CN105099568A - Microwave photon modulation method and device - Google Patents

Abstract

The invention discloses a microwave photon frequency conversion method. The method comprises the steps of: receiving a transponder signal; carrying out light modulation on the transponder signal to obtain a first modulation signal, wherein the first modulation signal is a single-sideband modulation signal; utilizing a first carrier wave set for carrying out frequency conversion processing on the first modulation signal so as to generating a plurality of second modulation signals, wherein the second modulation signals are distributed on different carrier wave frequency points and are identical in signal intensity; and converting the plurality of second modulation signals into a plurality of light signals, and outputting the light signals. The invention further discloses a corresponding microwave photon frequency conversion circuit. According to the invention, carrier waves of the signals after the modulation can be inhibited, the method is simply realized, and the multi-frequency frequency conversion requirement in satellite communication is met.

Description

Microwave photon modulator approach and equipment

Technical field

The invention belongs to satellite application field, relate to a kind of microwave photon modulator approach and equipment, particularly a kind of microwave photon conversion method and equipment that can be used for satellite repeater.

Background technology

Along with the expansion of broadband connections satellite application demand, on star, signal processing system scale is increasing, powerful synchronous track (GEO) satellite more and more used higher frequency range (as Ka, V etc.),

And the complexity of the spatial key due to satellite application due to satellite, and carry out multiple channel to satellite-signal and exchange, forward multiple wave beam, needs to propose the little and simple modulator approach of frequency conversion of a kind of interference.

Summary of the invention

In view of this, for overcoming at least one shortcoming above-mentioned, and following at least one advantage is provided.The invention discloses a kind of microwave photon modulator approach and equipment, adopt the present invention can suppress the carrier wave modulating rear signal, and realize simple, the demand of multi-frequency frequency conversion in satellite communication can be met.

On the one hand, adopt the present invention can carry out single-side band modulation to intermediate frequency satellite-signal, and reduce the crosstalk of the rear signal of modulation.

On the other hand, the present invention is adopted can to realize satellite-signal fast modulation, on multiple carrier wave, meeting the multichannel requirement of satellite.

For solving the problems of the technologies described above, the present invention by the following technical solutions:

On the one hand, the invention provides a kind of microwave photon conversion method, comprising:

Receive transponder signal;

Carry out light modulation to described transponder signal and obtain the first modulation signal, described first modulation signal is single sideband modulated signal;

Utilize first carrier group to carry out frequency-conversion processing to described first modulation signal and generate multiple second modulation signal; Described second modulation signal is distributed on multiple different carrier frequency point, and has identical signal strength signal intensity;

Export after multiple described second modulation signal is converted to multiple light signal respectively.

Further, also comprise:

Export after described multiple light modulating signal bandpass filtering.

Further, described the step that light modulation obtains the first modulation signal is carried out to described transponder signal, comprising:

Described transponder signal is converted into in-phase branch signal and phase shifted branch signal;

Respectively to described in-phase branch signal and described phase shifted branch signal madulation in the frequency of the continuous light of input, and utilizing increase bias voltage carry out the rear in-phase branch signal of biased rear generation modulation to described in-phase branch signal and described phase shifted branch signal and modulate rear phase shifted branch signal respectively, described bias voltage is for determining described in-phase branch signal and the frequency shift (FS) of described phase shifted branch signal after modulation;

Phase shifted branch Signal averaging after in-phase branch signal after described modulation and described modulation is generated and carries out biased rear described first modulation signal.

Further, have identical frequency interval between adjacent carrier component in described first carrier group, and the intensity of each carrier component is equal, described frequency interval is identical with radio frequency clock signals frequency.

On the other hand, the invention provides a kind of microwave photon frequency changer circuit, comprising:

First modulation circuit, for carrying out light modulation to transponder signal, obtains the first modulation signal, and described first modulation signal is single sideband modulated signal;

Second modulation circuit, carries out frequency-conversion processing for utilizing first carrier group to described first modulation signal and generates multiple second modulation signal; Described second modulation signal is distributed on multiple different carrier frequency point, and has identical signal strength signal intensity;

Output circuit, exports after multiple described second modulation signal is converted to multiple light signal respectively.

Further, described output circuit comprises band pass filter, for exporting after described multiple light modulating signal bandpass filtering.

Further, described first modulation circuit comprises:

Branching unit, for being converted into in-phase branch signal and phase shifted branch signal by described transponder signal;

First modulating unit, with respectively to described in-phase branch signal and described phase shifted branch signal madulation in the frequency of the continuous light of input, and utilizing increase bias voltage carry out the rear in-phase branch signal of biased rear generation modulation to described in-phase branch signal and described phase shifted branch signal and modulate rear phase shifted branch signal respectively, described bias voltage is for determining described in-phase branch signal and the frequency shift (FS) of described phase shifted branch signal after modulation;

With road unit, for phase shifted branch Signal averaging after in-phase branch signal after described modulation and described modulation being generated and carrying out biased rear described first modulation signal.

