Reciprocal circuit leakage electromagnetic signal single-station detection system and method based on photoconductive effect

Abstract

The invention discloses a reciprocity circuit leakage electromagnetic signal single-station detection system and method based on a photoconductive effect, and the system employs the reciprocity characteristic of a circuit as a receiving device, and measures the scattered signal of a leakage electromagnetic signal by a plasma formed by the photoconductive effect of a semiconductor material. The leakage electromagnetic vector signal measuring device comprises a light source module, a semiconductor chip, a signal receiving and transmitting module and an upper control module. According to the method, interference of a non-uniform probe on a field is avoided, a mechanical scanning mode is replaced by an optical scanning mode, the measurement efficiency is greatly improved, the reciprocity characteristic of a circuit is used as a receiving device, dependence on an additional receiving device is eliminated, and therefore the remarkable ultra-wideband measurement capacity is achieved; particularly, a brand-new ultra-wideband and super-resolution measurement means is provided for detection of leakage electromagnetic signals of a radio frequency circuit and a high-speed digital circuit which are low in frequency.

Description

Technical Field

[0001] The invention belongs to the field of electromagnetic wave measurement, and in particular relates to a single-port detection system and method for electromagnetic leakage signals of a reciprocal circuit based on the photoconductive effect. Background Art

[0002] With the continuous development of information technology, the operating frequency of electronic circuit systems continues to increase. In the design and application process of RF circuits, microwave circuits, millimeter wave chips and high-speed digital circuits used for transceiver front-ends, it is necessary to pay attention to the electromagnetic leakage signals generated by circuit components or systems in the working state. The effective detection of electromagnetic leakage signals of circuits has become an important tool in the design, production and application of high-frequency circuit chips, components and systems, and is also an important basis for electromagnetic compatibility analysis of complex electronic circuit systems.

[0003] The common practice of detecting leakage electromagnetic signals in existing circuits is to use various types of probes to convert electric fields or magnetic fields into electrical signals, and then use a mechanical scanning structure to drive the probe to scan in the area to be tested, thereby realizing the detection of leakage electromagnetic signals in a certain area on the circuit surface. Since the irregular shape of the probe itself will cause unpredictable damage and influence on the leakage electromagnetic signals on the circuit surface, this method is difficult to detect leakage signals at a distance very close to the circuit surface. On the other hand, due to the reliance on a mechanical scanning structure to measure the distribution of leakage electromagnetic signals, there are pain points such as long scanning time and low measurement efficiency, and a single measurement is usually on the order of several hours. In addition, the size of existing probes also limits the resolution of scanning measurements, making it difficult to achieve super-resolution measurements. Ultra-close-range, ultra-fast and super-resolution circuit leakage electromagnetic signal detection has become a long-awaited technology in the field.

[0004] In order to improve the measurement efficiency, a probe array can be used for measurement, such as the PCB and chip leakage electric field probe array proposed by Li Xiao Wang et al. (L. Wang, Y. Zhong, L. Chen, Z. He, J. Zhou, and QH Liu, "Radiation Diagnosis of PCBs and ICs Using Array Probes and Phaseless Inverse Source Method With a Joint Regularization," IEEE Trans. Microw. Theory Tech., vol. 70, no. 2, pp. 1442–1453, Feb. 2022), but the complex feeding system leads to high cost, and the distribution of array units limits the measurement frequency and resolution, making it difficult to achieve ultra-wideband measurement. In order to reduce the interference of the probe, specially designed conventional probes (W.Shao et al., “Simultaneous Measurement of Electric and MagneticFields With a Dual Probe for Efficient Near-Field Scanning,” IEEE Trans.Antennas Propag., vol.67, no.4, pp.2859–2864, Apr.2019) or new probes based on quantum effects (B.Yang et al., “Using Diamond Quantum Magnetometer to Characterize Near-Field Distribution of Patch Antenna,” IEEE Trans.Microw.Theory Tech., vol.67, no.6, pp.2451–2460, Jun.2019) have been proposed, but they still cannot get rid of the dependence on mechanical scanning structures, resulting in low measurement efficiency. Bai Ming and others published the patent "Light Scanning Electromagnetic Wave Amplitude and Phase Distribution Rapid Measurement Method and System" (Patent No.: ZL202110759705.1), proposing a method of using a light beam to scan and measure the distribution of electromagnetic waves on a semiconductor wafer. This measurement method can effectively improve the test efficiency, but this solution requires reliance on additional receiving devices, which limits the flexibility and bandwidth of the measurement.

