阅读说明：本技术 一种基于ps-cfbg的可调谐多倍频毫米波发生器 (Tunable multiple frequency millimeter wave generator based on PS-CFBG ) 是由 王一群 于 2021-06-24 设计创作，主要内容包括：本发明为一种基于PS-CFBG的可调谐多倍频毫米波发生器,包括激光器、毫米波本振源、马赫增德尔调制器、PS-CFBG型可调滤波器、光纤放大器、光电探测器和带通滤波器；激光器的输出端与马赫增德尔调制器的光输入端连接,毫米波本振源的输出端与马赫增德尔调制器的电调制端连接,马赫增德尔调制器的光输出端与PS-CFBG型可调滤波器的一端连接,PS-CFBG型可调滤波器的另一端与光纤放大器的输入端连接,光纤放大器的输出端与光电探测器的输入端连接,光电探测器的输出端与带通滤波器连接。只需改变施加在啁啾光纤光栅上的两个π相移点之间的距离即可实现任意倍频因子,且倍频因子可调谐的毫米波信号的输出。(The invention relates to a tunable multi-frequency multiplication millimeter wave generator based on PS-CFBG, which comprises a laser, a millimeter wave local vibration source, a Mach-Zehnder modulator, a PS-CFBG type adjustable filter, an optical fiber amplifier, a photoelectric detector and a band-pass filter, wherein the millimeter wave local vibration source is connected with the Mach-Zehnder modulator through the tunable multi-frequency multiplication millimeter wave generator; the output end of the laser is connected with the optical input end of the Mach-Zehnder modulator, the output end of the millimeter wave local oscillation source is connected with the electrical modulation end of the Mach-Zehnder modulator, the optical output end of the Mach-Zehnder modulator is connected with one end of the PS-CFBG-type adjustable filter, the other end of the PS-CFBG-type adjustable filter is connected with the input end of the optical fiber amplifier, the output end of the optical fiber amplifier is connected with the input end of the photoelectric detector, and the output end of the photoelectric detector is connected with the band-pass filter. The output of millimeter wave signals with any frequency doubling factor and tunable frequency doubling factor can be realized only by changing the distance between two pi phase shift points applied to the chirped fiber grating.)

1. A tunable frequency multiplication millimeter wave generator based on PS-CFBG is characterized in that the device comprises: the device comprises a laser (11), a millimeter wave local oscillation source (12), a Mach-Zehnder modulator (13), a PS-CFBG type adjustable filter (14), an optical fiber amplifier (15), a photoelectric detector (16) and a band-pass filter (17); the concrete connection mode is as follows:

the output end of the laser (11) is connected with the optical input end of the Mach-Zehnder modulator (13), the output end of the millimeter wave local oscillation source (12) is connected with the electrical modulation end of the Mach-Zehnder modulator (13), the optical output end of the Mach-Zehnder modulator (13) is connected with one end of the PS-CFBG-type adjustable filter (14), the other end of the PS-CFBG-type adjustable filter (14) is connected with the input end of the optical fiber amplifier (15), the output end of the optical fiber amplifier (15) is connected with the input end of the photoelectric detector (16), and the output end of the photoelectric detector (16) is connected with the band-pass filter (17); wherein the PS-CFBG type adjustable filter (14) consists of a piezoelectric ceramic piece and a chirped fiber grating.

2. The PS-CFBG-based tunable frequency-multiplied millimeter wave generator of claim 1, wherein the mach-zehnder modulator (13) outputs an optical double sideband modulated signal comprising an optical carrier and an order optical sideband.

3. The PS-CFBG-based tunable frequency-multiplied millimeter wave generator of claim 2, wherein the mach-zehnder modulator (13) is capable of optical double sideband modulation when operated in a suitable operating mode.