Further, described first modulation circuit adopts lithium niobate material to make.

Further, described second modulation circuit comprises:

Carrier wave set generation unit, for generating the first carrier group comprising multiple carrier component, have identical frequency interval between adjacent carrier component in described first carrier group, and the intensity of each carrier component is equal, described frequency interval is identical with radio frequency clock signals frequency.

Further, described second modulation circuit adopts lithium niobate material to make.

The present invention's beneficial effect compared with prior art:

This invention, by the first modulation to transponder signal, effectively can suppress light carrier, and realize letter

Number single-side band modulation.Meanwhile, by utilizing first carrier group, be convenient to the second modulation signal

Gross power controls, and can use the requirement of different frequency passage.

Accompanying drawing explanation

In order to be illustrated more clearly in the technical scheme in the embodiment of the present invention, below the accompanying drawing used required in describing the embodiment of the present invention is briefly described, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to the content of the embodiment of the present invention and these accompanying drawings.

Fig. 1 is embodiment of the present invention microwave photon modulator approach flow chart;

Fig. 2 is the first modulation flow chart in an embodiment of the present invention;

Fig. 3 is embodiment of the present invention microwave photon modulation circuit schematic diagram;

Fig. 4 is that the one of embodiment of the present invention microwave photon modulation circuit can way of realization;

Fig. 5 is that the one of embodiment of the present invention microwave photon modulation circuit can the second modulator schematic diagram in way of realization.

Embodiment

The technical problem solved for making the present invention, the technical scheme of employing and the technique effect that reaches are clearly, be described in further detail below in conjunction with the technical scheme of accompanying drawing to the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those skilled in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

Technical scheme of the present invention is further illustrated by embodiment below in conjunction with accompanying drawing.

Fig. 1 is embodiment of the present invention microwave photon modulator approach flow chart.

Fig. 2 is the first modulation flow chart in an embodiment of the present invention.

With reference to figure 1, S101, receive transponder signal, this transponder signal is the data-signal by carrying effective information in ground satellite station, the binary data of original data signal for characterizing by 01 produced in satellite station, carry out after mixing through radio-frequency carrier, produce the signal that is arranged in Mid Frequency thus as the transponder signal of this step S101.

It will be understood by those skilled in the art that and can generate by the original data signal of binary form and radio-frequency carrier being carried out mixing the Mid Frequency satellite uplink signal (i.e. the input signal of Fig. 4) being arranged in desired frequency band in satellite ground.

S102, carries out light modulation process to the transponder signal received through S101, herein for ease of illustrating, the modulation treatment in step S102 is labeled as the first modulation treatment.The transponder signal being in continuous light frequency, according to the continuous light of input, with continuous light frequency for transponder signal is modulated by benchmark, and is carried out frequency translation thus the first modulation signal of generation single-side belt according to added being biased by this first modulation treatment.

S103, carries out frequency-conversion processing for utilizing first carrier group to described first modulation signal and generates multiple second modulation signal; Described second modulation signal is distributed on multiple different carrier frequency point, and has identical signal strength signal intensity.

S104, exports after multiple described second modulation signal is converted to multiple light signal respectively.

As a kind of extendible embodiment of the present invention, after the multiple light signal of generation, for the signal be more than outside desired frequency range, before output, by bandpass filtering, the unexpected component of filtering filtering is carried out to multiple light signal in area of light, then output optical signal.

With reference to figure 2, corresponding to above-mentioned steps S102, further, as the extendible embodiment of the present invention, according to following step, the first modulation is carried out to transponder signal.

S1021, is converted into in-phase branch signal and phase shifted branch signal by transponder signal, the in-phase branch signal and phase shifted branch signal that transform rear generation are had to the phase difference of 90, thus can be convenient to process respectively this two-way tributary signal.

S1022, according to the continuous light with preset frequency and intensity of input, in-phase branch and phase shifted branch are modulated in the preset frequency of continuous light, and on the basis of phase deviation, be that in-phase branch and phase shifted branch load bias voltage further, thus realize the frequency translation to in-phase branch and phase shifted branch.

S1023, superposes the in-phase branch after step S1022 and phase shifted branch, offsets unnecessary frequency component, and realizes the object of suppressed carrier, thus complete light modulation process by superposition, generates the first modulation signal of monolateral dullness system.

Same, as the expansion of first carrier group in above-mentioned steps S103, in embodiments of the present invention, between adjacent carrier component, there is identical frequency interval in first carrier group, and the intensity of each carrier component is equal, described frequency interval is identical with radio frequency clock signals frequency.

Fig. 3 is embodiment of the present invention microwave photon modulation circuit schematic diagram.

With reference to figure 3, in microwave photon modulation circuit, comprise the first modulation circuit, the second modulation circuit, output circuit.

