Radar sensor device and method for a motor vehicle

Abstract

The present invention relates to a radar sensor device (2) for a motor vehicle (1), comprising at least: - a central electronic computing device (3) configured to generate an electrical control signal (7) for a transmitting device (4); - a laser device (8) generating an optical transmission signal (9) for transmission to the transmitting device (4) based on the electrical control signal (7); - a conversion device (6) having at least one first optical ring resonator (10) generating a pulse sequence (11) based on the optical transmission signal (9), wherein the conversion device (6) is configured to generate an electrical transmission signal (12) based on the pulse sequence (11); - a transmitting device (4) configured to transmit the electrical transmission signal (12); and - a receiving device (5) for receiving an electrical reception signal (14) and for transmitting the electrical reception signal (14) to the central electronic computing device (3). Furthermore, the present invention relates to a method.

Description

Technical Field

[0001] The present invention relates to a radar sensor device for a motor vehicle and a method for operating such a radar sensor device. Background Technology

[0002] Radar sensor devices for motor vehicles are already known from motor vehicle manufacturing. In particular, such radar sensor devices are used in, for example, at least partially autonomous motor vehicles, but especially in fully autonomous motor vehicles. However, reliable environmental perception is essential for achieving such automated driving. Here, the surrounding environment, or environment, is detected by means of sensors such as radar, lidar, and cameras. Of particular importance is the overall 360-degree three-dimensional detection of the environment, enabling the detection of all static and dynamic objects. Lidar plays a major role in redundant and stable environmental detection, especially because this type of sensor accurately measures distances and can also be used for classification. However, lidar sensors are costly and structurally complex. 360-degree three-dimensional environmental detection is particularly problematic because it either requires multiple smaller individual sensors (which typically operate using multiple individual light sources and detector elements) to ensure environmental detection, or the installation of large lidar sensors. Furthermore, lidar sensors are susceptible to weather conditions such as rain, fog, or direct sunlight.

[0003] Radar sensors, or radar sensor devices, are also established in vehicle manufacturing and provide reliable, fail-safe data in all weather conditions. Even poor visibility conditions (such as rain, fog, snow, dust, or darkness) have little impact on their perception reliability. However, the resolution capability is currently limited by existing technology, especially in series radars in use which are configured to have a resolution of only about 7 degrees. To meet the requirements of higher levels of automation in the manufacturing of vehicles with safe driving functions, radar sensor devices are configured to provide high-resolution three-dimensional images with a range of 0.1 degrees and high insensitivity to interference from their environment. This cannot be achieved using conventional radar technology according to existing technology because the resolution capability of such systems is too low.

[0004] Furthermore, photonic radar sensor devices are already known, which achieve improved resolution by co-integrating electronic and photonic components at a single semiconductor point. Here, the tracking of the FMCW signal and all signal processing and evaluation are performed by a central station. Each transmitting and receiving module has an electronic-photonic co-integrated chip, the so-called Epic chip. Silicon photonics technology is applied for co-integration. This technology enables the monolithic integration of photonic components, high-frequency electronic equipment, and digital electronic equipment onto a single chip. The technological innovation of this system lies in the transmission of gigahertz signals using optical carrier signals in the terahertz frequency range. The central station, also known as a central electronic computing device, generates an optical carrier frequency within the terahertz range. The signal to be transmitted, having one-eighth of the radar frequency, is modulated onto this carrier frequency and transmitted optically to the antenna chip. The frequency is multiplied by eight on the antenna chip, allowing the antenna chip to emit radar rays. Signal detection occurs along the opposite path. All data is processed at the central station. However, this implementation is very costly in terms of implementing gigahertz electronic equipment at the chip level. In particular, the frequency quadrupling on the chip after photodiode detection is technically extremely challenging and expensive in generating gigahertz signals with a high signal-to-noise ratio and as low a jitter as possible. This necessitates costly stabilization of the gigahertz signal in other steps. Furthermore, gigahertz electronics are cost-intensive. Additionally, high power requirements are placed on the optical carrier, especially the laser, as high optical power is needed to generate high-precision gigahertz signals, making it difficult to implement a uniquely phased loop for radar arrays with multiple distributed radar-semiconductor chips. Moreover, the need for two separate photonics-electronics semiconductor chips for the respective transmit and receive channels further increases costs.

[0005] US 8,805,130 B2 discloses an integrated electro-optic structure, a modulator and switch, and a method for manufacturing the same. In an illustrative embodiment, the device includes a matrix having a waveguide and an optical resonator, the resonator comprising polycrystalline silicon disposed on the matrix. Regions of first and second doped semiconductors also comprise polycrystalline silicon and are disposed near the first optical resonator. The first optical resonator is communicatively coupled to the waveguide.

