Miniaturized to-be-measured microwave signal phase noise measurement system

Abstract

The invention provides a miniaturized to-be-measured microwave signal phase noise measurement system, and the system comprises a laser which is used for generating an optical carrier signal and outputting the optical carrier signal to an on-chip circulation phase modulator; the on-chip cyclic phase modulator is used for cyclically modulating a microwave signal to be measured onto an optical carrier and outputting the microwave signal to the adjustable optical filter; the delay modulation device is used for modulating the optical carrier signal which is output by the on-chip circulating phase modulator and is modulated for the first time, and outputting the modulated optical carrier signal to the on-chip circulating phase modulator; the adjustable optical filter extracts the optical carrier signal which is output by the on-chip cyclic phase modulator and is modulated for the second time, and outputs the optical carrier signal to the signal processing module; and the signal processing module is used for processing the to-be-processed optical signal output by the adjustable optical filter to obtain the phase noise of the to-be-detected microwave signal. The miniaturized phase noise measurement system for the microwave signal to be measured is simple in structure, easy to integrate and not limited by the working bandwidth of any electrical device.

Description

Technical Field

[0001] The present disclosure relates to the fields of microwave signal phase noise measurement and microwave photon technology, and in particular to a miniaturized microwave signal phase noise measurement system to be measured. Background Art

[0002] Currently, the most commonly used phase noise test methods include direct spectrum technology and frequency discrimination technology. Depending on whether a reference source is required, frequency discrimination technology is divided into heterodyne frequency discrimination technology and self-heterodyne frequency discrimination technology.

[0003] Direct spectrum technology directly calculates the phase noise of the microwave source to be measured by performing spectrum analysis on the input microwave signal. The system's operating bandwidth and minimum noise floor are limited by the performance of the spectrum analyzer, and the phase noise and amplitude noise of the source to be measured cannot be distinguished. Heterodyne demodulation technology uses a reference source to mix with the source to be measured. The bandwidth and phase noise floor of the system are limited by indicators such as the bandwidth and phase noise of the reference source. The self-heterodyne delay demodulation method uses an electrical phase shifter and an electrical mixer, which is difficult to meet the measurement requirements of low phase noise at bandwidths above 12G.

[0004] The phase noise measurement system based on the cascaded electro-optical modulation unit structure avoids the use of an electrical mixer, but still uses an electrical phase shifter and an electrical coupler, which does not avoid the bandwidth limitation caused by electrical devices.

[0005] In view of the above problems, the present disclosure provides a miniaturized microwave signal phase noise measurement system based on microwave photons and an on-chip cyclic phase modulator, which has the characteristics of simple system structure, high measurement bandwidth, easy integration and miniaturized packaging. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] In view of this, the present disclosure provides a miniaturized microwave signal phase noise measurement system to be tested, which uses an on-chip cyclic phase modulator to load the microwave signal to be tested twice into an optical carrier signal, at least partially solving the above-mentioned and other technical problems.

[0008] (II) Technical solution

[0009] In order to achieve the above-mentioned purpose, the present disclosure provides a miniaturized microwave signal phase noise measurement system, comprising: a laser, used to generate an optical carrier signal, and output it to an on-chip cyclic phase modulator; the on-chip cyclic phase modulator, used to modulate the optical carrier signal generated by the laser twice using the microwave signal to be measured, and output it to an adjustable optical filter; a delay modulation device, used to modulate the optical carrier signal after the first modulation output by the on-chip cyclic phase modulator, and output it to the on-chip cyclic phase modulator; the tunable optical filter, used to extract the optical carrier signal after the second modulation output by the on-chip cyclic phase modulator, and output it to a signal processing module; the signal processing module, used to process the extracted optical carrier signal output by the tunable optical filter, and obtain the phase noise of the microwave signal to be measured.

[0010] According to an embodiment of the present disclosure, the laser is a semiconductor laser with low phase noise and continuous light output; the wavelength of the optical carrier signal is between 1260 and 1360 nm or between 1530 and 1565 nm.

[0011] According to an embodiment of the present disclosure, an on-chip cyclic phase modulator at least includes a first electro-optical modulation unit, a second electro-optical modulation unit, a first input port, a second input port, a first output port, and a second output port; wherein the first input port is connected to the input port of the first electro-optical modulation unit; the output port of the first electro-optical modulation unit is connected to the first output port; the second input port is connected to the input port of the second electro-optical modulation unit; the output port of the second electro-optical modulation unit is connected to the second output port; the electro-optical modulation unit is used to modulate the microwave signal to be measured onto an optical carrier signal; the first input port is used to receive the optical carrier signal generated by a laser; the first output port is used to output the optical carrier signal after the first modulation; the second input port is used to receive the optical carrier signal after the first modulation after the phase is modulated by a delay modulation device; and the second output port is used to output the optical carrier signal after the second modulation.