Wherein, the first modulation circuit receives the transponder signal of input, and carries out light modulation to the transponder signal that this is positioned at intermediate frequency, and the transponder signal after modulation is single sideband modulated signal.

In embodiments of the present invention, as the expansion of the first modulation circuit, the first modulation circuit comprises branching unit, the first modulating unit and road unit further.Branching unit completes the shunt to transponder signal, generates in-phase branch and the phase shifted branch of phase 90 degree.First modulation circuit receives in-phase branch and phase shifted branch respectively, and receive the continuous light signal of outside input simultaneously, under the control of continuous light signal, by in-phase branch signal and phase shifted branch signal madulation in the frequency of continuous light, and for being in after in-phase branch in continuous light frequency and phase shifted branch add bias voltage, be input to combiner unit.Combiner unit superposes two-way input signal, in two-way tributary signal after superposition, less desirable component can be cancelled out each other, then export the first modulation signal after the first modulation, complete the single-side band modulation to transponder signal, and this single sideband modulated signal has the effect of suppressed carrier.

Second modulation circuit carries out frequency translation for the first modulation signal produced the first modulation circuit and then directly the first modulation signal is transferred to the carrier frequency of expectation.The first modulation signal after frequency translation is converted to the second modulation signal be distributed on multiple different carrier frequency point, and each second modulation signal of generation has identical signal strength signal intensity, thus can control the total signal strength of each second modulation signal.

Output circuit carries out opto-electronic conversion to the second modulation signal, exports after multiple second modulation signal is converted to multiple light signal respectively.

Achieve through above-mentioned modulation circuit and the multichannel of transponder signal is modulated, and the transponder signal after modulation is converted into light signal, thus the signal transacting of area of light can be carried out in larger bandwidth range, and the demand that different transponder signal is modulated simultaneously can be met, improve the ability of satellite data communication

Lithium niobate material is all adopted to make for meeting to transponder signal above-mentioned first modulation circuit of modulation and the second modulation circuit.

Fig. 4 is that the one of embodiment of the present invention microwave photon modulation circuit can way of realization.

Fig. 5 is that the one of embodiment of the present invention microwave photon modulation circuit can the second modulator schematic diagram in way of realization.

With reference to figure 4, the one as the above embodiment of the present invention can way of realization, adopting two parallel Mach zehnder modulators (DP-MZM) as the first modulator, for realizing the single-side band modulation to transponder signal, and meeting the requirement suppressing light carrier.Adopt light polarization modulator (PolM) as the core component of the second modulator of generation carrier wave set, adopt photodetector (PD) as output circuit, realize the conversion of the signal of telecommunication to light signal.

With reference to Data in figure 4 as the input of transponder signal, the satellite input signal through receiving is input in DP-MZM respectively, and wherein, in-phase branch signal is through bias voltage v _bias=V _πafter be input to MZM1, phase shifted branch signal be in-phase branch after 90 ° of phase shifts, equally through bias voltage v _bias=V _πbe input to MZM2.

For MZM1 upper arm, output signal and be:

Above formula is carried out trigonometric function launch:

Wherein it is the phase changing capacity through signal madulation generation on MZM1.

ω _rF, m is carrier frequency and the amplitude of transponder signal, ω ₀be the angular frequency of continuous light, E0 is the field intensity of continuous light.

By formula substitution arranges:

$E_{\mathrm{MZM}1-\mathrm{upper}}\left(t\right)=\frac{1}{\sqrt{2}}{E}_0[\cos \left({\mathrm{\ω}}_{0}t\right)\cos \left(m\cos \left({\mathrm{\ω}}_{\mathrm{RF}}t\right)\right)-\sin \left({\mathrm{\ω}}_{0}t\right)\sin \left(m\cos \left({\mathrm{\ω}}_{\mathrm{RF}}t\right)\right)]$

Trigonometric function in above formula is carried out first-order bessel function launch:

$\begin{array}{c}{E}_{\mathrm{MZM}1-\mathrm{upper}}\left(t\right)=\frac{1}{\sqrt{2}}{E}_0\left\{\left(\cos \left({\mathrm{\ω}}_{0}t\right)\right[J_0\left(m\right)+2\underset{n=1}{\overset{\∞}{\mathrm{\Σ}}}{(-1)}^n{J}_{2n}\left(m\right)\cos \left(2n{\mathrm{\ω}}_{\mathrm{RF}}t\right)\right]\\ -\sin \left({\mathrm{\ω}}_{0}t\right)\left[2\underset{n=1}{\overset{\∞}{\mathrm{\Σ}}}{(-1)}^n{J}_{2n-1}\left(m\right)\cos \left((2n-1){\mathrm{\ω}}_{\mathrm{RF}}t\right)\right]\}\end{array}$

As n>3, the value of Jn (x) is very little, can ignore, then can abbreviation be:

$\begin{array}{c}{E}_{\mathrm{MZM}1-\mathrm{upper}}\left(t\right)=\frac{1}{\sqrt{2}}{E}_0\left\{\cos {\mathrm{\ω}}_{0}t\right[J_0\left(m\right)-2J_2\left(m\right)\cos \left(2{\mathrm{\ω}}_{\mathrm{RF}}t\right)]\\ -\sin {\mathrm{\ω}}_{0}t[-2J_1\left(m\right)\cos \left({\mathrm{\ω}}_{\mathrm{RF}}t\right)+2J_3\left(m\right)\cos \left(3{\mathrm{\ω}}_{\mathrm{RF}}t\right)]\}\end{array}$

Triangle relation formula abbreviation is utilized to obtain:

$\begin{array}{c}{E}_{\mathrm{MZM}1-\mathrm{upper}}\left(t\right)=\frac{1}{\sqrt{2}}{E}_0\{J_0\left(m\right)\cos {\mathrm{\ω}}_{0}t+J_1\left(m\right)[\sin \left(({\mathrm{\ω}}_0-{\mathrm{\ω}}_{\mathrm{RF}})t\right)+\sin \left(({\mathrm{\ω}}_0+{\mathrm{\ω}}_{\mathrm{RF}})t\right)]\\ -J_2\left(m\right)[\cos \left(({\mathrm{\ω}}_0-2{\mathrm{\ω}}_{\mathrm{RF}})t\right)+\cos \left(({\mathrm{\ω}}_0+2{\mathrm{\ω}}_{\mathrm{RF}})t\right)]\\ -J_3\left(m\right)[\sin \left(({\mathrm{\ω}}_0-3{\mathrm{\ω}}_{\mathrm{RF}})t\right)+\sin \left(({\mathrm{\ω}}_0+3{\mathrm{\ω}}_{\mathrm{RF}})t\right)]\}\end{array}$

For MZM1 underarm:

The voltage being loaded into branch road under MZM1 be loaded into the contrary of upper branch road

It is v that underarm loads bias voltage _bias=V _π, corresponding fixed phase offsets is

Then have:

Launch:

$E_{\mathrm{MZM}1-\mathrm{lower}}\left(t\right)=-\frac{1}{\sqrt{2}}{E}_0[\cos \left({\mathrm{\ω}}_{0}t\right)\cos \left(m\cos \left({\mathrm{\ω}}_{\mathrm{RF}}t\right)\right)+\sin \left({\mathrm{\ω}}_{0}t\right)\sin \left(m\cos \right({\mathrm{\ω}}_{\mathrm{RF}}t)]$

Carry out first-order bessel function to above formula to launch:

$\begin{array}{c}{E}_{\mathrm{MZM}1-\mathrm{lower}}\left(t\right)=\frac{1}{\sqrt{2}}{E}_0\left\{\left(\cos \left({\mathrm{\ω}}_{0}t\right)\right[J_0\left(m\right)+2\underset{n=1}{\overset{\∞}{\mathrm{\Σ}}}{(-1)}^n{J}_{2n}\left(m\right)\cos \left(2n{\mathrm{\ω}}_{\mathrm{RF}}t\right)\right]\\ -\sin \left({\mathrm{\ω}}_{0}t\right)\left[2\underset{n=1}{\overset{\∞}{\mathrm{\Σ}}}{(-1)}^n{J}_{2n-1}\left(m\right)\cos \left((2n-1){\mathrm{\ω}}_{\mathrm{RF}}t\right)\right]\}\end{array}$

Ignore higher order term and can obtain following formula:

$\begin{array}{c}{E}_{\mathrm{MZM}1-\mathrm{lower}}\left(t\right)=\frac{1}{\sqrt{2}}{E}_0\left\{\cos {\mathrm{\ω}}_{0}t\right[J_0\left(m\right)-2J_2\left(m\right)\cos \left(2{\mathrm{\ω}}_{\mathrm{RF}}t\right)]\\ -\sin {\mathrm{\ω}}_{0}t[-2J_1\left(m\right)\cos \left({\mathrm{\ω}}_{\mathrm{RF}}t\right)+2J_3\left(m\right)\cos \left(3{\mathrm{\ω}}_{\mathrm{RF}}t\right)]\}\end{array}$

Triangle relation formula abbreviation is utilized to obtain:

$\begin{array}{c}{E}_{\mathrm{MZM}1-\mathrm{lower}}\left(t\right)=\frac{1}{\sqrt{2}}{E}_0\{J_0\left(m\right)\cos {\mathrm{\ω}}_{0}t+J_1\left(m\right)[\sin \left(({\mathrm{\ω}}_0-{\mathrm{\ω}}_{\mathrm{RF}})t\right)+\sin \left(({\mathrm{\ω}}_0+{\mathrm{\ω}}_{\mathrm{RF}})t\right)]\\ -J_2\left(m\right)[\cos \left(({\mathrm{\ω}}_0-2{\mathrm{\ω}}_{\mathrm{RF}})t\right)+\cos \left(({\mathrm{\ω}}_0+2{\mathrm{\ω}}_{\mathrm{RF}})t\right)]\\ -J_3\left(m\right)[\sin \left(({\mathrm{\ω}}_0-3{\mathrm{\ω}}_{\mathrm{RF}})t\right)+\sin \left(({\mathrm{\ω}}_0+3{\mathrm{\ω}}_{\mathrm{RF}})t\right)]\}\end{array}$