[0006] US 7,324,267 B2 discloses a wavelength converter device for generating a frequency-converted ray through the interaction between at least one signal ray having a frequency and at least one pump ray having a frequency, the wavelength converter device comprising: an input for at least one signal ray having a frequency; a pump source for generating at least one pump ray having a frequency; an output for extracting the frequency-converted ray; and a structure for transmitting the signal ray, the structure comprising two optical resonators made of nonlinear material, the optical resonators having an optical length of at least 40 times Lambda / 2, wherein Lambda is the wavelength of the pump ray, and the optical resonators resonate at the pump frequency, the signal frequency, and the conversion frequency, wherein the pump and signal rays generate the converted ray by propagating through the structure through a nonlinear interaction within the optical resonators.

[0007] In order to use not only photonic or optical components but also electronic circuit components, US 7,634,201 B2 discloses an adjustable receiver and a technique for receiving oscillating signals of electrons in the HF spectral range, microwave spectral range or millimeter spectral range based on photonic technology. Summary of the Invention

[0008] The purpose of this invention is to provide a radar sensor device and a method by means of which improved environmental detection can be achieved.

[0009] This objective is achieved by the radar sensor device and method according to the invention. Advantageous design options are given in the specification.

[0010] One aspect of the invention relates to a radar sensor device for a motor vehicle, wherein the motor vehicle can be configured to be, in particular, at least partially autonomous, and in particular, fully autonomous. The radar sensor device has a central electronic computing device configured to generate electrical control signals for a transmitting device of the radar sensor device. Furthermore, the radar sensor device includes a laser device that generates optical transmission signals for transmission to the transmitting device based on the electrical control signals.

[0011] The radar sensor device includes a conversion device having at least one first optical ring resonator, which may be configured as a micro-ring resonator, to generate a pulse sequence based on an optical transmission signal. The conversion device is additionally configured to generate an electrical transmission signal for a transmitting device based on this pulse sequence. The transmitting device is configured to transmit the electrical transmission signal to the environment of the vehicle. Furthermore, the radar sensor device includes a receiving device for receiving an electrical reception signal corresponding to the electrical transmission signal and reflected in the environment, and for transmitting the electrical reception signal to a central electronic computing device.

[0012] Therefore, the radar sensor device according to the invention particularly solves the problem that a standard telecommunications laser can be used in the radar sensor device. In particular, this eliminates the need for the costly and expensive design of a gigahertz circuit with an optical carrier for frequency conversion of RF signals. After conversion from the terahertz spectral range, the gigahertz signal is stabilized. This reduces the chip area compared to conventional electronic devices. Thus, the conversion device particularly replaces the one or more Epic chips. The conversion device can also be referred to as a chip. In particular, the loop can be implemented very simply, where the high quality factor of the optical ring resonator results in low power requirements for the laser, thereby compensating for coupling losses, and multiple chips can be operated using a single source. The gigahertz signal is particularly inherent and stable. Furthermore, the transmitting and receiving devices can be integrated on a single semiconductor chip, such as in CMOS, SiN-CMOS, Bi-CMOS, or composite Bi-CMOS, or can be integrated on a photonics-electronics co-integrated chip using processing.

[0013] Therefore, this invention utilizes, in particular, the rays of a laser device, which can also be configured as a CW laser, coupled into a photonic semiconductor via an optical interface. These rays propagate within a linear waveguide structure located in the semiconductor. On this semiconductor, another annular waveguide structure is arranged at a very small distance relative to the linear waveguide structure. If the distance between the two waveguides is so small that the evanescent electromagnetic ray field extends from the linear waveguide into the annular conductor, the ray is coupled from the linear waveguide into the annular conductor, where it propagates. If the optical path length of the annular conductor is chosen such that it is an integer multiple of the wavelength, the light propagating in the annular conductor structurally interferes with the coupled evanescent field after one cycle, and reinforcement occurs. Since the interaction region between the linear and annular waveguides is within the wavelength range, the interaction of the two fields is only short-lived, resulting only in structural interference. This forms an optical annular resonator. When losses occur, more laser rays are incorporated into the annular conductor until power saturation occurs within the resonator. After each cycle is fully completed, a portion of the light propagating within the ring waveguide is decoupled again in the linear waveguide and can be used as a signal. Amplification of the light is achieved through a ring resonator, with appropriate selection of the waveguide diameter and coupling ratio, thereby forming a pulse with high peak intensity from the CW input signal. In semiconductors, the diameter of the optical ring resonator ranges from several hundred micrometers to several micrometers. Here, the period time of the light determines the repetition rate f of the output signal or pulse sequence. rep .

