Millimeter wave signal generation device and method

Abstract

The invention provides a millimeter wave signal generation device and method, and the device comprises a local oscillator laser which is used for generating a laser signal. The first oscillation loop is used for generating a first radio frequency oscillation signal of a first angular frequency based on the laser signal. The second oscillation loop is used for generating a second radio frequency oscillation signal of a second angular frequency based on the laser signal; the first oscillation loop and the second oscillation loop share the optical filter, and the first radio frequency oscillation signal, the second radio frequency oscillation signal and the local oscillator laser keep the same frequency change by increasing the time delay of the optical filter and shortening the radio frequency link time delay of the first oscillation loop and the second oscillation loop. And the feedback control loop is used for mixing the radio frequency reference signal and the radio frequency oscillation signal to generate a feedback signal, and inputting the feedback signal into the local oscillator laser to adjust the frequency of the laser signal. And the first photoelectric detector is used for performing beat frequency on the band-pass filtering signal output by the optical filter to generate a millimeter wave signal after the frequency of the laser signal is stable.

Description

Technical Field

[0001] The present invention relates to the technical field of signal generation, and in particular to a millimeter wave signal generation device and method. Background Art

[0002] At present, millimeter waves are widely used in communication, imaging, radar and other fields. With the rapid development of mobile communication technology, the spectrum of the golden communication frequency band below 6 GHz has become very crowded, and it is difficult to meet the needs of future wireless high-speed communication. Millimeter wave communication can provide wider channel bandwidth and higher signal transmission rate than existing communication systems. Millimeter wave communication will be widely adopted in future mobile communication systems. Taking advantage of the penetration and security of millimeter waves, millimeter wave imaging can effectively image the detected objects, and its application in national security, airport security, atmospheric remote sensing and other fields has received widespread attention. Compared with radars in the microwave band, the short wavelength of millimeter waves can effectively reduce the system size and weight, and improve the resolution. Summary of the invention

[0003] In view of the above problems, the present invention provides a millimeter wave signal generating device and method.

[0004] An embodiment of the present invention provides a millimeter wave signal generating device, comprising: a local oscillator laser, used to generate and output a laser signal; a first oscillation loop, used to generate a first radio frequency oscillation signal of a first angular frequency based on the laser signal; a second oscillation loop, used to generate a second radio frequency oscillation signal of a second angular frequency based on the laser signal; wherein the first oscillation loop and the second oscillation loop share an optical filter, and by increasing the delay of the optical filter, the radio frequency link delay of the first oscillation loop and the second oscillation loop is shortened so that the first radio frequency oscillation signal, the second radio frequency oscillation signal and the local oscillator laser maintain the same frequency change; a feedback control loop, used to mix a radio frequency reference signal with one of the first radio frequency oscillation signal and the second radio frequency oscillation signal to generate a feedback signal, and input the feedback signal into the local oscillator laser to adjust the frequency of the laser signal output by the local oscillator laser; a first photodetector, used to beat the bandpass filter signal output by the optical filter to generate a millimeter wave signal when the frequency of the laser signal output by the local oscillator laser is stable.

[0005] According to an embodiment of the present invention, the first oscillation loop includes: a first optical phase modulator, an optical filter, a second photodetector, a first RF power divider, a first RF filter, a first RF amplifier and a RF coupler connected in sequence, wherein the output end of the RF coupler is connected to the input end of the first optical phase modulator; the first optical phase modulator is used to modulate the microwave signal onto the laser signal to obtain a modulated optical signal; the optical filter is used to perform notch filtering on the modulated optical signal to obtain an optical signal after notch filtering; the second photodetector is used to perform beat frequency on the optical signal after notch filtering to obtain an RF oscillation signal including a first angular frequency and a second angular frequency; the first RF power divider is used to divide the RF oscillation signal including the first angular frequency and the second angular frequency into two paths with equal power; the first RF filter is used to filter one of the RF oscillation signals including the first angular frequency and the second angular frequency to obtain an RF oscillation signal including the first angular frequency; the first RF amplifier is used to amplify the RF oscillation signal including the first angular frequency to obtain the first RF oscillation signal.

[0006] According to an embodiment of the present invention, the second oscillation loop includes: a first optical phase modulator, an optical filter, a second photodetector, a first RF power divider, a second RF filter, a second RF amplifier, a second RF power divider and an RF coupler connected in sequence, wherein the output end of the RF coupler is connected to the input end of the first optical phase modulator; the first optical phase modulator is used to modulate the microwave signal onto the laser signal to obtain a modulated optical signal; the optical filter is used to perform notch filtering on the modulated optical signal to obtain an optical signal after notch filtering; the second photodetector is used to perform beat frequency on the optical signal after notch filtering to obtain a RF signal including a first angular frequency and a second angular frequency. The first RF power divider is used to divide the power of the RF oscillation signal including the first angular frequency and the second angular frequency into two paths; the second RF filter is used to filter one of the RF oscillation signals including the first angular frequency and the second angular frequency to obtain a RF oscillation signal including the second angular frequency; the second RF amplifier is used to amplify the RF oscillation signal including the second angular frequency to obtain a second RF oscillation signal; the second RF power divider is used to divide the power of the second RF oscillation signal into two paths; the RF coupler is used to couple one of the second RF oscillation signals with the first RF oscillation signal and then input them into the first optical phase modulator.