Similar, for MZM2 upper arm:

Transponder signal phase shift be loaded on MZM2, then:

Carry out first-order bessel function to above formula formula to launch:

$\begin{array}{c}{E}_{\mathrm{MZM}2-\mathrm{upper}}\left(t\right)=\frac{1}{\sqrt{2}}{E}_0\left\{\cos {\mathrm{\ω}}_0[J_0\left(m\right)+2\underset{n=1}{\overset{\∞}{\mathrm{\Σ}}}{(-1)}^n{J}_{2n}\left(m\right)\cos \left(2n{\mathrm{\ω}}_{\mathrm{RF}}t\right)\right]\\ -\sin {\mathrm{\ω}}_{0}t\left[2\underset{n=1}{\overset{\∞}{\mathrm{\Σ}}}{J}_{2n-1}\sin \left((2n-1){\mathrm{\ω}}_{\mathrm{RF}}t\right)\right]\}\end{array}$

Ignore higher order term and can obtain following formula:

$\begin{array}{c}{E}_{\mathrm{MZM}2-\mathrm{upper}}\left(t\right)=\frac{1}{\sqrt{2}}{E}_0\{J_0\left(m\right)\cos {\mathrm{\ω}}_{0}t+2J_2\left(m\right)\cos {\mathrm{\ω}}_{0}t\left(2{\mathrm{\ω}}_{\mathrm{RF}}t\right)\\ +2J_1\left(m\right)\sin {\mathrm{\ω}}_{0}t\sin \left({\mathrm{\ω}}_{\mathrm{RF}}t\right)+2J_3\left(m\right)\sin {\mathrm{\ω}}_{0}t\sin \left(3{\mathrm{\ω}}_{\mathrm{RF}}t\right)\}\end{array}$

Triangle relation formula abbreviation is utilized to obtain:

$\begin{array}{c}{E}_{\mathrm{MZM}2-\mathrm{upper}}\left(t\right)=\frac{1}{\sqrt{2}}{E}_0\{J_0\left(m\right)\cos {\mathrm{\ω}}_{0}t+J_1\left(m\right)[\cos \left({\mathrm{\ω}}_{0}t-{\mathrm{\ω}}_{\mathrm{RF}}t\right)+\cos \left({\mathrm{\ω}}_0+{\mathrm{\ω}}_{\mathrm{RF}}t\right)]\\ -J_2\left(m\right)[\cos \left({\mathrm{\ω}}_0-2{\mathrm{\ω}}_{\mathrm{RF}}t\right)+\cos \left({\mathrm{\ω}}_{0}t+2{\mathrm{\ω}}_{\mathrm{RF}}t\right)]\\ -J_3\left(m\right)[\cos \left({\mathrm{\ω}}_0-3{\mathrm{\ω}}_{\mathrm{RF}}t\right)+\sin \left({\mathrm{\ω}}_0+3{\mathrm{\ω}}_{\mathrm{RF}}t\right)]\}\end{array}$

For MZM2 underarm:

It is V that MZM2 underarm loads bias voltage _bias=V _πcorresponding fixed phase offsets is

Carry out Bezier to above formula to launch:

$\begin{array}{c}{E}_{\mathrm{MZM}2-\mathrm{upper}}\left(t\right)=-\frac{1}{\sqrt{2}}{E}_0\left\{\cos {\mathrm{\ω}}_0[J_0\left(m\right)+2\underset{n=1}{\overset{\∞}{\mathrm{\Σ}}}{(-1)}^n{J}_{2n}\left(m\right)\cos \left(2n{\mathrm{\ω}}_{\mathrm{RF}}t\right)\right]\\ -\sin {\mathrm{\ω}}_{0}t\left[2\underset{n=1}{\overset{\∞}{\mathrm{\Σ}}}{J}_{2n-1}\sin \left((2n-1){\mathrm{\ω}}_{\mathrm{RF}}t\right)\right]\}\end{array}$

Ignore higher order term and can obtain following formula:

$\begin{array}{c}{E}_{\mathrm{MZM}2-\mathrm{upper}}\left(t\right)=-\frac{1}{\sqrt{2}}{E}_0\{J_0\left(m\right)\cos {\mathrm{\ω}}_{0}t+2J_2\left(m\right)\cos {\mathrm{\ω}}_{0}t\left(2{\mathrm{\ω}}_{\mathrm{RF}}t\right)\\ +2J_1\left(m\right)\sin {\mathrm{\ω}}_{0}t\sin \left({\mathrm{\ω}}_{\mathrm{RF}}t\right)+2J_3\left(m\right)\sin {\mathrm{\ω}}_{0}t\sin \left(3{\mathrm{\ω}}_{\mathrm{RF}}t\right)\}\end{array}$

Triangle relation formula abbreviation is utilized to obtain:

$\begin{array}{c}{E}_{\mathrm{MZM}2-\mathrm{lower}}\left(t\right)=\frac{1}{\sqrt{2}}{E}_0\{-J_0\left(m\right)\cos {\mathrm{\ω}}_{0}t+J_1\left(m\right)[\cos \left({\mathrm{\ω}}_{0}t-{\mathrm{\ω}}_{\mathrm{RF}}t\right)-\cos \left({\mathrm{\ω}}_{0}t+{\mathrm{\ω}}_{\mathrm{RF}}t\right)]\\ -J_2\left(m\right)[\cos \left({\mathrm{\ω}}_0-2{\mathrm{\ω}}_{\mathrm{RF}}t\right)+\cos \left({\mathrm{\ω}}_{0}t+2{\mathrm{\ω}}_{\mathrm{RF}}t\right)]\\ -J_3\left(m\right)[\cos \left({\mathrm{\ω}}_0-3{\mathrm{\ω}}_{\mathrm{RF}}t\right)+\cos \left({\mathrm{\ω}}_0+3{\mathrm{\ω}}_{\mathrm{RF}}t\right)]\}\end{array}$

The upper underarm signal plus of MZM2 obtains

$\begin{array}{c}{E}_{\mathrm{MZM}2}\left(t\right)=\sqrt{2}{E}_0\left\{J_1\left(m\right)\right[\cos ({\mathrm{\ω}}_{0}t-{\mathrm{\ω}}_{\mathrm{RF}}t)-\cos ({\mathrm{\ω}}_{0}t+{\mathrm{\ω}}_{\mathrm{RF}}t)]\\ +J_3\left(m\right)[\cos ({\mathrm{\ω}}_{0}t-3{\mathrm{\ω}}_{\mathrm{RF}}t)-\cos ({\mathrm{\ω}}_{0}t+3{\mathrm{\ω}}_{\mathrm{RF}}t)]\}\end{array}$

The DC offset voltage loaded as MZM3 is V _bias=V _π/ 2, corresponding fixed phase offsets is $\frac{V_{\mathrm{bias}}}{V_{\mathrm{\π}}}\·\mathrm{\π}=\frac{\mathrm{\π}}{2}$

Then above formula becomes

$\begin{array}{c}{E}_{\mathrm{MZM}2}\left(t\right)=\sqrt{2}{E}_0\left\{J_1\left(m\right)\right[\cos [{\mathrm{\ω}}_{0}t-{\mathrm{\ω}}_{\mathrm{RF}}t-\frac{\mathrm{\π}}{2}]-\cos {[\mathrm{\ω}}_{0}t+{\mathrm{\ω}}_{\mathrm{RF}}t-\frac{\mathrm{\π}}{2}]]\\ +J_3\left(m\right)[\cos [{\mathrm{\ω}}_{0}t-3{\mathrm{\ω}}_{\mathrm{RF}}t-\frac{\mathrm{\π}}{2}]-\cos [{\mathrm{\ω}}_{0}t+3{\mathrm{\ω}}_{\mathrm{RF}}t\left]\right]\}\end{array}$

Abbreviation is:

$\begin{array}{c}{E}_{\mathrm{MZM}2}\left(t\right)=\sqrt{2}{E}_0\left\{J_1\left(m\right)\right[\sin ({\mathrm{\ω}}_{0}t-{\mathrm{\ω}}_{\mathrm{RF}}t)-\sin ({\mathrm{\ω}}_{0}t+{\mathrm{\ω}}_{\mathrm{RF}}t)\left]\right]\\ +J_3\left(m\right)[\sin ({\mathrm{\ω}}_{0}t-3{\mathrm{\ω}}_{\mathrm{RF}}t)-\sin ({\mathrm{\ω}}_{0}t+3{\mathrm{\ω}}_{\mathrm{RF}}t)]\left]\right\}\end{array}$

Export behind MZM1 and MZM2 two-way output signal ECDC road, namely the output of DP-MZM is as the first modulation signal, specific as follows:

$E_{\mathrm{out}1}\left(1\right)=2\sqrt{2}{E}_0\left\{J_1\left(m\right)\right[\sin [{\mathrm{\ω}}_{0}t-{\mathrm{\ω}}_{\mathrm{RF}}t]-J_3\left(m\right)\sin [{\mathrm{\ω}}_{0}t+3{\mathrm{\ω}}_{\mathrm{RF}}t]\}$

According to first-order bessel function, J ₃m () will much smaller than J ₁(m), therefore ω 0+3 ω RF place signal amplitude very I ignore, namely achieve the single-side band modulation of suppressed carrier.

