JPH02290307A - High frequency oscillator - Google Patents

Abstract

PURPOSE:To prevent the deterioration in the electric characteristic of SIN or the like based on the spatial coupling by providing a strip line into a layer inserted between earth faces of a multi-layer printed wiring board. CONSTITUTION:The multi-layer printed wiring board 1 consists of layers 2, 3 made of an insulation material and earth faces 4, 5 are provided to a contact face between the layers 2 and 3 and a lower face of the layer 3. Mounted components 8 are components of an oscillating section and mount components 9 are components of an AMP section. Strip lines 6, 7 provided in the layer and the mount components 8, 9 are connected by using via-holes 10, 11 and the earth face 4 is processed so as not to be connected with the via-holes 10, 11. Moreover, the earth faces 4, 5 and the earth face formed on the surface of the layer 2 are interconnected by plural throughholes such as throughholes 12, 13, 14 to keep the equi-potential.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a high frequency oscillator used in high frequency radio equipment, etc., and particularly relates to its implementation on a strip line.

(Prior Art) In a high frequency oscillator that outputs a high frequency, particularly a UHF band oscillation signal, a strip line is used for the resonance circuit because the inductance and capacitance values of the resonant circuit are extremely small. An example of a high frequency oscillator using such a strip line is shown in FIG.

The example in FIG. 3 is a voltage controlled oscillator, in which the oscillation part and the AMP
It consists of two parts. In the AMP section, the collector is the power supply v
A CcK-connected 1-lansostar Q1, a capacitive element C connected between its collector and emitter, a capacitive element C2 connected between its base and emitter, and a strisozo line connected between its base and ground. An inductive reactance consisting of L1, a capacitive element c4 for DC cut, and a variable capacitance diode vD1, a pi-reactive capacitor C3 connected between its collector and ground, and a resistor R2 connected between its emitter and ground. , resistors R3 and R4 that divide the power supply vCc and supply the base voltage,
The oscillation frequency is determined by the inductive reactance, capacitive element (!1
+ (!It constitutes a Kolbitz oscillator determined by 2.

Next, the bottom part shows a field effect transistor Q2, a resistor R connected between its dirt and ground, a resistor R5 connected between its source and ground, and a bypass capacitor C6.
, drain and power supply V. An output matching circuit consisting of strip lines L2 and L3 connected between D, a nozzle/4' capacitor C7 connected between one end of strip line L3 and ground, and a connection point between strip lines L2 and L3. The oscillation signal from the oscillation section, which is input through the coupling capacitor C5, is amplified and output to the outside via the DC power capacitor C8. This is what is output.

By the way, the above-mentioned voltage controlled oscillator has conventionally been shown in FIGS. 4 and 5.
As shown in the figure, strip lines L1L2, L3 were formed along with other wiring circuits on the same surface of a printed wiring board 15, and mounting parts 16 such as transnosters, resistors, capacitive elements, etc. were attached.

(Problem to be Solved by the Invention) However, the mutual positions of the stripes and conductive lines formed on the surface of the printed wiring board and the mounted components are extremely difficult due to the extremely high frequencies involved and the requirement for high-density packaging. They often come close to each other, resulting in spatial coupling. Figure 4 shows the strip and pulley lines L of the oscillation section shown in Figure 3.
1 and the strip line L2 of the AMP section, and FIG. , indicates the state of spatial coupling between L3. Such spatial coupling between the oscillation section and the AMP section, and furthermore between the oscillation section and other circuits, causes deterioration of electrical characteristics such as S/N.

SUMMARY OF THE INVENTION An object of the present invention is to provide a high frequency oscillator which eliminates the above spatial coupling and prevents deterioration of electrical characteristics such as S C due to spatial coupling.

(Another Means to Solve the Problem) In order to achieve the above object, the present invention is aimed at achieving the above object. A line is provided in a layer sandwiched between the ground plane of a multilayer printed wiring board.

Further, in the present invention, a plurality of strip lines are provided in a layer sandwiched between the ground planes of a multilayer printed wiring board, and a plurality of through holes are provided between the strip lines.

(Function) A strip line provided in a layer sandwiched between the ground planes of the multilayer printed wiring board is connected to mounted components mounted on the surface of the multilayer printed wiring board or other circuits arranged nearby by the ground plane. are shielded from other parts to prevent spatial coupling.

Furthermore, the plurality of strip lines provided in the layers sandwiched between the ground planes of the multilayer printed wiring board are shielded by the plurality of through holes provided between the strip lines, thereby preventing spatial coupling. .