[0007] According to an embodiment of the present invention, the first oscillation loop includes: a first optical coupler, a second optical phase modulator, a second optical coupler, an optical filter, a second photodetector, a first radio frequency power divider, a first radio frequency filter and a first radio frequency amplifier connected in sequence, wherein the output end of the first radio frequency amplifier is connected to the input end of the second optical phase modulator; the first optical coupler is used to divide the laser signal into two paths; the second optical phase modulator is used to modulate the microwave signal onto one of the laser signals to obtain a modulated optical signal; the second optical coupler is used to couple the modulated optical signal into the optical filter; the optical filter is used to perform notch filtering on the modulated optical signal to obtain an optical signal after notch filtering; the second photodetector is used to perform beat frequency on the optical signal after notch filtering to obtain an radio frequency oscillation signal including a first angular frequency and a second angular frequency; the first radio frequency power divider is used to divide the radio frequency oscillation signal including the first angular frequency and the second angular frequency into two paths with equal power; the first radio frequency filter is used to filter one of the radio frequency oscillation signals including the first angular frequency and the second angular frequency to obtain an radio frequency oscillation signal including the first angular frequency; the first radio frequency amplifier is used to amplify the radio frequency oscillation signal including the first angular frequency to obtain the first radio frequency oscillation signal.

[0008] According to an embodiment of the present invention, the second oscillation loop includes: a first optical coupler, a third optical phase modulator, a second optical coupler, an optical filter, a second photodetector, a first RF power divider, a second RF filter, a second RF amplifier and a second RF power divider connected in sequence, wherein the output end of the second RF power divider is connected to the input end of the third optical phase modulator; the third optical phase modulator is used to modulate the microwave signal onto another laser signal to obtain a modulated optical signal; the second optical coupler is used to couple the two modulated optical signals into the optical filter; the optical filter is used to perform notch filtering on the modulated optical signal to obtain an optical signal after notch filtering; the second photodetector is used to The optical signal after the notch filtering is beat-frequencyed to obtain a radio frequency oscillation signal including a first angular frequency and a second angular frequency; the first radio frequency power divider is used to split the radio frequency oscillation signal including the first angular frequency and the second angular frequency into two paths with equal power; the second radio frequency filter is used to filter one of the radio frequency oscillation signals including the first angular frequency and the second angular frequency to obtain a radio frequency oscillation signal including the second angular frequency; the second radio frequency amplifier is used to amplify the radio frequency oscillation signal including the second angular frequency to obtain a second radio frequency oscillation signal; the second radio frequency power divider is used to split the second radio frequency oscillation signal into two paths with equal power, and one of the second radio frequency oscillation signals is input into a third optical phase modulator.

[0009] According to an embodiment of the present invention, the feedback control loop includes: a mixer, which is used to mix the radio frequency reference signal with one of the first radio frequency oscillation signal and the second radio frequency oscillation signal, extract the change of the central angular frequency of the local oscillator laser relative to the central angular frequency of the optical filter, and obtain an error signal carrying the frequency fluctuation information of the local oscillator laser; a feedback controller, which is used to generate a feedback signal from the error signal and feed it back to the local oscillator laser to adjust the frequency of the laser signal output by the local oscillator laser, and the angular frequency of the laser signal output by the local oscillator laser is equal to the sum of the central angular frequency of the optical filter and the angular frequency of the oscillating radio frequency signal or the absolute value of the difference between the two.

[0010] According to an embodiment of the present invention, a feedback signal is input into a tuning port of a local oscillator laser to adjust the frequency of a laser signal output by the local oscillator laser; or, a feedback signal is input into a voltage-controlled oscillator and combined with an acousto-optic frequency shifter to adjust the frequency of a laser signal output by the local oscillator laser.

[0011] According to an embodiment of the present invention, it also includes: a radio frequency phase shifter, which is arranged in one of the first oscillation loop and the second oscillation loop, wherein the signal transmitted in the first oscillation loop or the second oscillation loop is phase-shifted by the radio frequency phase shifter, and the angular frequency of the local oscillator laser is adjusted to make the first oscillation loop and the second oscillation loop oscillate stably.

[0012] According to an embodiment of the present invention, the bandpass filtered signal includes optical signals of two angular frequencies, and the angular frequency of the millimeter wave signal is equal to the absolute value of the difference between the two angular frequencies.