4. The PS-CFBG-based tunable frequency multiplication millimeter wave generator according to claim 2, wherein the Mach-Zehnder modulator (13) comprises a single-drive Mach-Zehnder modulator or a dual-drive Mach-Zehnder modulator, and the Mach-Zehnder modulator (13) is capable of cascading other types of modulators to increase the number of optical sidebands and achieve millimeter wave signal generation with more frequency multiplication factors.

5. The tunable frequency multiplication millimeter wave generator based on the PS-CFBG of claim 2, wherein two identical pi phase shifts are applied to the PS-CFBG type tunable filter (14) to enable two transmission peaks to appear in a transmission spectrum, the wavelengths of the two transmission peaks are matched with the wavelengths of two arbitrary components in an optical double-sideband modulation signal, the two harmonic components are selected for beat frequency, and the generation of millimeter wave signals with arbitrary frequency multiplication and tunable frequency multiplication factors can be realized; the distance d between the two pi phase shift points can be calculated according to the wavelength interval delta lambda between the two narrow bands in the frequency spectrum passband of the PS-CFBG type adjustable filter, the delta lambda and the distance d between the two pi phase shift points satisfy a direct proportion relation, and the slope is 0.1714 nm/cm.

6. The tunable PS-CFBG-based frequency multiplied millimeter wave generator of claim 5, wherein the introduction of the pi phase shift point on the chirped fiber grating in the PS-CFBG type tunable filter (14) is achieved by adjusting the driving voltage across the piezoceramic wafer.

7. The tunable PS-CFBG-based frequency-multiplied millimeter wave generator of claim 1, wherein the laser (11) comprises a pulsed mode-locked laser or a continuous wave laser.

Technical Field

The invention relates to a PS-CFBG-based tunable multi-frequency millimeter wave generator, belonging to the fields of optical fiber communication, electro-optical modulation and signal processing.

Background

Microwave photonics is a science for studying the interaction between microwaves and photons and the application thereof. In recent years, one of the most important applications of microwave photonics is the transmission of microwave carrier signals using optical fibers in wireless communication, which is called Radio over Fiber (RoF) communication system. The RoF communication system combines the advantages of traditional microwave communication and optical communication, and utilizes optical fiber remote extension to prolong the space transmission distance of high-frequency microwave signals, so that wireless broadband access up to Gbps magnitude can be realized on the basis, the network communication capacity is improved by one to two magnitude orders, and the application prospect is wide. The photonics generation method of high-quality millimeter waves is one of the research hotspots in the RoF field at present.

A device for generating a microwave signal using an optical domain method is called a microwave photon generator in microwave photonics, and can effectively solve an electrical domain bottleneck. If the microwave photon generator is used to generate microwave signals in the millimeter wave band, it is also called a millimeter wave generator. Millimeter wave frequencies generated based on optical methods can have a very high continuous tuning range. The millimeter wave optical domain generation technology has been diversified after decades of development, and research work on millimeter wave generators has been reported to be centered around the problem of millimeter wave generation, and because the working frequency range of millimeter waves per se is very high (30-300 GHz), experimental equipment is required to work in the millimeter wave frequency range, the research of the millimeter wave technology is focused on generating stable and frequency-tunable radio-frequency millimeter wave signals by using relatively low technical cost. Generally used millimeter wave generation methods mainly include a direct modulation method (internal modulation method), an indirect modulation method (external modulation method), a frequency up-conversion method, an optical heterodyne method, and the like. The external modulator is widely applied to the RoF system due to the flexible modulation mode and high modulation efficiency.

The chirp phase shift fiber grating (PS-CFBG) can realize multi-channel narrow-band filtering by introducing phase shift on the chirp fiber grating (CFBG) to enable one or more mutually independent narrow bands to appear in the frequency spectrum of the fiber grating. The PS-CFBG type tunable filter has the advantages of special transmission characteristics, simple structure and the like, and can be used for filtering, multiplexing, frequency selection of fiber lasers and the like.