[0005] Photoconductivity refers to the phenomenon that when light of a suitable wavelength is irradiated on a photosensitive semiconductor material, the semiconductor material is stimulated to generate electron-hole pairs, resulting in an increase in the conductivity of the irradiated area. From a microscopic perspective, the electron-hole pairs formed by this photoconductivity effect can be considered to constitute a special form of plasma, called photogenerated plasma. Due to the change in its conductivity, this photogenerated plasma will scatter the electromagnetic waves at the location, and then the amplitude and phase of the leakage electromagnetic field at the location can be obtained by measuring the scattered signal inversion. Considering that when the circuit is working, if the circuit itself does not contain non-reciprocal elements or structures, the circuit satisfies the reciprocity condition, and the process of leaking electromagnetic signals and the process of receiving the signal after the leakage electromagnetic signal is disturbed are reciprocal, so the circuit itself can be used as a transceiver to achieve the measurement of the surface leakage electric field. The present invention proposes a single-port detection system and method for electromagnetic leakage signals of a reciprocal circuit based on the photoconductivity effect, using the circuit itself as a single-station transceiver to receive the scattered signal of the circuit leakage electric field after the semiconductor material generates the photoconductivity effect, thereby achieving flexible and efficient detection of the circuit leakage electromagnetic signal. Summary of the invention

[0006] The main purpose of the present invention is to propose a single-port detection system and method for electromagnetic leakage signals of a reciprocal circuit based on the photoconductivity effect. The measurement system uses the scattered signal of a photogenerated plasma to measure the leakage electric field, thereby avoiding the interference of a large-size probe on the field and the limitation of the measurement resolution; the optical scanning method is used to replace the mechanical scanning structure, thereby greatly improving the measurement efficiency; no additional receiving antenna device is required, and the circuit to be tested itself is used as a transceiver of the leakage electromagnetic signal, thereby avoiding the limitation of the receiving device on the measurement bandwidth.

[0007] To achieve the purpose of the present invention, according to one aspect of the present invention, a single-port detection system for electromagnetic leakage signals of a reciprocal circuit based on the photoconductive effect is disclosed, which comprises a light source module; a semiconductor chip; a signal transceiver module; and an upper control module:

[0008] The reciprocal circuit is a circuit element or a part or the whole of a circuit system that meets the reciprocity condition and generates an electromagnetic leakage signal to be measured in a working state;

[0009] The single station means that the circuit to be tested itself serves as the source of the electromagnetic leakage signal and also as a device for receiving the electromagnetic leakage signal, without the need for an additional signal receiving device;

[0010] The light source module is used to generate and emit a light beam, and control the working state of the light source and the irradiation position of the light beam;

[0011] The semiconductor chip is located on the surface of the circuit to be tested, and is used to receive the light beam and form plasma at the position where the light beam is irradiated. The plasma can scatter the electromagnetic signal leaked from the circuit to be tested at the position where the semiconductor chip is located, and generate a scattered electromagnetic signal.

[0012] The signal transceiver module is used to generate an electromagnetic excitation signal and receive an electromagnetic response signal of the circuit to be tested;

[0013] The upper control module is connected to the light source module and the signal transceiver module, and is used to control the light source module and the signal receiving module to work together, excite plasma at a set measurement position and measure the scattered signal generated thereby, so as to measure the leakage electromagnetic signal or its distribution of the circuit to be tested.

[0014] The reciprocal circuit includes but is not limited to a transmission line, a passive circuit, an active reciprocal circuit or a system that meets the reciprocity condition. The reciprocity condition means that the process of sending and receiving signals of the circuit can be reciprocal, and the circuit itself serves as a source and receiver of leakage electromagnetic signals.

[0015] The semiconductor chip has a photoconductive effect, and after being irradiated by a light beam, plasma is formed in the irradiated area, and its shape and size can be prepared into a plane or a curved surface according to the requirements of the measurement area.

[0016] The light source module includes a light source device and a light source control device. The light source device is used to generate a light beam. The wavelength of the light source is within the wavelength range that can cause the semiconductor to produce a photoconductive effect. The form includes but is not limited to laser and visible light. The light source control device is used to control the state of the light source and the irradiation position of the light beam emitted by the light source. The light source state is not limited to the switch, on and off, power or operating frequency of the light source. The irradiation position includes but is not limited to a specified position on the semiconductor chip or a plurality of sampling positions within a specified range. The light source module includes but is not limited to a laser scanning device, a laser array or a projector. Preferably, the laser beam position is adjusted by rotating the mirror and the corresponding light path to control the laser beam path, or controlling the laser array and the units therein, or the projection module or device.

