CN103326789A - System and method for frequency tunable microwave phase shifting - Google Patents

Abstract

The invention belongs to the field of microwave photonics, and discloses a system and method for frequency tunable microwave phase shifting. The method comprises the following steps that after a continuous light carrier is splitted, one beam of the continuous light carrier is processed by a MZ Mach-zehnder, and double-sideband optical signals restrained by the carrier are produced; the other beam of the continuous light carrier is processed by a phase modulator, and phase-shifted light carrier signals are produced; two beams of light signals are combined in a wave mode, one one-step sideband is removed through a tunable micro-ring filter in a filtering mode, a frequency-moved carrier signal and a phase-shifted carrier signal are obtained, photovoltaic conversion is carried out through a photoelectric detector, and a phase shift microwave electrical signal is produced; the resonant frequency of the tunable micro-ring filter is equal to any one-step sideband of the two one-step sidebands output by the MZ Mach-zehnder by changing the frequency of an input voltage drive signal and the resonant wavelength of the tunable micro-ring filter, and the frequency of the phase shift microwave signal is changed. The system and method for the frequency tunable microwave phase shifting is stable in output performance, fast in phase shift adjusting response, small in output microwave range fluctuation and continuously adjustable in wide frequency range.

Description

A kind of microwave Phase Shifting System and method of frequency-tunable

Technical field

The invention belongs to the Microwave photonics field, more specifically, relate to a kind of frequency-tunable microwave Phase Shifting System and method based on double-parallel modulator and tunable little ring wave filter structure.

Background technology

Primary Component during the microwave Phase Shifting System is processed as microwave signal phase, be mainly used in that the Microwave photonics signal is processed and light-operated phased array radar system, all have important application in various fields such as satellite communication, mobile communication, military affairs, space flight and aviation.Traditional microwave Phase Shifting System mainly is the electronics phase-shifter, is subject to the restriction of electronic bottleneck, and the microwave signal band bandwidth of generation is little, a little less than the antijamming capability, and phase shift range is little, can not satisfy the active demand of advanced capabilities radar.

In recent years, the realization principle of microwave photon Phase Shifting System and technology mainly contain three kinds: optics (Optical True Time Delay, the OTTD) technology of really delaying time, heterodyne mixing technology and vector sum technique.Wherein the microwave photon Phase Shifting System research based on the true delay technique of optics occurs the earliest, but its structure generally is made of a lot of delay units, the interchannel of different delay produces phase difference, behind the photodetector beat frequency, form the phase shift microwave signal, but the adjusting of system phase is comparatively complicated.In the microwave photon Phase Shifting System based on the optical heterodyne mixing, owing to very easily introducing the random phase noise that is caused by environmental factor in the two-way optical interference circuit, cause the unsteadiness of microwave photon phase shift output.Based on vector and the microwave photon phase-shifter mainly realize the microwave signal phase shift of vector after synthetic by changing two-way with the amplitude of microwave signal frequently, but have the shortcomings such as the controllable phase shift scope is little, output microwave amplitude jitter is large.

Obviously, the method that above existing tradition produces the microwave phase shift is Shortcomings all, and in the increasing Microwave photonics of application system, how in large frequency range, producing amplitude fluctuation little, the microwave signal of telecommunication of the continuously adjustable high-quality stable output of phase place will be a major challenge.

Summary of the invention

Defective for prior art, the invention provides a kind of microwave Phase Shifting System of the frequency-tunable based on double-parallel modulator and little ring wave filter structure, this system can produce in large frequency range that amplitude fluctuation is little, the continuously adjustable microwave signal of telecommunication of phase place.

The microwave Phase Shifting System of frequency-tunable provided by the invention comprises: laser is used for the single continuous light carrier signal of output frequency; Beam splitter, its input is connected with the output of described laser, is used for described continuous light carrier signal is divided into the two-beam signal; Intensity modulator, its first input end is connected to the first output of described beam splitter, the second input of described intensity modulator is used for receiving input voltage and drives signal, the 3rd input of described intensity modulator is used for receiving bias voltage, be used for being set to the operating state that carrier wave suppresses according to the described intensity modulator of described bias voltage, and drive signal is modulated rear outgoing carrier inhibition to the light beam signal double-side band light signal according to described input voltage; Phase-modulator, its first input end is connected to the second output of described beam splitter, the second input of described phase-modulator is used for receiving driving voltage, for the light carrier after according to described driving voltage another bundle light signal being carried out phase-modulation and exports phase shift; Bundling device, its first input end is connected to the output of described intensity modulator, the second input of described bundling device is connected to the output of described phase-modulator, is used for the light carrier after described double-side band light signal and the described phase shift is closed ripple and exports a branch of hybrid frequency light; Tunable little ring wave filter, its input is connected to the output of described bundling device, is used for described hybrid frequency light is carried out filtering, exports carrier signal and a dephased carrier signal behind the frequency translation; And photodetector, be connected to the output of described tunable little ring wave filter, be used for the carrier signal behind the described frequency translation and dephased carrier signal are carried out opto-electronic conversion and output phase shift microwave signal.

