Reconfigurable microwave photonic band-pass filter chip

Abstract

The invention discloses a reconfigurable microwave photonic band-pass filter chip which comprises a laser, a phase modulator, an insertion type micro-ring, an interleaver, a first phase shifter, a first adjustable coupler, a coupling resonance optical waveguide, a first coupler, a second phase shifter, a second adjustable coupler, a second coupler and a photoelectric detector. An optical carrier wave emitted by the laser enters the phase modulator and generates two optical sidebands through small signal modulation. The interpolation type micro ring realizes separation of an optical carrier and an optical sideband, the interleaver separates two optical sidebands, the CROW carries out band-pass filtering on a + 1-order optical sideband, the first phase shifter and the first adjustable coupler realize phase and amplitude adjustment of the-1-order optical sideband, and the second phase shifter and the second adjustable coupler realize phase and amplitude adjustment of the optical carrier. The processed signals are combined through the two couplers, and radio frequency band-pass response is achieved after frequency beating is conducted through the photoelectric detector. The invention has the characteristics of high integration level, low loss and flexible tuning, and is suitable for the field of microwave photons.

Description

Technical Field

[0001] The present invention belongs to the fields of microwave photonic communication and microwave photonic radar, and relates to a reconfigurable microwave photonic bandpass filter chip. Background Art

[0002] The microwave photonic filter is one of the core devices in microwave photonic communication and microwave photonic radar systems. The integrated microwave photonic filter based on on-chip integration technology can achieve flexible regulation of radio frequency responses, such as bandwidth reconfiguration and frequency tuning, etc., and can effectively reduce the system size, link loss, power consumption, and cost. The integrated microwave photonic bandpass filter can filter out interference signals and has important application value. Generally, it is required to have a high out-of-band rejection ratio, a steep roll-off degree, a large frequency tuning range, and a bandwidth reconfiguration range. For the integrated microwave photonic bandpass filter implemented based on optical single-sideband modulation, its radio frequency response and performance almost completely depend on the performance of the integrated optical filter. This method is difficult to achieve both a high out-of-band rejection ratio and a large bandwidth, and places very high requirements on the performance of the integrated optical filter. The microwave photonic bandpass filter implemented based on phase modulation and notch filter is usually limited by the residual phase difference, so the out-of-band rejection ratio is generally low. In summary, there is an urgent need for a solution to realize an integrated microwave photonic bandpass filter with a high out-of-band rejection ratio, a large frequency tuning range, and a steep roll-off degree. Summary of the Invention

[0003] Aiming at the above problems of the prior art, the present invention provides a reconfigurable microwave photonic bandpass filter chip, which can achieve a high out-of-band rejection ratio, a large frequency tuning range, and a steep roll-off degree, and has a high integration level and good stability.

[0004] The reconfigurable microwave photonic bandpass filter chip of the present invention includes: a laser, a phase modulator, a drop-type micro-ring, an interleaver, a first phase shifter, a first tunable coupler, a coupled resonant optical waveguide, a first coupler, a second coupler, a second phase shifter, a second tunable coupler, and a photodetector;

[0005] The optical input end of the phase modulator is connected to the optical output end of the laser; the input end of the plug-in type micro-ring is connected to the optical output end of the phase modulator; the input end of the interleaver is connected to the through end of the plug-in type micro-ring; the input end of the first phase shifter is connected to the upper right output end of the interleaver; the input end of the first adjustable coupler is connected to the output end of the first phase shifter; the upper left input end or the lower left input end of the coupled resonant optical waveguide is connected to the lower right output end of the interleaver; the two input ends of the first coupler are respectively connected to the output end of the first adjustable coupler and the lower right output end or the upper right output end of the coupled resonant optical waveguide; the input end of the second phase shifter is connected to the drop end of the plug-in type micro-ring; the input end of the second adjustable coupler is connected to the output end of the second phase shifter; the two input ends of the second coupler are respectively connected to the output end of the first coupler and the output end of the second adjustable coupler; the optical input end of the photodetector is connected to the output end of the second coupler.

