Interconnection structure for converting high-speed electric signals into wireless signals and preparation method thereof

Abstract

The invention provides an interconnection structure for converting a high-speed electric signal into a wireless signal and a preparation method thereof, and the structure comprises a signal transmitting module which generates a laser signal and modulates a to-be-transmitted data signal to the laser signal to form a transmitting signal; the optical signal beam splitting module is used for receiving the transmitted signals and splitting the transmitted signals into a plurality of beam splitting optical signals; the signal processing module comprises a plurality of signal processing sub-modules, and the signal processing sub-modules are correspondingly connected with one path of beam splitting optical signals and are used for carrying out amplification, photoelectric conversion, signal modulation and delay processing on the beam splitting optical signals; the signal radiation module is used for receiving a superposed signal formed by each beam of electric signals after modulation, signal modulation and delay processing, converting the superposed signal into an amplified signal and radiating the amplified signal; wherein the signal processing sub-module comprises a signal amplification unit, a signal conversion unit and a signal modulation and delay unit. According to the scheme, the power of the electric signal at the front end of the antenna is automatically controlled, so that the ROF system structure is simplified, and the transmission performance of the ROF system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber wired and wireless communications, and particularly relates to an interconnection structure for converting high-speed electrical signals into wireless signals and a preparation method therefor. Background Art

[0002] Radio-over-fiber (ROF) technology is a wireless access technology that has emerged in response to the demand for high-speed and large-capacity wireless communications and combines optical fiber communication and radio frequency communication. Simply put, at the central station, a radio frequency signal is modulated onto an optical signal, and this high-speed electrical signal can be a SerDes electrical signal. In the future, after the radio frequency signal is modulated onto the optical signal, the optical signal is transmitted through a complex optical fiber link. When it reaches the base station, an optoelectronic conversion device demodulates the radio frequency signal and then transmits it through an antenna for users to use. ROF technology combines the advantages of optical fiber communication and mobile communication technologies and is an effective means for realizing broadband wireless signal transmission. This technology utilizes the almost infinite bandwidth resources and low-loss advantages of optical fibers, enabling the transmission distance of multiple broadband wireless signals to reach dozens of kilometers through optical fiber transmission, solving the problem of serious transmission loss of wireless signals, and can transfer the high-frequency equipment originally placed in the base station to the central station to achieve resource sharing. Furthermore, the structure and function of a large number of base stations can be simplified, enabling the base station to only perform optoelectronic, electro-optical conversion and antenna transceiver, greatly reducing the system cost and making it possible to put it into practical use. At the same time, using optical methods to generate millimeter wave / terahertz wave signals in the ROF system can also simplify the structure of the central station. Therefore, a millimeter wave / terahertz wave communication system based on ROF technology can make it easier to achieve broadband wireless access.

[0003] In the ROF system, as a key device, the photodetector is used to convert an optical signal into an electrical signal. A high-power and large-bandwidth photodetector can not only improve the performance of the ROF system, but also change its system structure, cancel the millimeter wave / terahertz wave power amplifier, and realize an all-optical system.

[0004] The ROF system requires the photodetector to operate in a system with high speed, high power, and wide dynamic range. However, due to the limitation of the space charge effect caused by the accumulation of hole carriers in traditional PIN-PD photodiodes, these requirements cannot be met simultaneously. The uni-traveling-carrier photodiode (UTC-PD) is a new type of photodiode, and only electrons flow through the depletion region as conductive carriers. Therefore, compared with traditional PIN-PD photodiodes, it has no space charge effect, faster response speed, higher saturation current, and wider linear dynamic range. The ultra-high-speed and high-power UTC-PD is a photodiode improved on the basis of the traditional PIN-PD structure, realizing the transport of uni-traveling carriers, that is, electron carriers, and obtaining a higher saturated output photocurrent. Since the structure of UTC-PD was proposed, it has always been a research focus, and the research in this area has been very in-depth. However, although the UTC-PD has obtained a higher saturated output photocurrent, the output power of a single photodiode is still limited after all, and it still cannot fully meet the requirements of the ROF system for high power and high bandwidth in photoelectric conversion. Therefore, it can be considered to integrate multiple photodiodes to form a photodetector array, and improve the conversion output power of the photodetector by synthesizing the output powers of multiple photodiodes, while ensuring that the radio frequency signal bandwidth of the photodetector will not decrease. Such research is of great significance.

[0005] Based on the low power of a single UTC-PD in the ROF system, the existing technical solutions cannot meet the requirements of the ROF system for high power and high bandwidth in photoelectric conversion. Summary of the Invention

[0006] The embodiments of the present invention provide an interconnection structure for converting high-speed electrical signals into wireless signals and a preparation method thereof, effectively overcoming the technical problems in the prior art that the power of a single UTC-PD in the ROF system is low and cannot meet the requirements of the ROF system for high power and high bandwidth in photoelectric conversion.