[0012] According to an embodiment of the present disclosure, an on-chip cyclic phase modulator at least includes an electro-optical modulation unit, a mode multiplexing unit, a first input port, a second input port, a first output port, and a second output port; wherein the first input port and the second input port are connected to the input end of the mode multiplexing unit; the output end of the mode multiplexing unit is connected to the first output port and the second output port; the electro-optical modulation unit is used to modulate the microwave signal to be measured onto an optical carrier signal; the mode multiplexing unit is used to separate the optical carrier signal after the first modulation and the optical carrier signal after the second modulation in the on-chip cyclic phase modulator; the first input port is used to receive the optical carrier signal generated by the laser; the first output port is used to output the optical carrier signal after the first modulation; the second input port is used to receive the optical carrier signal after the first modulation after the phase is modulated by the delay modulation device; and the second output port is used to output the optical carrier signal after the second modulation.

[0013] According to an embodiment of the present disclosure, an input port and an output port of an on-chip cyclic phase modulator are coupled to a single-mode optical fiber through a lens fiber or a lens.

[0014] According to an embodiment of the present disclosure, the delay modulation device includes an adjustable optical fiber delay line and a delay optical fiber, which are used for delaying and modulating the phase so that the phase of the optical carrier signal after the first modulation is orthogonal to that of the optical carrier signal after the second modulation.

[0015] According to an embodiment of the present disclosure, the adjustable delay range of the adjustable optical fiber delay line is greater than the minimum period of the microwave signal to be measured.

[0016] According to an embodiment of the present disclosure, the delay optical fiber has a fixed delay; the length of the delay optical fiber satisfies Wherein, L represents the length of the delay optical fiber, c represents the speed of light, n represents the refractive index of the delay optical fiber, and p represents the maximum frequency deviation of the phase noise of the microwave signal to be measured.

[0017] According to an embodiment of the present disclosure, the tunable optical filter is used to extract the positive first-order sideband of the optical carrier signal after the second modulation to obtain the optical signal to be processed.

[0018] According to an embodiment of the present disclosure, the signal processing module also includes a photoelectric detection unit, a data processing device, and a data acquisition card; the photoelectric detection unit is used to convert the selected optical carrier signal output by the tunable optical filter into an electrical signal; and the data acquisition card is used to convert the electrical signal into a digital signal.

[0019] (III) Beneficial effects

[0020] The present invention simplifies the structure of the microwave signal phase noise measurement system to be measured by an on-chip cyclic phase modulator, and the measurement system has a simple structure and is easy to integrate and package in a miniaturized form. At the same time, the on-chip cyclic phase modulator replaces the functions of the electrical phase shifter and the electrical coupler, and the measurement system is not limited by the working bandwidth of any electrical device, but is only determined by the working bandwidth of the on-chip cyclic phase modulator, and the measurement system has a high measurement bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of a miniaturized microwave signal phase noise measurement system to be measured according to an embodiment of the present disclosure is shown;

[0022] Figure 2 A schematic diagram of an on-chip cyclic phase modulator according to an embodiment of the present disclosure is shown;

[0023] Figure 3 A schematic diagram of an on-chip cyclic phase modulator according to another embodiment of the present disclosure is shown;

[0024] Description of reference numerals:

[0025] 1-laser; 2-microwave signal to be measured; 3-on-chip cyclic phase modulator; 4-delay modulation device; 5-adjustable optical filter; 6-signal processing module; 7-adjustable optical fiber delay line; 8-delay optical fiber; 9-photoelectric detection unit; 10-data processing device; 11-first input port; 12-second input port; 13-first output port; 14-second output port. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present disclosure more clearly understood, the present invention is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present disclosure.

[0027] The embodiment of the present disclosure provides a miniaturized microwave signal phase noise measurement system to be measured. The system includes: a laser, an on-chip cyclic phase modulator, a delay modulation device, an adjustable optical filter, and a signal processing module. The miniaturized microwave signal phase noise measurement system to be measured provided in the embodiment of the present disclosure has at least the following beneficial effects:

[0028] (1) Low cost, simple system structure, easy integration and miniaturization.

