Multi-band microwave / millimeter wave signal source with dual-port output

Abstract

The invention discloses a multi-band microwave / millimeter wave signal source with dual-port output. Comprising a narrow linewidth laser, a first optical circulator, an optical fiber coupler, a first optical amplification module, a first Brillouin gain optical fiber, a first optical filter, a first optical detector, a second optical amplification module, a second optical circulator, a second Brillouin gain optical fiber, a second optical filter and a second optical detector. On the basis of stimulated Brillouin scattering in the first Brillouin gain optical fiber and the second Brillouin gain optical fiber and light amplification of the first optical amplifier and the second optical amplifier, even-order Brillouin Stokes light with the wavelength interval being two times of Brillouin frequency shift can be obtained from the upper optical branch and the lower optical branch. The two paths of even-order Brillouin Stokes light respectively pass through two optical filters with specific wavelength selection characteristics, and the required dual-wavelength Brillouin Stokes light is selected. And the two paths of dual-wavelength Brillouin Stokes light respectively enter corresponding optical detectors for photoelectric conversion, so that the output of two paths of multi-band microwave / millimeter wave signals is realized.

Description

Technical Field

[0001] The present invention relates to fiber laser technology and microwave signal photonics generation technology, specifically to a multi-band microwave / millimeter wave signal source with dual-port output, belonging to the field of microwave photonics technology. Background Art

[0002] The rapid development of wireless communications has led to numerous challenges, such as a lack of communication capacity and the need for wider bandwidth. To address these emerging challenges, researchers are considering using new frequency bands, such as 20 GHz, 30 GHz, and even 60 GHz—the high-frequency bands for the emerging 5G / 6G communications. High-frequency microwave signals hold broad application prospects in wireless access, radar, satellite communication systems, and other fields. Traditional electrical methods, due to the "electronics bottleneck," make microwave signal generation systems more complex and costly. Optical methods offer cost-effectiveness and facilitate the generation of higher-frequency microwave / millimeter-wave signals. Furthermore, due to the low transmission loss of optical fiber, microwave signals can be easily loaded onto optical waves in wireless-over-light transmission systems, enabling efficient, long-distance transmission. Therefore, generating high-frequency microwave / millimeter-wave signals using optical methods will play a crucial role in future ultra-wideband wireless access networks.

[0003] This invention uses optical heterodyning to generate microwave signals. The frequency difference between two optical carrier waves is the desired microwave / millimeter-wave signal frequency. By using pump light and Brillouin-Stokes light, or two Brillouin-Stokes light beams, the microwave signal frequency is relatively stable, the optical path structure is simple, and the system cost is low. Depending on the specific optical path, microwave / millimeter-wave signals with frequencies of 20 GHz, 40 GHz, or even higher can be easily obtained, and microwave / millimeter-wave signals can be output from multiple ports. Summary of the Invention

[0004] Among the existing technical solutions, there are many reports on the use of dual-wavelength beat frequency or optical heterodyne method to generate high-frequency microwave signals / millimeter wave signals, and there are also many good results. However, there are few implementation solutions with simple structure and dual-port output. Dual-port or multi-port output of microwave / millimeter signals has very important research significance, because in many applications, multiple microwave / millimeter wave carriers may be required for signal transmission or main and backup microwave / millimeter wave signal sources may be required. Dual-channel microwave / millimeter wave signal sources improve the reliability of system operation. In addition, in an optical path system, providing microwave / millimeter wave signals of multiple frequency bands at the same time greatly simplifies the system structure and saves system costs compared to multiple systems that generate one microwave / millimeter wave signal separately.

[0005] The dual-port output multi-band microwave / millimeter wave signal source proposed in the present invention comprises a narrow linewidth laser (1), a first optical circulator (2), an optical fiber coupler (3), a first optical amplifier module (4), a first Brillouin gain fiber (5), a first optical filter (6), a first optical detector (7), a second optical amplifier module (8), a second optical circulator (9), a second Brillouin gain fiber (10), a second optical filter (11), and a second optical detector (12).