[0017] The signal transceiver module is electrically connected to a single port of the circuit to be tested, and includes a signal excitation and / or signal receiving device, which is used to provide an electromagnetic excitation signal to the circuit to be tested, and receive an electromagnetic response signal fed back to the port by the circuit to be tested, wherein the electromagnetic excitation signal is used to provide an electromagnetic source signal for the radio frequency circuit, or a high-frequency analog signal for the non-radio frequency circuit. Preferably, the signal excitation device is used to provide a working signal required by the radio frequency circuit, or a radio frequency source signal of a frequency that needs to be observed by the non-radio frequency circuit.

[0018] The upper control module can coordinately control the light source module and / or the signal transceiver module, synchronize state information and process transceiver data, and realize the excitation of the plasma at the specified position, the scattering of the leakage electromagnetic signal, the measurement of the scattered signal and the inversion of the electromagnetic signal to be measured by controlling the state of the light source and the irradiation position, as well as the excitation of the electromagnetic source signal and the reception of the electromagnetic response signal, so as to realize the detection of the distribution of the leakage electromagnetic signal at the specified position or including multiple sampling positions. Preferably, the upper control module controls the signal transceiver module to provide the electromagnetic source signal of the circuit to form the leakage electromagnetic signal of the circuit to be measured, controls the switch, power and beam irradiation position of the light source through the light source module, excites the plasma at the beam irradiation position on the semiconductor material, forms a scattered electromagnetic signal for the circuit leakage electromagnetic signal, receives the scattered electromagnetic signal through the signal transceiver module, and the upper control module uses the transceiver electromagnetic signal to invert and obtain the leakage electromagnetic signal at the location of the plasma, and the upper control module repeats the above process to complete the sampling measurement of the set measurement point within the range to be measured, and realizes the measurement of the circuit leakage electromagnetic signal within the range to be measured.

[0019] According to another aspect of the present invention, a single-station detection method for reciprocal circuit leakage electromagnetic signals based on the photoconductive effect is provided, characterized in that it comprises the following steps:

[0020] Step 1: Determine the position of the surface to be tested and the scanning area for detecting the leakage electromagnetic signal of the circuit, and place the semiconductor chip at the position of the surface to be tested;

[0021] Step 2: Set the signal transceiver module and measurement parameters through the upper control module to generate a circuit electromagnetic excitation signal;

[0022] Step 3: Set the measurement position or measurement area through the upper control module;

[0023] Step 4: Control the light source to illuminate a set position on the semiconductor wafer through the light source control module, generate plasma and scatter the leakage electromagnetic signal at the position;

[0024] Step 5: The scattered signal is received by the circuit under test itself to the signal transceiver module;

[0025] Step 6: The upper control module processes the scattered signal received by the signal transceiver module and inverts the vector value of the leakage electromagnetic signal at the beam irradiation position;

[0026] Step 7: For distribution measurements involving multiple positions, repeat steps 4-6 so that the light source beam illuminates the remaining positions in turn to obtain the vector value of the electromagnetic signal to be measured at the corresponding position, thereby obtaining the amplitude and phase distribution of the circuit leakage electromagnetic signal in the area to be measured.

[0027] Advantages of the present invention:

[0028] Compared with the existing measurement technology, the measurement system of the present invention has a simple structure. Compared with the traditional electric / magnetic probe scanning method, the dielectric properties of the semiconductor material have less interference with the field, so that ultra-close-range measurement can be achieved. The small size of the plasma probe makes this method have the potential for super-resolution measurement. The use of laser scanning instead of the mechanical scanning structure greatly improves the measurement efficiency. In the single-ended measurement method using the circuit itself as a transceiver, the measurement frequency depends entirely on the frequency range in which the circuit can work, and gets rid of the limitation of the measurement bandwidth by the additional receiving antenna. The measurement experiment using the technical example of the present invention shows that the single-station system can achieve ultra-wideband measurement from hundreds of MHz to tens of GHz, covering most of the targets to be measured in high-frequency digital circuits, radio frequency circuits, microwave circuits and millimeter wave circuits. For high-frequency digital circuits, 200MHz ultra-wideband leakage electromagnetic signal detection can be achieved. The existing circuit electromagnetic leakage signal detection technology is limited by the size of the probe and cannot achieve such low-frequency high-resolution leakage electromagnetic signal measurement. This measurement system and method effectively expands the technical boundaries of the existing electromagnetic leakage signal detection technology in low-frequency high-resolution measurement. The present invention is a fast and concise circuit leakage electromagnetic signal detection system and method with ultra-wideband, ultra-resolution and ultra-fast characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The embodiments of the present invention described in the present invention will become more clear with reference to the accompanying drawings, in which:

[0030] Figure 1 A reciprocal circuit electromagnetic leakage signal single-port detection system based on the photoconductive effect according to the first embodiment of the present invention is shown.