[0006] Further, the plug-in type micro-ring is formed by connecting two bent optical waveguides with a third adjustable coupler and a fourth adjustable coupler respectively, and includes three ports: an input end, a through end and a drop end; the third adjustable coupler and the fourth adjustable coupler are parallel up and down. After the third adjustable coupler is connected to the left and right bent optical waveguides, the left side is the input end and the right side is the through end. After the fourth adjustable coupler is connected to the left and right bent optical waveguides, the left side is the drop end; the optical signal is input from the input end of the plug-in type micro-ring and output from the through end or the drop end of the plug-in type micro-ring.

[0007] Further, the coupled resonant optical waveguide is formed by connecting four bent optical waveguides with a fifth adjustable coupler, a sixth adjustable coupler and a seventh adjustable coupler respectively, and includes four ports: an upper left input end, a lower left input end, an upper right output end and a lower right output end; the fifth adjustable coupler, the sixth adjustable coupler and the seventh adjustable coupler are parallel up and down. After the fifth adjustable coupler is connected to the left and right bent optical waveguides, the left side is the upper left input end and the right side is the upper right output end; after the seventh adjustable coupler is connected to the left and right bent optical waveguides, the left side is the lower left input end and the right side is the lower right output end; the optical signal is input from the upper left input end or the lower left input end of the coupled resonant optical waveguide and output from the upper right output end or the lower right output end of the coupled resonant optical waveguide.

[0008] Further, the interleaver is formed by connecting an eighth tunable coupler, a ninth tunable coupler, a tenth tunable coupler, an eleventh tunable coupler, a fourth phase shifter, and a twelfth tunable coupler through straight waveguides and bent optical waveguides, and includes three ports: an input end, an upper right output end, and a lower right output end. The eighth tunable coupler is connected to the ninth tunable coupler and the eleventh tunable coupler respectively through bent optical waveguides. The ninth tunable coupler is connected in series with the tenth tunable coupler through a straight waveguide. The fourth phase shifter is connected to the eleventh tunable coupler through a bent optical waveguide. The eleventh tunable coupler is connected in parallel with the ninth and tenth tunable couplers respectively. The twelfth tunable coupler is connected to the tenth tunable coupler and the fourth phase shifter respectively through bent optical waveguides. Optical signals are input from the input end of the interleaver and output from the upper right output end or the lower right output end of the interleaver.

[0009] Further, the first to twelfth tunable couplers include four ports: an upper left input end, a lower left input end, an upper right output end, and a lower right output end. The upper left input end and the lower left input end are connected to a first coupler with a splitting ratio of 50:50. The upper right output end and the lower right output end are connected to a second coupler with a splitting ratio of 50:50. The third phase shifter is connected to the first coupler with a splitting ratio of 50:50 and the second coupler with a splitting ratio of 50:50 respectively. By adjusting the third phase shifter, the splitting ratio of the output ports of the first to twelfth tunable couplers is tuned.

[0010] The present invention also discloses a method for using a reconfigurable microwave photonic bandpass filter chip, including the following steps:

[0011] Step 1: The continuous wave emitted by the laser enters the phase modulator through the optical input end of the phase modulator. After being modulated by the radio frequency signal, the phase modulator generates positive and negative first-order optical sidebands in the optical domain. The add-drop micro-ring filters the modulated signal, and its through-port outputs the positive and negative first-order optical sidebands, and the drop-port outputs the optical carrier.

[0012] Step 2: The interleaver filters the signal at the through-port of the add-drop micro-ring to separate the positive and negative first-order optical sidebands. Its upper right output end outputs the -1 order optical sideband, and its lower right output end outputs the +1 order optical sideband. The second phase shifter and the second tunable coupler sequentially adjust the phase and amplitude of the optical carrier.

[0013] Step 3: The first phase shifter and the first tunable coupler sequentially adjust the phase and amplitude of the -1 order optical sideband. The coupled resonator optical waveguide performs bandpass filtering on the +1 order optical sideband.