The introduction of a tunable phase shift on a fiber grating is generally achieved by means of external modulation, the effect on the refractive index of the fiber grating being reversible. In principle, the methods commonly used to introduce phase-shifting are mainly two types, local heating resulting in refractive index changes in the phase-shifting regions and external forces resulting in small deformations of the phase-shifting regions.

When two same pi phase shifts are introduced to the CFBG at the same time, two narrow bands appear in the frequency spectrum pass band of the PS-CFBG type adjustable filter, and the filtering strengths of the two narrow bands in the frequency spectrum pass band of the PS-CFBG type adjustable filter are almost the same. The number of narrow bands in the frequency spectrum pass band of the PS-CFBG type tunable filter and the filtering strength of each narrow band are almost constant with the distance between two pi phase shifts changing, namely the number of narrow bands and the filtering strength of each narrow band are independent of the distance between the phase shift introduction positions. The wavelength separation between two narrow-band filtered wavelengths within the spectral passband of a PS-CFBG type tunable filter varies with the distance d between the two pi-phase shifts on the CFBG. The wavelength interval delta lambda between two narrow bands in the frequency spectrum passband of the PS-CFBG type tunable filter and the distance d between two phase shift points satisfy a direct proportion relation, and the slope is 0.1714 nm/cm.

Disclosure of Invention

The invention aims to solve the technical problems of complex generation technology, high cost and poor tuning performance of millimeter wave signals in the existing RoF system, and fully utilizes the characteristics of PS-CFBG (packet switched fiber-frequency group) to provide a tunable multi-frequency millimeter wave generator based on PS-CFBG (packet switched fiber-frequency group) so as to realize flexible generation of millimeter wave signals with any frequency multiplication and tunable frequency multiplication factors.

In order to achieve the above purposes, the technical scheme adopted by the invention is as follows:

a tunable frequency multiplication millimeter wave generator based on PS-CFBG, which comprises: the device comprises a laser, a millimeter wave local oscillation source, a Mach-Zehnder modulator, a PS-CFBG type adjustable filter, an optical fiber amplifier, a photoelectric detector and a band-pass filter; the concrete connection mode is as follows:

the output end of the laser is connected with the optical input end of the Mach-Zehnder modulator, the output end of the millimeter wave local vibration source is connected with the electrical modulation end of the Mach-Zehnder modulator, the optical output end of the Mach-Zehnder modulator is connected with one end of the PS-CFBG-type adjustable filter, the other end of the PS-CFBG-type adjustable filter is connected with the input end of the optical fiber amplifier, the output end of the optical fiber amplifier is connected with the input end of the photoelectric detector, and the output end of the photoelectric detector is connected with the band-pass filter; the PS-CFBG type tunable filter consists of a piezoelectric ceramic piece and a chirped fiber grating (CFBG).

Based on the scheme, the optical double sideband modulation signal output by the Mach-Zehnder modulator comprises an optical carrier and each order optical sideband.

Based on the scheme, when the Mach-Zehnder modulator works in a proper working mode, the optical double-sideband modulation can be realized.

On the basis of the scheme, the Mach-Zehnder modulator comprises a single-drive Mach-Zehnder modulator or a double-drive Mach-Zehnder modulator, and the Mach-Zehnder modulator can be connected with other types of modulators in a cascade mode to increase the number of optical sidebands, so that millimeter wave signals with more frequency multiplication factors can be generated.

On the basis of the scheme, two one-sample pi phase shifts are applied to the PS-CFBG type adjustable filter to enable two transmission peaks to appear in a transmission spectrum, the wavelengths of the two transmission peaks are matched with the wavelengths of two arbitrary components in an optical double-sideband modulation signal, the two harmonic components are selected for beat frequency, and arbitrary frequency multiplication and frequency multiplication factor tunable millimeter wave signals can be generated; the distance d between the two pi phase shift points can be calculated according to the wavelength interval delta lambda between the two narrow bands in the frequency spectrum passband of the PS-CFBG type tunable filter, the distance d between the delta lambda and the two pi phase shift points satisfies a direct proportion relation, and the slope is 0.1714 nm/cm.

