CN103267522A - Bidirectional locking frequency switching method for eliminating nonreciprocal error of optical microwave gyroscope - Google Patents

Abstract

The invention discloses a two-way frequency-locked exchange method for eliminating the non-reciprocity error of an optical-carrying microwave gyroscope. This method alternately locks the frequency of the forward and reverse photoelectric oscillators to a high-stability clock source by exchanging some devices and circuits that generate non-reciprocity errors, and realizes the alternation of the relative cavity lengths of the forward and reverse circuits, thereby achieving The purpose of compensating for non-reciprocity errors. This method can effectively improve the precision of optical-borne microwave gyroscope.

Description

Two-way frequency-locked exchange method for eliminating non-reciprocity errors of optical-borne microwave gyroscopes

technical field

The invention relates to a measurement technology, in particular to a two-way frequency-locked exchange method for eliminating the non-reciprocity error of an optical-carrying microwave gyroscope.

Background technique

In the field of inertial navigation, gyroscopes are usually used to measure the inertial angular velocity. Gyroscopes are widely used in the guidance and control of space vehicles, aircraft, missiles, submarines, ships, etc., and play an important role in precision measurement in military, industrial, and scientific fields. There are three main types of common high-precision gyroscopes: mechanical gyroscopes, laser gyroscopes, and fiber optic gyroscopes. Both laser gyroscopes and fiber optic gyroscopes are optical gyroscopes. Although they are not as stable as mechanical gyroscopes, they have the characteristics of compact structure and high sensitivity. They currently occupy most of the market share of high-precision gyroscopes.

The principle of optical gyroscope detecting angular velocity is based on the Sagnac effect. In a closed optical path, the light emitted by the same light source needs to be bidirectionally transmitted in both clockwise and counterclockwise directions. Since the optical paths of the clockwise and counterclockwise circuits are the same, the optical path difference between the two beams is only due to the angle change. Optical path difference will cause phase difference or frequency difference. Angular velocity detection is performed by detecting phase or frequency difference.

The optical-borne microwave gyroscope also needs to realize two-way microwave resonance, so as to detect the angular velocity through the frequency difference. At present, there is no single amplifier that can achieve bidirectional amplification of electrical signals, so two sets of devices need to be used to realize bidirectional microwave resonance. In the middle, there is the problem that the electrical circuits are not exactly the same, which introduces non-reciprocity errors and reduces the accuracy of the optical microwave gyroscope.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and provide a two-way frequency-locked exchange method for eliminating the non-reciprocity error of the light-borne microwave gyroscope.

The object of the present invention is achieved through the following technical solutions: a two-way frequency-locked exchange method, which is implemented on an optical-borne microwave gyroscope, and the optical-borne microwave gyroscope for eliminating non-reciprocity errors includes: a laser, an optical Beam splitter, first electro-optic modulator, first optical coupler, frequency adjuster, fiber ring cavity, second optical coupler, first photodetector, first electric filter, first microwave power divider, second An electric amplifier, a second electro-optic modulator, a second photodetector, a second electric filter, a second microwave power divider, a second electric amplifier, a difference frequency detection circuit, a frequency divider, a standard time source, and a phase detector , a low-pass filter, a first 2×2 optical switch, and a second 2×2 optical switch.

The method includes the following steps:

Step 1: Before the exchange, the light output by the laser passes through the optical beam splitter and is divided into two beams of light. One beam of light is sent to the first electro-optic modulator in a clockwise direction, and the modulated light enters the first 2×2 beam switch, the light enters the first optical coupler after passing through the first 2×2 optical switch, the light output from the first optical coupler enters the optical fiber ring cavity after passing through the frequency regulator, and the light emitted from the ring cavity passes through the second optical coupling The device enters the second 2×2 optical switch, then enters the first photodetector, converts the optical signal into an electrical signal, and then sends it to the first electrical filter, and the filtered microwave electrical signal is sent to the first microwave power splitter, The first microwave power divider has two outputs, the first output is connected to the first electro-optical modulator through the electric amplifier to form a positive feedback oscillation loop, and the second output is sent to the difference frequency detection circuit as RF output #1.