[0007] In a first aspect, according to the embodiments of the present invention, an interconnection structure for converting high-speed electrical signals into wireless signals is provided, including:

[0008] A signal transmitting module, configured to generate a laser signal and modulate the data signal to be transmitted onto the laser signal to form a transmitted signal;

[0009] An optical signal splitting module, receiving the transmitted signal and splitting it into several split optical signals;

[0010] A signal processing module, including a plurality of signal processing sub-modules, each signal processing sub-module is correspondingly connected to a split optical signal, and performs amplification, photoelectric conversion, signal modulation, and delay processing on the corresponding split optical signal;

[0011] A signal radiation module, which is configured to receive each of the electrical signals formed by modulation, signal delay processing, and signal conversion, and perform superposition on them to form an amplified signal for radiation.

[0012] Among them, the signal processing sub-module includes a signal amplification unit, a signal conversion unit, and a signal modulation and delay unit, and the signal modulation and delay unit is an electrical phase modulator or an optical phase modulator.

[0013] Preferably, if the signal modulation and delay unit is an electrical phase modulator, the connection relationship of the signal amplification unit, the signal conversion unit, and the signal modulation and delay unit in the signal processing sub-module is as follows:

[0014] The signal amplification unit is connected to the optical signal splitting module and is configured to perform amplification processing on the received split optical signal by a preset multiple.

[0015] The signal conversion unit is connected to the signal amplification unit and converts the amplified optical signal into an electrical signal.

[0016] The signal modulation and delay unit is connected to the signal conversion unit and performs modulation and delay processing on the electrical signal converted by the signal conversion unit.

[0017] Preferably, the signal conversion unit is a single-carrier photodiode.

[0018] Preferably, if the signal modulation and delay unit is an optical phase modulator, the connection relationship of the signal amplification unit, the signal conversion unit, and the signal modulation and delay unit in the signal processing sub-module is as follows:

[0019] The signal amplification unit is connected to the optical signal splitting module and is configured to perform amplification processing on the received split optical signal by a preset multiple.

[0020] The signal modulation and delay unit is connected to the signal amplification unit and is configured to perform modulation and delay processing on the optical signal amplified by the signal amplification unit to obtain a modulated optical signal.

[0021] The signal conversion unit is connected to the signal modulation and delay unit and is configured to convert the modulated optical signal into an electrical signal.

[0022] Preferably, the amplification multiple of the emission power of the amplified signal relative to the emission power of the emission signal is related to the number of beams of the split optical signal and the phase difference between two adjacent split optical signals after modulation and delay processing.

[0023] Preferably, the target amplification multiple is obtained based on the number of beams of the split optical signal and the phase difference between two adjacent split optical signals according to a first mathematical model, and the first mathematical model is:

[0024]

[0025] Among them, E total is the transmission power of the amplified electrical signal, E k is the output power of the k-th signal conversion unit, A is the amplitude output by the signal conversion unit, ω and t are the angular frequency and time of the optical signal, and j is the imaginary unit. is the phase difference between two adjacent signal conversion units.

[0026] Preferably, when the number M of the split optical signals is 2 or 4, and when the phase difference between two adjacent split optical signals is N*360°, the transmission power of the amplified signal is the largest, which is M times the transmission power of the transmitted signal.

[0027] Preferably, if the number of split optical signal beams M is a certain number of beams, and when the phase difference between two adjacent split optical signals is N*180°, the transmission power of the amplified signal is the smallest, which is zero.

[0028] Preferably, if the number of split optical signal beams M is 4, and when the phase difference between two adjacent split optical signals is N*90°, the transmission power of the transmitted signal is the smallest, which is zero.

[0029] A method for preparing an interconnection structure for converting a high-speed electrical signal into a wireless signal, characterized by comprising:

[0030] Providing a silicon-based substrate, determining a set of set regions on the silicon-based substrate, and preparing a silicon waveguide in the second set region, a coupling unit in the signal transmission module in the third set region, a transmission line in the fourth set region, and a signal radiation module in the fifth set region to form a silicon laser chip;

[0031] Setting a set of target regions on the silicon laser chip, and preparing a signal generation unit in the signal transmission module in the first target region and a signal amplification unit in the signal processing module in the second target region through a flip-chip bonding process to form the interconnection structure;

[0032] Among them, if the signal modulation and delay unit is an electrical phase modulator, the method further comprises:

[0033] Preparing an electrical phase modulator in the third target region of the silicon laser chip through a flip-chip bonding process;

[0034] Among them, if the signal modulation and delay unit is an optical phase modulator, the method further comprises:

[0035] Preparing an optical phase modulator in the signal processing module in the first set region on the silicon-based substrate.