On the basis of the scheme, the introduction of the pi phase shift point on the chirped fiber grating (CFBG) in the PS-CFBG type tunable filter is realized by adjusting the driving voltage at two ends of the piezoelectric ceramic piece, the adjustment is convenient, and the introduced phase shift can accurately control the phase shift amount.

On the basis of the above scheme, the laser includes a pulse mode-locked laser (MLL) or a continuous wave laser (CW).

Compared with the prior art, the invention has the following beneficial effects:

the invention adopts the PS-CFBG type adjustable filter, can realize any frequency multiplication factor by only changing the distance between two pi phase shift points applied on the CFBG, and can output the millimeter wave signal with the frequency multiplication factor adjustable. The whole device only comprises a laser, a millimeter wave local oscillator, a Mach-Zehnder modulator, a PS-CFBG type adjustable filter, an optical fiber amplifier, a photoelectric detector and a band-pass filter, wherein the PS-CFBG type adjustable filter only comprises a piezoelectric ceramic chip and a section of CFBG, the construction cost is low, the PS-CFBG type adjustable filter can be well matched with a communication optical fiber, and the connection loss is small. The invention can realize the generation of multiple frequency multiplication millimeter wave signals with any frequency multiplication and tunable frequency multiplication factors, thereby being suitable for the fields of design and optimization of millimeter wave generators in the microwave photon field and the like.

Drawings

The invention has the following drawings:

FIG. 1 is a schematic diagram of a tunable multiple frequency millimeter wave generator based on PS-CFBG.

Fig. 2 is a schematic diagram of a double sideband modulated signal output by a mach-zehnder modulator.

FIG. 3 is a diagram illustrating a transmission spectrum of a PS-CFBG type tunable filter according to an embodiment.

Fig. 4 is an electrical spectrum diagram of a frequency-2 multiplied millimeter wave signal generated in the first embodiment.

FIG. 5 is a diagram of the transmission spectrum of the PS-CFBG type tunable filter in the second embodiment.

Fig. 6 is an electrical spectrum diagram of a 4-frequency-doubled millimeter wave signal generated in the second embodiment.

FIG. 7 is a diagram showing the transmission spectrum of the PS-CFBG type tunable filter in the third embodiment.

Fig. 8 is an electrical spectrum diagram of a 6-frequency-doubled millimeter wave signal generated in the third embodiment.

FIG. 9 is a diagram of the transmission spectrum of the PS-CFBG type tunable filter in the fourth embodiment.

Fig. 10 is a spectrogram of the frequency-doubled 1 millimeter wave signal generated in the fourth embodiment.

FIG. 11 is a diagram of the transmission spectrum of the PS-CFBG type tunable filter in the fifth embodiment.

Fig. 12 is an electrical spectrum diagram of a frequency-3 multiplied millimeter wave signal generated in the fifth embodiment.

FIG. 13 is a diagram showing the transmission spectrum of the PS-CFBG type tunable filter in the sixth embodiment.

Fig. 14 is an electrical spectrum diagram of a 5-frequency-doubled millimeter wave signal generated in the sixth embodiment.

Detailed Description

The tunable multiple frequency millimeter wave generator based on PS-CFBG is further described with reference to fig. 1 to 14.

Example one

A tunable frequency multiplication millimeter wave generator based on PS-CFBG, which comprises: the device comprises a laser 11, a millimeter wave local oscillation source 12, a Mach-Zehnder modulator 13, a PS-CFBG type adjustable filter 14, an optical fiber amplifier 15, a photoelectric detector 16 and a band-pass filter 17; the specific connection mode is as follows:

the output end of the laser 11 is connected with the optical input end of a Mach-Zehnder modulator 13, the output end of a millimeter-wave local oscillation source 12 is connected with the electrical modulation end of the Mach-Zehnder modulator 13, the optical output end of the Mach-Zehnder modulator 13 is connected with one end of a PS-CFBG-type tunable filter 14, the other end of the PS-CFBG-type tunable filter 14 is connected with the input end of an optical fiber amplifier 15, the output end of the optical fiber amplifier 15 is connected with the input end of a photoelectric detector 16, and the output end of the photoelectric detector 16 is connected with a band-pass filter 17; wherein the PS-CFBG type tunable filter 14 is composed of a piezoelectric ceramic plate and a chirped fiber grating.