Further, with reference to figure 5, in the second modulator,

By adjustment PC (Polarization Controller), the drop shadow intensity of the light signal of continuous light (line polarisation) on two of light polarization modulator (PolM) vertical polarization directions can be adjusted, easily obtain intensity equal containing the frequency comb of 5 frequency components, ignore its coefficient entry and can obtain its expression formula and be:

$\begin{array}{c}{E}_{\mathrm{out}}=A_0\sin \left({\mathrm{\ω}}_{0}t\right)+A_1\sin ({\mathrm{\ω}}_{0}t+{\mathrm{\ω}}_{\mathrm{RF}0}t)+A_{-1}\sin ({\mathrm{\ω}}_{0}t-{\mathrm{\ω}}_{\mathrm{RF}0}t)\\ A_2\sin ({\mathrm{\ω}}_{0}t+2{\mathrm{\ω}}_{\mathrm{RF}0}t)+A_{-2}\sin ({\mathrm{\ω}}_{0}t-2{\mathrm{\ω}}_{\mathrm{RF}0}t)\end{array}$

Wherein ω 0, ω RF0 are respectively optical carrier frequency and radio frequency clock (CLK) signal frequency.

Adjust parameter by adjustment PC can realize | A ₀|=| A ₁|=| A _-1|=| A ₂|=| A _-2| the frequency comb that namely to be formed with ω RF0 be frequency interval.

Then above formula can be expressed as:

$\begin{array}{c}{E}_{\mathrm{out}}=A_0\sin \left({\mathrm{\ω}}_{0}t\right)+A_0\sin ({\mathrm{\ω}}_{0}t+{\mathrm{\ω}}_{\mathrm{RF}0}t)+A_0\sin ({\mathrm{\ω}}_{0}t-{\mathrm{\ω}}_{\mathrm{RF}0}t)\\ A_0\sin ({\mathrm{\ω}}_{0}t+2{\mathrm{\ω}}_{\mathrm{RF}0}t)+A_0\sin ({\mathrm{\ω}}_{0}t-2{\mathrm{\ω}}_{\mathrm{RF}0}t)\end{array}$

(3) input signal Ein (t)=Eout1 (the t)+Eout2 (t) of photoelectric detector PD as shown in Figure 4, then above-mentioned E _outcan be expressed as:

$\begin{array}{c}{E}_{\mathrm{out}}=A_0\sin \left({\mathrm{\ω}}_{0}t\right)+A_0\sin ({\mathrm{\ω}}_{0}t+{\mathrm{\ω}}_{\mathrm{RF}0}t)+A_0\sin ({\mathrm{\ω}}_{0}t-{\mathrm{\ω}}_{\mathrm{RF}0}t)\\ A_0\sin ({\mathrm{\ω}}_{0}t+2{\mathrm{\ω}}_{\mathrm{RF}0}t)+A_0\sin ({\mathrm{\ω}}_{0}t-2{\mathrm{\ω}}_{\mathrm{RF}0}t)+\sqrt{2}{E}_0{J}_1\left(m\right)\sin ({\mathrm{\ω}}_{0}t-{\mathrm{\ω}}_{\mathrm{RF}}t)\end{array}$

Utilize photoelectric detector PD to carry out beat, realize light frequency conversion and obtain, then output signal P (t) and can following formula be expressed as:

P(t)＝E _in(t)*E _in'(t)

Photoelectric detector PD beat, and ω 0 is far above the response range of detector, therefore can obtain:

$\begin{array}{c}P\left(t\right)\∝\sqrt{2}{A}_0{E}_0{J}_1\left(m\right)\cos \left({\mathrm{\ω}}_{\mathrm{RF}}t\right)+\sqrt{2}{A}_0{E}_0{J}_1\left(m\right)\cos \left(({\mathrm{\ω}}_{\mathrm{RF}0}+{\mathrm{\ω}}_{\mathrm{RF}})t\right)\\ -\sqrt{2}{A}_0{E}_0{J}_1\left(m\right)\cos \left(({\mathrm{\ω}}_{\mathrm{RF}}-{\mathrm{\ω}}_{\mathrm{RF}0})t\right)+\sqrt{2}{A}_0{E}_0{J}_1\left(m\right)\cos \left(({\mathrm{\ω}}_{\mathrm{RF}0}+{\mathrm{\ω}}_{\mathrm{RF}})t\right)\\ +\sqrt{2}{A}_0{E}_0{J}_1\left(m\right)\cos \left(({\mathrm{\ω}}_{\mathrm{RF}0}-{\mathrm{\ω}}_{\mathrm{RF}})t\right)+{A_{.0}}^2\cos \left({\mathrm{\ω}}_{\mathrm{RF}0}t\right)+\frac{3}{2}{A_0}^2\cos \left(2{\mathrm{\ω}}_{\mathrm{RF}0}t\right)\\ +\frac{{A_0}^2}{2}\cos \left(4{\mathrm{\ω}}_{\mathrm{RF}0}t\right)+{A_0}^2\cos \left(3{\mathrm{\ω}}_{\mathrm{RF}0}t\right)\end{array}$

Bandpass filtering treatment is carried out to the signal after beat and can obtain the transponder signal after the corresponding frequency conversion needed.