Step 2: Another beam of light split by the optical beam splitter is sent to the second electro-optic modulator in the counterclockwise direction, passes through the first 2×2 optical switch, and then enters the optical fiber ring cavity through the second optical coupler, from the ring cavity The outgoing light is sent to the second photodetector through the frequency regulator, the first optical coupler and the second 2×2 optical switch, and the optical signal is converted into an electrical signal, and then sent to the second electric filter, and the filtered The microwave electrical signal is sent to the second microwave power divider, the second microwave power divider has three outputs, the first output is connected to the second electro-optical modulator through the second electric amplifier, forming another positive feedback oscillation loop, the second output The output is sent to the difference frequency detection circuit as RF output #2, and the third output is sent to the phase detector together with the standard time source after being divided by the frequency divider. The phase detector output is connected to the frequency regulator after passing through the low-pass filter. It is used to adjust the resonant frequency to form a one-way frequency-locked loop.

Step 3: The difference frequency detection circuit detects the frequency difference between the clockwise resonant microwave output RF#1 obtained in step 1 and the counterclockwise resonant microwave output RF#2 obtained in step 2, which is denoted as

。 Step 4: After switching, the first 2×2 optical switch and the second 2×2 optical switch simultaneously switch optical paths. At this time, the first electro-optical modulator, the first photodetector, the first electric filter, the first microwave power divider, and the first electric amplifier of the clockwise loop become the components of the counterclockwise loop, and the first The second electro-optic modulator, the second photodetector, the second electric filter, the second microwave power divider, the second electric amplifier, the frequency divider, the standard time source, the phase detector, and the low-pass filter become a clockwise loop Part. At this time, the frequency difference detected by the difference frequency detection circuit 17 is denoted as

.

和步骤4获得的频率差

获得角速度： Step 5: According to the frequency difference obtained in step 3

and the frequency difference obtained in step 4

get angular velocity :

为交换后测量的角速度，

为光纤环半径， in, is the angular velocity measured before the exchange,

is the angular velocity measured after the exchange,

is the fiber ring radius,

为光速，

为回路长度，为p次谐波。

for the speed of light,

is the loop length, is the pth harmonic.

the

The purpose of the present invention can also be achieved through the following technical solutions: a two-way frequency-locked exchange method, which is implemented on an optical-borne microwave gyroscope, and the optical-borne microwave gyroscope for eliminating non-reciprocity errors includes: a laser, an optical Beam splitter, first electro-optic modulator, first optical coupler, frequency adjuster, fiber ring cavity, second optical coupler, first photodetector, first electric filter, first microwave power divider, second An electric amplifier, a second electro-optic modulator, a second photodetector, a second electric filter, a second microwave power divider, a second electric amplifier, a difference frequency detection circuit, a frequency divider, a standard time source, and a phase detector , a low-pass filter, a first 2×2 microwave switch, and a second 2×2 microwave switch.

Step 1: The light output by the laser passes through the optical beam splitter and is divided into two beams of light. One beam of light is sent to the first electro-optic modulator in a clockwise direction, and then enters the first optical coupler. The output from the first optical coupler The light enters the optical fiber ring cavity after passing through the frequency regulator, and the light exiting from the ring cavity passes through the second optical coupler, and then enters the first photodetector to convert the optical signal into an electrical signal, and then enters the second 2×2 microwave switch , and then enter the first electric filter, the filtered microwave electric signal is sent to the first microwave power divider, the first microwave power divider has two outputs, the first output passes through the electric amplifier, the first 2×2 microwave switch , connected to the first electro-optic modulator to form a positive feedback oscillation loop, and the second output is sent to the difference frequency detection circuit as RF output #1.