In this example, the sine wave signal generated by the millimeter wave local oscillation source 12 is 10GHz, the center frequency of the laser 11 is 1550.00nm, and the light double-sideband signal is modulated by the mach-zehnder modulator 13; carrier frequency 2g, +1 th order sideband 2a, -1 st order sideband 2b, +2 th order sideband 2c, -2 th order sideband 2d, +3 th order sideband 2e, and-3 th order sideband 2f, as shown in fig. 2. The distance between two pi phase shift points of the PS-CFBG type tunable filter is 9.33cm, the transmission spectrum is shown in FIG. 3, 2a and 2b are respectively amplified by 3a and 3b in FIG. 3 through an optical fiber amplifier 15, the beat frequency of a photoelectric detector 16 and the electric spectrum of a frequency doubling millimeter wave signal generated after filtering by a band-pass filter 17 with the center frequency of 20GHz and the bandwidth of 1GHz are shown in FIG. 4.

Example two

A tunable frequency multiplication millimeter wave generator based on PS-CFBG, which comprises: the device comprises a laser 11, a millimeter wave local oscillation source 12, a Mach-Zehnder modulator 13, a PS-CFBG type adjustable filter 14, an optical fiber amplifier 15, a photoelectric detector 16 and a band-pass filter 17; the specific connection mode is as follows:

the output end of the laser 11 is connected with the optical input end of a Mach-Zehnder modulator 13, the output end of a millimeter-wave local oscillation source 12 is connected with the electrical modulation end of the Mach-Zehnder modulator 13, the optical output end of the Mach-Zehnder modulator 13 is connected with one end of a PS-CFBG-type tunable filter 14, the other end of the PS-CFBG-type tunable filter 14 is connected with the input end of an optical fiber amplifier 15, the output end of the optical fiber amplifier 15 is connected with the input end of a photoelectric detector 16, and the output end of the photoelectric detector 16 is connected with a band-pass filter 17; wherein the PS-CFBG type tunable filter 14 is composed of a piezoelectric ceramic plate and a chirped fiber grating.

In this example, the sine wave signal generated by the millimeter wave local oscillation source 12 is 10GHz, the center frequency of the laser 11 is 1550.00nm, and the light double-sideband signal is modulated by the mach-zehnder modulator 13; carrier frequency 2g, +1 th order sideband 2a, -1 st order sideband 2b, +2 th order sideband 2c, -2 th order sideband 2d, +3 th order sideband 2e, and-3 th order sideband 2f, as shown in fig. 2. The distance between two pi phase shift points of the PS-CFBG type tunable filter is 18.67cm, the transmission spectrum is shown in fig. 5, 2c and 2d are amplified by the optical fiber amplifier 15, the beat frequency of the photoelectric detector 16 and the frequency spectrum of the generated 4-frequency-doubled millimeter wave signal after being filtered by the band-pass filter 17 with the center frequency of 40GHz and the bandwidth of 1GHz in fig. 5a and 5b, respectively, are shown in fig. 6.