[0013] An embodiment of the present invention provides a millimeter wave signal generation method, comprising: generating and outputting a laser signal through a local oscillator laser; generating a first radio frequency oscillation signal of a first angular frequency based on the laser signal through a first oscillation loop; generating a second radio frequency oscillation signal of a second angular frequency based on the laser signal through a second oscillation loop; wherein the first oscillation loop and the second oscillation loop share an optical filter, and by increasing the delay of the optical filter, the radio frequency link delay of the first oscillation loop and the second oscillation loop is shortened so that the first radio frequency oscillation signal, the second radio frequency oscillation signal and the local oscillator laser maintain the same frequency change; mixing a radio frequency reference signal with one of the first radio frequency oscillation signal and the second radio frequency oscillation signal through a feedback control loop to generate a feedback signal, and inputting the feedback signal into the local oscillator laser to adjust the frequency of the laser signal output by the local oscillator laser; when the frequency of the laser signal output by the local oscillator laser is stable, beating the bandpass filter signal output by the optical filter through a first photodetector to generate a millimeter wave signal.

[0014] The millimeter wave signal generating device and method provided by the present invention have at least the following technical effects:

[0015] Two RF oscillations with different frequencies are realized through two oscillation loops, and two optical sidebands are generated that are locked with the resonance peak of the optical filter. By increasing the delay of the optical filter, the RF link delay of the first oscillation loop and the second oscillation loop is shortened, so that the first RF oscillation signal, the second RF oscillation signal and the local oscillator laser maintain the same frequency change, and then after the photodetector beats, a millimeter wave signal with high frequency stability can be generated.

[0016] Since the two RF oscillation loops use the same local oscillator laser, only one control feedback loop is needed to achieve two stable RF oscillations, and the structure is simple. When expanding to more RF oscillations, only one feedback control loop is needed to achieve stable oscillation of multiple RF oscillations.

[0017] The local oscillator laser is locked to the optical filter using the optical filter as an optical reference for locking. After locking, the local oscillator laser has the same frequency stability as the optical filter. When the optical filter has a higher frequency stability, a laser signal with a stable frequency can be output simultaneously.

[0018] A radio frequency phase shifter is set in one of the first oscillation loop and the second oscillation loop, and the signal transmitted in the first oscillation loop or the second oscillation loop is phase-shifted by the radio frequency phase shifter. The angular frequency of the local oscillator laser is adjusted so that the first oscillation loop and the second oscillation loop can oscillate stably, that is, the phase self-reproduction condition is met. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above contents and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0020] Figure 1 A schematic diagram showing the structure of a millimeter wave signal generating device according to a first embodiment of the present invention;

[0021] Figure 2 Schematically shows the optical frequency and radio frequency spectrum diagrams of various parts in the millimeter wave signal generating device according to an embodiment of the present invention;

[0022] Figure 3 A schematic diagram showing the structure of a millimeter wave signal generating device according to a second embodiment of the present invention;

[0023] Figure 4 The structure of a millimeter wave signal generating device according to the third embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0024] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0025] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0026] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0027] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0028] The generation of high-stability millimeter-wave signals has become a major problem that limits the performance and practical application of millimeter-wave systems. According to the principle of millimeter-wave generation, optical millimeter-wave technology can be mainly divided into optical heterodyne method, modulator frequency doubling method and method based on nonlinear effects. The optical heterodyne method uses a photoelectric detector (PD) to generate a new frequency signal by beating two light waves of different wavelengths to obtain a millimeter-wave signal. This method is easy to generate millimeter waves, but it is greatly affected by phase noise and has high requirements on the phase correlation of the two beat-frequency lights. The modulator frequency doubling method generally uses electro-optical modulators, such as phase modulators, electro-absorption modulators or intensity modulators, to form the core of optical millimeter-wave signals. This method has high reliability and low system implementation cost. However, the millimeter-wave phase noise generated by the modulation frequency doubling method is limited by the RF signal before frequency doubling. Since the frequency of the millimeter-wave band has reached tens of GHz or even hundreds of GHz, a large frequency doubling factor is required to reach the millimeter-wave band, resulting in serious deterioration of the phase noise of the generated millimeter-wave signal. The nonlinear effect method uses the nonlinear effect of optical devices to generate new spectral components to generate millimeter waves. This method is easy to achieve high-frequency millimeter wave signals and can greatly simplify the system structure. However, nonlinearity requires a higher threshold power, and there are problems such as high spontaneous radiation noise and low efficiency.

[0029] In view of this, an embodiment of the present disclosure provides a millimeter wave signal generating device, including: a local oscillator laser, used to generate and output a laser signal. A first oscillation loop, used to generate a first radio frequency oscillation signal of a first angular frequency based on the laser signal. A second oscillation loop, used to generate a second radio frequency oscillation signal of a second angular frequency based on the laser signal; wherein the first oscillation loop and the second oscillation loop share an optical filter, and by increasing the delay of the optical filter, the radio frequency link delay of the first oscillation loop and the second oscillation loop is shortened, so that the first radio frequency oscillation signal, the second radio frequency oscillation signal and the local oscillator laser maintain the same frequency change. A feedback control loop, used to mix a radio frequency reference signal with one of the first radio frequency oscillation signal and the second radio frequency oscillation signal to generate a feedback signal, and input the feedback signal into the local oscillator laser to adjust the frequency of the laser signal output by the local oscillator laser. A first photodetector, used to beat the bandpass filter signal output by the optical filter to generate a millimeter wave signal when the frequency of the laser signal output by the local oscillator laser is stable. The device generates a millimeter wave signal with high frequency stability. The millimeter wave signal generating device is introduced in conjunction with specific embodiments below.