Step 2: Another beam of light split by the optical beam splitter is sent to the second electro-optic modulator in the counterclockwise direction, and enters the optical fiber ring cavity through the second optical coupler, and the light emitted from the ring cavity passes through the frequency regulator, the first An optical coupler is sent to the second photodetector to convert the optical signal into an electric signal, and then enters the second 2×2 microwave switch, and then enters the second electric filter, and the filtered microwave electric signal is sent to the second microwave power Divider, the second microwave power divider has three outputs, the first output passes through the second electric amplifier, the first 2×2 microwave switch, and is connected to the second electro-optical modulator to form another positive feedback oscillation loop, the second output The output is sent to the difference frequency detection circuit as RF output #2, and the third output is sent to the phase detector together with the standard time source after being divided by the frequency divider. The phase detector output is connected to the frequency regulator after passing through the low-pass filter. It is used to adjust the resonant frequency to form a one-way frequency-locked loop.

Step 3: The difference frequency detection circuit detects the frequency difference between the clockwise resonant microwave output RF#1 obtained in step 1 and the counterclockwise resonant microwave output RF#2 obtained in step 2, which is denoted as

。 Step 4: The first 2×2 microwave switch and the second 2×2 microwave switch switch the optical path at the same time. At this time, the first electric filter, the first microwave power divider, and the first electric amplifier of the clockwise loop become the components of the counterclockwise loop, while the second electric filter, the second microwave power divider, and The second electrical amplifier, frequency divider, standard time source, phase detector, and low-pass filter become components of the clockwise loop. At this time, the frequency difference detected by the difference frequency detection circuit is denoted as

.

通过下式获得角速度

： Step 5: According to the frequency difference obtained in step 3 and the frequency difference obtained in step 4

The angular velocity is obtained by

:

                                                  

                         

为交换前测量的角速度，

为交换后测量的角速度，为光纤环半径， in,

is the angular velocity measured before the exchange,

is the angular velocity measured after the exchange, is the fiber ring radius,

为光速，

为回路长度，

为p次谐波。

for the speed of light,

is the loop length,

is the pth harmonic.

The first exchange method is to exchange in the optical part, and the second exchange method is to exchange in the electrical part.

The first exchange method can compensate the first electro-optic modulator, the first photodetector, the first electric filter, the first microwave power splitter, the first electric amplifier and the second electro-optic modulator, the second photodetector, the first The non-reciprocity error of the second electric filter, the second microwave power divider, and the second electric amplifier. The second exchange method can compensate the non-reciprocity errors of the first electric filter, the first microwave power divider, the first electric amplifier and the second electric filter, the second microwave power divider, and the second electric amplifier.

The beneficial effect of the invention is: through the exchange, the non-reciprocity error of the light-borne microwave gyroscope is compensated, and the measurement accuracy of the light-borne microwave gyroscope is improved.

Description of drawings

Fig. 1 is the schematic diagram before the optical switch is changed by the two-way frequency-locked switching method of the present invention;

Fig. 2 is the schematic diagram before the microwave switch is changed by the two-way frequency-locked exchange method of the present invention;

Fig. 3 is the schematic diagram after the optical switch is changed by the two-way frequency-locked switching method of the present invention;

Fig. 4 is a schematic diagram of changing the microwave switch in the two-way frequency-locked switching method of the present invention.

In the figure, a laser 1, an optical beam splitter 2, a first electro-optic modulator 3, a first optical coupler 4, a frequency regulator 5, an optical fiber ring cavity 6, a second optical coupler 7, a first photodetector 8, The first electric filter 9, the first microwave power divider 10, the first electric amplifier 11, the second electro-optical modulator 12, the second photodetector 13, the second electric filter 14, the second microwave power divider 15, Second electrical amplifier 16, difference frequency detection circuit 17, frequency divider 18, standard time source 19, phase detector 20, low-pass filter 21, first 2×2 optical switch 22, second 2×2 optical switch 23 , the first 2×2 microwave switch 24 , and the second 2×2 microwave switch 25 . The part of the solid line represents the connection of the optical path, which is the optical path; the part of the dotted line represents the connection of the circuit, which is the electric path.