[0006] The dual-port output multi-band microwave / millimeter wave signal source has an output port of a narrow linewidth laser connected to a first port (21) of a first optical circulator, a second port (22) of the first optical circulator connected to a second port (32) of a fiber coupler, a third port (33) of the fiber coupler connected to one end of a first optical amplifier module, the other end of the first optical amplifier module connected to one end of a first Brillouin gain fiber, the other end of the first Brillouin gain fiber connected to the first port (31) of the fiber coupler, a fourth port (34) of the fiber coupler connected to an input port of a first optical filter, and an output port of the first optical filter connected to a The first optical circulator is connected to the input end of the first optical detector, and the output end of the first optical detector serves as the first output port of the microwave / millimeter wave signal source; the third port (23) of the first optical circulator is connected to one end of the second optical amplification module, the other end of the second optical amplification module is connected to the first port (61) of the second optical circulator, the second port (62) of the second optical circulator is connected to the second Brillouin gain optical fiber (8), the third port (63) of the second optical circulator is connected to the input port of the second optical filter, the output port of the second optical filter is connected to the input end of the second optical detector, and the output end of the second optical detector serves as the second output port of the microwave / millimeter wave signal source.

[0007] The multi-band microwave / millimeter wave signal source with dual-port output, its first Brillouin gain fiber and the 31 and 33 ports of the fiber coupler, the first optical amplifier module, and the first optical filter are connected to form a first optical branch, namely, optical branch 33-4-5-31-33; the second optical amplifier module and the second optical circulator and the second Brillouin gain fiber are connected to form a second optical branch, namely, optical branch 7-61-62-8-62-63.

[0008] The multi-band microwave / millimeter wave signal source with dual-port output, the narrow linewidth laser output by the narrow linewidth laser (1) is used as Brillouin pump (BP), BP is transmitted from the first port (21) and the second port (22) of the first optical circulator (2) to the 32nd port of the optical fiber coupler (3) for light splitting, and then a part of BP is output from the 34th port of the optical fiber coupler (3), that is, output from the 34th port of the optical fiber coupler in the first optical branch, and the other part of BP enters the first optical ring from the 33rd port of the optical fiber coupler (3), is amplified by the first optical amplifier module (4), and then is injected into one end of the first Brillouin gain optical fiber (5), when the power of BP (BP can be regarded as zero-order Brillouin Stokes light, that is, BS0) is greater than the power of the first Brillouin gain optical fiber When the stimulated Brillouin scattering threshold of the optical fiber (5) is reached, a first-order Brillouin Stokes light (BS1) with a frequency shifted down by a Brillouin frequency shift value relative to BP is generated. BS1 is transmitted clockwise through port 31 of the optical fiber coupler (3) and enters the first Brillouin gain optical fiber (5). When its power is greater than the stimulated Brillouin scattering threshold of the first Brillouin gain optical fiber (5), a second-order Brillouin Stokes light (BS2) with a frequency shifted down by a Brillouin frequency shift value relative to BS1 is generated. BS2 is transmitted counterclockwise in the same manner as BS0, and so on until the power of the 2n+1 order Stokes light amplified by the first amplifying module (4) is less than the stimulated Brillouin scattering threshold of the first Brillouin gain optical fiber (5). Then BS0, BS2, BS4, ..., BS 2n Even-order Stokes light is output from port 34 of the optical fiber coupler. The first optical filter (9) can selectively pass through BS0 and another Stokes light, and the two even-order Stokes lights are sent to the first optical detector for photoelectric conversion to obtain the first microwave / millimeter wave signal. Obviously, the microwave / millimeter wave signal has various possibilities, such as twice the Brillouin frequency shift value, four times the Brillouin frequency shift value, or even higher. The specific value or frequency band depends on the wavelength selection characteristics of the first optical filter. In addition, a part of BS1, BS3, BS5, ..., BS generated by the first optical branch 2n+1 The odd-order Stokes light enters the second optical branch through ports 33 and 32 of the optical fiber coupler (3) and ports 22 and 23 of the first optical circulator (2), is amplified by the second optical amplifier module (7), and is then transmitted to the first port (61) of the second optical circulator (6), and enters the second Brillouin gain optical fiber (8) from the second port (62) of the second circulator (6). When the power of the odd-order Stokes light is greater than the stimulated Brillouin scattering threshold of the second single-mode optical fiber (8), the corresponding even-order Brillouin Stokes light BS2, BS4, ..., BS4 with a frequency relatively shifted down by a Brillouin frequency shift value is generated. 2n ,BS (2n+2)The even-order Stokes light is output through the third port (63) of the second optical circulator (6), i.e., the output port of the second optical branch, and enters the second optical filter (11). The second optical filter can selectively pass BS2 and another even-order Stokes light, and send the two even-order Stokes lights into the second optical detector for photoelectric conversion to obtain a second microwave / millimeter wave signal. Obviously, the microwave / millimeter wave signal has various possibilities, such as twice the Brillouin frequency shift value, four times the Brillouin frequency shift value, or even higher. The specific value or frequency band depends on the wavelength selection characteristics of the second optical filter.