[0036] The interconnection structure for converting high-speed electrical signals into wireless signals and its preparation method provided by the embodiments of the present invention have at least the following technical effects:

[0037] For the interconnection structure for converting high-speed electrical signals into wireless signals and its preparation method provided by the embodiments of the invention, in order to meet the requirements of high power and high bandwidth for optoelectronic conversion in the ROF system, multiple UTC-PDs with high bandwidth and high power are interconnected, and an optical phase modulator is connected in front of each UTC-PD or an electrical phase controller is connected behind each UTC-PD to control the phase of the electrical signal after conversion by each UTC-PD. The electrical signals after conversion by multiple UTC-PDs are merged into one path through a microstrip line and then transmitted to a high-gain antenna, and are further converted into electromagnetic wave wireless signals through the antenna. According to the requirements of the conversion power of the ROF system, this solution can control the optical phase before conversion or the electrical phase after conversion of each UTC-PD through an algorithm, so that the electrical signals of each path are vectorially superposed, realizing the automatic control of the power magnitude of the electrical signal at the front end of the antenna, thereby simplifying the structure of the ROF system and improving the transmission performance of the ROF system. Description of the Drawings

[0038] Figure 1 It is a schematic structural diagram of an interconnection structure for converting high-speed electrical signals into wireless signals in an embodiment of the present invention;

[0039] Figure 2 It is a schematic structural diagram of an interconnection structure for converting high-speed electrical signals into wireless signals in a specific embodiment of the present invention;

[0040] Figure 3 It is a simulation and simulation system diagram for splitting a beam to form 4 split optical signals in a specific embodiment of the present invention;

[0041] Figure 4a It is a schematic diagram showing the change of the total power of the signal conversion units in parallel after splitting a beam to form two split optical signals with the phase difference;

[0042] Figure 4b It is a schematic diagram showing the change of the normalized power of the signal conversion units in parallel after splitting a beam to form two split optical signals with the phase difference;

[0043] Figure 5a It is a schematic diagram showing the change of the total power of the signal conversion units in parallel after splitting a beam to form four split optical signals with the phase difference;

[0044] Figure 5b It is a schematic diagram showing the change of the normalized power of the signal conversion units in parallel after splitting a beam to form four split optical signals with the phase difference;

[0045] Figure 6 It is a flowchart of a preparation method for an interconnection structure for converting high-speed electrical signals into wireless signals provided by an embodiment of the present invention;

[0046] Figure 7 This is a side schematic view of the interconnection structure for converting high-speed electrical signals into wireless signals provided by the embodiments of the present invention. Specific embodiments

[0047] The present invention will be further described below in conjunction with specific drawings and embodiments.

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Components of the embodiments of the present invention usually described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0049] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0050] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. It should be noted that the ordinal numbers such as "first", "second", "third", "fourth", etc. used in the following description are for convenience of description and are not specific limitations on whether the devices must be the same or different. The terms "bottom surface" and "top surface", "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component.

[0051] The technical problem solved by the present invention is: how to meet the requirements of the ROF system for high power and high bandwidth of optoelectronic conversion. In view of this technical problem, in the embodiments of the present invention, an array is formed by paralleling a plurality of signal processing sub-modules each including a uni-traveling-carrier photodiode (UTC-PD). Then, each uni-traveling-carrier photodiode (UTC-PD) in each signal processing sub-module in the array is respectively connected to a split optical signal to complete the optoelectronic conversion of each split optical signal into an electrical signal. At the same time, a signal amplification unit and a signal modulation and delay unit are connected in the signal processing sub-module including the uni-traveling-carrier photodiode. After amplifying each split optical signal, signal modulation and delay processing are performed, or after amplifying each split optical signal, signal modulation and delay processing are performed on the formed electrical signal. The multiple electrical signals with different phases after the delay processing are continued to be superimposed together and are converted into an electromagnetic wave signal through the signal radiation module and radiated out, so as to achieve the technical effect of improving the power of the transmitted signal, and thus achieve the purpose of meeting the requirements of the ROF system for high power and high bandwidth of optoelectronic conversion.

[0052] The present invention provides an interconnection structure for converting a high-speed electrical signal into a wireless signal. Refer to Figure 1 as shown in the figure, including:

[0053] A signal transmitting module 11, configured to generate a laser signal and modulate a data signal to be transmitted onto the laser signal to form a transmitted signal;

[0054] An optical signal splitting module 12, configured to receive the transmitted signal and split it into a plurality of split optical signals;

[0055] A signal processing module 13, including a plurality of signal processing sub-modules. As shown in the figure, it includes a signal processing sub-module 131, a signal processing sub-module 132, and a signal processing sub-module 133. Each signal processing sub-module is correspondingly connected to a split optical signal, and performs amplification, optoelectronic conversion, signal modulation, and delay processing on the corresponding split optical signal;

[0056] A signal radiation module 14, configured to receive each beam of electrical signals after modulation, signal modulation, and delay processing, and perform superposition on them to form an amplified signal and radiate it out;

[0057] Wherein, the signal processing sub-module includes a signal amplification unit, a signal conversion unit, and a signal modulation and delay unit, and the signal modulation and delay unit is an electrical phase modulator or an optical phase modulator.

[0058] As an optional embodiment, the signal transmitting module includes a laser signal generating unit and a modulation unit. If there are a plurality of laser signal generating units, the signal transmitting module further includes a signal coupling unit, and further couples the optical signals generated by the plurality of laser signal generating units to form a transmitted signal.

[0059] Specifically, refer to Figure 2 , in a specific embodiment, the laser signal generating unit in the signal transmitting module includes a first laser 111 and a second laser 112. Among them, the first laser 111 generates a first laser signal, and the second laser 112 generates a second laser signal. After the data signal to be transmitted is modulated onto the first laser signal by a modulator 113, a modulated optical signal is formed. The modulated optical signal and the second laser signal are coupled together. Specifically, the modulator and the second laser can be respectively connected to a coupler 114, and then the modulated optical signal and the second laser signal are coupled through the coupler 114 to form a transmitted signal.