Detailed ways

Example 1

Accompanying drawing 1 and accompanying drawing 3 are the first kind of concrete embodiment.

The two-way frequency-locking exchange method of the present invention is implemented on an optical-borne microwave gyroscope, and the optical-borne microwave gyroscope for eliminating non-reciprocity errors includes: a laser 1, an optical beam splitter 2, a first electro-optic modulator 3, a first Optical coupler 4, frequency adjuster 5, fiber ring cavity 6, second optical coupler 7, first photodetector 8, first electrical filter 9, first microwave power divider 10, first electrical amplifier 11, Second electro-optic modulator 12, second photodetector 13, second electric filter 14, second microwave power divider 15, second electric amplifier 16, difference frequency detection circuit 17, frequency divider 18, standard time source 19 , a phase detector 20 , a low-pass filter 21 , a first 2×2 optical switch 22 , and a second 2×2 optical switch 23 .

The method includes the following steps:

Step 1: As shown in Figure 1, the light output by the laser 1 passes through the optical beam splitter 2 and is divided into two beams of light. One beam of light is sent clockwise to the first electro-optic modulator 3, and the modulated light enters the first electro-optic modulator 3. 2 × 2 optical switch 22, the light enters the first optical coupler 4 after passing through the first 2 × 2 optical switch 22, the light output from the first optical coupler 4 enters the optical fiber ring cavity 6 after passing through the frequency regulator 5, and enters the optical fiber ring cavity 6 from the ring The light emitted from the cavity enters the second 2×2 optical switch 23 through the second optical coupler 7, and then enters the first photodetector 8 to convert the optical signal into an electrical signal, and then enters the first electric filter 9 for filtering The final microwave electrical signal is sent to the first microwave power divider 10, the first microwave power divider 10 has two outputs, the first output is connected to the first electro-optical modulator 3 through the electric amplifier 11, forming a positive feedback oscillation loop , the second output is sent to the difference frequency detection circuit 17 as RF output #1.

Step 2: Another beam of light split by the optical beam splitter 2 is sent to the second electro-optic modulator 12 in the counterclockwise direction, passes through the first 2×2 optical switch 22, and then enters the optical fiber ring cavity through the second optical coupler 7 6. The light emitted from the ring cavity is sent to the second photodetector 13 through the frequency regulator 5, the first optical coupler 4 and the second 2×2 optical switch 23, and the optical signal is converted into an electrical signal, and then sent to the The second electric filter 14, the filtered microwave electric signal is sent into the second microwave power divider 15, the second microwave power divider 15 has three outputs, and the first output is connected to the second electro-optical modulator through the second electric amplifier 16 12, forming another positive feedback oscillation loop, the second output is sent to the difference frequency detection circuit 17 as RF output #2, and the third output is sent to the phase detector together with the standard time source 19 after being divided by the frequency divider by 18 20, the phase detector output is connected to the frequency regulator 5 after passing through the low-pass filter 21, and is used to adjust the resonant frequency, thereby forming a one-way frequency-locked loop.

Step 3: The difference frequency detection circuit 17 detects the frequency difference between the clockwise resonant microwave output RF#1 obtained in step 1 and the counterclockwise resonant microwave output RF#2 obtained in step 2, which is denoted as

。 Step 4: As shown in FIG. 3 , the first 2×2 optical switch 22 and the second 2×2 optical switch 23 exchange optical paths at the same time. Now the first electro-optic modulator 3, the first photodetector 8, the first electric filter 9, the first microwave power divider 10, and the first electric amplifier 11 of the clockwise loop become the components of the counterclockwise loop, and The second electro-optic modulator 12, the second photodetector 13, the second electric filter 14, the second microwave power divider 15, the second electric amplifier 16, the frequency divider 18, the standard time source 19, the identification The phaser 20 and the low-pass filter 21 become components of the clockwise loop. At this time, the frequency difference detected by the difference frequency detection circuit 17 is denoted as

.