[0014] The ring resonator constructed in this way has a strength greater than 10. 6 The high quality factor Q within the resonator results in peak intensities capable of driving nonlinear optical processes (so-called multiphoton processes). These optical processes occur during high-intensity light-matter interactions. Here, the expansion of the polarization P is an established model used to describe multiphoton processes in light-matter interactions.

[0015]

[0016] Where P describes polarization, X describes sensitivity, and E describes the electric field, and Describes the electrical constant.

[0017] When it has electrosensitivity X (1) When a linear term is linearly amplified by an electric field, a higher-order term X with n greater than 1 is formed. (n) The scaling factor is nonlinear with respect to the electric field. This process is called a multiphoton process. Here, the required number of photons is magnified by X. (n)The order n. For example, the effects of frequency doubling or summing, and generating frequency differences, require two photons to produce photons of the corresponding frequency of the fundamental light frequency, thereby inducing a second-order nonlinearity in the matter. Third-order effects, such as frequency tripling, require three photons for third-order frequency conversion, and so on. This nonlinear light-matter interaction provides the possibility of nonlinearly modulating the incident light source.

[0018] Therefore, the nonlinear refractive coefficient cannot be ignored in optical ring resonators when fully coupled into the ring. Thus, due to the Kerr effect, especially at sensitivity X... (2) At high peak intensity, a four-wave mixing process occurs during the interaction between the light and the waveguide. This process initially declines as the intensity within the resonator ring continues to increase. Specifically, the two photons Y of the CW laser... P The electron is absorbed, specifically through what is known as optical pumping, and is raised to a virtual or real, higher energy level. After a short time, the electron returns to its base state, primarily in an excited manner. At this point, the electron is in the form of a signal and an inert sideband photon (Y). S Or Y I The absorbed energy is radiated in the form of a photon, which is only consistent with the energy of two photons from the CW laser in the sum of the photon energies. This generates a new spectral fraction within the ring resonator. The signal and inert sideband photons are correlated in phase, amplitude, and frequency through associated generation processes. This is achieved by increasing the amount of photons from the Y... P To Y S Or Y I The frequency shift causes the ring resonator to become bistable, resulting in slight changes in phase and frequency, which in turn generate new sidebands. A non-decaying four-wave mixing process begins and cascades new frequencies. The newly generated frequencies are in fixed phase and frequency relationships with each other, and the spectral modes couple accordingly. By initiating mode coupling, a fundamental soliton is generated, forming a pulse with a high spectral bandwidth that propagates in the ring resonator without dispersion and at its resonant frequency f. rep Replication. This generates a pulsed signal from the CW laser signal, characterized by an extremely high signal-to-noise ratio and minimal variation over time.

[0019] To generate pulse states, other complex waveguide structures can be applied. For example, a second waveguide on an opposite side of the ring resonator can be used for decoupling the pulse sequence. Furthermore, other resonant rings with coupling points can be used for further coupling between the ring resonators, which enables continuous adjustment of f. rep The corresponding frequency range. For example, a ring assembly can produce frequencies with f for values ​​of R = 15 micrometers and R = 5 micrometers.rep = A 100 MHz pulse.

[0020] According to an advantageous design, the conversion device has an optical coupling element configured to couple an optical transmission signal into an optical ring resonator. This allows, in particular, optical transmission signals generated by means of a laser device to be coupled into a semiconductor chip on which the optical ring resonator is constructed.

[0021] Furthermore, it is advantageous that the conversion device has an optical photodiode for generating a transmission signal based on a pulse sequence. This allows the optical pulse sequence to be transmitted to the diode, which in turn converts the optical pulse sequence into an electrical transmission signal. In particular, the pulse sequence can be further output to a power amplifier, which then transmits the signal via a transmitting device.

[0022] In another advantageous design, the transmitting and receiving devices are constructed as a single component. Specifically, the transmitting and receiving antennas are built on a common chip, forming a single unit. This allows a single chip to perform both functions, significantly reducing costs. Furthermore, by fine-tuning the laser frequency emitted by the laser device, excessive optical coupling into the optical ring resonator and mode coupling can be prevented. Consequently, pulsed signals cannot be generated in the transmitting channel of the transmitting device. In this case, the chip functions as the receiving channel. Thus, a single chip can fulfill both functions, reducing additional costs and minimizing the number of components.

