit section and the DC circuit section are integrally formed. Was. In particular, the higher the frequency of the signal, the more noticeable this problem becomes. Therefore, some measure is desired.

[0007] The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a structure of a high-frequency substrate that can be efficiently reduced in size while maintaining good characteristics.

[0008]

In order to achieve the above object, a high frequency substrate structure according to the present invention is a high frequency substrate structure in which a DC circuit and a high frequency circuit are formed on the same substrate. The circuit forming portion has a structure in which a wiring pattern is formed on an outer layer and an inner layer, and the high-frequency circuit forming portion has a structure in which a wiring pattern is formed only on an outer layer. In the high-frequency substrate structure according to the present invention, the high-frequency circuit includes a strip line formed on an outer layer of the substrate.

By taking such measures, the DC circuit (DC circuit) has a multi-layer substrate structure, it is possible to improve the degree of integration, and it is possible to reduce the size of the circuit. In addition, the inner layer pattern is not inserted in the high frequency circuit (RF circuit), and strip lines are formed on the front and back of the substrate by utilizing the thickness of the substrate. Thus, high-frequency signals can be transmitted via a strip line without a signal cable or the like, so that the size of the RF circuit unit can be reduced. For this reason, the high-frequency circuit and the DC circuit can be formed integrally on the same multilayer substrate to reduce the size and maintain good characteristics of the circuit.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view showing a structure of a high-frequency substrate according to an embodiment of the present invention. Figure 1
In the substrate 10, the substrates 11, 12, and 13 are laminated,
An inner layer pattern 1, an outer layer pattern 2, and a ground plane 3 are formed to form a so-called multilayer substrate structure. The outer layer pattern 2 is formed so as to sandwich both sides of an RF circuit (high-frequency circuit) 5 with a DC circuit (direct-current circuit) 4. DC
The circuit 4 generates a drive voltage or the like for the RF circuit 5, and the voltage generated by the DC circuit 4 is supplied to the RF circuit 5 via a power supply line (not shown).

An inner layer pattern 1 is provided in a portion of the substrate 10 where the DC circuit 4 is formed, and a wiring or ground pattern relating to the DC circuit 4 is formed in the inner layer pattern 1. The DC circuit 4 portion of the outer layer pattern 2, the inner layer pattern 1, and the ground plane 3 are connected by through holes, end face via holes, and the like (not shown). That is, in this embodiment, the inner layer pattern 1 is formed and the DC circuit 4
Has a multi-layer structure, thereby reducing the size of the DC circuit portion.

On the other hand, in the portion of the substrate 10 where the RF circuit 5 is formed, the inner layer pattern 1 is not provided.
A strip conductor 6 is provided on the RF circuit 5 portion of the outer layer pattern 2.
And the strip conductor 6 and the ground plane 3 form a microstrip line 7. In the RF circuit 5, a high-frequency signal is transmitted through the microstrip line 7. Further, the RF circuit 5 is connected to the ground plane 3 via the through hole 8.

As described above, in this embodiment, the common substrate 1
Since the DC circuit 4 and the RF circuit 5 are formed at 0,
There is no need to connect the DC circuit 4 and the RF circuit 5 via a connector or the like, so that the size can be reduced and the possibility of impedance mismatching can be eliminated. Furthermore, since the ground surface 3 is formed on the outermost layer of the substrate 10, it is convenient when grounding the housing case, and a good ground can be secured. Further, in this embodiment, since both sides of the RF circuit 5 are sandwiched between the DC circuits 4, it is possible to reduce the influence of the high frequency generated from the RF circuit on other circuits.

A structure of a high-frequency substrate according to another embodiment will be described with reference to FIG. The description of the same components as those in FIG. 1 is omitted.

Unlike the embodiment shown in FIG. 1, the outer layer pattern 2 is formed so that both sides of a DC circuit (DC circuit) 4 are sandwiched between RF circuits (high-frequency circuits) 5. For this reason,
Not only can the size be reduced, but also the risk of impedance mismatching can be eliminated, and it can be formed with the structure of a high-frequency substrate in which a transmitting and receiving circuit is integrated. This is because a DC circuit that supplies power and the like is formed between the RF circuit of the transmission system and the RF circuit of the reception system, so that a DC circuit that supplies common power and the like can be used, and the RF circuit of the transmission system can be used. And the RF circuit of the receiving system can be realized by sandwiching the DC circuit.

As described above, the present invention makes it possible to provide a structure of a high-frequency substrate that can be efficiently miniaturized while maintaining good characteristics.

[0017]

As described in detail above, in the present invention, the DC circuit portion and the RF circuit portion are integrally formed on a common substrate. At this time, the DC circuit portion was formed as a multilayer substrate structure having an inner layer pattern, and the RF circuit portion was formed as a single layer substrate structure having no inner layer pattern. With this configuration, it is possible to provide a high-frequency board structure that does not require a connection component such as a connector and can efficiently reduce the size while maintaining good electrical characteristics.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of a high-frequency multilayer substrate according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a structure of a high-frequency multilayer substrate according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Board 11, 12, 13 ... The board | substrate laminated | stacked 1 ... Inner layer pattern 2 ... Outer layer pattern 3 ... Ground surface 4 ... DC (DC) circuit 5 ... RF (wireless) circuit 6 ... Strip conductor 7 ... Microstrip line 8 ... Through hole

Claims (8)

[Claims] 1. A high-frequency circuit board structure in which a DC circuit and a high-frequency circuit are formed on the same substrate, wherein the DC circuit-forming portion of the substrate has a structure in which a wiring pattern is formed on an outer layer and an inner layer. Is a high-frequency substrate structure in which a wiring pattern is formed only on an outer layer. 2. The high-frequency substrate structure according to claim 1, wherein an outer layer of said DC circuit forming portion and an outer layer of said high-frequency circuit forming portion are formed in the same layer. 3. The high-frequency substrate according to claim 1, wherein one outer layer side of the substrate is used as a ground layer, and the other outer layer side is used as each outer layer of the DC circuit forming portion and the high-frequency circuit forming portion. Construction. 4. The high-frequency substrate structure according to claim 1, wherein said high-frequency circuit includes a strip line formed on an outer layer of said substrate. 5. The high-frequency substrate structure according to claim 1, wherein both outer layers of said substrate in said high-frequency circuit are connected by through holes. 6. A circuit according to claim 1, wherein each layer of said substrate in said DC circuit is connected by a through hole.
4. The high-frequency substrate structure according to any one of items 1 to 3. 7. The high-frequency substrate structure according to claim 1, wherein said DC circuits are provided on both sides of said high-frequency circuit. 8. The high-frequency substrate structure according to claim 1, wherein said high-frequency circuit is provided on both sides of said DC circuit.