Further, also comprise: radio frequency source, be connected to the second input of described intensity modulator, be used for providing described input voltage to drive signal; The first DC source is connected to the 3rd input of described intensity modulator, is used for providing described bias voltage; And second DC source, be connected to the second input of described phase-modulator, be used for providing described driving voltage.

Further, described intensity modulator is MZ Mach-Zehnder.

Further, the frequency of described input voltage driving signal equals the frequency of the phase shift microwave signal of photodetector output, and the amplitude of described input voltage driving signal equals the amplitude of the half-wave voltage of described MZ Mach-Zehnder; Described bias voltage is the half-wave voltage of described MZ Mach-Zehnder.

Further, described beam splitter, MZ Mach-Zehnder, phase-modulator and bundling device are that semi-conducting material is integrated in one.

The above technical scheme of conceiving by the present invention, compared with prior art, because its optical interference circuit is to finish in integrated double-parallel modulator inside, thereby the environment phase noise that may be subject to is little, whole microwave Phase Shifting System can also be integrated on a slice semi-conducting material simultaneously, reduces system bulk, strengthens stability.Adopted tunable little ring wave filter to realize exporting the frequency of microwave adjustable, can obtain and produce in large frequency range that amplitude fluctuation is little, the continuous beneficial effects such as microwave signal of adjustable, fast response time of phase place.

The present invention also provides a kind of phase shifting method of microwave Phase Shifting System, comprises the steps:

S1: equal the half-wave voltage of MZ Mach-Zehnder by the output voltage of setting the first DC source, so that MZ Mach-Zehnder is operated in the operating state that carrier wave suppresses;

S2: a branch of entering in the MZ Mach-Zehnder after the laser process beam splitter beam splitting that laser sends, another bundle enters phase-modulator;

S3: MZ Mach-Zehnder drives signal according to input voltage the light beam signal is carried out the double-side band frequency translation; Phase-modulator carries out phase shift according to driving voltage to another bundle light signal;

S4: light signal and the dephased light signal of bundling device after with the double-side band frequency translation closes output hybrid frequency light behind the ripple;

S5: tunable little ring wave filter carries out filtering to described hybrid frequency light and exports carrier signal and the dephased carrier signal behind the frequency translation;

S6: carrier signal and the dephased carrier signal of photodetector after to frequency translation carried out opto-electronic conversion and obtained the phase shift microwave signal.

Further, also comprise the steps: the driving voltage by changing the second DC source output size so that the phase generate of phase shift microwave signal change.

Further, also comprise the steps: to drive the frequency of signal and the resonance wavelength of the tunable little ring wave filter of change by changing described input voltage, make the resonance frequency of tunable little ring wave filter equal any one single order sideband in two single order sidebands of MZ Mach-Zehnder output, change the frequency of phase shift microwave signal.

Further, the frequency of described input voltage driving signal equals the frequency of phase shift microwave signal.

Further, change the resonance wavelength of little ring wave filter by hot optoelectronic pole.

Because the present invention adopts a Mach-Zehnder modulators to produce the double-side band light signal that carrier wave suppresses, and the method for utilizing tunable little ring wave filter to carry out linear filter produces the light carrier of a frequency translation, with carry out light carrier after the phase shift through phase-modulator and carry out beat frequency and produce that amplitude fluctuation is little, the stability microwave signal of telecommunication of the continuously adjustable high-quality output of phase place, and the frequency of the microwave signal of telecommunication of output also is continuously adjustable.