[0030] Figure 1 The structure of the millimeter wave signal generating device according to the first embodiment of the present invention is schematically shown.

[0031] like Figure 1As shown, in an embodiment of the present disclosure, the millimeter wave signal generating device may include: a local oscillator laser, a first oscillation loop, a second oscillation loop, a feedback control loop and a first photodetector.

[0032] The local oscillator laser is used to generate and output laser signals.

[0033] The first oscillation loop is used to generate a first radio frequency oscillation signal of a first angular frequency based on the laser signal.

[0034] The second oscillation loop is used to generate a second radio frequency oscillation signal of a second angular frequency based on the laser signal; wherein the first oscillation loop and the second oscillation loop share an optical filter, and the radio frequency link delay of the first oscillation loop and the second oscillation loop is shortened by increasing the delay of the optical filter, so that the first radio frequency oscillation signal, the second radio frequency oscillation signal and the local oscillator laser maintain the same frequency change.

[0035] The feedback control loop is used to mix the RF reference signal with one of the first RF oscillation signal and the second RF oscillation signal to generate a feedback signal, and input the feedback signal into the local oscillator laser to adjust the frequency of the laser signal output by the local oscillator laser.

[0036] The first photoelectric detector is used to generate a millimeter wave signal by beating the bandpass filter signal output by the optical filter when the frequency of the laser signal output by the local oscillator laser is stable.

[0037] Figure 2 The optical frequency and radio frequency spectrum diagrams of various parts in the millimeter wave signal generating device according to an embodiment of the present invention are schematically shown.

[0038] like Figure 2 As shown, the angular frequency generated by the local oscillator laser is The optical signal passes through the optical phase modulator to generate a modulated optical signal. When the high-order sidebands are ignored, the angular frequency is The angular frequencies of the upper and lower optical sidebands generated by the local oscillator laser modulation are and , where the angular frequency of the upper sideband is equal to the resonant angular frequency of the optical filter Equal, that is The angular frequency is The angular frequencies of the upper and lower optical sidebands generated by the local oscillator laser modulation are and , where the angular frequency of the lower sideband is equal to the resonant angular frequency of the optical filter Equal, that is After being filtered by the optical filter, the optical signals after bandpass filtering and notch filtering are output respectively. After the bandpass filtering, the optical signal only has the frequency component with the same angular frequency as the resonant angular frequency of the optical filter, that is, and , after the photodetector beats, it can generate an angular frequency of The optical signal after notch filtering generates an angular frequency of and The RF signal is divided into two paths by the splitter. After passing through the RF filter, the angular frequency components left in each path are and The RF signals are amplified by RF amplifiers and then coupled into one signal by a combiner. The output signal of the combiner is input to the RF input port of the optoelectronic phase modulator to modulate the output optical signal of the local oscillator laser.

[0039] Figure 3 The structure of a millimeter wave signal generating device according to the second embodiment of the present invention is schematically shown.

[0040] like Figure 3 As shown, based on the above embodiments, the first oscillation loop may include: a first optical phase modulator, an optical filter, a second photodetector, a first RF power divider, a first RF filter, a first RF amplifier and a RF coupler connected in sequence, and the output end of the RF coupler is connected to the input end of the first optical phase modulator.

[0041] The first optical phase modulator is used to modulate the microwave signal onto the laser signal to obtain a modulated optical signal.

[0042] The optical filter is used to perform notch filtering on the modulated optical signal to obtain an optical signal after notch filtering.

[0043] The second photodetector is used to perform a beat frequency on the optical signal after the notch filtering to obtain a radio frequency oscillation signal including a first angular frequency and a second angular frequency.

[0044] The first radio frequency power divider is used to divide the power of the radio frequency oscillation signal including the first angular frequency and the second angular frequency into two paths.

[0045] The first radio frequency filter is used to filter one of the radio frequency oscillation signals including the first angular frequency and the second angular frequency to obtain a radio frequency oscillation signal including the first angular frequency.

[0046] The first radio frequency amplifier is used to amplify the radio frequency oscillation signal including the first angular frequency to obtain a first radio frequency oscillation signal.

[0047] The second oscillation loop may include: a first optical phase modulator, an optical filter, a second photodetector, a first RF power divider, a second RF filter, a second RF amplifier, a second RF power divider and a RF coupler connected in sequence, and the output end of the RF coupler is connected to the input end of the first optical phase modulator.

[0048] The first optical phase modulator is used to modulate the microwave signal onto the laser signal to obtain a modulated optical signal.

[0049] The optical filter is used to perform notch filtering on the modulated optical signal to obtain an optical signal after notch filtering.