[0029] (2) The test bandwidth is large and is not limited by the operating bandwidth of any electrical device, but is only determined by the operating bandwidth of the on-chip cyclic phase modulator.

[0030] Figure 1 It is a schematic diagram of a miniaturized microwave signal phase noise measurement system in an embodiment of the present disclosure.

[0031] like Figure 1 As shown, the embodiment of the present disclosure provides a miniaturized phase noise measurement system for a microwave signal to be measured, including: a laser 1, used to generate an optical carrier signal, and output it to an on-chip cyclic phase modulator 3; the on-chip cyclic phase modulator 3, used to modulate the optical carrier signal generated by the laser 1 twice using the microwave signal 2 to be measured, and output it to an adjustable optical filter 5; a delay modulation device 4, used to modulate the optical carrier signal after the first modulation output by the on-chip cyclic phase modulator 3, and output it to the on-chip cyclic phase modulator 3; the tunable optical filter 5, used to extract the optical carrier signal after the second modulation output by the on-chip cyclic phase modulator 3, and output it to a signal processing module; a signal processing module 6, used to process the extracted optical carrier signal output by the tunable optical filter 5 to obtain the phase noise of the microwave signal to be measured.

[0032] In this embodiment, the electrical input port of the on-chip cyclic phase modulator is coupled via a planar waveguide, and the 3dB bandwidth of the on-chip cyclic modulator is higher than the output frequency of the microwave signal to be measured.

[0033] Through the embodiments of the present disclosure, a miniaturized microwave signal phase noise measurement system based on microwave photons and on-chip cyclic phase modulators is provided. The on-chip cyclic phase modulator is cyclically used through cyclic modulation and waveguide mode isolation methods, which effectively reduces the system cost. At the same time, the system operating bandwidth is not limited by the bandwidth limitation of electrical devices.

[0034] On the basis of the above-mentioned embodiment, the laser 1 is a semiconductor laser with low phase noise and continuous light output; the wavelength of the optical carrier signal is between 1260 and 1360 nm or between 1530 and 1565 nm.

[0035] Through the embodiments of the present disclosure, the bandwidth of the microwave signal to be measured is expanded through a high-frequency and high-energy optical carrier signal, the characteristics of the microwave signal to be measured are transmitted, and the anti-interference ability of the system is improved.

[0036] Based on the above embodiments, the on-chip cyclic phase modulator at least includes a first electro-optical modulation unit, a second electro-optical modulation unit, a first input port, a second input port, a first output port, and a second output port; wherein the first input port is connected to the input port of the first electro-optical modulation unit; the output port of the first electro-optical modulation unit is connected to the first output port; the second input port is connected to the input port of the second electro-optical modulation unit; the output port of the second electro-optical modulation unit is connected to the second output port; the electro-optical modulation unit is used to modulate the microwave signal to be measured onto an optical carrier signal; the first input port is used to receive the optical carrier signal generated by a laser; the first output port is used to output the optical carrier signal after the first modulation; the second input port is used to receive the optical carrier signal after the first modulation after the phase is modulated by a delay modulation device; and the second output port is used to output the optical carrier signal after the second modulation.

[0037] For example, Figure 2 A schematic diagram of an on-chip cyclic phase modulator according to an embodiment of the present disclosure is shown. The continuous optical carrier signal output by the laser enters the on-chip cyclic phase modulator through the first input port 11, and the first electro-optical modulation unit modulates the microwave signal to be measured for the first time and loads it onto the optical carrier signal, which is then output to the delay modulation device through the first output port 13; the optical carrier signal modulated by the delay modulation device enters the on-chip cyclic phase modulator through the second input port 12, and the second electro-optical modulation unit loads the microwave signal of the microwave signal to be measured onto the optical carrier signal to obtain the optical carrier signal after the second modulation, which is then output from the second output port 14.

[0038] Through the embodiments of the present disclosure, the on-chip cyclic phase modulator realizes double modulation of the optical carrier signal, realizes the separation of the optical carrier signal after the first modulation and the optical carrier signal after the second modulation, thereby simplifying the system structure while modulating the signal.