EXAMPLE III

A tunable frequency multiplication millimeter wave generator based on PS-CFBG, which comprises: the device comprises a laser 11, a millimeter wave local oscillation source 12, a Mach-Zehnder modulator 13, a PS-CFBG type adjustable filter 14, an optical fiber amplifier 15, a photoelectric detector 16 and a band-pass filter 17; the specific connection mode is as follows:

the output end of the laser 11 is connected with the optical input end of a Mach-Zehnder modulator 13, the output end of a millimeter-wave local oscillation source 12 is connected with the electrical modulation end of the Mach-Zehnder modulator 13, the optical output end of the Mach-Zehnder modulator 13 is connected with one end of a PS-CFBG-type tunable filter 14, the other end of the PS-CFBG-type tunable filter 14 is connected with the input end of an optical fiber amplifier 15, the output end of the optical fiber amplifier 15 is connected with the input end of a photoelectric detector 16, and the output end of the photoelectric detector 16 is connected with a band-pass filter 17; wherein the PS-CFBG type tunable filter 14 is composed of a piezoelectric ceramic plate and a chirped fiber grating.

In this example, the sine wave signal generated by the millimeter wave local oscillation source 12 is 10GHz, the center frequency of the laser 11 is 1550.00nm, and the light double-sideband signal is modulated by the mach-zehnder modulator 13; carrier frequency 2g, +1 th order sideband 2a, -1 st order sideband 2b, +2 th order sideband 2c, -2 th order sideband 2d, +3 th order sideband 2e, and-3 th order sideband 2f, as shown in fig. 2. The distance between two pi phase shift points of the PS-CFBG type tunable filter is 28.00cm, the transmission spectrum is shown in fig. 7, 2e and 2f are amplified by the optical fiber amplifier 15, the beat frequency of the photodetector 16 and the band-pass filter 17 with the center frequency of 60GHz and the bandwidth of 1GHz in fig. 7, respectively, and the generated 6 frequency-doubled millimeter wave signal electrical spectrum is shown in fig. 8.

Example four

A tunable frequency multiplication millimeter wave generator based on PS-CFBG, which comprises: the device comprises a laser 11, a millimeter wave local oscillation source 12, a Mach-Zehnder modulator 13, a PS-CFBG type adjustable filter 14, an optical fiber amplifier 15, a photoelectric detector 16 and a band-pass filter 17; the specific connection mode is as follows:

the output end of the laser 11 is connected with the optical input end of a Mach-Zehnder modulator 13, the output end of a millimeter-wave local oscillation source 12 is connected with the electrical modulation end of the Mach-Zehnder modulator 13, the optical output end of the Mach-Zehnder modulator 13 is connected with one end of a PS-CFBG-type tunable filter 14, the other end of the PS-CFBG-type tunable filter 14 is connected with the input end of an optical fiber amplifier 15, the output end of the optical fiber amplifier 15 is connected with the input end of a photoelectric detector 16, and the output end of the photoelectric detector 16 is connected with a band-pass filter 17; wherein the PS-CFBG type tunable filter 14 is composed of a piezoelectric ceramic plate and a chirped fiber grating.

In this example, the sine wave signal generated by the millimeter wave local oscillation source 12 is 10GHz, the center frequency of the laser 11 is 1550.00nm, and the light double-sideband signal is modulated by the mach-zehnder modulator 13; carrier frequency 2g, +1 th order sideband 2a, -1 st order sideband 2b, +2 th order sideband 2c, -2 th order sideband 2d, +3 th order sideband 2e, and-3 th order sideband 2f, as shown in fig. 2. The distance between two pi phase shift points of the PS-CFBG type tunable filter is 4.65cm, the transmission spectrum is shown in fig. 9, 2g and 2a are respectively amplified by 9a and 9b in fig. 9 through the optical fiber amplifier 15, the beat frequency of the photoelectric detector 16 and the electric spectrum of the generated 1 frequency doubling millimeter wave signal are shown in fig. 10 after being filtered by the band-pass filter 17 with the center frequency of 10GHz and the bandwidth of 1 GHz.