Description of drawings

Fig. 1 is the theory diagram of microwave Phase Shifting System provided by the invention;

Fig. 2 is the transmission curve of MZ Mach-Zehnder in the microwave Phase Shifting System provided by the invention, and wherein, A represents that the signal of telecommunication inputted, B represent the light signal of exporting;

Fig. 3 (a) is tunable micro-ring resonant cavity structural representation in the microwave Phase Shifting System provided by the invention;

Fig. 3 (b) is tunable micro-ring resonant cavity frequency response curve in the microwave Phase Shifting System provided by the invention;

Fig. 4 is that the phase shift size of the microwave Phase Shifting System output microwave signal that provides of the embodiment of the invention adds the direct voltage relation curve with phase-modulator;

Fig. 5 is that the microwave Phase Shifting System that the embodiment of the invention provides is exported the amplitude of microwave signal with the phase shift variations relation curve.

Embodiment

In order to make purpose of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, is not intended to limit the present invention.

The present invention relates to Microwave photonics field opto-electronic device technology of preparing, a kind of microwave photon Phase Shifting System of the frequency-tunable based on integrated double-parallel modulator (parallel MZ Mach-Zehnder (MZM) and phase-modulator (PM)) and the little ring structure of resonance tunable wave length is provided; Mainly for generation of frequency, the high-frequency microwave signal of telecommunication that phase place is adjustable; Have that transmission performance is stable, output phase shift microwave amplitude fluctuation is little, the continuous advantage such as adjustable of microwave frequency.The characteristics such as simultaneously, the present invention has also that the phase shift governing response is fast, output microwave frequency and phase adjustment range are large.

The microwave Phase Shifting System of frequency-tunable provided by the invention comprises: laser 1, beam splitter 2, MZ Mach-Zehnder 3, phase-modulator 4, bundling device 5, tunable little ring wave filter 6, photodetector 7, radio frequency source 8, the first DC source 9 and the second DC source 10, the continuous light carrier signal that laser 1 output frequency is single, beam splitter 2 is divided into the two-beam signal with the continuous light carrier signal, MZ Mach-Zehnder 3 is modulated the also double-side band light signal of outgoing carrier inhibition according to the bias voltage control signal of outside to the light beam signal of beam splitter 2 outputs, the optical carrier after the phase shift is modulated and exported to another bundle light signal that phase-modulator 4 is exported beam splitter 2 according to the voltage control signal of outside, bundling device 5 is with the output of MZ Mach-Zehnder 3 and the synthetic a branch of hybrid frequency light of output of phase-modulator 4, and its radio-frequency component comprises the light carrier after two 1 rank sidebands and the phase shift; 6 pairs of described hybrid frequency light signals of tunable little ring wave filter carry out carrier signal and dephased carrier signal behind frequency translation of output after the filtering; The output of 7 pairs of tunable little ring wave filters 6 of photodetector is carried out opto-electronic conversion and is obtained dephased microwave signal.

Wherein, frequency translation (Frequency shift) refers to that frequency with the signal of telecommunication or light signal is from a frequency translation to another frequency.

Laser 1 is used for providing frequency single continuous light carrier signal, and laser 1 can be selected the continuous light laser of narrow linewidth.

The input of beam splitter 2 is connected to the output of laser 1, is used for the continuous light carrier wave of laser 1 output is divided into identical two-beam.

Fig. 2 shows the transmission curve of MZ Mach-Zehnder in the microwave Phase Shifting System provided by the invention, wherein half-wave voltage refers to that the Output optical power of modulator changes to the corresponding bias voltage of minimum value from maximum, the Output optical power maximum of modulator and the corresponding bias voltage of minimum value are called maximum functional point and minimum working point, Max, Null among the figure, Vp are corresponding respectively maximum functional point, minimum working point, half-wave voltage.

The first input end of MZ Mach-Zehnder 3 is connected to the first output of beam splitter 2, the second input of MZ Mach-Zehnder 3 connects radio frequency source 8, the 3rd input of MZ Mach-Zehnder 3 connects the first DC source 9, MZ Mach-Zehnder 3 receives a branch of continuous light signal of the first output output of beam splitter 2, utilize the first DC source 9 to load suitable dc offset voltage (equaling the half-wave voltage of modulator) to MZ Mach-Zehnder 3, the working point of MZ Mach-Zehnder 3 is set in the minimum working point (Null) of transmission curve (as shown in Figure 2), the minimum working point (Null) of MZ Mach-Zehnder 3 transmission curves refers to the minimum corresponding bias voltage of Output optical power; Provide characteristic frequency (characteristic frequency equal'ss the frequency of the microwave signal of photodetector 7 outputs) the signal of telecommunication by radio frequency source 8 for it, final MZ Mach-Zehnder 3 is output as the double-side band light signal that carrier wave suppresses, be about to original optical signal frequency and move to both sides respectively, the amount of moving is the characteristic frequency of output signal in the radio frequency source 8.