[0039] On the basis of the above embodiments, the on-chip cyclic phase modulator at least includes an electro-optical modulation unit, a mode multiplexing unit, a first input port, a second input port, a first output port, and a second output port; wherein the first input port and the second input port are connected to the input end of the mode multiplexing unit; the output end of the mode multiplexing unit is connected to the first output port and the second output port; the electro-optical modulation unit is used to modulate the microwave signal to be measured onto the optical carrier signal; the mode multiplexing unit is used to separate the optical carrier signal after the first modulation and the optical carrier signal after the second modulation in the on-chip cyclic phase modulator; the first input port is used to receive the optical carrier signal generated by the laser; the first output port is used to output the optical carrier signal after the first modulation; the second input port is used to receive the optical carrier signal after the first modulation after the phase is modulated by the delay modulation device; and the second output port is used to output the optical carrier signal after the second modulation.

[0040] For example, Figure 3 A schematic diagram of an on-chip cyclic phase modulator according to another embodiment of the present disclosure is shown. The continuous optical carrier signal output by the laser enters the on-chip cyclic phase modulator through the first input port 11, and the electro-optical modulation unit modulates the microwave signal of the microwave signal to be measured for the first time and loads it onto the optical carrier signal. At this time, the optical mode is the optical carrier signal of the fundamental mode transverse electric field, which is output to the delay modulation device through the first output port 13; the optical carrier signal modulated by the delay modulation device enters the on-chip cyclic phase modulator through the second input port 12, and the mode multiplexing unit converts the optical carrier signal into the optical carrier signal of the second-order mode transverse electric field, and again loads the microwave signal of the microwave signal to be measured into the optical carrier signal, obtains the optical carrier signal after the second modulation, and converts it back into the optical carrier signal of the fundamental mode transverse electric field, which is output from the second output port 14; in this embodiment, the mode multiplexing unit is used to separate the optical carrier signal of the fundamental mode transverse electric field from the optical carrier signal of the second-order mode transverse electric field.

[0041] Through the embodiments of the present disclosure, the on-chip cyclic phase modulator uses a mode multiplexing unit to achieve separation of optical carrier signals without the need for an additional signal transmission optical path, thereby reducing the difficulty of integration.

[0042] On the basis of the above embodiment, the input port and the output port of the on-chip cyclic phase modulator 3 are coupled to the single-mode optical fiber through a lens optical fiber or a lens.

[0043] According to the embodiments of the present disclosure, the coupling between the optical fiber and the waveguide device is improved by using a lens optical fiber or a lens, thereby improving the stability of the system.

[0044] Based on the above embodiment, the delay modulation device 4 includes an adjustable optical fiber delay line 7 and a delay optical fiber 8, which are used for delaying and modulating the phase so that the phase of the optical carrier signal after the first modulation is orthogonal to that of the optical carrier signal after the second modulation.

[0045] Through the embodiments of the present disclosure, the optical carrier signal after the first modulation is orthogonal to the optical carrier signal after the second modulation, which is conducive to the signal processing module to smoothly restore the original signal.

[0046] On the basis of the above embodiment, the adjustable delay range of the adjustable optical fiber delay line 7 is greater than the minimum period of the microwave signal to be measured.

[0047] According to the embodiment of the present disclosure, an adjustable delay is provided by the adjustable optical fiber delay line 7, so as to adjust the phase quadrature of the signals of the two phase modulations.

[0048] On the basis of the above embodiment, the delay optical fiber 8 has a fixed delay; the length of the delay optical fiber satisfies Wherein, L represents the length of the delay fiber, c represents the speed of light, n represents the refractive index of the delay fiber, and p represents the maximum frequency deviation of the microwave signal phase noise.

[0049] According to the embodiments of the present disclosure, a fixed delay is provided by a delay optical fiber to modulate the phase of an optical carrier signal.

[0050] On the basis of the above embodiment, the tunable optical filter 5 is used to extract the positive first-order sideband of the optical carrier signal after the second modulation to obtain the optical signal to be processed.

[0051] In this embodiment, the adjustment range of the center frequency of the tunable optical filter 5 is greater than the microwave signal frequency of the microwave signal 2 to be measured, and the 3 dB filtering bandwidth of the tunable optical filter 5 is smaller than the microwave signal frequency of the microwave signal to be measured.

[0052] According to the embodiments of the present disclosure, the positive and negative first-order sidebands of the optical carrier signal contain the phase noise information of the microwave signal to be measured, so only the positive first-order sideband of the optical carrier signal needs to be selected for signal processing.

