JPH02276294A - Wiring of high frequency printed board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a wiring method for a high frequency printed circuit board in surface mounting which requires at least one high frequency amplifier circuit having a frequency band of IMH2 or higher.

2. Description of the Related Art As shown in FIG. 3, a conventional wiring method for a high-frequency printed circuit board includes an amplifier circuit having a frequency band of 1 MHz on both surfaces of an A signal pattern 13 having a multilayer conductor and a B signal pattern 14 having a different pattern arrangement. 7 are formed in parallel patterns, and the power supply pattern 15 of the amplifier circuit 7 is made into a second layer, the ground pattern 16 is made into a third layer, and each is made into an independent layer in the first layer.
Layer A signal pattern 13 and fourth layer B signal pattern 14
The wiring method used was a printed circuit board with a four-layer structure placed between the two.

Problems to be Solved by the Invention In such a conventional wiring method, since each amplifier circuit 7 is arranged in a multi-layered configuration, when the frequency band exceeds 1 MHz, stray capacitance occurs between the output signal and input signal of adjacent circuits. are in a coupled state, and the input signal becomes a positive feedback due to the influence of the stray capacitance, causing oscillation or mutual interference.

Furthermore, since the patterns 15 and 18 of the power supply layer and the ground layer are independent, there is a drawback that a potential difference occurs with respect to the ground, and that external noise is mixed in and affects the circuit characteristics.

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-frequency printed circuit board wiring method that solves the above-mentioned drawbacks, has a simple configuration, and can reduce mutual interference between circuits and the effects of external noise.

Means for Solving the Problems The present invention provides a multilayer printed wiring board in which at least one circuit of high frequency amplification ports having a frequency band of 1 MHz or more is formed.
The wiring pattern of the high frequency amplification circuit is the same pattern formed on both surface layers, and arranged so that the ground is common to the entire surface ground layer formed on the inner layer having one or more layers.

Function: According to the present invention, the signal pattern of the first layer multi-formed on one surface of the printed wiring board and the signal pattern of the final layer multi-formed on the other surface of the printed wiring board are formed in the same pattern. Therefore, the component placement and grounding point of the high frequency amplification circuit with a frequency of 1 MHz or more arranged on both the surfaces of the patterns of the first layer and the final layer are matched, and the influence of stray capacitance of adjacent circuits is reduced due to the pattern shielding effect, etc. canceled out.

Furthermore, since the amplifier circuits on both surface layers are grounded in common with respect to the entire surface ground layer formed on the second layer surface and the third layer surface, the potential difference with respect to the ground is reduced and the characteristic impedance can be matched.

Furthermore, an electromagnetic shielding effect can be achieved that prevents external noise from entering and radiation from the circuit.

Example Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a wiring method for a high frequency printed circuit board in one embodiment of the present invention. It has multilayer conductors.

The components 2 and the ground pattern 3 arranged in the first layer signal pattern 1 are formed in the same pattern in parallel so that they correspond to the components 5 and the ground pattern 6 arranged in the final layer signal pattern 4. It is something that On each surface of the first layer pattern 1 and the final layer pattern 4, amplifier circuits 7 having a frequency band of 1 MHz or more are arranged in a multi-layered manner. This amplifier circuit 7 and the adjacent circuit A
(See Figure 2) Earth pattern 8.9 formed between
Due to the pattern shield effect of , it is possible to cancel the stray capacitance coupled to the input signal of the adjacent circuit A, and prevent the influence on oscillation and crosstalk.

In addition, since the respective power supply patterns 10 and 17 are formed on the first layer number pattern 1 and the final layer signal pattern 4, the second layer ground pattern 11 and the third layer ground pattern 12 can obtain an entire surface ground layer. I can do it.

In the entire ground layer, the grounding points of the amplifier circuits 7 arranged in a multi-layered manner in the first layer number pattern 1 and the final layer signal pattern 4 are all common, so they have a common impedance and the potential difference with respect to the ground is reduced. Characteristic impedance can be matched. Furthermore, an electromagnetic shielding effect can be achieved to prevent external noise from entering and radiation from the circuit.

FIG. 2 is a schematic diagram showing crosstalk in the amplifier circuit 7. Normally, when the input signal a passes through the amplifier circuit 7, an inverted output signal is obtained. However, when a stray capacitance Cx is coupled between the output signal and the input signal of the adjacent circuit A, this stray capacitance Cx As a result, a positive feedback signal is supplied to the input signal, which inverts the phase and causes oscillation. In addition, even if it does not lead to oscillation, it affects crosstalk and worsens the S/N ratio, so by providing a ground pattern 8 (9) between the amplifier circuit 7 and the adjacent circuit A, the stray capacitance Cx can be reduced by the pattern shielding effect. Can be offset.

In this example, the double-sided 30 MHz amplifier circuit 7 was tested 64 times, and as a result, stable characteristics were obtained without mutual interference between the circuits.

The present invention can be configured in various ways other than those shown in the above embodiments. For example, in the above embodiment, a four-layer printed circuit board was used, but other multilayer printed boards can be used as well.

Effects of the Invention According to the present invention, high-frequency amplification circuits are configured in the same pattern on both surfaces of a multilayer printed wiring board, and the entire ground layer serving as the inner layer is arranged so as to be common to the ground of each amplifier circuit. , stable characteristics can be obtained without mutual interference between circuits.

Furthermore, the electromagnetic shielding effect against the influence of external noise and radiation noise from the circuit eliminates the need for a commonly used shield case, which is effective in reducing the weight, size, and cost of the device.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a high-frequency printed circuit board wiring method according to an embodiment of the present invention, FIG. 2 is a schematic diagram showing crosstalk of an amplifier circuit on the same board, and FIG. 3 is a perspective view showing a conventional example. . 119. First layer pattern, 3.611. Earth pattern, 4. , , final layer signal pattern, 7. ,,Amplification circuit, 8.911. Earth pattern, 10. ,,Power pattern, 11.,,Second layer ground pattern, 12. ,,
3rd layer earth pattern.

Claims (1)

[Claims] In a multilayer printed wiring board in which at least one high frequency amplifier circuit with a frequency band of 1 MHz or more is formed,
Wiring of a high-frequency printed circuit board, characterized in that the wiring pattern of the high-frequency amplification circuit is formed in the same pattern on both surface layers, and the grounding thereof is arranged in common with a full-surface ground layer formed on an inner layer having one or more layers. Method.