[0023] Also advantageously, the conversion device has at least one additional optical ring resonator configured differently from the first optical ring resonator, wherein pulse sequences are generated depending on both the first and additional optical ring resonators. By utilizing the additional ring resonator, a frequency range f for pulse sequences in the megahertz range can be generated accordingly. rep Therefore, for example, using a value of R = 15 micrometers for the first optical ring resonator and a value of R = 5 micrometers for the other optical ring resonator, it is possible to generate a value with f rep = A pulse with a frequency of 100 MHz.

[0024] Furthermore, it has proven advantageous that the conversion device has a heterodyne detection device or a homodyne detection device for generating the transmitted signal. This allows, in particular, the frequency comb to be used to synthesize a gigahertz frequency ramp. For this purpose, the homodyne detection device or heterodyne detection device is implemented on the electro-photonic chip, and thus, particularly on the conversion device. Optical heterodyne detection is preferably performed.

[0025] Furthermore, it is advantageous that the conversion device has at least one dispersive element configured to generate at least one frequency chirp based on the pulse sequence. This frequency comb or chirp can then be used to synthesize a gigahertz frequency ramp. Now, if the finite Fourier pulse sequence propagates through a dispersive medium (e.g., air), the high-frequency spectral components experience a greater time delay than the low-frequency spectral components. This causes the pulse sequence to chirp positively and thus extends it temporally. Furthermore, the peak intensity of the pulse sequence decreases. For example, a decoupled waveguide can be used as the dispersive element. It is particularly advantageous here for an isolated wave with a non-dispersive basis to propagate in a ring conductor.

[0026] According to another advantageous design, the conversion device has at least one second optical ring resonator, wherein a second pulse sequence different from the original pulse sequence is generated by means of the second optical ring resonator, and a heterodyne detection device of the conversion device generates a frequency chirp based on the pulse sequence and the second pulse sequence. This allows for the construction of a photonic-electronic co-integrated radar chip, particularly by means of two defined frequency combs and dispersive elements. The frequency comb is generated by two different ring resonators. By dispersing, the frequency chirp is applied to a single pulse, and the two signals are measured by means of a heterodyne detection device. The resulting frequency forms a ramp in the gigahertz spectral range.

[0027] Furthermore, it has proven advantageous that the conversion device possesses at least two nanoantennas on a semiconductor dielectric for generating a transmitted signal based on a pulse sequence. In particular, the pulse repetition rate is thus detected by means of nanoantennas located on a dielectric or semiconductor. These metallic antennas, with dimensions ranging from a few micrometers to nanometers, are particularly positioned apart from each other by the wavelength of the incident light. If a ray emitted by an optical ring resonator reaches the nanoantenna, it excites plasma resonance or induces surface plasma polarization that vibrates at the frequency of the incident light wave by the wavelength distance between the nanoantennas. This frequency oscillation can be directly measured electronically and can be used as a driving signal for a gigahertz antenna.

[0028] Another aspect of the invention relates to a motor vehicle having a radar sensor device according to the foregoing aspects. The motor vehicle is particularly configured to operate at least partially autonomously, and more particularly to operate fully autonomously.

[0029] Another aspect of the invention relates to a method for operating a radar sensor device according to the foregoing aspects. An electrical control signal for a transmitting device of the radar sensor device is generated by means of a central electronic computing device of the radar sensor device. An optical transmission signal is generated based on the electrical control signal and transmitted to the transmitting device by means of a laser device of the radar sensor device. A pulse sequence is generated based on the optical transmission signal by means of a conversion device of the radar sensor device having at least one first optical ring resonator, wherein, additionally, an electrical transmission signal is generated for the transmitting device based on the pulse sequence by means of the conversion device. Furthermore, the electrical transmission signal is transmitted to the environment of the motor vehicle by means of the transmitting device. An electrical reception signal corresponding to the electrical transmission signal and reflected in the environment is received by means of a receiving device of the radar sensor device, and the electrical reception signal is transmitted to the central electronic computing device by means of the receiving device. Furthermore, in particular, the received signal is then evaluated within the central electronic computing device.

[0030] The advantageous design of the radar sensor device should be considered as an advantageous design of the vehicle and the method. The radar sensor device and the vehicle possess specific characteristics that enable the implementation of the advantageous design of the method or approach.

[0031] The present invention also includes improvements to the motor vehicle and the method according to the invention, which have features already described in conjunction with improvements to the radar sensor device according to the invention. For this reason, corresponding improvements to the motor vehicle and the method according to the invention will not be described again herein.