[0053] On the basis of the above embodiment, the signal processing module 6 also includes a photoelectric detection unit 9, a data processing device 10, and a data acquisition card; the photoelectric detection unit 9 is used to convert the selected optical carrier signal output by the tunable optical filter into an electrical signal; the data acquisition card is used to convert the electrical signal into a digital signal.

[0054] In this embodiment, the data acquisition card is installed on the data processing device 10; the data processing device 10 digitally filters, amplifies, performs fast Fourier transform, and calibrates the transfer function of the output digital signal of the data acquisition card to obtain the phase noise of the microwave signal to be measured.

[0055] In this embodiment, the analog bandwidth of the photoelectric detection unit 9 is higher than the maximum frequency deviation of the phase noise of the microwave signal to be measured.

[0056] Through the embodiments of the present disclosure, the signal processing module realizes the conversion of optical signals to electrical signals to digital signals, which is convenient for data processing, and obtains the microwave signal noise to be measured through various data processing methods.

[0057] Embodiment 1

[0058] The optical carrier signal output by laser 1 is expressed as:

[0059] E in (t) = E c exp(jω c t) (1)

[0060] In the formula, E c The electric field amplitude of the optical signal, ω c is the angular frequency of the optical carrier, j is the imaginary unit, and t is the time.

[0061] The microwave signal output by the microwave signal to be measured 2 can be expressed as:

[0062]

[0063] In the formula, E RF is the amplitude of the microwave signal, ω RF is the angular frequency of the microwave signal, is the phase noise of the microwave signal to be measured, and t is the time.

[0064] The optical carrier signal after the first modulation by the on-chip cyclic phase modulator 3 is expressed as:

[0065]

[0066] In the formula, β0 is the modulation depth of the on-chip cyclic phase modulator 3, and the modulation depth β0 is determined by the amplitude of the microwave signal and β0 is the half-wave voltage of the on-chip cyclic phase modulator 3; written in the form of an imaginary exponential signal, it is a constant-amplitude sinusoidal signal.

[0067] The optical carrier signal after the delay modulation device 4 is expressed as:

[0068]

[0069] In the formula, τ is the total delay provided by the adjustable optical fiber delay line 7 and the delay optical fiber 8, and τ can be fine-tuned by the adjustable optical fiber delay line 7.

[0070] After the second modulation by the on-chip cyclic phase modulator 3, the expression of the output optical carrier signal is expressed as:

[0071]

[0072] The optical carrier signal output by the on-chip cyclic phase modulator 3 is expressed by Bessel function expansion:

[0073]

[0074] Simplifying the above formula, we can get:

[0075]

[0076] After passing through the tunable optical filter 5, the negative first-order sideband and the center carrier generated by the two modulations are filtered out, and the positive first-order sideband is retained. At this time, the output signal of the above formula n=0, m=1 and n=1, m=0 after passing through the tunable optical filter 5 can be expressed as:

[0077]

[0078] The photoelectric detection unit 9 receives the optical signal filtered by the adjustable optical filter 5, and outputs an electrical signal as follows:

[0079]

[0080] The output signal of the photoelectric detection unit 9 can be expressed as:

[0081]

[0082] The signal output by the photoelectric detection unit 9 is low-pass filtered, amplified, high-pass filtered, amplified, and then enters the data acquisition card and is converted into a digital signal:

[0083]

[0084] The k factor in the above formula can be obtained by changing the delay amount of the adjustable optical fiber delay line 4 before measurement; the k factor is a calibration parameter, and if this parameter is not obtained, the absolute value of the measured phase noise is inaccurate.

[0085] By adjusting the delay of the adjustable optical fiber delay line 4:

[0086]

[0087] The output signal is subjected to a fast Fourier transform by the signal processing module 8 to obtain the power spectrum density of the output signal:

[0088]

[0089] The phase noise of the microwave signal 2 to be measured is generally expressed as the single-sideband phase noise power spectral density:

[0090]

[0091] The phase noise of the microwave signal 4 to be measured can be obtained from the required power spectral density:

[0092]

[0093] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0094] In the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0095] Similarly, in order to simplify the present disclosure and help understand one or more of the various disclosed aspects, in the above description of the exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together into a single embodiment, figure, or description thereof. The description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0096] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present disclosure in detail. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A miniaturized microwave signal phase noise measurement system, characterized in that: include: A laser (1) for generating an optical carrier signal, which is output to an on-chip cyclic phase modulator (3); An on-chip cyclic phase modulator (3) is used to cyclically modulate the optical carrier signal generated by the laser (1) twice using the microwave signal to be measured (2), and output the modulated signal to the tunable optical filter (5); A delay modulation device (4) is used to modulate the optical carrier signal after the first modulation output by the on-chip cyclic phase modulator (3), and output it to the on-chip cyclic phase modulator (3); An adjustable optical filter (5) is used to extract the optical carrier signal after the second modulation output by the on-chip cyclic phase modulator (3) and output it to a signal processing module (8); The signal processing module (6) is used to process the extracted optical carrier signal output by the tunable optical filter (5) to obtain the phase noise of the microwave signal (2) to be measured.