(Embodiment) FIG. 1 is a partially sectional view showing a first embodiment of the present invention. In FIG. 1, a multilayer printed wiring board 1 consists of layers 2 and 3 made of an insulating material, and ground planes 4 and 5 are provided on the contact surface between the layers 2 and 3 and on the lower surface of the layer 3, respectively. layer 2
Necessary wiring circuits and ground/mother turns are formed on the upper surface, and components such as transistors, resistors, and capacitive elements are mounted. Note that the mounted component 8 shown in FIG. 1 is one of the components constituting the oscillation section in FIG. 3, and the mounted component 9 is one of the components constituting the AMP section. Furthermore, a strip line f6.7 is provided inside the layer 3 sandwiched between the ground planes 4 and 5, and the strip line 6 is connected to the third line.
The strip line L1 constitutes the oscillation section in the figure, and the strip line 7 is the IJ strip line L2 or L3 constituting the AMP section.

As shown in FIG. 2, i4 ear holes 10 and 11 are used between the strip lines 6 and 7 provided in the layer and the mounting components 8 and 9 mounted on the surface of the multilayer printed wiring board 1. The ground plane 4 is connected to the pipe hole 10.
．． Measures have been taken to prevent contact with 11.

Also, there is a through-hole 1 between the ground planes 4 and 5, and further between the ground plane (not shown) formed on the surface of the layer 2.
They are connected to each other by a plurality of through holes (not shown) including 2, IJ, and 14, and the same potential is maintained.

By adopting the above configuration, the space between the strip line 6 and the mounted component 9 is shielded by the ground planes 4 and 5, and spatial coupling is prevented, and the space between the strip line 7 and the mounted component 8 is also shielded. It is shielded by the ground surfaces 4 and 5, and spatial coupling is prevented. Further, a plurality of through holes (not shown) including the through hole 13 provided between the strip lines 6 and 7 are provided between the strip lines 6 and 7.
and is sealed 9 by ground planes 4 and 5, thereby preventing spatial coupling. This prevents spatial coupling between the oscillation section and the AMP section via the strip line or mounted components.

FIG. 6 is a partial sectional view showing a second embodiment of the present invention, in which there are more layers sandwiched between the ground planes than in the case of FIG. That is, strip lines 21 and 22 are provided separately in a layer sandwiched between ground planes 18 and 19 and in a layer sandwiched between ground planes 19 and 20. In the case of FIG. It is possible to obtain the same effect of preventing spatial coupling as in the case of FIG. 1, and it is also possible to reduce the occupied area compared to the case of FIG.

In addition, although each of the above embodiments prevents spatial coupling between the oscillation section and the AMP section, it is of course not limited to the oscillator section, and may be any other circuit. However, if necessary, only the strip and pulley lines of the oscillating section may be provided in a layer sandwiched between the ground planes.

(Effects of the Invention) As described above in detail, according to the present invention, Strino! Since the line is installed inside a layer that is twisted around the ground plane of the multilayer printed wiring board, the Strinoprop line and the components mounted on the surface of the multilayer printed wiring board, as well as the components of other circuits installed nearby, It is possible to prevent spatial coupling between

In addition, since the multiple strip lines provided in the same layer are shielded by through holes,
! Spatial coupling between lines can be prevented.

Therefore, it is possible to prevent deterioration of electrical characteristics such as S/'N due to the above-mentioned spatial coupling.

In addition, since the strip line is provided within the layer of the multilayer printed wiring board, it is possible to reduce the occupied area by that much.
The circuit can be made smaller.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing the first embodiment of the present invention;
The figure shows the connection method of the strip line and mounted components in Figure 1, Figure 3 is a circuit diagram of the voltage control excavator, Figures 4 and 5 are explanatory diagrams of spatial coupling in the conventional embodiment, FIG. 6 is a partial sectional view showing a second embodiment of the present invention. 1, 17... Multilayer printed wiring board, 2, 3... Insulating layer,
4, 5, 18γ20...Earth plane, 6, 7, 21.2
2...Strip line, 8,9,27.28...Mounted parts, 10,11,25.26...Pier hole,
12-14, 23.24...Through hole. Figure 1: Patent applicant: Oki Electric Industry Co., Ltd., Figure 1: Patent applicant: Oki Electric Industry Co., Ltd. Figure 3: Explanatory diagram of the invitation to all members Figure 4: Explanatory diagram of the declaration and combination Figure 5

Claims (1)

[Scope of Claims] 1. A high-frequency oscillator characterized in that a strip line is provided in a layer sandwiched between the ground planes of a multilayer printed wiring board. 2. A high frequency oscillator characterized in that a plurality of strip lines are provided in a layer sandwiched between the ground planes of a multilayer printed wiring board, and a plurality of through holes are provided between the strip lines.