和步骤4获得的频率差

获得角速度

： Step 5: According to the frequency difference obtained in step 3

and the frequency difference obtained in step 4

get angular velocity

:

。交换前，逆时针回路受到频率调节器5的调节，频率被锁定，相对长度一直保持

不变；顺时针回路的相对长度则受到真实旋转、频率调节器5的调节、以及自身回路腔长变化的影响而一直发生变化。 In the initial static state, the lengths of the clockwise loop and the counterclockwise loop are basically the same by using equal-length cables and optical fibers for connection, denoted as

. Before the exchange, the counterclockwise loop is regulated by the frequency regulator 5, the frequency is locked, and the relative length is kept

remains unchanged; the relative length of the clockwise loop is always changed due to the influence of the real rotation, the adjustment of the frequency regulator 5, and the change of the cavity length of the loop itself.

： The relative length change caused by the real rotation is recorded as

:

                                           

                                                

                                           

为真实运动角速度，

为光纤环半径，     

为光速 in:

is the real angular velocity of motion,

is the fiber ring radius,

for the speed of light

。 The adjustment of the frequency regulator 5 is divided into two parts: the compensation of the relative length change of the counterclockwise loop caused by the real rotation, which is also ; The compensation for the change of the cavity length of the counterclockwise loop is denoted as

.

。 The clockwise loop cavity length change by itself, denoted as

.

The standard locking frequency in a counterclockwise loop is:

                                                                                           

为p次谐波 in:

is the pth harmonic

The frequencies in the clockwise loop are:

                                   

                                        

                                   

The relationship between frequency difference and angular velocity is:

                         

                              

                         

Put formula (1) into formula (4) and simplify to get the angular velocity as:

                                                               

不变；逆时针回路的长度则受到真实旋转、频率调节器5的调节、以及自身回路腔长变化的影响而一直发生变化。 After the exchange, the clockwise loop is regulated by the frequency regulator 5, the frequency is locked, and the relative length is kept

remains unchanged; the length of the counterclockwise loop is always changing due to the influence of the real rotation, the adjustment of the frequency regulator 5, and the change of the cavity length of the loop itself.

。 The relative length change caused by the real rotation is the same as formula (1), recorded as

.

；顺时针回路腔长变化的补偿（即交换前逆时针回路腔长变化），记为

。 The adjustment of the frequency regulator 5 is divided into two parts: the compensation of the relative length change of the clockwise loop caused by the real rotation, which is also

; The compensation for the change of the cavity length of the clockwise loop (that is, the change of the cavity length of the counterclockwise loop before the exchange), denoted as

.

。 The change of the cavity length of the counterclockwise loop by itself (that is, the change of the cavity length of the clockwise loop before the exchange), denoted as

.

The standard locking frequency in a clockwise loop is:

                                           

                                                

                                           

The frequency in the counterclockwise loop is: .

                                   

                                        

                                   

The relationship between frequency difference and angular velocity is:

                         

                              

                         

Put formula (1) into formula (8) and simplify:

                             

                                  

                             

When the exchange process is carried out at a high speed, the change of the cavity length between two exchanges is basically unchanged, so the average angular velocity before and after exchange can be obtained by adding formula (5) and formula (9):

                   

                        

                   

It can be seen that the non-reciprocal error introduced by the difference in cavity length caused by the two-way loop can be compensated by the way of two-way frequency-locked exchange.

Example 2

Accompanying drawing 2 and accompanying drawing 4 are the second kind of specific embodiment.

The two-way frequency-locking exchange method of the present invention is implemented on an optical-borne microwave gyroscope, and the optical-borne microwave gyroscope for eliminating non-reciprocity errors includes: a laser 1, an optical beam splitter 2, a first electro-optic modulator 3, a first Optical coupler 4, frequency adjuster 5, fiber ring cavity 6, second optical coupler 7, first photodetector 8, first electrical filter 9, first microwave power divider 10, first electrical amplifier 11, Second electro-optic modulator 12, second photodetector 13, second electric filter 14, second microwave power divider 15, second electric amplifier 16, difference frequency detection circuit 17, frequency divider 18, standard time source 19 , a phase detector 20 , a low-pass filter 21 , a first 2×2 microwave switch 24 , and a second 2×2 microwave switch 25 .