[0014] Step 4: The processed positive and negative first-order optical sidebands are combined through the first coupler, and then combined with the processed optical carrier through the second coupler. Finally, beat frequency is performed through the photodetector to complete the transformation from phase to intensity and realize the microwave photonic bandpass filter.

[0015] Further, in the process of the first phase shifter and the first tunable coupler sequentially adjusting the phase and amplitude of the -1st order optical sideband, the interference cancellation technique is adopted to cancel the out-of-band radio frequency signal, thereby improving the out-of-band rejection ratio of the microwave photonic bandpass filter.

[0016] Further, the laser, phase modulator, add-drop micro-ring, interleaver, first phase shifter, first tunable coupler, coupled-resonator optical waveguide, first coupler, second coupler, second phase shifter, second tunable coupler, and photodetector include discrete devices and on-chip integrated devices.

[0017] Beneficial effects:

[0018] Compared with the prior art, the present invention is based on phase modulation and a reconfigurable chip, and uses a coupled-resonator optical waveguide, a phase shifter, and a tunable coupler to adjust the phase and amplitude of the optical sideband, realizing the cancellation interference of the out-of-band radio frequency signal, and improving the out-of-band rejection ratio and shape factor of the microwave photonic bandpass filter. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of the reconfigurable microwave photonic bandpass filter chip provided by the present invention.

[0020] Figure 2 It is a working principle diagram of the reconfigurable microwave photonic bandpass filter chip of the present invention.

[0021] Figure 3 It is the transmission spectrum of the add-drop port of the add-drop micro-ring of the present invention.

[0022] Figure 4 It is the transmission spectrum of the drop port of the add-drop micro-ring of the present invention.

[0023] Figure 5 It is the transmission spectrum of the two output ports of the interleaver of the present invention.

[0024] Figure 6 It is the transmission spectrum of the coupled-resonator optical waveguide of the present invention.

[0025] Figure 7 It is the radio frequency response of the microwave photonic bandpass filter of the present invention.

[0026] Figure 8 It is the frequency tuning of the microwave photonic bandpass filter of the present invention.

[0027] Description of the reference numerals in the figure: 1. Laser; 2. Phase modulator; 3. Drop-type microring; 4. Interleaver; 5. First phase shifter; 6. First tunable coupler; 7. Coupled-resonator optical waveguide; 8. First coupler; 9. Second coupler; 10. Second phase shifter; 11. Second tunable coupler; 12. Photoelectric detector. Detailed implementation manners

[0028] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further elaborates the present invention in detail with reference to specific embodiments and the accompanying drawings.

[0029] Figure 1 It is a structural schematic diagram of a reconfigurable microwave photonic bandpass filter chip provided by the present invention, including a filter architecture diagram, a reconfigurable chip schematic diagram, a tunable coupler structural schematic diagram, a drop-type microring structural schematic diagram, a coupled-resonator optical waveguide structural schematic diagram, and an interleaver structural schematic diagram. The filter architecture mainly consists of a laser 1, a phase modulator 2, a drop-type microring 3, an interleaver 4, a first phase shifter 5, a first tunable coupler 6, a coupled-resonator optical waveguide 7, a first coupler 8, a second coupler 9, a second phase shifter 10, a second tunable coupler 11, and a photoelectric detector 12. The drop-type microring 3 is formed by connecting a third tunable coupler and a fourth tunable coupler to two bent optical waveguides respectively, and includes three ports: an input end, a through end, and a drop end. An optical signal is input from the input end of the drop-type microring 3 and outputs from the through end or the drop end after entering the device. The coupled-resonator optical waveguide 7 is formed by connecting a fifth tunable coupler, a sixth tunable coupler, and a seventh tunable coupler to four bent optical waveguides respectively, and includes four ports: an upper left input end, a lower left input end, an upper right output end, and a lower right output end. An optical signal is input from the upper left input end or the lower left input end of the coupled-resonator optical waveguide 7 and outputs from the upper right output end or the lower right output end after entering the device. The interleaver 4 is formed by connecting an eighth tunable coupler, a ninth tunable coupler, a tenth tunable coupler, an eleventh tunable coupler, a fourth phase shifter, and a twelfth tunable coupler through straight optical waveguides and bent optical waveguides, and includes three ports: an input end, an upper right output end, and a lower right output end. An optical signal is input from the input end of the interleaver 4 and outputs from the upper right output end or the lower right output end after entering the device. All tunable couplers include four ports: an upper left input end, a lower left input end, an upper right output end, and a lower right output end, two couplers with a splitting ratio of 50:50, and a phase shifter.