EXAMPLE five

A tunable frequency multiplication millimeter wave generator based on PS-CFBG, which comprises: the device comprises a laser 11, a millimeter wave local oscillation source 12, a Mach-Zehnder modulator 13, a PS-CFBG type adjustable filter 14, an optical fiber amplifier 15, a photoelectric detector 16 and a band-pass filter 17; the specific connection mode is as follows:

the output end of the laser 11 is connected with the optical input end of a Mach-Zehnder modulator 13, the output end of a millimeter-wave local oscillation source 12 is connected with the electrical modulation end of the Mach-Zehnder modulator 13, the optical output end of the Mach-Zehnder modulator 13 is connected with one end of a PS-CFBG-type tunable filter 14, the other end of the PS-CFBG-type tunable filter 14 is connected with the input end of an optical fiber amplifier 15, the output end of the optical fiber amplifier 15 is connected with the input end of a photoelectric detector 16, and the output end of the photoelectric detector 16 is connected with a band-pass filter 17; wherein the PS-CFBG type tunable filter 14 is composed of a piezoelectric ceramic plate and a chirped fiber grating.

In this example, the sine wave signal generated by the millimeter wave local oscillation source 12 is 10GHz, the center frequency of the laser 11 is 1550.00nm, and the light double-sideband signal is modulated by the mach-zehnder modulator 13; carrier frequency 2g, +1 th order sideband 2a, -1 st order sideband 2b, +2 th order sideband 2c, -2 th order sideband 2d, +3 th order sideband 2e, and-3 th order sideband 2f, as shown in fig. 2. The distance between two pi phase shift points of the PS-CFBG type tunable filter is 13.95cm, the transmission spectrum is shown in fig. 11, 2g and 2e are amplified by optical fiber amplifiers 15 and respectively by 11a and 11b in fig. 11, the beat frequency of a photoelectric detector 16 and the electric spectrum of a frequency-doubled millimeter wave signal generated after filtering by a band-pass filter 17 with the center frequency of 30GHz and the bandwidth of 1GHz are shown in fig. 12.

EXAMPLE six

A tunable frequency multiplication millimeter wave generator based on PS-CFBG, which comprises: the device comprises a laser 11, a millimeter wave local oscillation source 12, a Mach-Zehnder modulator 13, a PS-CFBG type adjustable filter 14, an optical fiber amplifier 15, a photoelectric detector 16 and a band-pass filter 17; the specific connection mode is as follows:

the output end of the laser 11 is connected with the optical input end of a Mach-Zehnder modulator 13, the output end of a millimeter-wave local oscillation source 12 is connected with the electrical modulation end of the Mach-Zehnder modulator 13, the optical output end of the Mach-Zehnder modulator 13 is connected with one end of a PS-CFBG-type tunable filter 14, the other end of the PS-CFBG-type tunable filter 14 is connected with the input end of an optical fiber amplifier 15, the output end of the optical fiber amplifier 15 is connected with the input end of a photoelectric detector 16, and the output end of the photoelectric detector 16 is connected with a band-pass filter 17; wherein the PS-CFBG type tunable filter 14 is composed of a piezoelectric ceramic plate and a chirped fiber grating.

In this example, the sine wave signal generated by the millimeter wave local oscillation source 12 is 10GHz, the center frequency of the laser 11 is 1550.00nm, and the light double-sideband signal is modulated by the mach-zehnder modulator 13; carrier frequency 2g, +1 th order sideband 2a, -1 st order sideband 2b, +2 th order sideband 2c, -2 th order sideband 2d, +3 th order sideband 2e, and-3 th order sideband 2f, as shown in fig. 2. The distance between two pi phase shift points of the PS-CFBG type tunable filter is 23.25cm, the transmission spectrum is shown in fig. 13, 2d and 2e are amplified by optical fiber amplifier 15 and beat frequency of photodetector 16 and band pass filter 17 with center frequency of 50GHz and bandwidth of 1GHz in fig. 13, respectively, and then 5 frequency multiplication millimeter wave signal electric spectrum diagram is shown in fig. 14.

Those not described in detail in this specification are within the skill of the art.