The first input end of phase-modulator 4 is connected to the second output of beam splitter 2, the second input of phase-modulator 4 connects the second DC source 10, phase-modulator 4 receives another bundle continuous light signal of the second output output of beam splitter 2, utilize the second DC source 10 to provide a certain suitable voltage to phase-modulator 4, make its output light produce a fixing phase difference with respect to input light, namely obtain the light carrier after the phase shift.Described a certain suitable voltage V _DCPhase shift with the desired output of system

Relevant, the relation of both correspondences by Determine V _{π PM}Be the half-wave voltage of phase-modulator 4, k represents the rejection coefficient of tunable little ring wave filter 6.

The first input end of bundling device 5 connects the output of MZ Mach-Zehnder 3, the second input of bundling device 5 connects the output of phase-modulator 4, be used for the light signal of MZ Mach-Zehnder 3 outputs and the light signal of phase-modulator 4 outputs are closed waveform bunchy hybrid frequency light, its radio-frequency component comprises the light carrier after two 1 rank sidebands and the phase shift.

The input of tunable little ring wave filter 6 is connected to the output of bundling device 5, be used for the hybrid frequency light of bundling device 5 outputs is carried out filtering, remove wherein any one single order sideband, export carrier signal and a dephased carrier signal behind the frequency translation.

Shown in Fig. 3 (a), the concrete structure of tunable little ring wave filter 6 is that a semiconductor microactuator annular resonant cavity with hot optoelectronic pole consists of, and makes the material production thermo-optic effect change the resonance wavelength of little ring wave filter by electrode power supply.

The transmission curve of the transmission spectrum of tunable little ring wave filter 6 is shown in Fig. 3 (b), the hybrid frequency light that is input as bundling device 5 outputs of tunable little ring wave filter 6, carrying out filtering processes, with one of them single order sideband (that frequency component after moving to left or moving to right) filtering, and the light of remaining two frequencies of output, comprise one behind frequency translation carrier wave and one through dephased carrier wave.Wherein, tunable little ring wave filter 6 utilizes hot optoelectronic pole that microwave is heated, realize the tunable of filter resonance frequency (wavelength), thereby can guarantee the single order sideband of system works in also can the hybrid frequency light signal of filtering bundling device 5 outputs when different frequency.

The input of photodetector 7 is connected to the output of tunable little ring wave filter 6, be used for opto-electronic conversion is carried out in the output of tunable little ring wave filter 6, namely the light signal of two different frequencies carries out beat frequency and obtains the corresponding signal of telecommunication, is through the signal of telecommunication after the phase shift.

In the embodiment of the invention, when using double-parallel modulator, by the bias voltage of regulating on the MZM NULL point that it is arranged on the MZM transmission curve is realized the function that Double Sideband Suppressed Carrier is modulated, load a direct current voltage on the phase-modulator, be used for changing light beam through the phase place behind the phase-modulator.Obtain phase modulated signal through little ring wave filter filtering 1 rank sideband wherein of cascade through interfering after synthetic, obtain the single-side belt output light field.The microwave current signal of single-side belt light field after obtaining phase shift behind the photoelectric detector PD beat frequency of output.

Wherein, double-parallel modulator can be based on the integrated device of semi-conducting material, and little ring wave filter also can be the integrated a plurality of little ring of semi-conducting material simultaneously, thereby can realize integrated microwave phase shifter, increases stability.

Radio frequency source 8 is used for providing input electrical signal to MZ Mach-Zehnder 3, and its output frequency and amplitude are set as required.The frequency of radio frequency source 8 output voltages equals the frequency of the microwave signal of photodetector 7 outputs, and the amplitude of radio frequency source 8 output voltages equals the half-wave voltage of MZ Mach-Zehnder 3.

The first DC source 9 is used for providing bias voltage to MZ Mach-Zehnder 3.The output of the first DC source 9 can be set as the half-wave voltage of MZ Mach-Zehnder 3.

The second DC source 10 is used for providing input voltage to phase-modulator 4, so that phase-modulator 4 can be realized needed phase shift.