[0031] Specific implementation methods

[0032] Figure 1 The first embodiment of the present invention is a reciprocal circuit electromagnetic leakage signal single-port detection system based on the photoconductive effect. Figure 1 As shown, the reciprocal circuit electromagnetic leakage signal single-port detection system based on the photoconductive effect of this embodiment includes:

[0033] The reciprocal circuit 10 to be tested has an input port 11 connected to a signal transceiver module 40. The port 11 is in a single-port working mode as both an input port for radio frequency signals and a receiving port for receiving radio frequency signal changes. When the circuit has an output port, the output port is connected to a matching load. When the signal transceiver module feeds the radio frequency input signal, the components or structures 13 in the circuit are in a working state and will generate a leakage electromagnetic signal 14 in the upper space.

[0034] The semiconductor material 30 is fixed above the circuit to be tested, and the upper control module 50 controls the light source module 20 to generate and control the light beam to irradiate the specified point in the set scanning area 22 on the semiconductor material. The semiconductor material generates a photoconductive effect at this position and forms a plasma 31, and the plasma 31 scatters the circuit leakage electromagnetic signal 14 to form an electromagnetic scattering signal 15. Since the circuit is a reciprocal circuit, the scattered signal 15 is received by the circuit itself and transmitted to the input port 11, and then can be received by the signal transceiver module 40. By analyzing the ratio of the received signal to the output signal of the signal transceiver module, that is, the signal reflection coefficient of the port 11, the amplitude and phase of the leakage electromagnetic field at the irradiation point can be inverted.

[0035] The upper control module 50 coordinates the control of the light source 20 and the signal transceiver module 40, repeats the above process, realizes the beam scanning irradiation and signal measurement of the remaining points on the set scanning trajectory 22, and obtains the amplitude and phase of the leakage electromagnetic signal of all scanning sampling points in the test area.

[0036] The semiconductor material is fixed in the electromagnetic field region to be measured. Preferably, it is an n-type doped gallium arsenide semiconductor material. Preferably, a sheet-like semiconductor material is used. Compared with a probe with a protruding structure, the interference of the sheet-like semiconductor material on the relative distribution characteristics of the unknown electromagnetic field plane can be ignored, thereby ensuring more accurate measurement.

[0037] The light source module includes a light source device and a beam control device to realize the generation of a light beam and to flexibly irradiate a set position on the semiconductor material. Preferably, the light source device can select a laser or a visible light source, and the beam control device can control the laser beam path by rotating a mirror and a corresponding light path, or adopt a laser array and its unit control, or a projection module or device to adjust the laser beam position.

[0038] In particular, Figure 1 The reciprocal circuit to be tested shown may be a passive circuit, an active reciprocal circuit or a part of an active circuit that meets the reciprocity condition, and may be a separate circuit element, a radio frequency microwave circuit, a high frequency digital circuit or a circuit system.

[0039] In particular, Figure 1 The signal transceiver module shown may adopt an integrated transceiver device such as a vector network analyzer, or an independent transceiver device such as a signal source or a spectrum analyzer, or a separately designed signal transceiver link.

[0040] In particular, Figure 1 The shape and size of the semiconductor chip include but are not limited to a plane, and can be designed as a plane of different sizes, a cylinder, a sphere or other shapes as needed. The positional relationship between the semiconductor chip and the circuit to be tested includes but is not limited to parallel, vertical or at a certain angle.

[0041] In particular, Figure 1 The beam irradiation direction shown is not limited to the angle or direction shown in the figure, and the positions of the circuit to be tested, the semiconductor chip, the light source module, the signal transceiver module and the upper control module include but are not limited to the positions shown in the figure.