In above-mentioned implementation, DP-MZM and PolM all adopts lithium niobate material to make, and structure is simple, and be easy to realize, can be used as the key technology of satellite repeater system upgrade, engineering applicability is stronger.

Note, above are only preferred embodiment of the present invention and institute's application technology principle.Skilled person in the art will appreciate that and the invention is not restricted to specific embodiment described here, various obvious change can be carried out for a person skilled in the art, readjust and substitute and can not protection scope of the present invention be departed from.Therefore, although be described in further detail invention has been by above embodiment, the present invention is not limited only to above embodiment, when not departing from the present invention's design, can also comprise other Equivalent embodiments more, and scope of the present invention is determined by appended right.

Claims (10)

1. a microwave photon conversion method, is characterized in that, comprising:

Receive transponder signal;

Carry out light modulation to described transponder signal and obtain the first modulation signal, described first modulation signal is single sideband modulated signal;

Utilize first carrier group to carry out frequency-conversion processing to described first modulation signal and generate multiple second modulation signal; Described second modulation signal is distributed on multiple different carrier frequency point, and has identical signal strength signal intensity;

Export after multiple described second modulation signal is converted to multiple light signal respectively.

2. method as claimed in claim 1, is characterized in that, also comprise:

Export after described multiple light modulating signal bandpass filtering.

3. method as claimed in claim 1 or 2, is characterized in that: describedly carry out to described transponder signal the step that light modulation obtains the first modulation signal, comprising:

Described transponder signal is converted into in-phase branch signal and phase shifted branch signal;

Respectively to described in-phase branch signal and described phase shifted branch signal madulation in the frequency of the continuous light of input, and utilizing increase bias voltage carry out the rear in-phase branch signal of biased rear generation modulation to described in-phase branch signal and described phase shifted branch signal and modulate rear phase shifted branch signal respectively, described bias voltage is for determining described in-phase branch signal and the frequency shift (FS) of described phase shifted branch signal after modulation;

Phase shifted branch Signal averaging after in-phase branch signal after described modulation and described modulation is generated and carries out biased rear described first modulation signal.

4. method as claimed in claim 1 or 2, is characterized in that: have identical frequency interval between adjacent carrier component in described first carrier group, and the intensity of each carrier component is equal, described frequency interval is identical with radio frequency clock signals frequency.

5. a microwave photon frequency changer circuit, is characterized in that, comprising:

First modulation circuit, for carrying out light modulation to transponder signal, obtains the first modulation signal, and described first modulation signal is single sideband modulated signal;

Second modulation circuit, carries out frequency-conversion processing for utilizing first carrier group to described first modulation signal and generates multiple second modulation signal; Described second modulation signal is distributed on multiple different carrier frequency point, and has identical signal strength signal intensity;

Output circuit, exports after multiple described second modulation signal is converted to multiple light signal respectively.

6. circuit as claimed in claim 5, it is characterized in that, described output circuit comprises band pass filter, for exporting after described multiple light modulating signal bandpass filtering.

7. circuit as described in claim 5 or 6, is characterized in that, described first modulation circuit comprises:

Branching unit, for being converted into in-phase branch signal and phase shifted branch signal by described transponder signal;

First modulating unit, with respectively to described in-phase branch signal and described phase shifted branch signal madulation in the frequency of the continuous light of input, and utilizing increase bias voltage carry out the rear in-phase branch signal of biased rear generation modulation to described in-phase branch signal and described phase shifted branch signal and modulate rear phase shifted branch signal respectively, described bias voltage is for determining described in-phase branch signal and the frequency shift (FS) of described phase shifted branch signal after modulation;

With road unit, for phase shifted branch Signal averaging after in-phase branch signal after described modulation and described modulation being generated and carrying out biased rear described first modulation signal.

8. circuit as claimed in claim 7, is characterized in that, described first modulation circuit adopts lithium niobate material to make.

9. circuit as described in claim 5 or 6, is characterized in that, described second modulation circuit comprises:

Carrier wave set generation unit, for generating the first carrier group comprising multiple carrier component, have identical frequency interval between adjacent carrier component in described first carrier group, and the intensity of each carrier component is equal, described frequency interval is identical with radio frequency clock signals frequency.

10. circuit as claimed in claim 9, is characterized in that, described second modulation circuit adopts lithium niobate material to make.