In embodiments of the present invention, beam splitter 2, MZ Mach-Zehnder 3, phase-modulator 4 and bundling device 5 can utilize semi-conducting material to be integrated in one, can reduce light signal in beam splitting and close asymmetry and the loss that produces in the bundle process so on the one hand, can also reduce on the other hand owing to the noise that produces in the discrete device, integrated double-parallel modulator has more stable optical property.

In embodiments of the present invention, laser 1, beam splitter 2, MZ Mach-Zehnder 3, phase-modulator 4, bundling device 5 and tunable little ring wave filter 6 all can be integrated on the same semi-conducting material, can reduce volume, reduction complexity, increase stability and the reliability of system of the present invention.

The present invention compares with traditional microwave photon phase-shifting technique, the present invention is because its optical interference circuit is to finish in integrated double-parallel modulator inside, thereby the environment phase noise that is subject to is little, whole Phase Shifting System volume I is integrated on the semiconductor simultaneously, not only can stable transfer, have also that the shake of microwave signal output amplitude is little, the speed of response fast, the bandwidth scope is tunable, a continuous advantage such as adjustable of 360 ° in output microwave.

Reach technological means and the effect that predetermined goal of the invention is taked for further setting forth the present invention, below in conjunction with accompanying drawing, embodiment and the operation principle of the substantially integrated double-parallel modulator that foundation the present invention is proposed and the microwave Phase Shifting System of resonance tunable wave length are elaborated.

If the input optical carrier is E ₀=A ₀Cos (ω ₀T), A wherein ₀, ω ₀Amplitude and frequency for light carrier.Input voltage driving signal RF1 is V in the MZ Mach-Zehnder 3 ₁Cos (ω ₁T), wherein, V ₁, ω ₀Respectively amplitude and the frequency of driving voltage.By the bias voltage DC1 that regulates on the MZ Mach-Zehnder 3 it is arranged on Null point (seeing accompanying drawing 2) on the transmission curve, i.e. V _Bias=V _{π 1}, realize the function that Double Sideband Suppressed Carrier is modulated.Wherein voltage drive signals RF1 is provided by radio frequency source 8, and bias voltage DC1 is provided by the first DC source 9.

Output signal E after MZ Mach-Zehnder 3 modulation ₁Expression formula be:

$E_1=\frac{\sqrt{2}}{2}{\mathrm{\&beta;}}_1{\mathrm{<figure-callout\; id="0"\; label="A"\; filenames="HDA00003140038000022.png,HDA00003140038000031.png"\; state="\{\{state\}\}">A</figure-callout>}}_0\cos \left({\mathrm{\&omega;}}_{0}t\right)\cos \left(\mathrm{\&pi;}\frac{V_{\mathrm{\&pi;}}+V_1\sin \left({\mathrm{\&omega;}}_{1}t\right)}{2V_{\mathrm{\&pi;}1}}\right)......\left(1\right);$ β wherein ₁Cause the decay of amplitude for the loss of 3 pairs of light fields of MZ Mach-Zehnder; V _{π 1}Half-wave voltage for MZ Mach-Zehnder 3.Input electric drive signal amplitude hour makes modulation depth Ignore the high-order sideband, adopt Bezier (Bessel) functional expansion and only keep the single order sideband to obtain:

$E_1=-\frac{\sqrt{2}}{2}{\mathrm{\&beta;}}_1{A}_0\cos \left({\mathrm{\&omega;}}_{0}t\right)\sin \left(m_f\sin \left({\mathrm{\&omega;}}_{1}t\right)\right)$

$=-2\frac{\sqrt{2}}{2}{\mathrm{\&beta;}}_1{A}_0\cos \left({\mathrm{\&omega;}}_{0}t\right)(J_1\left(m_f\right)\sin \left({\mathrm{\&omega;}}_{1}t\right)+o\left(m_f\right))$

$\&ap;\frac{\sqrt{2}}{2}{\mathrm{<figure-callout\; id="0"\; label="A"\; filenames="HDA00003140038000022.png,HDA00003140038000031.png"\; state="\{\{state\}\}">A</figure-callout>}}_0{\mathrm{\&beta;}}_1{J}_1\left(m_f\right)[\sin \left(({\mathrm{\&omega;}}_o-{\mathrm{\&omega;}}_1)t\right)-\sin \left(({\mathrm{\&omega;}}_o+{\mathrm{\&omega;}}_1)t\right)]......\left(2\right)$