[0060] In the embodiment of the present invention, after the signal transmitting module forms a transmitted signal, the transmitted signal is transmitted to the signal splitting module 12, and the signal splitting module 12 splits the received transmitted signal into several transmitted sub-signals. As a specific embodiment, the signal splitting module 12 can specifically be a beam splitter.

[0061] In the embodiment of the present invention, after the signal splitting module 12 splits the transmitted signal, the formed multiple split optical signals respectively enter the corresponding signal processing sub-modules. Refer to Figure 2 As shown, each signal processing sub-module includes a signal amplification unit to amplify the corresponding split optical signal. The optical signal after being amplified by the signal amplification unit continues to be subjected to photoelectric conversion, signal modulation, and delay processing by a signal conversion unit and a signal modulation and delay unit, and then multiple electrical signals with different phases are formed. It should be noted here that the connection sequence of the signal conversion unit and the signal modulation and delay unit is different according to the type of the signal modulation and delay unit. For this, there is a specific description later.

[0062] In the embodiment of the present invention, multiple (at least 2, including 2) electrical signals with different phases formed after being processed by the signal processing sub-modules are superimposed and then enter the signal radiation module 14. The signal radiation module 14 receives the amplified electrical signal formed after the superimposition of each electrical signal with different phases, and then converts the amplified electrical signal into an electromagnetic wave signal and radiates it out. Specifically, the signal radiation module 14 can be a high-gain antenna.

[0063] In the embodiment of the present invention, the signal modulation and delay unit is not limited to one type. It can be an electrical phase modulator or an optical phase modulator. The difference between using two different signal modulation and delay units lies in the different connection relationships of the units in the signal processing sub-module. The specific description is as follows:

[0064] When the signal modulation and delay unit is an electrical phase modulator, the connection relationship of the signal amplification unit, the signal conversion unit, and the signal modulation and delay unit in the signal processing module is:

[0065] A signal amplification unit, connected to the optical signal beam splitting module, for performing amplification processing on the received split optical signal by a preset multiple; the signal amplification unit can be an amplifier;

[0066] A signal conversion unit, connected to the signal amplification unit, for converting the amplified optical signal into an electrical signal; in a specific embodiment, the signal conversion unit can be a uni-travelling-carrier photodiode (UTC-PD).

[0067] A signal modulation and delay unit, i.e., an electrical phase modulator, connected to the signal conversion unit, for performing signal modulation and delay processing on the electrical signal formed by the signal conversion unit.

[0068] Specifically, in the embodiment of the present invention, multiple split optical signals formed by the beam splitter enter the corresponding signal processing sub-modules. In each signal processing sub-module, there are at least one signal amplification unit, at least one signal conversion unit, and at least one signal modulation and delay unit. In this specific embodiment, the signal modulation and delay unit is an electrical phase modulator. It can be seen from the figure that when each signal processing sub-module includes and only includes one signal amplification unit, one signal conversion unit, and one signal modulation and delay unit, each split optical signal first undergoes optical signal amplification processing by the signal amplification unit in the corresponding signal processing sub-module, and then the amplified optical signal continues to enter the signal conversion unit for optoelectronic conversion to form an electrical signal. The formed electrical signal continues to enter the signal modulation and delay unit for signal modulation and delay processing, thereby forming multiple split electrical signals with different phases. Each split electrical signal after signal modulation and delay processing is superimposed and then enters the signal radiation module 14. The signal radiation module 14 converts the electrical signal into an electromagnetic wave signal and radiates it out. Specifically, in the embodiment of the present invention, the signal radiation module 14 can be a high-gain antenna.

[0069] In the embodiment of the present invention, the signal conversion unit is a uni-travelling-carrier photodiode, i.e., UTC-PD. In this uni-travelling-carrier photodiode, only electrons flow through the depletion region as conductive carriers. Therefore, compared with the traditional PIN-PD photodiode, it does not have a space charge effect, has a faster response speed, a higher saturation current, and a wider linear dynamic range. The ultra-high-speed and high-power UTC-PD is a photodiode improved on the basis of the traditional PIN-PD structure, realizing the transport of uni-travelling-carriers, i.e., electron carriers, and obtaining a higher saturated output photocurrent.

[0070] As another embodiment of the present invention, if the signal modulation and delay unit is an optical phase modulator, the connection relationship of the signal amplification unit, the signal conversion unit, and the signal modulation and delay unit in the signal processing module is:

[0071] A signal amplification unit, connected to the optical signal splitting module, for amplifying the received split optical signal by a preset multiple; the same as the previous specific embodiment, the split optical signal formed by the optical splitting module first enters the signal amplification unit to obtain amplification processing by several multiples.

