An Adjustable Symmetrical Triangular Waveform Generator Based on Channelized Frequency Synthesis

Abstract

This invention proposes a tunable symmetrical triangular waveform generator based on channelized frequency synthesis. It relates to fields such as microwave photonics, optoelectronic devices, and high-speed signal processing. The device comprises two channels: Channel 1 includes a continuous-wave laser (1), a continuous-wave laser (2), an RF signal source (3), an electrical amplifier (4), an electrical power divider (5), an electrical phase shifter (6), a QPSK modulator (7), a bias voltage source (8), a bias voltage source (9), a bias voltage source (10), and a balanced photodetector (11); Channel 2 includes a continuous-wave laser (12), a continuous-wave laser (13), an RF signal source (14), an electrical amplifier (15), an electrical power divider (16), an electrical phase shifter (17), a QPSK modulator (18), a bias voltage source (19), a bias voltage source (20), a bias voltage source (21), a balanced photodetector (22), and an electrical adder (23). The waveform generated in this invention features a tunable function waveform output fitted by a high-order Fourier series.

Description

Technical Field

[0001] This invention relates to an adjustable symmetrical triangular waveform generator based on channelized frequency synthesis, and relates to the fields of microwave photonics, optoelectronic devices, and high-speed signal processing. Background Technology

[0002] Function signal generators provide electro-optic signal processing systems with various frequencies, waveforms, output levels, and light intensity signals. Function waveform signals with unique time-domain characteristics can be widely used in military radar guidance, satellite remote sensing, signal processing, and wireless communication. In high-frequency signal measurements, they can also be used as test signal sources and excitation sources. OAWG (Optical Arbitrary Waveform Generation) leverages advantages such as large bandwidth, high repetition rate, small size, and resistance to electromagnetic interference to generate arbitrary waveforms by changing the amplitude of light pulses, thus breaking the rate bottleneck of EAWG (Electronic Arbitrary Waveform Generation). In recent years, researchers have mainly studied methods for generating third-order arbitrary waveforms, but research on the generation of triangular waves with adjustable symmetry factors in higher orders is scarce. In 2017, G. Bai et al. proposed an arbitrary waveform generator based on dual parallel Mach-Zehnder modulators. By setting the bias voltage of the modulator, the amplitude and phase of the input RF signal can be generated, thus producing triangular waves, trapezoidal waves, Gaussian waves, and sawtooth waves (Versatile photonic microwave waveforms generation using dual-parallel Mach-Zehnder modulator without other dispersive elements, OPTICSCOMMUNICATIONS 396, 134-140 (2017)). In 2018, Y. He et al. proposed a waveform generation scheme based on two cascaded single-drive Mach-Zehnder modulators. By adjusting the polarization state of the incident light, two independent spectra are obtained in the polarization components, thus generating square waves, triangular waves, and trapezoidal waves (Photonic microwave waveforms generation based on two cascaded single-drive Mach-Zehnder modulators, OPTICSEXPRESS 26(6), 7829-7841 (2018)). In 2020, J. Li et al. proposed a triangular waveform generator based on an I / Q modulator with adjustable symmetry coefficients. By adjusting the bias voltage and radio frequency phase shift of the modulator, a triangular wave with adjustable symmetry coefficient is generated (Generation of an optical triangular-shaped pulse train with variable symmetry by using an I / Q modulator, OPTICAL LETTERS 45, 1411-1414 (2020)).In 2022, C. Chen et al. proposed a microwave photonics scheme, whose main structure is based on a Mach-Zehnder modulator and a tunable optical delay line. By power distribution and delay tuning of the two polarization branches, high repetition and high-quality waveform output can be achieved (Photonic generation of rectangular and triangular microwave waveforms with tunable duty cycle, IEEE PHOTONICS TECHNOLOGY LETTERS 34(7), 1041-1135(2022)). This invention proposes a tunable symmetrical triangular waveform generator based on channelized frequency synthesis. By changing the system parameter settings, triangular waveforms with symmetry factors ranging from 0% to 100% can be generated, and the generated waveform is a high-order tunable wavefunction waveform. Summary of the Invention

[0003] This invention proposes an adjustable symmetrical triangular waveform generator based on channelized frequency synthesis.