[0009] The concept of the multi-band microwave / millimeter wave signal source with dual-port output is further described as follows: the multi-wavelength Brillouin Stokes light generated by the first optical branch and the second optical branch is twice the Brillouin frequency shift wavelength interval (2νGHz or 2λ ν nm) multi-wavelength Brillouin-Stokes light, wherein the multi-wavelength Brillouin-Stokes light entering the first optical filter is BS0, BS2, BS4, BS6, ..., BS 2n , the multi-wavelength Brillouin-Stokes light entering the second optical filter is BS2, BS4, BS6, ..., BS 2n+2When the optical filter selects two Brillouin Stokes lights (or two adjacent Brillouin Stokes lights) separated by two times the Brillouin frequency shift, for example, for the first output port of the microwave / millimeter wave signal source, when the Brillouin pump BP or the zero-order Brillouin Stokes light BS0 and the second-order Brillouin Stokes light BS2 are selected to pass through the first optical wave filter and enter the first photodetector, the microwave signal obtained at the output end of the first photodetector is 2ν GHz. When the first optical filter selects to pass two Brillouin Stokes lights separated by four times the Brillouin frequency shift, such as the Brillouin pump BP and the fourth-order Brillouin Stokes light BS4, the microwave signal obtained at the output end of the first photodetector is 4ν GHz, and so on, up to 2nν GHz. Similarly, for the second output port of the microwave / millimeter-wave signal source, when second-order Stokes light BS2 and fourth-order Brillouin Stokes light BS4 are selected to pass through the second optical filter and enter the second photodetector, the microwave signal obtained at the output port of the second photodetector is 2ν GHz. When the second optical filter selects to pass two Brillouin Stokes lights separated by four Brillouin frequency shifts, such as BS2 and sixth-order Brillouin Stokes light BS6, the microwave signal obtained at the output port of the second photodetector is 4ν GHz. This continues in this manner, up to 2nν GHz. Theoretically, depending on the wavelength selectivity of the two optical filters in the first and second optical branches, microwave / millimeter-wave signals of the desired frequency band can be obtained at the two output ports of the microwave / millimeter-wave signal source. That is, the two signal output ports can output microwave signals of the same frequency band or different frequency bands. The highest frequency band of the output microwave / millimeter-wave signal depends on the order of the highest available even-order Brillouin Stokes light and the wavelength selectivity of the optical filter.