[0072] A signal modulation and delay unit, connected to the signal amplification unit, for performing signal modulation and delay processing on the optical signal amplified by the signal amplification unit to obtain a modulated optical signal; different from the previous embodiment, the optical signal amplified by the signal amplification unit first undergoes signal modulation and delay processing by the signal modulation and delay unit to obtain a delayed optical signal, so that the phases of the delayed optical signals are different, and then further converted into electrical signals with different phases by the signal conversion unit.

[0073] A signal conversion unit, connected to the signal modulation and delay unit, for converting the signal modulation and delay modulated optical signal into an electrical signal. Different from the previous embodiment, the signal conversion unit is located at the very end of the split optical signal processing link in the signal processing sub-module, and performs photoelectric conversion on the delayed optical signal obtained after amplifying, signal modulating, and delaying the split optical signal to form electrical signals with different phases.

[0074] In the embodiment of the present invention, electrical signals with different phases are superimposed to form an amplified electrical signal, and the amplification multiple of the amplified electrical signal to the transmitted signal is related to the number of beams of the split optical signal and the phase difference between two adjacent split optical signals after modulation and delay processing. Specifically, for example, when the number of beams of the split optical signal is 2 beams and 4 beams, the phase difference between two adjacent split optical signals after signal modulation and delay processing is different, and only then can the amplified electrical signal obtained by their superposition reach the maximum transmitted power.

[0075] Specifically, the relationship between the number of beams of the split optical signal, the phase difference between two adjacent split optical signals, and the transmitted power of the formed amplified electrical signal satisfies a certain mathematical relationship model. Therefore, in the embodiment of the present invention, according to the first mathematical model, based on the number of beams of the split optical signal and the phase difference between two adjacent split optical signals, the amplification multiple of the transmitted power of the amplified electrical signal relative to the transmitted power of the original transmitted signal is obtained, where the first mathematical model is:

[0076]

[0077] wherein, E total is the transmitted power of the amplified electrical signal, E k is the output power of the kth signal conversion unit, A is the amplitude output by the signal conversion unit, ω and t are the angular frequency and time of the optical signal, and j is the imaginary unit. is the phase difference between two adjacent signal conversion units.

[0078] It is pointed out here that assuming that the amplitudes of the signals output by the signal conversion units in each signal processing sub-module are equal, all being A, the phase difference between two adjacent signal conversion units is φ, and the power magnitude of the electrical signals output by the signal conversion units in each branch is where k represents the number of the k-th signal conversion unit, ω and t are the angular frequency and time of the optical signal, and j is the imaginary unit.

[0079] It can be obtained that after k photodetectors are connected in parallel, the vector superposition sum of the output electrical signals is E total ,

[0080]

[0081] Applying the geometric series summation formula, it can be obtained that:

[0082]

[0083] Further expanding the above formula, it can be obtained that:

[0084]

[0085] Thus, it can be known that the signal amplitude |E total | after k photodetectors are connected in parallel is:

[0086]

[0087] According to the formula of |E total |, when is kπ (k is an integer), |E total | = 0; when is close to 0, |E total | will increase to nA as increases. That is, as n or increases, the relationship between the amplitude of the parallel output signal and the phase difference can be calculated through the above formula.

[0088] Therefore, for the parallel connection of multiple signal conversion units, the output amplitude of the electrical signal after parallel connection is not only related to the amplitudes of each split optical signal, but also closely related to the phase difference between each split optical signal. The phase difference between each split optical signal affects the result of the electrical signal superposition, making the result may range from complete enhancement to complete cancellation, which depends on the size of the phase difference and the number of parallel signal conversion units.

[0089] In an embodiment of the present invention, when the number of beams M of the split optical signals is 2 or 4, when the phase difference between two adjacent split optical signals is N*360°, the transmission power of the amplified electrical signal formed after superposition is the largest, which is M times the transmission power of the transmitted signal. That is, when the number of beams of the split optical signals is 2, when the phase difference between two adjacent split optical signals is N*360°, the transmission power of the amplified electrical signal formed after superposition can reach 2 times the transmission power of the original transmitted signal; when the number of beams of the split optical signals is 4, when the phase difference between two adjacent split optical signals is N*360°, the transmission power of the amplified electrical signal formed after superposition of the 4 split optical signals after signal amplification processing, photoelectric conversion and modulation, and delay processing can reach 4 times the transmission power of the original transmitted signal.

[0090] In an embodiment of the present invention, if the number of beams M of the split optical signals is 2, when the phase difference between two adjacent split optical signals is N*180°, the transmission power of the amplified electrical signal formed after superposition is the smallest, which is zero. In an embodiment of the present invention, if the number of beams M of the split optical signals is 4, when the phase difference between two adjacent split optical signals is N*90°, the transmission power of the amplified electrical signal formed after superposition is the smallest, which is zero. That is, regardless of whether the number of beams of the split optical signals is 2 or 4, by adjusting the phase difference between two adjacent split optical signals, the minimum transmission power can be achieved, that is, almost zero.