[0004] This invention is achieved through the following technical solution:

[0005] An adjustable symmetrical triangular waveform generator based on channelized frequency synthesis is characterized in that: the arbitrary waveform generator includes two channels; channel 1 includes a continuous wave laser 1, a continuous wave laser 2, an RF signal source 3, an electrical amplifier 4, an electrical power divider 5, an electrical phase shifter 6, a QPSK modulator 7, a bias voltage source 8, a bias voltage source 9, a bias voltage source 10, and a balanced photodetector 11; channel 2 includes a continuous wave laser 12, a continuous wave laser 13, an RF signal source 14, an electrical amplifier 15, an electrical power divider 16, an electrical phase shifter 17, a QPSK modulator 18, a bias voltage source 19, a bias voltage source 20, a bias voltage source 21, a balanced photodetector 22, and an electrical adder 23; the specific connection method is as follows:

[0006] In channel 1, the output of continuous wave laser 1 is connected to the optical input of QPSK modulator 7; the output of RF signal source 3 is connected to the input of electrical amplifier 4; the output of electrical amplifier 4 is connected to the input of electrical power divider 5; the output port 51 of electrical power divider 5 is connected to the first electrical drive port 71 of QPSK modulator 7; the output port 52 of electrical power divider 5 is connected to the input of electrical phase shifter 6; the output of electrical phase shifter 6 is connected to the second electrical drive port 72 of QPSK modulator 7; bias voltage source 8 is connected to the voltage bias port 73 of QPSK modulator 7; bias voltage source 9 is connected to the voltage bias port 74 of QPSK modulator 7; bias voltage source 10 is connected to the voltage bias port 75 of QPSK modulator 7; and the output of continuous wave laser 2 and the optical output of QPSK modulator 7 are connected to the input of balanced photodetector 11. In channel 2, the output of continuous wave laser 12 is connected to the optical input of QPSK modulator 18; and the output of RF signal source 14... The output terminal is connected to the input terminal of the power amplifier 15. The output terminal of the power amplifier 15 is connected to the input terminal of the power divider 16. The output port 161 of the power divider 16 is connected to the first electrical drive port 181 of the QPSK modulator 18. The output port 162 of the power divider 16 is connected to the input terminal of the phase shifter 17. The output terminal of the phase shifter 17 is connected to the second electrical drive port 182 of the QPSK modulator 18. The bias voltage source 19 is connected to the voltage bias port 183 of the QPSK modulator 18. The bias voltage source 20 is connected to the voltage bias port 184 of the QPSK modulator 18. The bias voltage source 21 is connected to the voltage bias port 185 of the QPSK modulator 18. The output terminal of the continuous wave laser 13 and the optical output terminal of the QPSK modulator 18 are connected to the input terminal of the balanced photodetector 22. The output terminals of the balanced photodetector 11 and the balanced photodetector 22 are connected to the input terminal of the electrical adder 23. The output terminal of the electrical adder 23 is connected to an oscilloscope.

[0007] In channel 1, continuous wave laser 1 is connected to QPSK modulator 7, QPSK modulator 7 to balanced photodetector 11, and continuous wave laser 2 to balanced photodetector 11 via optical fiber. In channel 2, continuous wave laser 12 is connected to QPSK modulator 18, QPSK modulator 18 to balanced photodetector 22, and continuous wave laser 13 to balanced photodetector 22 via optical fiber. In channel 1, RF signal source 3 is connected to electrical amplifier 4, electrical amplifier 4 to electrical power divider 5, electrical power divider 5 to electrical phase shifter 6, electrical power divider 5 to QPSK modulator 7, and balanced photodetector 11 to electrical adder 23 via RF cable. In channel 2, RF signal source 14 is connected to electrical amplifier 15, electrical amplifier 15 to electrical power divider 16, electrical power divider 16 to electrical phase shifter 17, electrical power divider 16 to QPSK modulator 18, and balanced photodetector 22 to electrical adder 23 via RF cable.