[0050] The second photodetector is used to perform a beat frequency on the optical signal after the notch filtering to obtain a radio frequency oscillation signal including a first angular frequency and a second angular frequency.

[0051] The first radio frequency power divider is used to divide the power of the radio frequency oscillation signal including the first angular frequency and the second angular frequency into two paths.

[0052] The second radio frequency filter is used to filter one of the radio frequency oscillation signals including the first angular frequency and the second angular frequency to obtain a radio frequency oscillation signal including the second angular frequency.

[0053] The second radio frequency amplifier is used to amplify the radio frequency oscillation signal including the second angular frequency to obtain a second radio frequency oscillation signal.

[0054] The second radio frequency power divider is used to divide the second radio frequency oscillation signal into two paths with equal power.

[0055] The radio frequency coupler is used to couple one of the second radio frequency oscillation signals with the first radio frequency oscillation signal and then input the coupled signals into the first optical phase modulator.

[0056] In one example, a Fabry-Perot cavity can be used as an optical filter and as an optical reference for locking. As shown in the figure, the optical signal generated by the local oscillator laser passes through the optical phase modulator to generate a modulated optical signal, which is filtered by the optical filter, and the optical signal after bandpass filtering is used as the output. The optical signal after band-notch filtering is input to the photodetector and generates an angular frequency of and The oscillating RF signal is output into two paths after passing through the RF power divider. One of the paths only contains the angular frequency of The RF signal is input to the RF coupler after passing through the RF amplifier. The other path only contains the angular frequency The RF signal is amplified by the RF amplifier and then input into the RF power divider to be divided into two paths, one of which is The RF signal is input to the optical phase modulator through the RF coupler. The other path is used for feedback control of the local oscillator laser. In the feedback control part, the angular frequency is The RF signal is mixed with the RF reference through the RF mixer to generate an error signal carrying the frequency fluctuation information of the local oscillator laser. After the error signal passes through the feedback controller, it outputs a control signal to the local oscillator laser for frequency control.

[0057] It should be noted that for details not provided in the millimeter wave signal generating device of this embodiment, please refer to the millimeter wave signal generating device of the above embodiment.

[0058] Figure 4 The structure of a millimeter wave signal generating device according to the third embodiment of the present invention is schematically shown.

[0059] like Figure 4 As shown, based on the above embodiments, the first oscillation loop may include: a first optical coupler, a second optical phase modulator, a second optical coupler, an optical filter, a second photodetector, a first RF power divider, a first RF filter and a first RF amplifier connected in sequence, and the output end of the first RF amplifier is connected to the input end of the second optical phase modulator.

[0060] The first optical coupler is used to split the laser signal into two paths.

[0061] The second optical phase modulator is used to modulate the microwave signal onto one of the laser signals to obtain a modulated optical signal.

[0062] The second optical coupler is used to couple the modulated optical signal into the optical filter.

[0063] The optical filter is used to perform notch filtering on the modulated optical signal to obtain an optical signal after notch filtering.

[0064] The second photodetector is used to perform a beat frequency on the optical signal after the notch filtering to obtain a radio frequency oscillation signal including a first angular frequency and a second angular frequency.

[0065] The first radio frequency power divider is used to divide the power of the radio frequency oscillation signal including the first angular frequency and the second angular frequency into two paths.

[0066] The first radio frequency filter is used to filter one of the radio frequency oscillation signals including the first angular frequency and the second angular frequency to obtain a radio frequency oscillation signal including the first angular frequency.

[0067] The first radio frequency amplifier is used to amplify the radio frequency oscillation signal including the first angular frequency to obtain a first radio frequency oscillation signal.

[0068] The second oscillation loop may include: a first optical coupler, a third optical phase modulator, a second optical coupler, an optical filter, a second photodetector, a first RF power divider, a second RF filter, a second RF amplifier and a second RF power divider connected in sequence, and the output end of the second RF power divider is connected to the input end of the third optical phase modulator.

[0069] The third optical phase modulator is used to modulate the microwave signal onto another laser signal to obtain a modulated optical signal.

[0070] The second optical coupler is used to couple the two-path modulated optical signals into the optical filter.

[0071] The optical filter is used to perform notch filtering on the modulated optical signal to obtain an optical signal after notch filtering.

[0072] The second photodetector is used to perform a beat frequency on the optical signal after the notch filtering to obtain a radio frequency oscillation signal including a first angular frequency and a second angular frequency.

[0073] The first radio frequency power divider is used to divide the power of the radio frequency oscillation signal including the first angular frequency and the second angular frequency into two paths.

[0074] The second radio frequency filter is used to filter one of the radio frequency oscillation signals including the first angular frequency and the second angular frequency to obtain a radio frequency oscillation signal including the second angular frequency.

[0075] The second radio frequency amplifier is used to amplify the radio frequency oscillation signal including the second angular frequency to obtain a second radio frequency oscillation signal.