[0030] The connection method is as follows: First, connect the optical output end of the laser 1 to the optical input end of the phase modulator 2. Then, connect the input end of the drop-type micro-ring 3 to the optical output end of the phase modulator 2. Next, connect the input end of the interleaver 4 to the through-end of the drop-type micro-ring 3. Connect the upper right output end of the interleaver 4 to the input end of the first phase shifter 5; connect the optical input end of the first tunable coupler 6 to the output end of the first phase shifter 5; connect the lower right output end of the interleaver 4 to the upper left input end (or lower left input end) of the coupled-resonator optical waveguide 7; connect the two input ends of the first coupler 8 to the output end of the first tunable coupler 6 and the lower right output end (or upper right output end) of the coupled-resonator optical waveguide 7 respectively; connect the input end of the second phase shifter 10 to the drop-end of the drop-type micro-ring 3; connect the input end of the second tunable coupler 11 to the output end of the second phase shifter 10; connect the two input ends of the second coupler 9 to the output end of the first coupler 8 and the output end of the second tunable coupler 11 respectively; connect the optical input end of the photodetector 12 to the output end of the second coupler 9.

[0031] Figure 2 This is the working principle diagram of the reconfigurable microwave photonic bandpass filter chip. Set the continuous optical signal output by the laser 1 as an optical carrier with a fixed frequency, as shown by the optical signal A in Figure 2 The phase modulator 2 generates +1st optical sideband and -1st optical sideband in the optical domain through small-signal modulation, as shown in Figure 2As shown by the optical signal B, the two optical sidebands have a π phase difference. Adjust the third adjustable coupler and the fourth adjustable coupler of the add-drop micro-ring 3 to obtain a notch response at its through port and a band-pass response at its drop port simultaneously. Its through port filters out the optical carrier by means of the notch response and outputs the +1st optical sideband and the -1st optical sideband, as shown by the optical signal C; its drop port outputs the optical carrier and filters out the two optical sidebands by means of the band-pass response, as shown by the optical signal D. Adjust all the adjustable couplers and phase shifters in the interleaver 4 to achieve an interleaving response with a high extinction ratio and a high steepness at its output port. Furthermore, separate the two optical sideband signals by using two output ports, with the -1st optical sideband output from its upper right output port, as shown by the optical signal E; and the +1st optical sideband output from its lower right output port, as shown by the optical signal F. Adjust the first phase shifter 5 to perform phase adjustment on the -1st optical sideband, and then adjust the phase shifter of the first adjustable coupler 6 to perform amplitude adjustment on the -1st optical sideband, and output the optical signal G. Adjust the three adjustable couplers of the coupled-resonator optical waveguide 7 to perform band-pass filtering on the +1st optical sideband, and output the optical signal H. The first coupler 8 can combine the optical signal G and the optical signal H and output the optical signal I. Adjust the second phase shifter 10 to perform phase adjustment on the optical carrier, and then adjust the phase shifter of the second adjustable coupler 11 to perform amplitude adjustment on the optical carrier, and output the optical signal J. The second coupler 9 can combine the optical signal I and the optical signal J and output the optical signal K. Finally, perform beat frequency through the photodetector 12 to complete the transformation from phase to intensity and realize the microwave photonic band-pass filter.

[0032] Figure 3 is the transmission spectrum of the through port of the add-drop micro-ring. When the optical signal enters the add-drop micro-ring 3 from the input end, its through port can exhibit a notch response. The device is modeled, simulated, and optimized by using the transfer matrix method. Set the ring length of the add-drop micro-ring 3 to be 2500 μm, and both amplitude transmission coefficients are 0.975. The simulation calculation shows that the free spectral range is 77.2 GHz, and one resonant wavelength is 1.5499 μm (set as the relative frequency 0 GHz). And the extinction ratio at the resonant frequency is 25 dB, and the 3-dB bandwidth is 1.3 GHz. Adjust the phase shifters of the third adjustable coupler and the fourth adjustable coupler to obtain the above simulation parameters and results.