[0008] The specific working principle of this invention is as follows:

[0009] The optical signal emitted by the continuous-wave laser 1 in channel 1 enters the QPSK modulator 7. Let the optical field expression of the optical signal emitted by the continuous-wave laser 1 be: E 01 (t)=E0exp(jω1t), where E0 and ω1 represent the amplitude and angular frequency of the optical signal, respectively. The electric field expression of the radio frequency signal emitted by radio frequency signal source 3 is: V in (t)=V RF cos(Ωt), V RF Ω and Ω represent the amplitude and angular frequency of the electrical signal, respectively. In the QPSK modulator 7, the bias phase shift introduced by the bias voltage source 10 is π, and the bias phase shift introduced by the bias voltage source 8 and the bias voltage source 9 are equal.

[0010] The optical field expression of the output optical signal of QPSK modulator 7 is:

[0011]

[0012] Where m1=πV RF / 2V π V represents the modulation coefficient of QPSK modulator 7. π This represents the half-wave voltage.

[0013] Let the expression for the optical field of the light signal emitted by the continuous wave laser 2 be: E 02 (t) = E1exp(jω2t), where E1 and ω2 represent the amplitude and angular frequency of the optical signal, respectively. Two coherent optical signals E1(t) and E2exp(jω2t) are given. 02 (t) Simultaneously injected into the balanced photodetector 11 for photoelectric detection, the output photocurrent can be expressed as:

[0014]

[0015] When two coherent optical signals have the same center angular frequency, i.e., ω1 = ω2, the photocurrent expression can be given as:

[0016] i1(t)∝a1sin(Ωt)+a2sin(2Ωt)+a3sin(3Ωt) (3)

[0017] in It is the amplitude weighting value in channel 1, which can be determined by three variables. Controlled by Φ1 and m1.

[0018] The optical signal emitted by the continuous wave laser 12 in channel 2 enters the QPSK modulator 18. Let the optical field expression of the optical signal emitted by the continuous wave laser 12 be: E 03(t) = E²exp(jω³t), where E² and ω³ represent the amplitude and angular frequency of the optical signal, respectively. The electric field expression of the radio frequency signal emitted by radio frequency signal source 14 is: V in (t)=V RF cos(Ωt), V RF Ω and Ω represent the amplitude and angular frequency of the electrical signal, respectively. The bias phase shift introduced by bias voltage source 21 in QPSK modulator 18 is π, and the bias phase shift introduced by bias voltage source 19 and bias voltage source 20 are equal.

[0019] The optical field expression of the output optical signal of QPSK modulator 18 is:

[0020]

[0021] Where m2=πV RF / 2V π This represents the modulation coefficient of QPSK modulator 18.

[0022] Let the optical field expression of the optical signal emitted by the continuous wave laser 13 be: E 04 (t) = E3exp(jω4t), where E3 and ω4 represent the amplitude and angular frequency of the optical signal, respectively. Two coherent optical signals E2(t) and E... 04 (t) Simultaneously injected into the balanced photodetector 22 for photoelectric detection, the output photocurrent can be expressed as:

[0023]

[0024] When two coherent optical signals have different center angular frequencies, and the frequency interval satisfies three times the modulation angular frequency, i.e., ω₄ = ω₃ + 3Ω, the photocurrent expression can be given as:

[0025] i2(t)∝a4sin(4Ωt)+a5sin(5Ωt)+a6sin(6Ωt) (6)

[0026] in It is the amplitude weighting value in channel 2, which can be determined by three variables. Controlled by Φ2 and m2.

[0027] Finally, the photocurrents i1(t) and i2(t) can be combined using the electric adder 23. The final photocurrent expression can be given as:

[0028]

[0029] The beneficial effects of this invention are:

[0030] This invention, based on channelized frequency synthesis, achieves a sixth-order adjustable symmetrical (0%-100%) triangular waveform by changing the settings of six system parameters. It primarily employs a multi-channel system architecture, dividing the spectrum of the target waveform signal into multiple isolated sub-channels, each serving a specific order of harmonics. Within a single sub-channel, a combination of electro-optic modulation and coherent dual-wavelength balanced detection is used to achieve optical up-conversion and suppress mixing interference during the conversion process. Attached Figure Description

[0031] Figure 1 It is an adjustable symmetrical triangular waveform generator based on channelized frequency synthesis.

[0032] Figure 2 This is a schematic diagram of the time-domain waveform of the triangular waveform with a symmetry factor of 0% generated by the triangular waveform generator in Example 1.

[0033] Figure 3 This is a time-domain waveform diagram of a triangular waveform with a symmetry factor of 20% generated by the triangular waveform generator in Example 2.