[0010] The present invention adopts a narrow linewidth laser, two optical circulators, a fiber coupler, two optical amplifier modules and two disks. The Brillouin frequency shift value at room temperature is νGHz (corresponding to the Brillouin wavelength drift λ ν The invention relates to a Brillouin gain fiber having a wavelength of 100 nm and a wavelength of 200 nm. The narrow linewidth laser is a C-band narrow linewidth laser, and the output wavelength and power can be continuously tuned. The maximum output power is 15 dBm, and the linewidth is less than 1 MHz. The first and second optical amplifier modules are connected by a 980 nm pump laser, a 4 m long erbium-doped optical fiber and a 1550 / 980 wavelength division multiplexer, and can realize bidirectional amplification of optical signals. The first and second optical filters are both dual-wavelength selection optical filters. The even-order Brillouin Stokes light output from the 34 port of the optical fiber coupler (3) and the even-order Brillouin Stokes light output from the 63 port of the second optical circulator (6) are filtered by the first and second optical filters respectively, and the two required wavelength channels can be selected. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1This is a schematic diagram of the composition structure of a multi-band microwave / millimeter wave signal source with dual-port output.

[0012] Figure 2 This is a schematic diagram of the wavelength selection characteristics of two optical filters.

[0013] Figure 1 The reference numerals in the figure are explained as follows: 1- narrow linewidth laser, 2- first optical circulator, 21, 22, 23 are the first port, second port and third port of the optical circulator respectively, 3- fiber coupler, 31, 32, 33, 34 are the four ports of the fiber coupler respectively, 4- first optical amplifier module, 5- first Brillouin gain fiber, 6- second optical circulator, 61, 62, 63 are the first port, second port and third port of the second optical circulator respectively, 7- second optical amplifier module, 8- second Brillouin gain fiber, 9- first optical filter, 10- first photodetector, 11- second optical filter, 12- second photodetector. n is a positive integer greater than or equal to 1, λ BS0 ,λ BS2 , ν and λ ν They are the Brillouin pump (BP) wavelength, the second-order Brillouin Stokes light wavelength, the Brillouin frequency shift and the Brillouin wavelength drift. DETAILED DESCRIPTION

[0014] The technical solution of the present invention is further described below with reference to the accompanying drawings.

[0015] The dual-port output multi-band microwave / millimeter wave signal source proposed in the present invention comprises a narrow linewidth laser (1), a first optical circulator (2), an optical fiber coupler (3), a first optical amplifier module (4), a first Brillouin gain fiber (5), a first optical filter (6), a first optical detector (7), a second optical amplifier module (8), a second optical circulator (9), a second Brillouin gain fiber (10), a second optical filter (11), and a second optical detector (12).

[0016] The dual-port output multi-band microwave / millimeter wave signal source has an output port of a narrow linewidth laser connected to a first port (21) of a first optical circulator, a second port (22) of the first optical circulator connected to a second port (32) of a fiber coupler, a third port (33) of the fiber coupler connected to one end of a first optical amplifier module, the other end of the first optical amplifier module connected to one end of a first Brillouin gain fiber, the other end of the first Brillouin gain fiber connected to the first port (31) of the fiber coupler, a fourth port (34) of the fiber coupler connected to an input port of a first optical filter, and an output port of the first optical filter connected to a The first optical circulator is connected to the input end of the first optical detector, and the output end of the first optical detector serves as the first output port of the microwave / millimeter wave signal source; the third port (23) of the first optical circulator is connected to one end of the second optical amplification module, the other end of the second optical amplification module is connected to the first port (61) of the second optical circulator, the second port (62) of the second optical circulator is connected to the second Brillouin gain optical fiber (8), the third port (63) of the second optical circulator is connected to the input port of the second optical filter, the output port of the second optical filter is connected to the input end of the second optical detector, and the output end of the second optical detector serves as the second output port of the microwave / millimeter wave signal source.