[0032] The present invention also includes combinations of features of the described embodiments. Attached Figure Description

[0033] The embodiments of the present invention will now be described. Wherein:

[0034] Figure 1 A schematic diagram illustrating an embodiment of a motor vehicle equipped with a radar sensor device is shown.

[0035] Figure 2 A schematic block diagram illustrating an embodiment of a conversion device for a radar sensor apparatus is shown.

[0036] Figure 3 Another schematic block diagram of another embodiment of the conversion device of the radar sensor device is shown;

[0037] Figure 4 Another schematic block diagram illustrating an embodiment of the conversion device for a radar sensor apparatus is shown; and

[0038] Figure 5Another schematic block diagram illustrating an embodiment of a conversion device for a radar sensor apparatus is shown. Detailed Implementation

[0039] The embodiments explained below are preferred embodiments of the invention. In the embodiments, the described components represent individual, independent features of the invention, which also independently improve the invention, and thus should be considered individually or in combination with the examples shown as part of the invention. Furthermore, the described embodiments may be supplemented by other features of the invention already described.

[0040] Components with the same function in the figure are given the same reference numerals.

[0041] Figure 1 A schematic top view of an embodiment of a motor vehicle 1 having a radar sensor device 2 is shown. The radar sensor device 2 includes at least one central electronic computing device 3, a transmitting device 4, and a receiving device 5. Furthermore, the radar sensor device 2 has... Figure 1 Conversion device 6 (not shown) Figure 2 ).

[0042] The radar sensor device 2 includes a central electronic computing device 3 configured to generate an electrical control signal 7 for a transmitting device 4. A laser device 8 is also provided, which generates an optical transmission signal 9 for transmission to the transmitting device 4 based on the electrical control signal 7. The conversion device 6 includes at least one optical ring resonator 10. Figure 2 The ring resonator generates a pulse sequence 11 based on the optical transmission signal 9. Figure 2 The conversion device 6 is additionally configured to generate an electrical transmission signal 12 for the transmitting device 4 according to the pulse sequence 11. Figure 2 The transmitting device 4 is configured to transmit the electrical transmitting signal 12 into the environment 13 of the vehicle 11. The receiving device 5 is configured to receive a received signal 14 corresponding to the electrical transmitting signal 12, wherein the received signal 14 is reflected in the environment 13, for example, at the object 15. Furthermore, the receiving device 5 transmits the electrical received signal 14 to the central electronic computing device 3.

[0043] Here, the generation of the FMCW signal and all signal processing and evaluation are performed by the central electronic computing device 3. The transmitting device 4 and receiving device 5 can each be individually composed of electro-photonic related chips. In particular, there is a technically feasible solution where gigahertz signal transmission (in particular, corresponding to the transmission signal 9) is performed using an optical carrier signal in the terahertz frequency range. Here, the central electronic computing device 3 generates the optical carrier frequency. The signal to be transmitted, having 1 / 8 of the radar frequency, is modulated onto this carrier frequency (shown by box 37) and transmitted to the transmitting device 4 via the optical phase 16. Frequency multiplication by eight times is performed on the optical phase, allowing the transmitting device 4 to emit radar beams. Signal detection occurs along the opposite path. All data is processed on the central electronic computing device 3.

[0044] Figure 2 A schematic block diagram illustrating an embodiment of the conversion device 6 is shown. The transmission signal 9 is coupled in via an optical coupling element 17. The optical coupling element 17 is already located on the semiconductor 18. Furthermore, a radio frequency driver 19, an optical modulator 20, and another optical coupling element 21 are constructed on the semiconductor 18. Figure 2 As shown, photodiode 22 and power amplifier 23 are constructed on semiconductor 18.

[0045] Especially Figure 2 As shown, by appropriately selecting the geometry of the optical ring resonator 10, a pulse repetition rate f of, for example, 76 GHz can be generated. rep The pulse sequence 11 can be detected by the photodiode 22 on the semiconductor 18 and directly transmitted to the transmitting device 4 via the power amplifier 23, because the photocurrent and f rep Proportional. Advantageously, this reduces the need for other expensive and design-intensive gigahertz electronic devices. Because the optical ring resonator 10 has extremely low power consumption of 1 microwatt, the transmission signal 9 can continue to be guided and, for example, a ring arrangement for radar chips can be implemented. Furthermore, the received signal 14 can be modulated back into the transmission signal 9 by means of an optical modulator 20.