[0034] Figure 4 This is a time-domain waveform diagram of a triangular waveform with a symmetry factor of 40% generated by the triangular waveform generator in Example 3.

[0035] Figure 5 This is a time-domain waveform diagram of a triangular waveform with a symmetry factor of 50% generated by the triangular waveform generator in Example 4.

[0036] Figure 6 This is a time-domain waveform diagram of a triangular waveform with a symmetry factor of 60% generated by the triangular waveform generator in Example 5.

[0037] Figure 7 This is a time-domain waveform diagram of a triangular waveform with a symmetry factor of 100% generated by the triangular waveform generator in Example 6. Detailed Implementation

[0038] The invention will be further described below with reference to the accompanying drawings and implementation examples.

[0039] Example 1

[0040] An adjustable symmetrical triangular waveform generator based on channelized frequency synthesis is characterized in that: the arbitrary waveform generator includes two channels; channel 1 includes a continuous wave laser 1, a continuous wave laser 2, an RF signal source 3, an electrical amplifier 4, an electrical power divider 5, an electrical phase shifter 6, a QPSK modulator 7, a bias voltage source 8, a bias voltage source 9, a bias voltage source 10, and a balanced photodetector 11; channel 2 includes a continuous wave laser 12, a continuous wave laser 13, an RF signal source 14, an electrical amplifier 15, an electrical power divider 16, an electrical phase shifter 17, a QPSK modulator 18, a bias voltage source 19, a bias voltage source 20, a bias voltage source 21, a balanced photodetector 22, and an electrical adder 23; the specific connection method is as follows:

[0041] In channel 1, the output of continuous wave laser 1 is connected to the optical input of QPSK modulator 7; the output of RF signal source 3 is connected to the input of electrical amplifier 4; the output of electrical amplifier 4 is connected to the input of electrical power divider 5; the output port 51 of electrical power divider 5 is connected to the first electrical drive port 71 of QPSK modulator 7; the output port 52 of electrical power divider 5 is connected to the input of electrical phase shifter 6; the output of electrical phase shifter 6 is connected to the second electrical drive port 72 of QPSK modulator 7; bias voltage source 8 is connected to the voltage bias port 73 of QPSK modulator 7; bias voltage source 9 is connected to the voltage bias port 74 of QPSK modulator 7; bias voltage source 10 is connected to the voltage bias port 75 of QPSK modulator 7; and the output of continuous wave laser 2 and the optical output of QPSK modulator 7 are connected to the input of balanced photodetector 11. In channel 2, the output of continuous wave laser 12 is connected to the optical input of QPSK modulator 18; and the output of RF signal source 14... The output terminal is connected to the input terminal of the power amplifier 15. The output terminal of the power amplifier 15 is connected to the input terminal of the power divider 16. The output port 161 of the power divider 16 is connected to the first electrical drive port 181 of the QPSK modulator 18. The output port 162 of the power divider 16 is connected to the input terminal of the phase shifter 17. The output terminal of the phase shifter 17 is connected to the second electrical drive port 182 of the QPSK modulator 18. The bias voltage source 19 is connected to the voltage bias port 183 of the QPSK modulator 18. The bias voltage source 20 is connected to the voltage bias port 184 of the QPSK modulator 18. The bias voltage source 21 is connected to the voltage bias port 185 of the QPSK modulator 18. The output terminal of the continuous wave laser 13 and the optical output terminal of the QPSK modulator 18 are connected to the input terminal of the balanced photodetector 22. The output terminals of the balanced photodetector 11 and the balanced photodetector 22 are connected to the input terminal of the electrical adder 23. The output terminal of the electrical adder 23 is connected to an oscilloscope.

[0042] In channel 1, the bias phase shift introduced by bias voltage source 10 in QPSK modulator 7 is π, and the bias phase shift introduced by bias voltage source 8 and bias voltage source 9 is equal; in channel 2, the bias phase shift introduced by bias voltage source 21 in QPSK modulator 18 is π, and the bias phase shift introduced by bias voltage source 19 and bias voltage source 20 is equal.