Step 1: As shown in Figure 2, the light output by the laser 1 passes through the optical beam splitter 2 and is divided into two beams of light, one beam of light is sent clockwise to the first electro-optic modulator 3, and then enters the first optical coupler 4 , the light output from the first optical coupler 4 enters the optical fiber ring cavity 6 after passing through the frequency adjuster 5, and the light emitted from the ring cavity passes through the second optical coupler 7, and then enters the first photodetector 8, and the optical signal converted into an electrical signal, then enters the second 2×2 microwave switch 25, and then enters the first electrical filter 9, and the filtered microwave electrical signal is sent to the first microwave power divider 10, and the first microwave power divider 10 has two The first output is connected to the first electro-optical modulator 3 through the electric amplifier 11 and the first 2×2 microwave switch 24 to form a positive feedback oscillation loop, and the second output is sent to the difference frequency as RF output #1 detection circuit 17.

Step 2: Another beam of light split by the optical beam splitter 2 is sent to the second electro-optic modulator 12 in the counterclockwise direction, passes through the second optical coupler 7 and enters the optical fiber ring cavity 6, and the light emitted from the ring cavity passes through the frequency The regulator 5 and the first optical coupler 4 are sent to the second photodetector 13 to convert the optical signal into an electrical signal, and then enter the second 2×2 microwave switch 25, and then enter the second electric filter 14, and the filtered The microwave electric signal is sent into the second microwave power divider 15, and the second microwave power divider 15 has three outputs, the first output passes through the second electric amplifier 16 and the first 2×2 microwave switch 24, and is connected to the second electro-optical modulator 12, forming another positive feedback oscillation loop, the second output is sent to the difference frequency detection circuit 17 as RF output #2, and the third output is sent to the phase detector together with the standard time source 19 after being divided by the frequency divider by 18 20, the phase detector output is connected to the frequency regulator 5 after passing through the low-pass filter 21, and is used to adjust the resonant frequency, thereby forming a one-way frequency-locked loop.

Step 3: The difference frequency detection circuit 17 detects the frequency difference between the clockwise resonant microwave output RF#1 obtained in step 1 and the counterclockwise resonant microwave output RF#2 obtained in step 2, which is denoted as

。 Step 4: As shown in FIG. 4 , the first 2×2 microwave switch 24 and the second 2×2 microwave switch 25 switch the optical paths at the same time. Now the first electric filter 9, the first microwave power divider 10, and the first electric amplifier 11 of the clockwise loop become components of the counterclockwise loop, while the second electric filter 14, the second microwave The power divider 15, the second electrical amplifier 16, the frequency divider 18, the standard time source 19, the phase detector 20, and the low-pass filter 21 become components of the clockwise loop. At this time, the frequency difference detected by the difference frequency detection circuit 17 is denoted as

.

和步骤4获得的频率差

通过下式获得角速度

： Step 5: According to the frequency difference obtained in step 3

and the frequency difference obtained in step 4

The angular velocity is obtained by

:

                                                  

                         

为交换前测量的角速度，

为交换后测量的角速度，

为光纤环半径， in,

is the angular velocity measured before the exchange,

is the angular velocity measured after the exchange,

is the fiber ring radius,

为光速，

为回路长度，

为p次谐波。

for the speed of light,

is the loop length,

is the pth harmonic.

the

The first implementation is switching in the optical part, and the second implementation is switching in the electrical part.

The first embodiment can compensate the first electro-optic modulator 3, the first photodetector 8, the first electric filter 9, the first microwave power divider 10, the first electric amplifier 11 and the second electro-optic modulator 12, the first The non-reciprocity error of the second photodetector 13, the second electric filter 14, the second microwave power divider 15, and the second electric amplifier 16. The second embodiment can compensate the first electric filter 9, the first microwave power divider 10, the first electric amplifier 11 and the second electric filter 14, the second microwave power divider 15, and the second electric amplifier 16. nonreciprocity error.