Phase-modulator on another road loads direct voltage V _DC, be used for changing light beam through the phase place of output optical signal behind the phase-modulator, like this, through the light field expression formula behind the phase-modulator be:

${\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="HDA00003140038000011.png"\; state="\{\{state\}\}">E</figure-callout>}}_2=\frac{\sqrt{2}}{2}{A}_0{\mathrm{\&beta;}}_2\cos ({\mathrm{\&omega;}}_{0}t+{\mathrm{\&phi;}}_{\mathrm{PM}})......\left(3\right);$ β wherein ₂The loss of light field is caused the decay of amplitude for phase-modulator, V _{π PM}Be the half-wave voltage of phase-modulator, As seen, the phase place that just can regulate light carrier by the direct voltage that changes on the phase-modulator.

Relevant synthetic light wave electric field is behind double-parallel modulator like this:

${\mathrm{<figure-callout\; id="3"\; label="E"\; filenames="HDA00003140038000011.png"\; state="\{\{state\}\}">E</figure-callout>}}_3=\frac{\sqrt{2}}{2}[E_1+E_2]$

$=\frac{1}{2}{A}_0\{{\mathrm{\&beta;}}_2\cos ({\mathrm{\&omega;}}_{0}t+{\mathrm{\&phi;}}_{\mathrm{PM}})+{\mathrm{\&beta;}}_1{J}_1\left(m_f\right)[\sin \left(({\mathrm{\&omega;}}_o-{\mathrm{\&omega;}}_1)t\right)-\sin \left(({\mathrm{\&omega;}}_o+{\mathrm{\&omega;}}_1)t\right)\left]\right\}......\left(4\right);$

Above-mentioned signal is through one of them single order sideband of little ring wave filter (or little ring of a plurality of cascades) filtering, wherein the frequency response curve of little ring wave filter as shown in Figure 3, then final single-side belt output light field is: $E_{\mathrm{out}}=\frac{1}{2}{A}_0\{{\mathrm{\&beta;}}_2\cos ({\mathrm{\&omega;}}_{0}t+{\mathrm{\&phi;}}_{\mathrm{PM}})+{\mathrm{\&beta;}}_1{J}_1\left(m_f\right)[\sin \left(({\mathrm{\&omega;}}_o-{\mathrm{\&omega;}}_1)t\right)-k\sin \left(({\mathrm{\&omega;}}_o+{\mathrm{\&omega;}}_1)t\right)\left]\right\}......\left(5\right);$ Wherein k is little ring wave filter right+1 rank sideband light field amplitude rejection coefficient, the light intensity attenuation coefficient that defines its logarithmic form be α=-microwave current signal that 20lgk obtains behind the photoelectric detector PD beat frequency, because the restriction of photoelectric detector PD bandwidth, the higher order term that can ignore the photoelectric current that produces behind the beat frequency, approximate expression is: $I_{\mathrm{out}}=\frac{1}{4}R{A}_0^2{J}_1\left(m_f\right){\mathrm{\&beta;}}_1{\mathrm{\&beta;}}_2[k\sin ({\mathrm{\&omega;}}_{1}t-{\mathrm{\&phi;}}_{\mathrm{PM}})+\sin ({\mathrm{\&omega;}}_{1}t+{\mathrm{\&phi;}}_{\mathrm{PM}})]\}......\left(6\right);$ Wherein R is the responsiveness of PD.Then can be write the photoelectric current of output as following form according to vector sum technique:

Wherein the amplitude of microwave and phase place are respectively:

$A=\frac{1}{4}\mathrm{<figure-callout\; id="0"\; label="R\; A"\; filenames="HDA00003140038000022.png,HDA00003140038000031.png"\; state="\{\{state\}\}">R</figure-callout>}{A}_{}^{}{}_0^2{J}_1\left(m_f\right){\mathrm{\&beta;}}_1{\mathrm{\&beta;}}_2\sqrt{{(1+k)}^2{\cos }^2\left({\mathrm{\&phi;}}_{\mathrm{PM}}\right)+{(1-k)}^2{\sin }^2\left({\mathrm{\&phi;}}_{\mathrm{PM}}\right)}$

Following formula shows, by regulating different φ _PMJust can be to the microwave continuous phase shift of output.If filter is right+inhibition of 1 rank sideband is enough strong, namely k is enough little, when α 〉=25dB, and the microwave phase shift after the phase shift of system's output

With the basic retention wire sexual intercourse of the variation of phase-modulator phase place, namely

And output microwave amplitude is insensitive to the variation of phase shift, i.e. the amplitude fluctuation little (being no more than 0.5dB) of this system's output microwave.Accompanying drawing 4 and accompanying drawing 5 have provided respectively, when filter right+when the attenuation coefficient of 1 rank sideband maximum is 25dB, output microwave signal phase shift size with the amplitude of the direct voltage magnitude relationship curve that loads on the phase-modulator 4 and output microwave signal with the phase shift variations curve.