[0043] In channel 1, the power and wavelength of continuous-wave laser 1 are set to 10 dBm and 1553.33 nm, respectively, and the linewidth of continuous-wave laser 1 is set to 1 MHz. The power and wavelength of continuous-wave laser 2 are also set to 10 dBm and 1553.33 nm, respectively, and the linewidth of continuous-wave laser 2 is set to 1 MHz. The insertion loss and half-wave voltage of QPSK modulator 7 are set to 5 dB and 3.14 V, respectively, and the extinction ratio is set to 100 dB. The bias phase shift introduced by bias voltage source 8... The phase of the electrical phase shifter 6 is Φ1 = 1.3924 rad. The modulation coefficient of the QPSK modulator 7 is m1 = 2.4. The frequency of the RF signal source 3 is set to 10 GHz. The power and wavelength of the continuous wave laser 12 in channel 2 are set to 14 dBm and 1552.52 nm, respectively, and the linewidth of the continuous wave laser 12 is set to 1 MHz. The power and wavelength of the continuous wave laser 13 are set to 14 dBm and 1552.28 nm, respectively, and the linewidth of the continuous wave laser 13 is set to 1 MHz. The insertion loss and half-wave voltage of the QPSK modulator 18 are set to 5 dB and 3.14 V, respectively, and the extinction ratio is set to 100 dB. The bias phase shift introduced by the bias voltage source 19... The phase of the phase shifter 17 is Φ2 = 1.5510 rad. The modulation coefficient of the QPSK modulator 18 is m2 = 2.8. The frequency of the RF signal source 14 is set to 10 GHz. The time-domain plot of the oscilloscope output signal is shown below. Figure 2 As shown.

[0044] Example 2

[0045] An adjustable symmetrical triangular waveform generator based on channelized frequency synthesis is characterized in that: the arbitrary waveform generator includes two channels; channel 1 includes a continuous wave laser 1, a continuous wave laser 2, an RF signal source 3, an electrical amplifier 4, an electrical power divider 5, an electrical phase shifter 6, a QPSK modulator 7, a bias voltage source 8, a bias voltage source 9, a bias voltage source 10, and a balanced photodetector 11; channel 2 includes a continuous wave laser 12, a continuous wave laser 13, an RF signal source 14, an electrical amplifier 15, an electrical power divider 16, an electrical phase shifter 17, a QPSK modulator 18, a bias voltage source 19, a bias voltage source 20, a bias voltage source 21, a balanced photodetector 22, and an electrical adder 23; the specific connection method is as follows:

[0046] In channel 1, the output of continuous wave laser 1 is connected to the optical input of QPSK modulator 7; the output of RF signal source 3 is connected to the input of electrical amplifier 4; the output of electrical amplifier 4 is connected to the input of electrical power divider 5; the output port 51 of electrical power divider 5 is connected to the first electrical drive port 71 of QPSK modulator 7; the output port 52 of electrical power divider 5 is connected to the input of electrical phase shifter 6; the output of electrical phase shifter 6 is connected to the second electrical drive port 72 of QPSK modulator 7; bias voltage source 8 is connected to the voltage bias port 73 of QPSK modulator 7; bias voltage source 9 is connected to the voltage bias port 74 of QPSK modulator 7; bias voltage source 10 is connected to the voltage bias port 75 of QPSK modulator 7; and the output of continuous wave laser 2 and the optical output of QPSK modulator 7 are connected to the input of balanced photodetector 11. In channel 2, the output of continuous wave laser 12 is connected to the optical input of QPSK modulator 18; and the output of RF signal source 14... The output terminal is connected to the input terminal of the power amplifier 15. The output terminal of the power amplifier 15 is connected to the input terminal of the power divider 16. The output port 161 of the power divider 16 is connected to the first electrical drive port 181 of the QPSK modulator 18. The output port 162 of the power divider 16 is connected to the input terminal of the phase shifter 17. The output terminal of the phase shifter 17 is connected to the second electrical drive port 182 of the QPSK modulator 18. The bias voltage source 19 is connected to the voltage bias port 183 of the QPSK modulator 18. The bias voltage source 20 is connected to the voltage bias port 184 of the QPSK modulator 18. The bias voltage source 21 is connected to the voltage bias port 185 of the QPSK modulator 18. The output terminal of the continuous wave laser 13 and the optical output terminal of the QPSK modulator 18 are connected to the input terminal of the balanced photodetector 22. The output terminals of the balanced photodetector 11 and the balanced photodetector 22 are connected to the input terminal of the electrical adder 23. The output terminal of the electrical adder 23 is connected to an oscilloscope.