[0017] The multi-band microwave / millimeter wave signal source with dual-port output, its first Brillouin gain fiber and the 31 and 33 ports of the fiber coupler, the first optical amplifier module, and the first optical filter are connected to form a first optical branch, namely, optical branch 33-4-5-31-33; the second optical amplifier module and the second optical circulator and the second Brillouin gain fiber are connected to form a second optical branch, namely, optical branch 7-61-62-8-62-63.

[0018] The multi-band microwave / millimeter wave signal source with dual-port output, the narrow linewidth laser output by the narrow linewidth laser (1) is used as Brillouin pump (BP), BP is transmitted from the first port (21) and the second port (22) of the first optical circulator (2) to the 32nd port of the optical fiber coupler (3) for light splitting, and then a part of BP is output from the 34th port of the optical fiber coupler (3), that is, output from the 34th port of the optical fiber coupler in the first optical branch, and the other part of BP enters the first optical ring from the 33rd port of the optical fiber coupler (3), is amplified by the first optical amplifier module (4), and then is injected into one end of the first Brillouin gain optical fiber (5), when the power of BP (BP can be regarded as zero-order Brillouin Stokes light, that is, BS0) is greater than the power of the first Brillouin gain optical fiber When the stimulated Brillouin scattering threshold of the optical fiber (5) is reached, a first-order Brillouin Stokes light (BS1) with a frequency shifted down by a Brillouin frequency shift value relative to BP is generated. BS1 is transmitted clockwise through port 31 of the optical fiber coupler (3) and enters the first Brillouin gain optical fiber (5). When its power is greater than the stimulated Brillouin scattering threshold of the first Brillouin gain optical fiber (5), a second-order Brillouin Stokes light (BS2) with a frequency shifted down by a Brillouin frequency shift value relative to BS1 is generated. BS2 is transmitted counterclockwise in the same manner as BS0, and so on until the power of the 2n+1 order Stokes light amplified by the first amplifying module (4) is less than the stimulated Brillouin scattering threshold of the first Brillouin gain optical fiber (5). Then BS0, BS2, BS4, ..., BS 2n Even-order Stokes light is output from port 34 of the optical fiber coupler. The first optical filter (9) can selectively pass through BS0 and another Stokes light, and the two even-order Stokes lights are sent to the first optical detector for photoelectric conversion to obtain the first microwave / millimeter wave signal. Obviously, the microwave / millimeter wave signal has various possibilities, such as twice the Brillouin frequency shift value, four times the Brillouin frequency shift value, or even higher. The specific value or frequency band depends on the wavelength selection characteristics of the first optical filter. In addition, a part of BS1, BS3, BS5, ..., BS generated by the first optical branch 2n+1 The odd-order Stokes light enters the second optical branch through ports 33 and 32 of the optical fiber coupler (3) and ports 22 and 23 of the first optical circulator (2), is amplified by the second optical amplifier module (7), and is then transmitted to the first port (61) of the second optical circulator (6), and enters the second Brillouin gain optical fiber (8) from the second port (62) of the second circulator (6). When the power of the odd-order Stokes light is greater than the stimulated Brillouin scattering threshold of the second single-mode optical fiber (8), the corresponding even-order Brillouin Stokes light BS2, BS4, ..., BS4 with a frequency relatively shifted down by a Brillouin frequency shift value is generated. 2n ,BS (2n+2)The even-order Stokes light is output through the third port (63) of the second optical circulator (6), i.e., the output port of the second optical branch, and enters the second optical filter (11). The second optical filter can selectively pass BS2 and another even-order Stokes light, and send the two even-order Stokes lights into the second optical detector for photoelectric conversion to obtain a second microwave / millimeter wave signal. Obviously, the microwave / millimeter wave signal has various possibilities, such as twice the Brillouin frequency shift value, four times the Brillouin frequency shift value, or even higher. The specific value or frequency band depends on the wavelength selection characteristics of the second optical filter.