Because being driving signal (output of the radio frequency source 8) frequency by MZ Mach-Zehnder 3, the frequency of the last output microwave signal of telecommunication determines, therefore as long as the little ring wave filter among the present invention is made the tunable filter of resonance wavelength (tunable such as hot optic tunable or electric light), make its keep filtering always 3 produce+1 rank (or-1 rank) sideband can realize output frequency microwave photon phase-shifter adjustable, that amplitude fluctuation is little.

In the embodiment of the invention, double-parallel modulator in the microwave photon Phase Shifting System can be based on the integrated device of semi-conducting material, also can be integrated in easily on the semi-conducting material owing to little ring wave filter simultaneously, thereby proposed realization microwave photon Phase Shifting System can be made integrated device, reduce size, strengthen stability.

The present invention also provides a kind of phase shifting method of microwave Phase Shifting System, comprises the steps:

S1: equal the half-wave voltage of MZ Mach-Zehnder 3 by the bias voltage of setting 9 outputs of the first DC source, so that MZ Mach-Zehnder 3 is operated in the operating state that carrier wave suppresses;

S2: a branch of entering in the MZ Mach-Zehnder 3 after laser process beam splitter 2 beam splitting that laser 1 sends, another bundle enters phase-modulator 4;

S3: MZ Mach-Zehnder 3 carries out the double-side band frequency translation according to the signal of telecommunication that radio frequency source 8 produces to the light beam signal;

Phase-modulator 4 carries out phase shift according to the driving voltage of the second DC source 10 outputs to another bundle light signal;

S4: light signal and the dephased light signal of bundling device 5 after with the double-side band frequency translation closes output hybrid frequency light behind the ripple, and its radio-frequency component comprises the light carrier after two 1 rank sidebands and the phase shift;

S5: 6 pairs of hybrid frequency light of tunable little ring wave filter carry out filtering and export carrier signal and the dephased carrier signal behind the frequency translation;

S6: the carrier signal behind 7 pairs of frequency translations of photodetector and dephased carrier signal are carried out opto-electronic conversion and are obtained the phase shift microwave signal.

This phase shifting method also comprises the steps: by the driving voltage that changes 10 outputs of the second DC source so that the phase generate of phase shift microwave signal changes; Driving voltage and phase place are periodic linear relationship, and namely in one-period, phase place is linear increasing along with the increase of driving voltage.

This phase shifting method also comprises the steps: the resonance wavelength by the frequency of the output voltage that changes radio frequency source 8 and the tunable little ring wave filter 6 of change, make the resonance frequency of tunable little ring wave filter 6 equal any one single order sideband in two single order sidebands of MZ Mach-Zehnder 3 outputs, change the frequency of phase shift microwave signal.

Wherein, the frequency of the output voltage of radio frequency source 8 equals the frequency of phase shift microwave signal.Can change by hot optoelectronic pole the resonance wavelength of little ring wave filter 6.

Because the present invention adopts a Mach-Zehnder modulators to produce the double-side band light signal that carrier wave suppresses, and the method for utilizing tunable little ring wave filter to carry out linear filter produces the light carrier of a frequency translation, with carry out light carrier after the phase shift through phase-modulator and carry out beat frequency and produce that amplitude fluctuation is little, the stability microwave signal of telecommunication of the continuously adjustable high-quality output of phase place, and the frequency of the microwave signal of telecommunication of output also is continuously adjustable.

Those skilled in the art will readily understand; the above only is preferred embodiment of the present invention; not in order to limiting the present invention, all any modifications of doing within the spirit and principles in the present invention, be equal to and replace and improvement etc., all should be included within protection scope of the present invention.