[0047] In channel 1, the bias phase shift introduced by bias voltage source 10 in QPSK modulator 7 is π, and the bias phase shift introduced by bias voltage source 8 and bias voltage source 9 is equal; in channel 2, the bias phase shift introduced by bias voltage source 21 in QPSK modulator 18 is π, and the bias phase shift introduced by bias voltage source 19 and bias voltage source 20 is equal.

[0048] In channel 1, the power and wavelength of continuous-wave laser 1 are set to 13 dBm and 1553.33 nm, respectively, and the linewidth of continuous-wave laser 1 is set to 1 MHz. The power and wavelength of continuous-wave laser 2 are also set to 13 dBm and 1553.33 nm, respectively, and the linewidth of continuous-wave laser 2 is set to 1 MHz. The insertion loss and half-wave voltage of QPSK modulator 7 are set to 5 dB and 3.14 V, respectively, and the extinction ratio is set to 100 dB. A bias phase shift is introduced by bias voltage source 8. The phase of the electrical phase shifter 6 is Φ1 = 1.1990 rad. The modulation coefficient of the QPSK modulator 7 is m1 = 2.4. The frequency of the RF signal source 3 is set to 10 GHz. The power and wavelength of the continuous wave laser 12 in channel 2 are set to 4 dBm and 1552.52 nm, respectively, and the linewidth of the continuous wave laser 12 is set to 1 MHz. The power and wavelength of the continuous wave laser 13 are set to 4 dBm and 1552.28 nm, respectively, and the linewidth of the continuous wave laser 13 is set to 1 MHz. The insertion loss and half-wave voltage of the QPSK modulator 18 are set to 5 dB and 3.14 V, respectively, and the extinction ratio is set to 100 dB. The bias phase shift introduced by the bias voltage source 19... The phase of the phase shifter 17 is Φ2 = 0.8688 rad. The modulation coefficient of the QPSK modulator 18 is m2 = 2.8. The frequency of the RF signal source 14 is set to 10 GHz. The time-domain plot of the oscilloscope output signal is shown below. Figure 3 As shown.

[0049] Example 3

[0050] An adjustable symmetrical triangular waveform generator based on channelized frequency synthesis is characterized in that: the arbitrary waveform generator includes two channels; channel 1 includes a continuous wave laser 1, a continuous wave laser 2, an RF signal source 3, an electrical amplifier 4, an electrical power divider 5, an electrical phase shifter 6, a QPSK modulator 7, a bias voltage source 8, a bias voltage source 9, a bias voltage source 10, and a balanced photodetector 11; channel 2 includes a continuous wave laser 12, a continuous wave laser 13, an RF signal source 14, an electrical amplifier 15, an electrical power divider 16, an electrical phase shifter 17, a QPSK modulator 18, a bias voltage source 19, a bias voltage source 20, a bias voltage source 21, a balanced photodetector 22, and an electrical adder 23; the specific connection method is as follows:

[0051] In channel 1, the output of continuous wave laser 1 is connected to the optical input of QPSK modulator 7; the output of RF signal source 3 is connected to the input of electrical amplifier 4; the output of electrical amplifier 4 is connected to the input of electrical power divider 5; the output port 51 of electrical power divider 5 is connected to the first electrical drive port 71 of QPSK modulator 7; the output port 52 of electrical power divider 5 is connected to the input of electrical phase shifter 6; the output of electrical phase shifter 6 is connected to the second electrical drive port 72 of QPSK modulator 7; bias voltage source 8 is connected to the voltage bias port 73 of QPSK modulator 7; bias voltage source 9 is connected to the voltage bias port 74 of QPSK modulator 7; bias voltage source 10 is connected to the voltage bias port 75 of QPSK modulator 7; and the output of continuous wave laser 2 and the optical output of QPSK modulator 7 are connected to the input of balanced photodetector 11. In channel 2, the output of continuous wave laser 12 is connected to the optical input of QPSK modulator 18; and the output of RF signal source 14... The output terminal is connected to the input terminal of the power amplifier 15. The output terminal of the power amplifier 15 is connected to the input terminal of the power divider 16. The output port 161 of the power divider 16 is connected to the first electrical drive port 181 of the QPSK modulator 18. The output port 162 of the power divider 16 is connected to the input terminal of the phase shifter 17. The output terminal of the phase shifter 17 is connected to the second electrical drive port 182 of the QPSK modulator 18. The bias voltage source 19 is connected to the voltage bias port 183 of the QPSK modulator 18. The bias voltage source 20 is connected to the voltage bias port 184 of the QPSK modulator 18. The bias voltage source 21 is connected to the voltage bias port 185 of the QPSK modulator 18. The output terminal of the continuous wave laser 13 and the optical output terminal of the QPSK modulator 18 are connected to the input terminal of the balanced photodetector 22. The output terminals of the balanced photodetector 11 and the balanced photodetector 22 are connected to the input terminal of the electrical adder 23. The output terminal of the electrical adder 23 is connected to an oscilloscope.