[0091] As follows, taking the example of the optical signal splitting module splitting into 4 split optical signals, the specific optical signal is taken as an example for simulation verification and elaboration:

[0092] Specifically, the simulation system diagram is as Figure 3As shown in the figure, the system includes two continuous-wave lasers, one optical combiner, one optical splitter, four signal amplification units (optical amplifiers), four signal conversion units (photodetectors), four signal modulation and delay units (electrical phase modulators), three signal coupling units (optical-electrical combiners), and four power monitors. In this simulation system, the power of the first laser signal generation unit (continuous-wave laser CW Laser 1) is set to 0 dBm and the frequency is set to 193.1 THz, and the power of the second laser signal generation unit (continuous-wave laser CW Laser 2) is set to 0 dBm and the frequency is set to 193.4 THz; the amplification factor of the signal amplification unit (optical signal amplifier) in each signal processing sub-module is 10 times (gain = 10 dB), and the responsivity of the signal conversion unit (photodetector) is the system default value of 1 A / W. The electrical signals generated by the four parallel signal conversion units are combined into one electrical signal after passing through the signal modulation and delay unit and output to the signal radiation module. In order to verify the variation of the output electrical signal power with the phase difference of each path after the combination of two and four paths in parallel, in this system, the combination of two paths is first performed and then the four electrical signals are further combined.

[0093] After simulation, the average output power of the photodetector in a single branch is 220.40 μW. By changing the phase difference between each branch That is, the phases of the four branches are 0, are changed, and the relationship between the optical power after the parallel combination of two paths and the phase difference is simulated, as shown in Figure 4a and 4b shown. Figure 4a It is the curve of the total power output after the two simulated electrical signals pass through the signal modulation and delay unit (phase modulator) with respect to the phase difference between the two signals. In order to more intuitively reflect the influence of the phase difference change on the output power, the signal power on a single branch is set to 1, and the total power is normalized. The specific results are shown in Figure 4b shown. It can be seen from this that when the phase difference changes from 0 to 180°, the output power of the two parallel photodetectors can vary from 0 to 440.80 μW. As shown in Figure 4b shown, through the coherence principle, the output power can be increased to up to 2 times at most, and can be made almost zero output at least. Therefore, by modulating the change of the phase difference, the effective regulation of the total output power of the system can be realized.

[0094] Similarly, the curve of the relationship between the total output power of the four photodetectors and the phase difference is shown in Figure 5a and Figure 5b shown. From Figure 5aAs can be seen, when the phase difference between the two optical signals varies from 0 to 90°, the output power of the four-way parallel photodetector can vary from 0 to 881.60 μW. From Figure 5b As can be seen from the normalized results in Figure 5b , the output power can be maximally increased by 4 times and minimally almost zero. Compared with the parallel connection of two signal conversion units (photodetectors), the more signal conversion units (photodetectors) are connected in parallel, the smaller the change in the phase difference, but the total output power increases with the increase in the number of parallel signal processing sub-modules. The maximum power is approximately equal to N times the output power of a single optical signal conversion unit (uni-travelling-carrier photodiode UTC-PD) in the signal processing sub-module, where N is the number of parallel signal conversion units (photodetectors), i.e., the number of split optical signals. Therefore, from the simulation results, it can be known that by connecting N signal conversion units (photodetectors) in parallel and controlling the phase of the electrical signal after conversion by the signal conversion unit (uni-travelling-carrier photodiode UTC-PD), the signal transmission power of the parallel structure ROF system of the signal conversion unit (uni-travelling-carrier photodiode UTC-PD) can be adjusted, thus solving the problem of insufficient optoelectronic conversion power in the ROF system.

[0095] The high-speed electrical signal to wireless signal interconnection structure provided by the embodiment of the present invention is composed of an array formed by parallel connection of multiple signal processing sub-modules each containing a uni-travelling-carrier photodiode (UTC-PD). Then, the uni-travelling-carrier photodiode (UTC-PD) in each signal processing sub-module in the array is respectively connected to a split optical signal to complete the optoelectronic conversion of each split optical signal into an electrical signal. At the same time, a signal amplification unit and a signal modulation and delay unit are connected in the signal processing sub-module containing the uni-travelling-carrier photodiode. After amplifying each split optical signal, signal modulation and delay processing are performed, or after amplifying each split optical signal and converting it into an electrical signal, signal modulation and delay processing are performed on the electrical signal. The multiple electrical signals with different phases after the delay processing are continued to be superimposed together and are converted into an electromagnetic wave signal through the signal radiation module and radiated out, thereby achieving the technical effect of increasing the power of the transmitted signal, and thus achieving the purpose of meeting the requirements of the ROF system for high optoelectronic conversion power and high bandwidth.

[0096] Embodiment 2

[0097] The embodiment of the present invention provides a preparation method for a high-speed electrical signal to wireless signal interconnection structure, as Figure 6 shown, the method includes:

[0098] Step S61: Provide a silicon-based substrate, determine a set of preset regions on the silicon-based substrate, fabricate a signal modulation and delay unit (MZM modulator) in the signal processing module in the first preset region, fabricate a silicon waveguide in the second preset region, fabricate a coupling unit (MMI coupler) in the signal emission module in the third preset region, fabricate a transmission line in the fourth preset region, and fabricate a signal radiation module (antenna) in the fifth preset region to form a silicon laser chip.

