Noise injection apparatus for printed circuit board

Abstract

A noise injection apparatus for injecting noise to a printed circuit board is disclosed that includes a signal generator that generates noise, a coaxial cable having one end connected to an output of the signal generator, and a probe that is connected to another end of the coaxial cable and is configured to convey the noise generated by the signal generator to a power supply and a ground pin of a device element of the printed circuit board via the coaxial cable.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG.1 is a diagram showing a configuration of a noise injection apparatus according to a first embodiment of the present invention;

FIG. 2 is a diagram showing a configuration of a noise injection apparatus according to a second embodiment of the present invention;

FIG. 3 is a diagrams illustrating impedance matching performed at the noise injection apparatus according to the second embodiment;

FIG. 4 is a diagram showing a configuration of an impedance matching unit of the noise injection apparatus according to the second embodiment;

FIG. 5 is a circuit diagram of the impedance matching unit;

FIG. 6 is a diagram showing a configuration of a noise injection apparatus according to a third embodiment of the present invention;

FIG. 7 is an external perspective view of a Type-A miniature oscillator that is used in a noise injection apparatus according to a fourth embodiment of the present invention;

FIG. 8 is an internal perspective view of the Type-A miniature oscillator;

FIG. 9 is a circuit diagram of an oscillating circuit of the Type-A miniature oscillator;

FIG. 10 is a diagram showing a configuration of a noise injection apparatus according to the fourth embodiment;

FIG. 11 is a diagram showing a configuration of a low-output buffer circuit that is used in a noise injection apparatus according to a fifth embodiment of the present invention;

FIG. 12 is an external perspective view of a Type-B miniature oscillator that is used in the noise injection apparatus according to the fifth embodiment;

FIG. 13 is an internal perspective view of the Type-B miniature oscillator;

FIG. 14 is a circuit diagram of the low-output buffer circuit;

FIG. 15 is a diagram showing a configuration of the noise injection apparatus according to the fifth embodiment;

FIG. 16 is a flowchart illustrating process steps for performing magnetic near-field measurement on a printed circuit board; and

FIG. 17 is a diagram illustrating a noise visualization system for measuring the magnetic near-field of a noise-injected printed circuit board.

Claims

1. A noise injection apparatus that injects noise to a printed circuit board, the apparatus comprising: a signal generator that generates noise;a coaxial cable having one end connected to an output of the signal generator; anda probe that is connected to another end of the coaxial cable and is configured to convey the noise generated by the signal generator to a power supply and a ground pin of a device element of the printed circuit board via the coaxial cable.

2. The noise injection apparatus as claimed in claim 1, wherein the probe is a semi-rigid cable that includes an SMA connector.

3. A noise injection apparatus that injects noise to a printed circuit board, the apparatus comprising: a signal generator that generates noise;a coaxial cable having one end connected to the signal generator; andan impedance matching unit that is connected to another end of the coaxial cable and is configured to convey the noise generated by the signal generator to a power supply and a ground pin of a device element of the printed circuit board via the coaxial cable.

4. The noise injection apparatus as claimed in claim 3, wherein the impedance matching unit includes an SMA connector that is connected to the coaxial cable, a matching circuit that matches an impedance of the signal generator to an impedance of the printed circuit board, a copper substrate on which one or more circuit components including the matching circuit are mounted, a ground connecting copper plate member that is connected to the ground pin of the printed circuit board, and a wire that is connected to the power supply of the printed circuit board.

5. The noise injection apparatus as claimed in claim 4, wherein the matching circuit includes a first capacitor, a second capacitor, a resistor, a first inductor, and a second inductor;the first capacitor has one end connected to a signal output of the signal generator and another end connected to one end of the second capacitor and one end of the resistor;the resistor has another end connected to one end of the first inductor and one end of the second inductor; andthe second capacitor and the second inductor each have another end connected to ground.

6. A noise injection apparatus that injects noise to a printed circuit board, the apparatus comprising: a printed circuit board support member that fastens the printed circuit board in place;a probe including an SMA connector; anda probe support member that fastens the probe such that the SMA connector of the probe is positioned perpendicular to a measuring surface of the printed circuit board.

7. A noise injection apparatus that injects noise to a printed circuit board, the apparatus comprising: an oscillator unit that includes an oscillating circuit that uses a band pass filter to output a sine wave signal, the oscillating circuit including an oscillator that outputs a signal at a given frequency, a coil that removes spurious components included in the output of the oscillator, a substrate on which circuit components including the oscillator and the coil are mounted, a battery for operating the circuit components, and a probe connecting SBA connector.

8. The noise injection apparatus as claimed in claim 7, wherein the band pass filter includes a first tuned circuit having a first inductor and a first capacitor, a second capacitor, and a second tuned circuit having a second inductor and a third capacitor;the oscillator outputs a rectangular wave signal at the given frequency;the first tuned circuit removes spurious components included in the output of the oscillator and passes a resulting output to the second tuned circuit via the second capacitor; andthe second tuned circuit secures bandwidth and attenuation of the resulting output from the first tuned circuit and outputs a signal at the given frequency to the printed circuit board via the probe connecting SMA connector.

9. A noise injection apparatus that injects noise to a printed circuit board, the apparatus comprising: a dedicated fastener that fastens the printed circuit board in place;an oscillator unit that is placed under the printed circuit board; anda base that places the oscillator unit under the printed circuit board.

10. The noise injection apparatus as claimed in claim 9, wherein the oscillator unit is directly attached to the printed circuit board without using the base.

11. A noise injection apparatus that injects noise to a printed circuit board, the apparatus comprising: an oscillator unit that includes an oscillator that outputs a signal at a given frequency, a buffer circuit having a plurality of inverters that are connected in parallel, a substrate on which circuit components including the oscillator and the buffer circuit are mounted, a battery for operating the circuit components, and a signal output wire that is connected to the printed circuit board.

12. The noise injection apparatus as claimed in claim 11, further comprising: a dedicated fastener for fastening the printed circuit board in place; anda base that places the oscillator unit under the printed circuit board.

13. The noise injection apparatus as claimed in claim 11, wherein the signal output wire is soldered to a power supply and ground of a device element of the printed circuit board.