[0076] The second radio frequency power divider is used to divide the second radio frequency oscillation signal into two paths with equal power, and input one of the second radio frequency oscillation signals into the third optical phase modulator.

[0077] That is, the output of the local oscillator laser is divided into two paths through an optical coupler, and then passes through an oscillation loop composed of optical phase modulators and other devices to generate an angular frequency of and oscillating RF signal.

[0078] It should be noted that for details not provided in the millimeter wave signal generating device of this embodiment, please refer to the millimeter wave signal generating device of the above embodiment.

[0079] exist Figure 4 On the basis of the signal generating device shown, a polarization combiner can also be used to replace the second optical coupler. First, the polarization state of the modulated optical signal after one of the optical phase modulators is adjusted by a polarization feedback controller so that the polarization states of the two optical signals are orthogonal, and then the two optical signals with orthogonal polarization states are combined into one by a polarization combiner and input into the optical filter.

[0080] For the feedback control part, the RF oscillation signal output by the RF power divider has the same frequency fluctuation as the local oscillator laser. By extracting the frequency of the oscillating RF signal and outputting the feedback control signal through the feedback controller, the frequency of the local oscillator laser can be stably controlled to achieve long-term continuous and stable operation.

[0081] Based on this, on the basis of the above embodiment, the feedback control loop includes: a mixer and a feedback controller.

[0082] The mixer is used to mix the radio frequency reference signal with one of the first radio frequency oscillation signal and the second radio frequency oscillation signal, extract the change of the central angular frequency of the local oscillator laser relative to the central angular frequency of the optical filter, and obtain an error signal carrying the frequency fluctuation information of the local oscillator laser.

[0083] The feedback controller is used to generate a feedback signal from the error signal and feed it back to the local oscillator laser to adjust the frequency of the laser signal output by the local oscillator laser. The angular frequency of the laser signal output by the local oscillator laser is equal to the sum of the central angular frequency of the optical filter and the angular frequency of the oscillating radio frequency signal or the absolute value of the difference between the two.

[0084] Exemplarily, the bandpass filtered signal includes two corner frequencies and The angular frequency of the millimeter wave signal is equal to the absolute value of the difference between the two angular frequencies. After the feedback control loop is locked, the frequency of the local oscillator laser is locked with the optical filter. The bandpass filtered optical signal output by the optical filter contains two angular frequencies, and The optical signal has an angular frequency equal to the resonant peak angular frequency of the optical filter. After the photodetector beats the frequency, it can output an angular frequency of Any oscillating RF signal can be used as the input signal of the feedback control loop.

[0085] Based on the above embodiment, the feedback signal is input into the tuning port of the local oscillator laser to adjust the frequency of the laser signal output by the local oscillator laser. Alternatively, the feedback signal is input into a voltage-controlled oscillator and combined with an acousto-optic frequency shifter to adjust the frequency of the laser signal output by the local oscillator laser.

[0086] Exemplarily, the control signal output by the feedback control can be directly applied to the PZT tuning port of the local oscillator laser source, or the local oscillator laser frequency can be controlled by a voltage-controlled oscillator (VCO) combined with an acousto-optic frequency shifter.

[0087] Based on the above embodiment, it also includes:

[0088] The radio frequency phase shifter is arranged in one of the first oscillation loop and the second oscillation loop, wherein the radio frequency phase shifter is used to shift the phase of the signal transmitted in the first oscillation loop or the second oscillation loop, and the angular frequency of the local oscillator laser is adjusted so that the first oscillation loop and the second oscillation loop can oscillate stably.

[0089] A single local oscillator laser is used to realize two RF oscillation loops at the same time. Due to the limitation of the starting conditions, the frequency of the local oscillator laser and the frequency of the optical filter must meet a certain phase relationship to achieve stable oscillation, which is also called the phase self-reproduction condition. For single-channel oscillation, the oscillation phase self-reproduction condition can be met by adjusting the angular frequency of the local oscillator laser. However, to meet the requirements of two-channel oscillation at the same time, an RF phase shifter can be added to one of the loops. By adjusting the angular frequency of the local oscillator laser source and the phase shifter in the loop, the two oscillations can meet the oscillation phase conditions at the same time.

[0090] It should be noted that for details not provided in the millimeter wave signal generating device of this embodiment, please refer to the millimeter wave signal generating device of the above embodiment.

[0091] Based on the above-mentioned millimeter wave signal generating device, the embodiment of the present disclosure further provides a millimeter wave signal generating method, including:

[0092] The laser signal is generated and output by the local oscillator laser.

[0093] A first radio frequency oscillation signal with a first angular frequency is generated based on the laser signal through a first oscillation loop.

[0094] A second RF oscillation signal of a second angular frequency is generated based on the laser signal through a second oscillation loop; wherein the first oscillation loop and the second oscillation loop share an optical filter, and the RF link delay of the first oscillation loop and the second oscillation loop is shortened by increasing the delay of the optical filter, so that the first RF oscillation signal, the second RF oscillation signal and the local oscillator laser maintain the same frequency change.