[0019] The concept of the multi-band microwave / millimeter wave signal source with dual-port output is further explained as follows: the multi-wavelength Brillouin Stokes light generated by the first optical branch and the second optical branch is a multi-wavelength Brillouin Stokes light with a wavelength interval of twice the Brillouin frequency shift (22 GHz or 2*0.088 nm), wherein the multi-wavelength Brillouin Stokes light entering the first optical filter is BS0, BS2, BS4, BS6, ..., BS 2n , the multi-wavelength Brillouin-Stokes light entering the second optical filter is BS2, BS4, BS6, ..., BS 2n+2When the optical filter selects two Brillouin Stokes lights (or two adjacent Brillouin Stokes lights) separated by two times the Brillouin frequency shift, for example, for the first output port of the microwave / millimeter wave signal source, when the Brillouin pump BP or the zero-order Brillouin Stokes light BS0 and the second-order Brillouin Stokes light BS2 are selected to pass through the first optical wave filter and enter the first photodetector, the microwave signal obtained at the output end of the first photodetector is 22 GHz. When the first optical filter selects to pass two Brillouin Stokes lights separated by four times the Brillouin frequency shift, such as the Brillouin pump BP and the fourth-order Brillouin Stokes light BS4, the microwave signal obtained at the output end of the first photodetector is 44 GHz, and so on, up to 44n GHz. Similarly, for the second output port of the microwave / millimeter-wave signal source, when second-order Stokes light BS2 and fourth-order Brillouin Stokes light BS4 are selected to pass through the second optical filter and enter the second photodetector, the microwave signal obtained at the output port of the second photodetector is 22 GHz. When the second optical filter selects to pass two Brillouin Stokes lights separated by four Brillouin frequency shifts, such as BS2 and sixth-order Brillouin Stokes light BS6, the microwave signal obtained at the output port of the second photodetector is 44 GHz. This frequency range continues, up to 44n GHz. Theoretically, depending on the wavelength selectivity of the two optical filters in the first and second optical branches, microwave / millimeter-wave signals of the desired frequency band can be obtained at the two output ports of the microwave / millimeter-wave signal source. That is, the two signal output ports can output microwave signals of the same frequency band or different frequency bands. The highest frequency band of the output microwave / millimeter-wave signal depends on the order of the highest available even-order Brillouin Stokes light and the wavelength selectivity of the optical filter.

[0020] The narrow linewidth laser is a C-band narrow linewidth semiconductor laser, the output wavelength and power of which can be continuously tuned, the maximum output power is 15dBm, and the linewidth is less than 1MHz.

[0021] The first and second optical amplification modules are both connected by a 980nm pump laser, a 4m long erbium-doped optical fiber and a 1550 / 980 wavelength division multiplexer, and can achieve bidirectional amplification of optical signals.

[0022] The first and second Brillouin gain fibers are common single-mode fibers with the same Brillouin frequency value, and the Brillouin frequency shift value is 11 GHz.

[0023] The first and second optical filters are both dual-wavelength selective optical filters. After the even-order Brillouin-Stokes light output from the fiber coupler 34 port and the even-order Brillouin-Stokes light output from the second circulator 63 port are filtered by the first and second optical filters, two desired wavelength channels can be selected. The wavelength interval between the two wavelength channels of the first and second optical filters (the corresponding frequency is equal to the frequency of the microwave signal) can be matched and designed as needed. For example, the dual-wavelength selective optical filter can be designed as follows: the wavelengths of the two desired output Brillouin-Stokes lights are used as the center wavelengths of two fiber Bragg gratings, and the two fiber Bragg gratings are cascaded to form the desired optical filter.

[0024] The first and second photoelectric detectors are both broadband and high-speed photoelectric detectors, and the specific bandwidth is configured according to the frequency band of the microwave / millimeter signal to be generated.