Claims (2)

1. A two-way frequency-locked exchange method is characterized in that, the method is realized on the optical-borne microwave gyroscope that eliminates non-reciprocity error, and the optical-borne microwave gyroscope that eliminates non-reciprocal error includes: laser (1 ), optical beam splitter (2), first electro-optic modulator (3), first optical coupler (4), frequency adjuster (5), optical fiber ring cavity (6), second optical coupler (7) , the first photodetector (8), the first electric filter (9), the first microwave power divider (10), the first electric amplifier (11), the second electro-optic modulator (12), the second photodetector device (13), second electric filter (14), second microwave power divider (15), second electric amplifier (16), difference frequency detection circuit (17), frequency divider (18), standard time source (19), phase detector (20), low-pass filter (21), first 2×2 optical switch (22), second 2×2 optical switch (23), etc.; the method includes the following steps: Step 1: The light output by the laser 1 passes through the optical beam splitter (2), and is divided into two beams of light, one beam of light is sent clockwise to the first electro-optic modulator (3), and the modulated light enters the first 2 ×2 optical switch (22), the light enters the first optical coupler (4) after passing through the first 2×2 optical switch (22), and the output light from the first optical coupler (4) passes through the frequency regulator (5) After entering the optical fiber ring cavity (6), the light emitted from the ring cavity passes through the second optical coupler (7) and enters the second 2×2 optical switch (23), and then enters the first photodetector (8), and the light The signal is converted into an electric signal, and then sent to the first electric filter (9), and the filtered microwave electric signal is sent to the first microwave power splitter (10), and the first microwave power splitter (10) has two outputs, The first output is connected to the first electro-optic modulator (3) through the electric amplifier (11) to form a positive feedback oscillation loop, and the second output is sent to the difference frequency detection circuit (17) as RF output #1; Step 2: Another beam of light split by the optical beam splitter (2) is sent counterclockwise to the second electro-optic modulator (12), passes through the first 2×2 optical switch (22), and then passes through the second optical coupling The optical device (7) enters the optical fiber ring cavity (6), and the light emitted from the ring cavity is sent to the second optical coupler (4) and the second 2×2 optical switch (23) The photodetector (13) converts the optical signal into an electrical signal, and then sends it to the second electrical filter (14), and the filtered microwave electrical signal is sent to the second microwave power divider (15), and the second microwave power divider The device (15) has three outputs, the first output is connected to the second electro-optic modulator (12) through the second electric amplifier (16), forming another positive feedback oscillation loop, and the second output is sent as RF output #2 The difference frequency detection circuit (17), the third output is sent to the phase detector (20) together with the standard time source (19) after frequency division by the frequency divider (18), and the phase detector output is passed through the low-pass filter (21) Afterwards, it is connected to the frequency regulator (5) for adjusting the resonant frequency, thereby forming a one-way frequency-locking loop; Step 3: The difference frequency detection circuit (17) detects the frequency difference between the clockwise resonant microwave output RF#1 obtained in step 1 and the counterclockwise resonant microwave output RF#2 obtained in step 2, which is denoted as

Step 4: The first 2×2 optical switch (22) and the second 2×2 optical switch (23) exchanged the optical path at the same time; at this time, the first electro-optic modulator (3) and the first photodetector in the clockwise loop The device (8), the first electric filter (9), the first microwave power divider (10), and the first electric amplifier (11) become the components of the counterclockwise loop, and the second electro-optic modulator of the counterclockwise loop (12), second photodetector (13), second electric filter (14), second microwave power divider (15), second electric amplifier (16), frequency divider (18), standard time source (19), phase detector (20), and low-pass filter (21) become components of the clockwise loop; at this time, the frequency difference detected by the difference frequency detection circuit (17) is recorded as