2. The miniaturized microwave signal phase noise measurement system according to claim 1, characterized in that: The laser (1) is a semiconductor laser with low phase noise and continuous light output; the wavelength of the optical carrier signal is between 1260 and 1360 nm or between 1530 and 1565 nm.

3. The miniaturized microwave signal phase noise measurement system according to claim 1, characterized in that: The on-chip cyclic phase modulator (3) comprises at least a first electro-optical modulation unit, a second electro-optical modulation unit, a first input port (11), a second input port (12), a first output port (13), and a second output port (14); The first input port is connected to the input port of the first electro-optical modulation unit; the output port of the first electro-optical modulation unit is connected to the first output port; the second input port is connected to the input port of the second electro-optical modulation unit; the output port of the second electro-optical modulation unit is connected to the second output port; the electro-optical modulation unit is used to modulate the microwave signal to be measured onto the optical carrier signal; the first input port is used to receive the optical carrier signal generated by the laser (1); the first output port is used to output the optical carrier signal after the first modulation; the second input port is used to receive the optical carrier signal after the first modulation after the phase is modulated by the delay modulation device (4); and the second output port is used to output the optical carrier signal after the second modulation.

4. The miniaturized microwave signal phase noise measurement system according to claim 1, characterized in that: The on-chip cyclic phase modulator (3) comprises at least an electro-optical modulation unit, a mode multiplexing unit, a first input port (11), a second input port (12), a first output port (13), and a second output port (14); The first input port and the second input port are connected to the input end of the mode multiplexing unit; the output end of the mode multiplexing unit is connected to the first output port and the second output port; the electro-optical modulation unit is used to modulate the microwave signal to be measured onto the optical carrier signal; the mode multiplexing unit is used to separate the optical carrier signal after the first modulation and the optical carrier signal after the second modulation in the on-chip cyclic phase modulator (3); the first input port is used to receive the optical carrier signal generated by the laser (1); the first output port is used to output the optical carrier signal after the first modulation; the second input port is used to receive the optical carrier signal after the first modulation after the phase is modulated by the delay modulation device (4); and the second output port is used to output the optical carrier signal after the second modulation.

5. The miniaturized microwave signal phase noise measurement system according to claim 1, characterized in that: The input port and the output port of the on-chip cyclic phase modulator (3) are coupled to a single-mode optical fiber through a lens optical fiber or a lens.

6. The miniaturized microwave signal phase noise measurement system according to claim 1, characterized in that: The delay modulation device (4) comprises an adjustable optical fiber delay line (7) and a delay optical fiber (8), which are used for delaying and modulating the phase so that the phase of the optical carrier signal after the first modulation is orthogonal to that of the optical carrier signal after the second modulation.

7. The miniaturized microwave signal phase noise measurement system according to claim 6, characterized in that: The adjustable delay range of the adjustable optical fiber delay line (7) is greater than the minimum period of the microwave signal to be measured.

8. The miniaturized microwave signal phase noise measurement system according to claim 6, characterized in that: The length of the delay optical fiber (8) satisfies Wherein, L represents the length of the delay optical fiber, c represents the speed of light, n represents the refractive index of the delay optical fiber, and p represents the maximum frequency deviation of the phase noise of the microwave signal to be measured.

9. The miniaturized microwave signal phase noise measurement system according to claim 1, characterized in that: The adjustable optical filter (6) is used to extract the positive first-order sideband of the optical carrier signal after the second modulation to obtain the optical signal to be processed.

10. The miniaturized microwave signal phase noise measurement system according to claim 1, characterized in that: The signal processing module (6) further comprises a photoelectric detection unit (9), a data processing device (10), and a data acquisition card; the photoelectric detection (9) is used to convert the selected optical carrier signal output by the tunable optical filter (5) into an electrical signal; and the data acquisition card is used to convert the electrical signal into a digital signal.

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