Claims (10)

1. the microwave Phase Shifting System of a frequency-tunable is characterized in that, comprising:

Laser is used for output continuous light carrier signal;

Beam splitter, its input is connected with the output of described laser, is used for described continuous light carrier signal is divided into the two-beam signal;

Intensity modulator, its first input end is connected to the first output of described beam splitter, the second input of described intensity modulator is used for receiving input voltage and drives signal, the 3rd input of described intensity modulator is used for receiving bias voltage, be used for being set to the operating state that carrier wave suppresses according to the described intensity modulator of described bias voltage, and drive signal is modulated rear outgoing carrier inhibition to the light beam signal double-side band light signal according to described input voltage;

Phase-modulator, its first input end is connected to the second output of described beam splitter, the second input of described phase-modulator is used for receiving driving voltage, for the light carrier after according to described driving voltage another bundle light signal being carried out phase-modulation and exports phase shift;

Bundling device, its first input end is connected to the output of described intensity modulator, the second input of described bundling device is connected to the output of described phase-modulator, is used for the light carrier after described double-side band light signal and the described phase shift is closed ripple and exports a branch of hybrid frequency light;

Tunable little ring wave filter, its input is connected to the output of described bundling device, is used for described hybrid frequency light is carried out filtering, exports carrier signal and a dephased carrier signal behind the frequency translation; And

Photodetector is connected to the output of described tunable little ring wave filter, is used for the carrier signal behind the described frequency translation and dephased carrier signal are carried out opto-electronic conversion and output phase shift microwave signal.

2. microwave Phase Shifting System as claimed in claim 1 is characterized in that, also comprises:

Radio frequency source is connected to the second input of described intensity modulator, is used for providing described input voltage to drive signal;

The first DC source is connected to the 3rd input of described intensity modulator, is used for providing described bias voltage; And

The second DC source is connected to the second input of described phase-modulator, is used for providing described driving voltage.

3. microwave Phase Shifting System as claimed in claim 1 or 2 is characterized in that, described intensity modulator is MZ Mach-Zehnder.

4. microwave Phase Shifting System as claimed in claim 3, it is characterized in that, the frequency of described input voltage driving signal equals the frequency of the phase shift microwave signal of photodetector output, and the amplitude of described input voltage driving signal equals the amplitude of the half-wave voltage of described MZ Mach-Zehnder; Described bias voltage is the half-wave voltage of described MZ Mach-Zehnder.

5. microwave Phase Shifting System as claimed in claim 3 is characterized in that, described beam splitter, MZ Mach-Zehnder, phase-modulator and bundling device are that semi-conducting material is integrated in one.

6. the phase shifting method of a microwave Phase Shifting System is characterized in that, comprises the steps:

S1: equal the half-wave voltage of MZ Mach-Zehnder by the output voltage of setting the first DC source, so that MZ Mach-Zehnder is operated in the operating state that carrier wave suppresses;

S2: a branch of entering in the MZ Mach-Zehnder after the laser process beam splitter beam splitting that laser sends, another bundle enters phase-modulator;

S3: MZ Mach-Zehnder drives signal according to input voltage the light beam signal is carried out the double-side band frequency translation; Phase-modulator carries out phase shift according to driving voltage to another bundle light signal;

S4: light signal and the dephased light signal of bundling device after with the double-side band frequency translation closes output hybrid frequency light behind the ripple;

S5: tunable little ring wave filter carries out filtering to described hybrid frequency light and exports carrier signal and the dephased carrier signal behind the frequency translation;

S6: carrier signal and the dephased carrier signal of photodetector after to frequency translation carried out opto-electronic conversion and obtained the phase shift microwave signal.

7. phase shifting method as claimed in claim 6 is characterized in that, also comprises the steps:

The size of the driving voltage by changing the second DC source output so that the phase generate of phase shift microwave signal change.

8. such as claim 6 or 7 described phase shifting methods, it is characterized in that, also comprise the steps:

The resonance wavelength that drives the frequency of signal and change tunable little ring wave filter by changing described input voltage, make the resonance frequency of tunable little ring wave filter equal any one single order sideband in two single order sidebands of MZ Mach-Zehnder output, change the frequency of phase shift microwave signal.

9. phase shifting method as claimed in claim 8 is characterized in that, the frequency of described input voltage driving signal equals the frequency of phase shift microwave signal.

10. phase shifting method as claimed in claim 8 is characterized in that, changes the resonance wavelength of little ring wave filter by hot optoelectronic pole.

Images