[0025] The working process of the present invention is described in detail above. For those skilled in the art, based on the concept provided by the present invention, there may be changes in the specific implementation method, such as changing the position of the optical amplifier module, changing the splitting ratio of the optical fiber coupler and the length of the single-mode optical fiber in the optical path, etc. These changes should also be considered within the scope of protection of the present invention.

Claims

1. A multi-band microwave / millimeter wave signal source with dual-port output, characterized in that: The invention comprises a narrow linewidth laser (1), a first optical circulator (2), an optical fiber coupler (3), a first optical amplifier module (4), a first Brillouin gain optical fiber (5), a first optical wave filter (6), a first optical detector (7), a second optical amplifier module (8), a second optical circulator (9), a second Brillouin gain optical fiber (10), a second optical filter (11), and a second optical detector (12); the output port of the narrow linewidth laser is connected to the first port (21) of the first optical circulator, the second port (22) of the first optical circulator is connected to the second port (32) of the optical fiber coupler, the third port (33) of the optical fiber coupler is connected to one end of the first optical amplifier module, the other end of the first optical amplifier module is connected to one end of the first Brillouin gain optical fiber, and the other end of the first Brillouin gain optical fiber is connected to the optical fiber. The first port (31) of the coupler is connected to the first optical filter, the fourth port (34) of the optical fiber coupler is connected to the input port of the first optical filter, the output port of the first optical filter is connected to the input end of the first optical detector, and the output end of the first optical detector serves as the first output port of the microwave / millimeter wave signal source; the third port (23) of the first optical circulator is connected to one end of the second optical amplification module, the other end of the second optical amplification module is connected to the first port (61) of the second optical circulator, the second port (62) of the second optical circulator is connected to the second Brillouin gain optical fiber (8), the third port (63) of the second optical circulator is connected to the input port of the second optical filter, the output port of the second optical filter is connected to the input end of the second optical detector, and the output end of the second optical detector serves as the second output port of the microwave / millimeter wave signal source.

2. The dual-port output multi-band microwave / millimeter wave signal source according to claim 1, characterized in that: The laser light output by the narrow-linewidth laser is used as Brillouin pump light. The Brillouin pump light enters an optical loop circuit composed of a fiber coupler, a first optical amplifier module, and a first Brillouin gain fiber through the second port of the first optical circulator. The even-order Brillouin Stokes light generated in the optical loop circuit and a portion of the Brillouin pump light from the narrow-linewidth laser are output from the fourth port of the fiber coupler and enter the first optical filter to receive dual-wavelength gating by the first optical filter. The dual-wavelength Brillouin Stokes light output by the gating enters the first optical detector for photoelectric conversion to generate a microwave / millimeter wave signal of a required frequency band; the odd-order Brillouin Stokes light generated in the optical loop enters and serves as Brillouin pump light into an optical branch composed of a second optical amplifier module, a second optical circulator, and a second Brillouin gain fiber through the second port and the third port of the first optical circulator, thereby generating even-order Brillouin Stokes light in the second Brillouin gain fiber in the optical branch; the generated even-order Brillouin Stokes light is output from the third port of the second optical circulator and enters the second optical filter to receive dual-wavelength gating by the second optical filter; The dual-wavelength Brillouin-Stokes light output by the strobe enters the second photodetector for photoelectric conversion to generate a microwave / millimeter wave signal of a required frequency band.

3. The multi-band microwave / millimeter wave signal source with dual-port output according to claim 1, characterized in that: The first optical amplifying module and the second optical amplifying module can both bidirectionally amplify optical signals.

4. The multi-band microwave / millimeter wave signal source with dual-port output according to claim 1, characterized in that: The first Brillouin gain fiber and the second Brillouin gain fiber have the same Brillouin frequency shift value.

5. The dual-port output multi-band microwave / millimeter wave signal source according to claim 1, characterized in that The first and second optical filters are both optical filters that can selectively pass dual wavelengths. The interval between the dual wavelengths is n times twice the Brillouin frequency shift, where n is a positive integer greater than or equal to 1.

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