[0033] Figure 4 is the transmission spectrum of the drop port of the add-drop micro-ring. When the optical signal enters the add-drop micro-ring 3 from the input end, its drop port can exhibit a pass-band response. Using Figure 3 the simulation parameters corresponding to the results and substituting them into the transfer matrix, the free spectral range of 77.2 GHz and the resonant wavelength of 1.5499 μm (set as the relative frequency 0 GHz) are also obtained. The extinction ratio at the resonant frequency is 32 dB, and the 3-dB bandwidth is 1.3 GHz. Adjust the phase shifters of the third adjustable coupler and the fourth adjustable coupler to obtain the above simulation parameters and results.

[0034] Figure 5 They are the transmission spectra of the two output ports of the interleaver. When an optical signal enters the interleaver 4 from the input end, the two output ports can exhibit an interleaved response. The transmission matrix method is used to model, simulate, and optimize this device. The ring length of the microring composed of three tunable couplers is set to 2750 μm, the length difference between the two arms is 1375 μm, the splitting ratios of the eighth and twelfth tunable couplers of the interleaver are both adjusted to 50:50, and the amplitude transmission coefficients of the ninth, tenth, and eleventh tunable couplers are set to 0.965, 0.755, and 0.435. Through simulation calculations, a high-performance interleaved response is obtained. Its free spectral range is 140.5 GHz, the extinction ratio is 31 dB, and the frequency transition range is 4.6 GHz. The upper-right output port exhibits a band-pass response from -70 GHz to 0 GHz and a band-stop response from 0 GHz to 70 GHz, which is used to pass the -1st optical sideband and suppress the +1st optical sideband; the lower-right output port exhibits a band-stop response from -70 GHz to 0 GHz and a band-pass response from 0 GHz to 70 GHz, which is used to pass the +1st optical sideband and suppress the -1st optical sideband.

[0035] Figure 6 They are the transmission spectra of the coupled-resonator optical waveguide. It is set that the optical signal enters the coupled-resonator optical waveguide 7 from the upper-left input end, and the lower-right output end can exhibit a band-pass response. The transmission matrix method is used to model, simulate, and optimize this device. The ring lengths of the two microrings composed of the fifth, sixth, and seventh tunable couplers and four bent optical waveguides are both set to 2410 μm, and the power coupling coefficients of the fifth, sixth, and seventh tunable couplers are set to 0.3, 0.03, and 0.3 respectively. Through simulation calculations, a band-pass response is obtained at the lower-right output end. Its free spectral range is 80 GHz, the extinction ratio is 35 dB, and the 3-dB bandwidth is 6.38 GHz. One of the resonant wavelengths deviates from the optical carrier (wavelength 1.5499 μm, relative frequency 0 GHz) by 40 GHz. This band-pass response can perform band-pass filtering on the 0-80 GHz passband range of the output response of the lower-right output port of the interleaver.

[0036] Figure 7 They are the radio-frequency responses of the microwave photonic band-pass filter. The processed optical carrier and two optical sidebands are beat through the photodetector 12, and the entire system outputs a radio-frequency band-pass response. As Figure 7As shown, the center frequency of the radio frequency bandpass response is 40 GHz, the radio frequency gain is -38.8 dB, the 3-dB bandwidth is 6.38 GHz, and the 10-dB bandwidth is 11.04 GHz. The shape factor is defined as the ratio of the 10-dB bandwidth to the 3-dB bandwidth, and the calculated result is 1.73. In addition, the out-of-band rejection ratio is as high as 71 dB. By adjusting the first phase shifter 5 and the first tunable coupler 6 to achieve the cancellation interference of the radio frequency signal outside the passband, the out-of-band rejection ratio can be further optimized.