[0095] The RF reference signal is mixed with one of the first RF oscillation signal and the second RF oscillation signal through a feedback control loop to generate a feedback signal, which is input into the local oscillator laser to adjust the frequency of the laser signal output by the local oscillator laser.

[0096] When the frequency of the laser signal output by the local oscillator laser is stable, the bandpass filter signal output by the optical filter is beat by the first photodetector to generate a millimeter wave signal.

[0097] It should be noted that for details not provided in the millimeter wave signal generating method of this embodiment, please refer to the millimeter wave signal generating device of the above embodiment, which will not be described again here.

[0098] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems and methods according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram may represent a module, a program segment or a part of a code, and the above-mentioned module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box may also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0099] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present invention may be combined and / or combined in various ways, even if such combinations and / or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments and / or claims of the present invention may be combined and / or combined in various ways without departing from the spirit and teachings of the present invention. All of these combinations and / or combinations fall within the scope of the present invention.

[0100] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although each embodiment is described above, it does not mean that the measures in each embodiment cannot be used in combination. The scope of the present invention is defined by the attached claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A millimeter wave signal generating device, characterized in that: include: A local oscillator laser, used to generate and output a laser signal; A first oscillation loop, used for generating a first radio frequency oscillation signal of a first angular frequency based on the laser signal; a second oscillation loop, for generating a second RF oscillation signal of a second angular frequency based on the laser signal; wherein the first oscillation loop and the second oscillation loop share an optical filter, and the RF link delay of the first oscillation loop and the second oscillation loop is shortened by increasing the delay of the optical filter, so that the first RF oscillation signal, the second RF oscillation signal and the local oscillator laser maintain the same frequency change; a feedback control loop, configured to mix a radio frequency reference signal with one of the first radio frequency oscillation signal and the second radio frequency oscillation signal to generate a feedback signal, and input the feedback signal into the local oscillator laser to adjust the frequency of the laser signal output by the local oscillator laser; The first photodetector is used to generate the millimeter wave signal by performing beat frequency analysis on the bandpass filter signal output by the optical filter when the frequency of the laser signal output by the local oscillator laser is stable.

2. The device according to claim 1, characterized in that The first oscillation loop comprises: a first optical phase modulator, the optical filter, a second photodetector, a first RF power divider, a first RF filter, a first RF amplifier and a RF coupler connected in sequence, wherein the output end of the RF coupler is connected to the input end of the first optical phase modulator; The first optical phase modulator is used to modulate the microwave signal onto the laser signal to obtain a modulated optical signal; The optical filter is used to perform notch filtering on the modulated optical signal to obtain an optical signal after notch filtering; The second photodetector is used to perform a beat frequency on the optical signal after the notch filtering to obtain a radio frequency oscillation signal including a first angular frequency and a second angular frequency; The first radio frequency power divider is used to divide the power of the radio frequency oscillation signal including the first angular frequency and the second angular frequency into two paths; The first radio frequency filter is used to filter one of the radio frequency oscillation signals including the first angular frequency and the second angular frequency to obtain a radio frequency oscillation signal including the first angular frequency; The first radio frequency amplifier is used to amplify the radio frequency oscillation signal including the first angular frequency to obtain the first radio frequency oscillation signal.

3. The device according to claim 2, characterized in that The second oscillation loop comprises: a first optical phase modulator, the optical filter, a second photodetector, a first RF power divider, a second RF filter, a second RF amplifier, a second RF power divider and a RF coupler connected in sequence, wherein the output end of the RF coupler is connected to the input end of the first optical phase modulator; The first optical phase modulator is used to modulate the microwave signal onto the laser signal to obtain a modulated optical signal; The optical filter is used to perform notch filtering on the modulated optical signal to obtain an optical signal after notch filtering; The second photodetector is used to perform a beat frequency on the optical signal after the notch filtering to obtain a radio frequency oscillation signal including a first angular frequency and a second angular frequency; The first radio frequency power divider is used to divide the power of the radio frequency oscillation signal including the first angular frequency and the second angular frequency into two paths; The second radio frequency filter is used to filter one of the radio frequency oscillation signals including the first angular frequency and the second angular frequency to obtain a radio frequency oscillation signal including the second angular frequency; The second radio frequency amplifier is used to amplify the radio frequency oscillation signal including the second angular frequency to obtain the second radio frequency oscillation signal; The second radio frequency power divider is used to divide the second radio frequency oscillation signal into two paths with equal power; The radio frequency coupler is used to couple one of the second radio frequency oscillation signals with the first radio frequency oscillation signal and then input the coupled signals into the first optical phase modulator.