[0099] Specifically, in the embodiment of the present invention, first, a silicon substrate is provided, then a set of preset regions is determined on the upper surface of the silicon substrate, and the first preset region, the second preset region, the third preset region, the fourth preset region, and the fifth preset region are divided in the set of preset regions. And a silicon waveguide for transmitting optical signals, such as the silicon waveguide in the figure, is fabricated in the second preset region, a coupling unit in the signal emission module, such as an MMI coupler, is fabricated in the third preset region, a transmission line is fabricated in the fourth preset region, and a signal radiation module, such as an antenna, is fabricated in the fifth preset region to form a silicon laser chip.

[0100] Step S62: Set a set of target regions on the silicon laser chip, and fabricate a signal generation unit (DFB laser) in the signal emission module in the first target region through a flip-chip bonding process, and fabricate a signal amplification unit (SOA amplifier) in the signal processing module in the second target region to form the interconnection structure.

[0101] Wherein, if the signal modulation and delay unit is an electro-optic phase modulator, the method further includes:

[0102] Step S63: Fabricate an electro-optic phase modulator 9 in the third target region of the silicon laser chip through a flip-chip bonding process.

[0103] Wherein, if the signal modulation and delay unit is an optical phase modulator, the method further includes:

[0104] Step S64: Fabricate an optical phase modulator in the signal processing module in the first preset region on the silicon-based substrate.

[0105] In an embodiment of the present invention, in step S51, a first SiO2 interlayer with a certain thickness may be provided between the signal modulation and delay unit and the upper surface of the first set area on the silicon substrate. Specifically, the thickness of the first SiO2 interlayer provided is set according to requirements. As for the silicon waveguide, it can be directly provided on the upper surface of the first set area on the silicon substrate, and a signal amplification unit in the signal processing module is fabricated on the second target area on the silicon waveguide, and SiO2 is provided on both sides of the signal amplification unit. In an embodiment of the present invention, a signal coupling unit is fabricated above the third set area, where the coupling unit may be located on the same layer or an upper layer of the silicon waveguide in the vertical direction, so as to be coupled to the silicon waveguide. A transmission line is fabricated in the fourth set area, where the fourth set area is located between the areas corresponding to the signal conversion unit and the signal modulation and delay unit, so that the transmission line transmits the electrical signal formed by the signal conversion unit to the signal modulation and delay unit. A signal radiation module, such as an antenna, is fabricated in the fifth set area, where a certain thickness of SiO2 may be provided between the signal radiation module and the upper surface of the silicon substrate. As a specific embodiment, the thicknesses of the SiO2 layers under the signal radiation module, the transmission line, and the signal modulation and delay control unit (electrical phase modulator) are the same.

[0106] Continuing, in an embodiment of the present invention, a set of target areas is set on the silicon laser chip, and a signal generation unit in the signal emission module, such as a first DFB laser and a second DFB laser, is fabricated in the first target area through a flip-chip bonding process, and a signal amplification unit in the signal processing module is fabricated in the second target area, where the signal amplification unit may be an SOA amplifier.

[0107] In an embodiment of the present invention, the signal modulation and delay unit may be an optical phase modulator or an electrical phase modulator. If the signal conversion and delay unit can be an optical phase modulator, then the optical phase modulator is fabricated in the first set area. If the signal modulation and delay unit can be an electrical phase modulator, then the fabrication method further includes the step of fabricating the electrical phase modulator in the third target area.

[0108] Continuing, in an embodiment of the present invention, if the signal conversion and delay unit is an optical phase modulator, the incoming optical signal first passes through the optical phase modulator and then enters the signal conversion unit; conversely, if the signal conversion and delay unit is an electrical phase modulator, the optical signal is first converted into an electrical signal by the signal conversion unit and then undergoes signal modulation and delay processing by the electrical phase modulator. For the specific structure and the positions of each set area and target area, see Figure 7 as shown. It should be noted here that the present solution only makes a Figure 7 structural schematic diagram shown for the case where the signal modulation and delay unit is an electrical phase modulator. The illustration for the case where the signal modulation and delay unit is an optical phase modulator can be deduced by analogy and will not be elaborated here.

[0109] The preparation method of the interconnection structure for converting high-speed electrical signals into wireless signals provided by the embodiments of the present invention can prepare an interconnection structure for converting high-speed electrical signals into wireless signals. The interconnection structure for converting high-speed electrical signals into wireless signals is formed by paralleling a plurality of signal processing sub-modules each including a uni-traveling-carrier photodiode (UTC-PD) to form an array. Then, each uni-traveling-carrier photodiode (UTC-PD) in each signal processing sub-module in the array is respectively connected to a split optical signal to complete the photoelectric conversion of each split optical signal into an electrical signal. At the same time, a signal amplification unit and a signal modulation and delay unit are connected in the signal processing sub-module including the uni-traveling-carrier photodiode. After amplifying each split optical signal, signal modulation and delay processing are performed, or after amplifying each split optical signal, signal modulation and delay processing are performed on the formed electrical signal. The plurality of electrical signals with different phases after the delay processing are continuously superimposed together and are converted into an electromagnetic wave signal through the signal radiation module and radiated out, thereby achieving the technical effect of improving the power of the transmitted signal, and thus achieving the purpose of meeting the requirements of the ROF system for high power and high bandwidth of photoelectric conversion.