[0037] Figure 8 For the frequency tuning of the microwave photonic bandpass filter. The frequency tuning of the microwave photonic bandpass filter can be achieved by tuning the resonant wavelength of the transmission spectrum of the coupled resonant optical waveguide 7 or the frequency of the optical carrier. The resonant wavelength of the transmission spectrum of the coupled resonant optical waveguide 7 is shifted 8 GHz to the high frequency, and a radio frequency passband response with a center frequency of 48 GHz is obtained. The resonant wavelength of the transmission spectrum of the coupled resonant optical waveguide 7 is shifted 8 GHz and 16 GHz to the low frequency respectively, and radio frequency bandpass responses with center frequencies of 32 GHz and 24 GHz are obtained respectively. Increasing the free spectral range of the split-type micro-ring, interleaver, and coupled resonant optical waveguide can further increase the frequency tuning range of the microwave photonic bandpass filter.

[0038] It can be understood that the present invention is described through some embodiments. Those skilled in the art know that without departing from the spirit and scope of the present invention, various changes or equivalent replacements can be made to these features and embodiments. In addition, under the teaching of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

Claims

1. A reconfigurable microwave photonic bandpass filter chip, characterized in that, Including: a laser (1), a phase modulator (2), an add-drop micro-ring (3), an interleaver (4), a first phase shifter (5), a first tunable coupler (6), a coupled-resonator optical waveguide (7), a first coupler (8), a second coupler (9), a second phase shifter (10), a second tunable coupler (11) and a photodetector (12); The optical input end of the phase modulator (2) is connected to the optical output end of the laser (1); the input end of the add-drop micro-ring (3) is connected to the optical output end of the phase modulator (2); the input end of the interleaver (4) is connected to the through-end of the add-drop micro-ring (3); the input end of the first phase shifter (5) is connected to the upper right output end of the interleaver (4); the input end of the first tunable coupler (6) is connected to the output end of the first phase shifter (5); the upper left input end or the lower left input end of the coupled-resonator optical waveguide (7) is connected to the lower right output end of the interleaver (4); the two input ends of the first coupler (8) are respectively connected to the output end of the first tunable coupler (6) and the lower right output end or the upper right output end of the coupled-resonator optical waveguide (7); the input end of the second phase shifter (10) is connected to the drop-end of the add-drop micro-ring (3); the input end of the second tunable coupler (11) is connected to the output end of the second phase shifter (10); the two input ends of the second coupler (9) are respectively connected to the output end of the first coupler (8) and the output end of the second tunable coupler (11); the optical input end of the photodetector (12) is connected to the output end of the second coupler (9).

2. The reconfigurable microwave photonic bandpass filter chip according to claim 1, wherein The add-drop micro-ring (3) is formed by connecting two bent optical waveguides with a third tunable coupler and a fourth tunable coupler respectively, and includes three ports: an input end, a through-end and a drop-end; the third tunable coupler and the fourth tunable coupler are parallel up and down. After the third tunable coupler is connected to the left and right bent optical waveguides, the left side is the input end and the right side is the through-end. After the fourth tunable coupler is connected to the left and right bent optical waveguides, the left side is the drop-end; the optical signal is input from the input end of the add-drop micro-ring (3) and output from the through-end or the drop-end of the add-drop micro-ring (3).

3. The reconfigurable microwave photonic bandpass filter chip according to claim 1, wherein The coupled-resonator optical waveguide (7) is formed by connecting four bent optical waveguides with a fifth tunable coupler, a sixth tunable coupler and a seventh tunable coupler respectively, and includes four ports: an upper left input end, a lower left input end, an upper right output end and a lower right output end; the fifth tunable coupler, the sixth tunable coupler and the seventh tunable coupler are parallel up and down. After the fifth tunable coupler is connected to the left and right bent optical waveguides, the left side is the upper left input end and the right side is the upper right output end; after the seventh tunable coupler is connected to the left and right bent optical waveguides, the left side is the lower left input end and the right side is the lower right output end; the optical signal is input from the upper left input end or the lower left input end of the coupled-resonator optical waveguide (7) and output from the upper right output end or the lower right output end of the coupled-resonator optical waveguide (7).