[0046] thus Figure 2 In particular, a schematic diagram of a photonic-electronic radar chip with an optical ring resonator 10 is shown. The pulse sequence 11 is directly detected by the photodiode 22. Here, the photocurrent is related to f rep The signal is proportional and can be directly output as a drive signal to the power amplifier 23, which transmits the output signal 12 through the transmitting device 4. The received signal 14 is mixed into the initial transmission signal 9 by the optical modulator 20 and continues to be transmitted to the central electronic computing device 3 for data processing.

[0047] Figure 3 Another illustrative embodiment of the conversion device 6 is shown. In particular, the transmitting device 4 and the receiving device 5 are constructed as a common component, which is thus constructed as a single chip. The same conversion device 6 is thus used for both the transmitting device 4 and the receiving device 5. By fine-tuning the laser frequency of the transmission signal 9, excessive optical coupling into the optical ring resonator 10 and mode coupling are prevented. Therefore, no pulsed signal is generated in the receiving channel. In this case, the conversion device 6 operates as the receiving channel. Thus, a single chip can fulfill both functions, reducing additional costs.

[0048] Figure 4 Another schematic block diagram of another embodiment of the conversion device 6 is shown. In particular, as shown in the following embodiments, the conversion device 6 may have a second optical ring resonator 24, by means of which a second pulse sequence 25 different from the pulse sequence 11 is generated, wherein a frequency chirp 27 may be generated by means of the heterodyne detection device 26 of the conversion device 6 based on the pulse sequence 11 and the second pulse sequence 25. Specifically, for this purpose, the conversion device 6 has at least one dispersive element 28 configured to generate at least one frequency chirp 27 based on the pulse sequence 11 and / or the second pulse sequence 25. Alternatively to the heterodyne detection device 26, the conversion device 6 may also have a homodyne detection device for generating the transmitted signal 12.

[0049] also Figure 4 As shown, the conversion device 6 may have at least one additional optical ring resonator 29 configured differently from the first optical ring resonator 10 and currently, in particular, from the second optical ring resonator 24, wherein pulse sequence 11, and currently, in particular, second pulse sequence 25, are generated according to the first optical ring resonator 10, currently according to the second optical ring resonator 24, and the other optical ring resonator 29.

[0050] also Figure 4 As shown, the optical coupling element 17 can be coupled to the linear waveguide 30.

[0051] Especially Figure 4 As shown, the pulse sequences constructed in the optical ring resonators 10, 24, and 29 in Fourier space can be frequency combs. Here, the pulse length defines the spectral bandwidth of the entire comb when the bandwidth of a single mode is given by the length of the pulse sequences 11 and 25. The interval between single modes in the frequency comb is further defined by the pulse repetition rate f. rep definition.

[0052] This frequency comb can be used for the synthesis of gigahertz frequency ramps. For this purpose, a homodyne detection device is implemented on an electron-photonic chip (currently, for example, on semiconductor 18), or a heterodyne detection device 26 is implemented as currently shown. Frequency comb E S The optical signal is transmitted through the beam splitter 34 and the signal E of the local oscillator. LO (For example, a CW laser signal) is superimposed on two photodiodes 31 and 32. The photocurrent generated here can be measured.

[0053]

[0054] The signal (S) passes through:

[0055]

[0056] The description, while local oscillation (LO) is achieved through:

[0057]

[0058] Given. Through the phase abrupt change π at beam splitter 34, the signal of LO undergoes a sign change in the exponent. The measured photocurrent yields:

[0059]

[0060] By measuring two photocurrents I phot1 and I phot2 The difference can be subtracted from two constant terms. And it preserves both the frequency difference and the phase difference. The frequency difference is at f rep Within its range, it can be used again as a gigahertz signal. Furthermore, the mixed term E... S ×E LO Provided a weak signal E S Its own magnification.

[0061] Here, the heterodyne detection device 26 may in particular have a mirror element 33 and a beam splitter 34.