Claims

1. An interconnection structure for converting high-speed electrical signals into wireless signals, characterized in that, Comprising: A signal transmitting module, configured to generate a laser signal and modulate a data signal to be transmitted onto the laser signal to form a transmitted signal; An optical signal splitting module, receiving the transmitted signal and splitting it into a plurality of split optical signals; A signal processing module, including a plurality of signal processing sub-modules, each signal processing sub-module being correspondingly connected to one path of split optical signal, and performing amplification, optoelectronic conversion, signal modulation, and delay processing on the corresponding split optical signal; A signal radiation module, configured to receive each electrical signal formed by modulation, signal delay processing, and signal conversion, and perform superposition on them to form an amplified signal and radiate it out; Wherein, the signal processing sub-module includes a signal amplification unit, a signal conversion unit, and a signal modulation and delay unit, and the signal modulation and delay unit is an electrical phase modulator or an optical phase modulator.

2. The interconnection structure for converting high-speed electrical signals into wireless signals according to claim 1, wherein If the signal modulation and delay unit is an electrical phase modulator, the connection relationship of the signal amplification unit, the signal conversion unit, and the signal modulation and delay unit in the signal processing sub-module is: The signal amplification unit, connected to the optical signal splitting module, is configured to perform amplification processing on the received split optical signal by a preset multiple; The signal conversion unit, connected to the signal amplification unit, converts the amplified optical signal into an electrical signal; The signal modulation and delay unit, connected to the signal conversion unit, performs modulation and delay processing on the electrical signal converted by the signal conversion unit.

3. The interconnection structure for converting high-speed electrical signals into wireless signals according to claim 2, wherein The signal conversion unit is a single-carrier photodiode.

4. The interconnection structure for converting high-speed electrical signals into wireless signals according to claim 1, characterized in that, If the signal modulation and delay unit is an optical phase modulator, the connection relationship of the signal amplification unit, the signal conversion unit, and the signal modulation and delay unit in the signal processing sub-module is: The signal amplification unit, connected to the optical signal splitting module, is configured to perform amplification processing on the received split optical signal by a preset multiple; The signal modulation and delay unit, connected to the signal amplification unit, is configured to perform modulation and delay processing on the optical signal amplified by the signal amplification unit to obtain a modulated optical signal; The signal conversion unit, connected to the signal modulation and delay unit, is configured to convert the modulated optical signal into an electrical signal.

5. The interconnection structure for converting a high-speed electrical signal into a wireless signal according to claim 2 or 4, characterized in that The amplification multiple of the emission power of the amplified signal relative to the emission power of the transmitted signal is related to the number of split optical signals and the phase difference between adjacent split optical signals after modulation and delay processing.

6. The interconnect structure for converting high-speed electrical signals to wireless signals according to claim 5, characterized in that, The target amplification multiple is obtained according to a first mathematical model based on the number of split optical signals and the phase difference between adjacent split optical signals. The first mathematical model is: Among them, E total is the transmission power for amplifying the electrical signal, E k is the output power of the k-th signal conversion unit, A is the amplitude output by the signal conversion unit, ω and t are the angular frequency and time of the optical signal, and j is the imaginary unit, is the phase difference between two adjacent signal conversion units.

7. The interconnection structure for converting high-speed electrical signals into wireless signals according to claim 5, wherein When the number M of split optical signals is 2 or 4, and when the phase difference between adjacent two split optical signals is N * 360°, the emission power of the amplified signal is the largest, which is M times the emission power of the transmitted signal.

8. The interconnection structure for converting high-speed electrical signals into wireless signals according to claim 5, wherein If the number M of split optical signals is a certain number of beams, when the phase difference between adjacent two split optical signals is N * 180°, the emission power of the amplified signal is the smallest, which is zero.

9. The interconnection structure for converting high-speed electrical signals into wireless signals according to claim 5, wherein If the number M of split optical signals is 4, when the phase difference between adjacent two split optical signals is N * 90°, the emission power of the transmitted signal is the smallest, which is zero.

10. A method for preparing an interconnection structure for converting a high-speed electrical signal into a wireless signal, characterized in that, Comprising: Provide a silicon-based substrate, determine a set of set regions on the silicon-based substrate, fabricate silicon waveguides in the second set region, fabricate coupling units in the signal emission module in the third set region, fabricate transmission lines in the fourth set region, and fabricate signal radiation modules in the fifth set region to form a silicon laser chip; Set a set of target regions on the silicon laser chip, and fabricate signal generation units in the signal emission module in the first target region through flip-chip bonding technology, and fabricate signal amplification units in the signal processing module in the second target region to form the interconnection structure; Wherein, if the signal modulation and delay unit is an electrical phase modulator, the method further includes: Fabricate an electrical phase modulator in the third target region of the silicon laser chip through flip-chip bonding technology; Wherein, if the signal modulation and delay unit is an optical phase modulator, the method further includes: Fabricate an optical phase modulator in the signal processing module in the first set region on the silicon-based substrate.

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