4. A reconfigurable microwave photonic bandpass filter chip according to claim 1, characterized in that, The interleaver (4) is formed by connecting an eighth tunable coupler, a ninth tunable coupler, a tenth tunable coupler, an eleventh tunable coupler, a fourth phase shifter, and a twelfth tunable coupler through straight optical waveguides and bent optical waveguides, and includes three ports: an input end, an upper right output end, and a lower right output end. Among them, the eighth tunable coupler is connected to the ninth tunable coupler and the eleventh tunable coupler respectively through bent optical waveguides. The ninth tunable coupler is connected in series with the tenth tunable coupler through a straight optical waveguide. The fourth phase shifter is connected to the eleventh tunable coupler through a bent optical waveguide. The eleventh tunable coupler is connected in parallel with the ninth and tenth tunable couplers respectively. The twelfth tunable coupler is connected to the tenth tunable coupler and the fourth phase shifter respectively through bent optical waveguides. An optical signal is input from the input end of the interleaver (4) and output from the upper right output end or the lower right output end of the interleaver (4).

5. A reconfigurable microwave photonic bandpass filter chip according to claim 1, characterized in that The first to twelfth tunable couplers include four ports: an upper left input end, a lower left input end, an upper right output end, and a lower right output end. The upper left input end and the lower left input end are connected to a first coupler with a splitting ratio of 50:

50. The upper right output end and the lower right output end are connected to a second coupler with a splitting ratio of 50:

50. The third phase shifter is connected to the first coupler with a splitting ratio of 50:50 and the second coupler with a splitting ratio of 50:50 respectively. By adjusting the third phase shifter, the splitting ratio of the output ports of the first to twelfth tunable couplers is tuned.

6. A method for using a reconfigurable microwave photonic bandpass filter chip, which uses a reconfigurable microwave photonic bandpass filter chip according to any one of claims 1-5, characterized in that , including the following steps: Step 1: The continuous wave emitted by the laser (1) enters the phase modulator (2) through the optical input end of the phase modulator (2). After being modulated by the radio frequency signal, the phase modulator (2) generates positive and negative first-order optical sidebands in the optical domain. The add-drop micro-ring (3) filters the modulated signal, and its through-port outputs the positive and negative first-order optical sidebands, and the drop-port outputs the optical carrier. Step 2: The interleaver (4) filters the signal at the through-port of the add-drop micro-ring (3) to separate the positive and negative first-order optical sidebands. Its upper right output end outputs the -1 order optical sideband, and its lower right output end outputs the +1 order optical sideband. The second phase shifter (10) and the second tunable coupler (11) sequentially perform phase adjustment and amplitude adjustment on the optical carrier. Step 3: The first phase shifter (5) and the first tunable coupler (6) sequentially perform phase adjustment and amplitude adjustment on the -1 order optical sideband. The coupled-resonator optical waveguide (7) performs band-pass filtering on the +1 order optical sideband. Step 4: The processed positive and negative first-order optical sidebands are combined through the first coupler (8), and then combined with the processed optical carrier through the second coupler (9). Finally, beat frequency is performed through the photodetector to complete the transformation from phase to intensity, and a microwave photonic band-pass filter is realized.

7. The method for using a reconfigurable microwave photonic bandpass filter chip according to claim 6, characterized in that, During the process that the first phase shifter (5) and the first tunable coupler (6) sequentially perform phase adjustment and amplitude adjustment on the -1 order optical sideband, an interference cancellation technique is used to cancel the out-of-band radio frequency signal.

8. The usage method of a reconfigurable microwave photonic bandpass filter chip according to claim 6, characterized in that, The laser (1), phase modulator (2), split-type micro-ring (3), interleaver (4), first phase shifter (5), first tunable coupler (6), coupled resonant optical waveguide (7), first coupler (8), second coupler (9), second phase shifter (10), second tunable coupler (11) and photodetector (12) include discrete devices and on-chip integrated devices.

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