; Step 5: According to the frequency difference obtained in step 3

and the frequency difference obtained in step 4

The angular velocity is obtained by

:     

in,

is the angular velocity measured before the exchange, is the angular velocity measured after the exchange,

is the fiber ring radius,

for the speed of light,

is the loop length, is the pth harmonic. 2. A two-way frequency-locked exchange method is characterized in that the method is implemented on an optical-borne microwave gyroscope that eliminates non-reciprocity errors, and the optical-borne microwave gyroscope that eliminates non-reciprocal errors includes: laser (1 ), optical beam splitter (2), first electro-optic modulator (3), first optical coupler (4), frequency adjuster (5), optical fiber ring cavity (6), second optical coupler (7) , the first photodetector (8), the first electric filter (9), the first microwave power divider (10), the first electric amplifier (11), the second electro-optic modulator (12), the second photodetector device (13), second electric filter (14), second microwave power divider (15), second electric amplifier (16), difference frequency detection circuit (17), frequency divider (18), standard time source (19), phase detector (20), low-pass filter (21), first 2×2 microwave switch (24), second 2×2 microwave switch (25), etc.; Step 1: The light output from the laser (1) passes through the optical beam splitter (2), and is divided into two beams of light, and one beam of light is sent clockwise to the first electro-optic modulator (3), and then enters the first optical coupler (4), the light output from the first optical coupler (4) enters the fiber ring cavity (6) after passing through the frequency adjuster (5), and the light emitted from the ring cavity passes through the second optical coupler (7), and then Enter the first photodetector (8), convert the optical signal into an electrical signal, then enter the second 2×2 microwave switch (25), and then enter the first electrical filter (9), the filtered microwave electrical signal is sent into The first microwave power divider (10), the first microwave power divider (10) has two outputs, and the first output passes through the electric amplifier (11) and the first 2×2 microwave switch (24), and is connected to the first The electro-optic modulator (3) forms a positive feedback oscillation loop, and the second output is sent to the difference frequency detection circuit (17) as RF output #1; Step 2: Another beam of light split by the optical beam splitter (2) is sent counterclockwise to the second electro-optic modulator (12), passes through the second optical coupler (7) and enters the optical fiber ring cavity (6), from The light emitted from the ring cavity is then sent to the second photodetector (13) through the frequency regulator (5) and the first optical coupler (4), where the optical signal is converted into an electrical signal, and then enters the second 2×2 microwave switch (25), then enter the second electric filter (14), the filtered microwave electric signal is sent to the second microwave power splitter (15), the second microwave power splitter (15) has three outputs, the first output After the second electrical amplifier (16), the first 2×2 microwave switch (24), it is connected to the second electro-optical modulator (12), forming another positive feedback oscillation loop, and the second output is sent as RF output #2 The difference frequency detection circuit (17), the third output is sent to the phase detector (20) together with the standard time source (19) after frequency division by the frequency divider (18), and the phase detector output is passed through the low-pass filter (21) Afterwards, it is connected to the frequency regulator (5) for adjusting the resonant frequency, thereby forming a one-way frequency-locking loop; Step 3: The difference frequency detection circuit (17) detects the frequency difference between the clockwise resonant microwave output RF#1 obtained in step 1 and the counterclockwise resonant microwave output RF#2 obtained in step 2, which is denoted as

Step 4: The first 2×2 microwave switch (24) and the second 2×2 microwave switch (25) exchange the optical path at the same time; at this time, the first electric filter (9) and the first microwave power Divider (10), the first electrical amplifier (11) become part of the counterclockwise loop, and the second electrical filter (14), second microwave power divider (15), and second electrical amplifier of the counterclockwise loop (16), frequency divider (18), standard time source (19), phase detector (20), low-pass filter (21) become the constituent part of clockwise loop; At this moment, difference frequency detection circuit (17 ) The detected frequency difference is denoted as

; Step 5: According to the frequency difference obtained in step 3 and the frequency difference obtained in step 4

The angular velocity is obtained by :      in,

is the angular velocity measured before the exchange,

is the angular velocity measured after the exchange,

is the fiber ring radius,

for the speed of light,

is the loop length,

is the pth harmonic.

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