[0062] exist Figure 4 The diagram, in particular, illustrates a method for generating a defined frequency comb. To synthesize a gigahertz frequency ramp for an FMCW radar system, two pulses with different repetition rates f can be used here. rep The frequency combs are designed differently. To achieve this, the diameters of the ring resonators 10, 24, and 29 are designed differently, so that the frequency combs are slightly offset from each other in the spectrum. The frequency difference can be measured again by superimposing the two frequency combs using a heterodyne detection device 26. The sequence of frequency differences between the two combs thus provides the individual frequencies. For example, the pulse repetition rate f of the first comb... rep It can be 81 gigahertz, while the pulse repetition rate f of the second combrep The frequency can be 0.1 GHz. The two frequency combs are pumped by the same transmitted signal 9, meaning they have a correlated phase relationship and the same carrier frequency. Therefore, in heterodyne detection, the frequency difference f is obtained. Dn = 81 gigahertz - n * 0.1 gigahertz, where n is the element If the spectral bandwidth of the second comb is large enough, the entire automotive spectral range of 76 GHz to 81 GHz can be synthesized with a step size of 0.1 GHz. The 0.1 GHz step size is merely exemplary and should not be considered definitive.

[0063] To cause frequencies to lag behind each other in time, especially to generate so-called frequency chirp 27, a dispersive element 28 can be used. In particular, all spectral components propagate simultaneously, thus the pulse has a theoretically minimum pulse length. If a finite Fourier pulse propagates through a dispersive medium (e.g., air), the higher-frequency spectral components experience a greater time delay than the lower-frequency spectral components. This causes the pulse to chirp positively and thus prolongs its time. Furthermore, the peak intensity of the pulse decreases. For example, a decoupled waveguide can be used as a dispersive element. It is particularly advantageous here for an isolated wave, which is itself non-dispersive, to propagate in a ring conductor.

[0064] Here, Figure 4 This demonstrates a possible implementation of radar chirp. Two optical ring resonators 10 and 24 are pumped by one or more transmitted signals 9 and generate pulse repetition rates f with different frequencies. rep A frequency comb is used. After decoupling, a desired slope of the frequency ramp is generated using one or more dispersive elements 28, and converted to the gigahertz frequency range by a heterodyne detection device 26. Specifically, a frequency chirp is applied to a single pulse by dispersion, and two signals are measured using the heterodyne detection device 26. The resulting frequency forms a ramp in the gigahertz spectral range.

[0065] Figure 5 Another illustrative embodiment of the conversion device 6 is shown. In particular... Figure 5 It is shown that the pulse repetition rate f can be detected. rep Or frequency difference. For this purpose, the conversion device 6 has at least two nanoantennas 35 on the semiconductor medium 36 for generating a transmitted signal 12 according to the pulse sequence 11. Thus, in particular, an optical ring resonator 10 is used to generate the pulse sequence 11. The pulse repetition rate f is detected by means of the nanoantennas 35 applied to the semiconductor medium 36. repThese metallic antennas, with dimensions ranging from a few micrometers to nanometers, are positioned at a distance equal to the wavelength of the incident light. If a ray emitted by the optical ring resonator 10 reaches the nanoantenna 35, it excites plasma resonance or induces surface plasma polarization that vibrates at the frequency of the incident light wave through the wavelength distance between the nanoantennas 35. This frequency oscillation can be measured directly electronically and can be used as a driving signal for the gigahertz antenna.

[0066] The proposed invention also relates to a method for operating a radar sensor device 2. An electrical control signal 7 is generated for a transmitting device 4 by means of an electronic computing device 3. An optical transmission signal 9 is generated based on the electrical control signal 7 and transmitted to the transmitting device 4 by means of a laser device 8. A pulse sequence 11 is generated based on the optical transmission signal 9 by means of a conversion device 6 of the radar sensor device 2 having at least one first optical ring resonator 10, wherein, additionally, an electrical transmission signal 12 is generated for the transmitting device 4 based on the pulse sequence 11 by means of the conversion device 6. The electrical transmission signal 12 is transmitted to an environment 13 by means of the transmitting device 4. A received signal 14 is received by means of a receiving device, and the received signal 14 is transmitted to the central electronic computing device 3 by means of a receiving device 5.

[0067] In general, the accompanying drawings illustrate a method for generating gigahertz frequencies in a photonic-electronic co-integrated semiconductor by means of optical ring resonators 10, 24, 29.

[0068] List of reference numerals in the attached diagram:

[0069] 1 motor vehicle

[0070] 2 Radar sensor devices

[0071] 3 Electronic computing devices

[0072] 4. Transmitting equipment

[0073] 5 Receiving Equipment

[0074] 6 Conversion Equipment

[0075] 7 Electrical control signals

[0076] 8 laser devices

[0077] 9 Transmission Signal

[0078] 10 First optical ring resonator

[0079] 11-pulse sequence

[0080] 12 Send signal

[0081] 13 Environment

[0082] 14 Electrically received signals

[0083] 15 objects

[0084] 16th Ring Road

[0085] 17 Optical Coupling Elements

[0086] 18 Semiconductors

[0087] 19 radio frequency drivers

[0088] 20 Optical modulators

[0089] 21. Other optical coupling elements

[0090] 22 photodiodes

[0091] 23 power amplifier

[0092] 24 Second optical ring resonator

[0093] 25 Second Pulse Sequence

[0094] 26 heterodyne detection equipment

[0095] 27 frequency chirps

[0096] 28 dispersive elements

[0097] 29. Other optical ring resonators

[0098] 30 optical waveguide

[0099] 31 photodiode

[0100] 32 photodiodes

[0101] 33 mirror elements

[0102] 34 beam splitters

[0103] 35 nanometer antenna

[0104] 36 Semiconductor Dielectric

[0105] 37 frames.

Claims

1. A radar sensor device (2) for a motor vehicle (1), comprising at least: - A central electronic computing device (3), which is configured to generate an electrical control signal (7) for a transmitting device (4) of the radar sensor device (2); - A laser device (8), which generates an optical transmission signal (9) for transmission to the transmitting device (4) according to the electrical control signal (7); - a conversion device (6) having at least one first optical ring resonator (10) generating a pulse sequence (11) from the optical transmission signal (9), wherein The conversion device (6) is additionally configured to generate an electrical transmission signal (12) for the transmitting device (4) according to the pulse sequence (11); - A transmitting device (4) configured to transmit the electrical transmitting signal (12) into the environment (13) of the motor vehicle (1); as well as - A receiving device (5) for receiving an electrical receiving signal (14) corresponding to the electrical transmitting signal (12) and reflected in the environment (13) and for transmitting the electrical receiving signal (14) to the central electronic computing device (3).

2. The radar sensor device (2) according to claim 1, characterized in that, The conversion device (6) has an optical coupling element (17) configured to couple the optical transmission signal (9) into at least the first optical ring resonator (10).

3. The radar sensor device (2) according to claim 1, characterized in that, The conversion device (6) has a photodiode (22) for generating a transmission signal (12) according to the pulse sequence (11).

4. The radar sensor device (2) according to any one of claims 1-3, characterized in that, The transmitting device (4) and the receiving device (5) are constructed as a common component.

5. The radar sensor device (2) according to any one of claims 1-3, characterized in that, The conversion device (6) has at least one additional optical ring resonator (29) configured differently from the first optical ring resonator (10), wherein the pulse sequence (11) is generated based on the first optical ring resonator (10) and the additional optical ring resonator (29).

6. The radar sensor device (2) according to any one of claims 1-3, characterized in that, The conversion device (6) has a heterodyne detection device (26) or a zero-difference detection device for generating the transmitted signal (12).

7. The radar sensor device (2) according to any one of claims 1-3, characterized in that, The conversion device (6) has at least one dispersive element (28) configured to generate at least one frequency chirp (27) according to the pulse sequence (11).

8. The radar sensor device (2) according to claim 7, characterized in that, The conversion device (6) has at least one second optical ring resonator (24), wherein a second pulse sequence (25) different from the pulse sequence (11) is generated by means of the second optical ring resonator (24), wherein the frequency chirp (27) is generated by means of the heterodyne detection device (26) of the conversion device (6) based on the pulse sequence (11) and the second pulse sequence (25).

9. The radar sensor device (2) according to any one of claims 1-3, characterized in that, The conversion device (6) has at least two nanoantennas (35) on a semiconductor medium (36) for generating the transmission signal (12) according to the pulse sequence (11).

10. A method for operating a radar sensor device (2) according to any one of claims 1 to 9, comprising the steps of: - An electrical control signal (7) for the transmitting device (4) of the radar sensor device (2) is generated by means of the central electronic computing device (3); - Using the laser device (8) of the radar sensor device (2), an optical transmission signal (9) is generated according to the electrical control signal (7) for transmission to the transmitting device (4); - By means of the conversion device (6) of the radar sensor device (2) having at least one first optical ring resonator (10), a pulse sequence (11) is generated according to the optical transmission signal (9), wherein, additional The conversion device (6) generates an electrical transmission signal (12) for the transmitting device (4) according to the pulse sequence (11); - The electrical transmission signal (12) is transmitted to the environment (13) of the motor vehicle (1) by means of the transmitting device (4); and - By means of the receiving device (5) of the radar sensor device (2), an electrical receiving signal (14) corresponding to the electrical transmitting signal (12) and reflected in the environment (13) is received, and the electrical receiving signal (14) is transmitted to the central electronic computing device (3) by means of the receiving device (5).

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