4. The device according to claim 1, characterized in that The first oscillation loop comprises: a first optical coupler, a second optical phase modulator, a second optical coupler, the optical filter, a second photodetector, a first radio frequency power divider, a first radio frequency filter and a first radio frequency amplifier connected in sequence, wherein the output end of the first radio frequency amplifier is connected to the input end of the second optical phase modulator; The first optical coupler is used to split the laser signal into two paths; The second optical phase modulator is used to modulate the microwave signal onto one of the laser signals to obtain a modulated optical signal; The second optical coupler is used to couple the modulated optical signal into the optical filter; The optical filter is used to perform notch filtering on the modulated optical signal to obtain an optical signal after notch filtering; The second photodetector is used to perform a beat frequency on the optical signal after the notch filtering to obtain a radio frequency oscillation signal including a first angular frequency and a second angular frequency; The first radio frequency power divider is used to divide the power of the radio frequency oscillation signal including the first angular frequency and the second angular frequency into two paths; The first radio frequency filter is used to filter one of the radio frequency oscillation signals including the first angular frequency and the second angular frequency to obtain a radio frequency oscillation signal including the first angular frequency; The first radio frequency amplifier is used to amplify the radio frequency oscillation signal including the first angular frequency to obtain the first radio frequency oscillation signal.

5. The device according to claim 4, characterized in that The second oscillation loop comprises: a first optical coupler, a third optical phase modulator, a second optical coupler, the optical filter, a second photodetector, a first RF power divider, a second RF filter, a second RF amplifier and a second RF power divider connected in sequence, wherein the output end of the second RF power divider is connected to the input end of the third optical phase modulator; The third optical phase modulator is used to modulate the microwave signal onto another laser signal to obtain a modulated optical signal; The second optical coupler is used to couple two modulated optical signals into the optical filter; The optical filter is used to perform notch filtering on the modulated optical signal to obtain an optical signal after notch filtering; The second photodetector is used to perform a beat frequency on the optical signal after the notch filtering to obtain a radio frequency oscillation signal including a first angular frequency and a second angular frequency; The first radio frequency power divider is used to divide the power of the radio frequency oscillation signal including the first angular frequency and the second angular frequency into two paths; The second radio frequency filter is used to filter one of the radio frequency oscillation signals including the first angular frequency and the second angular frequency to obtain a radio frequency oscillation signal including the second angular frequency; The second radio frequency amplifier is used to amplify the radio frequency oscillation signal including the second angular frequency to obtain the second radio frequency oscillation signal; The second radio frequency power divider is used to divide the second radio frequency oscillation signal into two paths with equal power, and input one of the second radio frequency oscillation signals into the third optical phase modulator.

6. The device according to any one of claims 1 to 5, characterized in that: The feedback control loop includes: a mixer, configured to mix a radio frequency reference signal with one of the first radio frequency oscillation signal and the second radio frequency oscillation signal, extract a change in the central angular frequency of the local oscillator laser relative to the central angular frequency of the optical filter, and obtain an error signal carrying frequency fluctuation information of the local oscillator laser; A feedback controller is used to generate a feedback signal from the error signal and feed it back to the local oscillator laser to adjust the frequency of the laser signal output by the local oscillator laser, wherein the angular frequency of the laser signal output by the local oscillator laser is equal to the sum of the central angular frequency of the optical filter and the angular frequency of the oscillating radio frequency signal or the absolute value of the difference between the two.

7. The device according to claim 6, characterized in that Inputting the feedback signal into the tuning port of the local oscillator laser to adjust the frequency of the laser signal output by the local oscillator laser; Alternatively, the feedback signal is input into a voltage-controlled oscillator, and combined with an acousto-optic frequency shifter to adjust the frequency of the laser signal output by the local oscillator laser.

8. The device according to any one of claims 1 to 5, characterized in that: Also includes: A radio frequency phase shifter is arranged in one of the first oscillation loop and the second oscillation loop, wherein the radio frequency phase shifter is used to shift the phase of the signal transmitted in the first oscillation loop or the second oscillation loop, and the angular frequency of the local oscillator laser is adjusted so that the first oscillation loop and the second oscillation loop oscillate stably.

9. The device according to any one of claims 1 to 5, characterized in that: The bandpass filter signal includes optical signals of two angular frequencies, and the angular frequency of the millimeter wave signal is equal to the absolute value of the difference between the two angular frequencies.

10. A method for generating a millimeter wave signal, characterized in that: include: Generate and output laser signal through local oscillator laser; Generate a first radio frequency oscillation signal of a first angular frequency based on the laser signal through a first oscillation loop; Generate a second RF oscillation signal of a second angular frequency based on the laser signal through a second oscillation loop; wherein the first oscillation loop and the second oscillation loop share an optical filter, and by increasing the delay of the optical filter, the RF link delay of the first oscillation loop and the second oscillation loop is shortened, so that the first RF oscillation signal, the second RF oscillation signal and the local oscillator laser maintain the same frequency change; Mixing a radio frequency reference signal with one of the first radio frequency oscillation signal and the second radio frequency oscillation signal through a feedback control loop to generate a feedback signal, and inputting the feedback signal into the local oscillator laser to adjust the frequency of the laser signal output by the local oscillator laser; When the frequency of the laser signal output by the local oscillator laser is stable, the bandpass filter signal output by the optical filter is beat by the first photodetector to generate the millimeter wave signal.

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