Claims

1. A single-station detection system for reciprocal circuit leakage electromagnetic signals based on photoconductive effect, characterized in that: Contains light source module; semiconductor chip; signal transceiver module; upper control module: The reciprocal circuit is a circuit element or a part or the whole of a circuit system that meets the reciprocity condition and generates an electromagnetic leakage signal to be measured in a working state; The single station means that the circuit to be tested itself serves as the source of the electromagnetic leakage signal and also as a device for receiving the electromagnetic leakage signal, without the need for an additional signal receiving device; The light source module is used to generate and emit a light beam, and control the working state of the light source and the irradiation position of the light beam; The semiconductor chip is located on the surface of the circuit to be tested, and is used to receive the light beam and form plasma at the position where the light beam is irradiated. The plasma can scatter the electromagnetic signal leaked from the circuit to be tested at the position where the semiconductor chip is located, and generate a scattered electromagnetic signal. The signal transceiver module is used to generate an electromagnetic excitation signal and receive an electromagnetic response signal of the circuit to be tested; The upper control module is connected to the light source module and the signal transceiver module, and is used to control the light source module and the signal receiving module to work together, excite plasma at a set measurement position and measure the scattered signal generated thereby, so as to measure the leakage electromagnetic signal or its distribution of the circuit to be tested.

2. A single-station detection system for reciprocal circuit leakage electromagnetic signals based on photoconductive effect as claimed in claim 1, characterized in that: The reciprocal circuit includes but is not limited to a transmission line, a passive circuit, an active reciprocal circuit or a system that meets the reciprocity condition. The reciprocity condition means that the process of sending and receiving signals of the circuit can be reciprocal, and the circuit itself serves as a source and receiver of leakage electromagnetic signals.

3. A single-station detection system for reciprocal circuit leakage electromagnetic signals based on photoconductive effect as claimed in claim 1, characterized in that: The semiconductor chip has a photoconductive effect, and after being irradiated by a light beam, plasma is formed in the irradiated area, and its shape and size can be prepared into a plane or a curved surface according to the requirements of the measurement area.

4. A single-station detection system for reciprocal circuit leakage electromagnetic signals based on photoconductive effect as claimed in claim 1, characterized in that: The light source module includes a light source device and a light source control device. The light source device is used to generate a light beam. The wavelength of the light source is within the wavelength range that can cause the semiconductor to produce a photoconductive effect, and the form includes but is not limited to laser and visible light. The light source control device is used to control the light source state and the irradiation position of the light beam emitted by the light source. The light source state is not limited to the switch, on and off, power or operating frequency of the light source. The irradiation position is not limited to a specified position on a semiconductor chip or a plurality of sampling positions within a specified range. The light source module is not limited to a laser scanning device, a laser array or a projector.

5. The single-station detection system for reciprocal circuit leakage electromagnetic signals based on photoconductive effect as claimed in claim 1, characterized in that: The signal transceiver module is electrically connected to a single port of the circuit to be tested, and includes a signal excitation and / or signal receiving device, which is used to provide an electromagnetic excitation signal to the circuit to be tested and receive an electromagnetic response signal fed back to the port by the circuit to be tested. The electromagnetic excitation signal is used to provide an electromagnetic source signal for the radio frequency circuit, or a high-frequency analog signal for the non-radio frequency circuit.

6. A single-station detection system for reciprocal circuit leakage electromagnetic signals based on photoconductive effect as claimed in claim 1, characterized in that: The upper control module can coordinately control the light source module and / or the signal transceiver module, synchronize state information and process transceiver data, and realize the excitation of plasma at a specified position, the scattering of leakage electromagnetic signals, the measurement of scattered signals and the inversion of electromagnetic signals to be measured by controlling the state of the light source and the irradiation position, as well as the excitation of electromagnetic source signals and the reception of electromagnetic response signals, thereby realizing the detection of the distribution of leakage electromagnetic signals at a specified position or including multiple sampling positions.

7. A single-station detection method for reciprocal circuit leakage electromagnetic signal based on photoconductivity effect, characterized in that: The following steps are involved: Step 1: Determine the position of the surface to be tested and the scanning area for detecting the leakage electromagnetic signal of the circuit, and place the semiconductor chip at the position of the surface to be tested; Step 2: Set the signal transceiver module and measurement parameters through the upper control module to generate a circuit electromagnetic excitation signal; Step 3: Set the measurement position or measurement area through the upper control module; Step 4: Control the light source to illuminate a set position on the semiconductor wafer through the light source control module, generate plasma and scatter the leakage electromagnetic signal at the position; Step 5: The scattered signal is received by the circuit under test itself to the signal transceiver module; Step 6: The upper control module processes the scattered signal received by the signal transceiver module and inverts the vector value of the leakage electromagnetic signal at the beam irradiation position; Step 7: For distribution measurements involving multiple positions, repeat steps 4-6 so that the light source beam illuminates the remaining positions in turn to obtain the vector value of the electromagnetic signal to be measured at the corresponding position, thereby obtaining the amplitude and phase distribution of the circuit leakage electromagnetic signal in the area to be measured.

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