[0052] In channel 1, the bias phase shift introduced by bias voltage source 10 in QPSK modulator 7 is π, and the bias phase shift introduced by bias voltage source 8 and bias voltage source 9 is equal; in channel 2, the bias phase shift introduced by bias voltage source 21 in QPSK modulator 18 is π, and the bias phase shift introduced by bias voltage source 19 and bias voltage source 20 is equal.

[0053] In channel 1, the power and wavelength of continuous-wave laser 1 are set to 13 dBm and 1553.33 nm, respectively, and the linewidth of continuous-wave laser 1 is set to 1 MHz. The power and wavelength of continuous-wave laser 2 are also set to 13 dBm and 1553.33 nm, respectively, and the linewidth of continuous-wave laser 2 is set to 1 MHz. The insertion loss and half-wave voltage of QPSK modulator 7 are set to 5 dB and 3.14 V, respectively, and the extinction ratio is set to 100 dB. A bias phase shift is introduced by bias voltage source 8. The phase of the electrical phase shifter 6 is Φ1 = 0.9666 rad. The modulation coefficient of the QPSK modulator 7 is m1 = 2.4. The frequency of the RF signal source 3 is set to 10 GHz. The power and wavelength of the continuous wave laser 12 in channel 2 are set to 5 dBm and 1552.52 nm, respectively, and the linewidth of the continuous wave laser 12 is set to 1 MHz. The power and wavelength of the continuous wave laser 13 are set to 5 dBm and 1552.28 nm, respectively, and the linewidth of the continuous wave laser 13 is set to 1 MHz. The insertion loss and half-wave voltage of the QPSK modulator 18 are set to 5 dB and 3.14 V, respectively, and the extinction ratio is set to 100 dB. The bias phase shift introduced by the bias voltage source 19... The phase of the phase shifter 17 is Φ2 = 0.8690 rad. The modulation coefficient of the QPSK modulator 18 is m2 = 2.8. The frequency of the RF signal source 14 is set to 10 GHz. The time-domain plot of the oscilloscope output signal is shown below. Figure 4 As shown.

[0054] Example 4

[0055] An adjustable symmetrical triangular waveform generator based on channelized frequency synthesis is characterized in that: the arbitrary waveform generator includes two channels; channel 1 includes a continuous wave laser 1, a continuous wave laser 2, an RF signal source 3, an electrical amplifier 4, an electrical power divider 5, an electrical phase shifter 6, a QPSK modulator 7, a bias voltage source 8, a bias voltage source 9, a bias voltage source 10, and a balanced photodetector 11; channel 2 includes a continuous wave laser 12, a continuous wave laser 13, an RF signal source 14, an electrical amplifier 15, an electrical power divider 16, an electrical phase shifter 17, a QPSK modulator 18, a bias voltage source 19, a bias voltage source 20, a bias voltage source 21, a balanced photodetector 22, and an electrical adder 23; the specific connection method is as follows:

[0056] In channel 1, the output of continuous wave laser 1 is connected to the optical input of QPSK modulator 7; the output of RF signal source 3 is connected to the input of electrical amplifier 4; the output of electrical amplifier 4 is connected to the input of electrical power divider 5; the output port 51 of electrical power divider 5 is connected to the first electrical drive port 71 of QPSK modulator 7; the output port 52 of electrical power divider 5 is connected to the input of electrical phase shifter 6; the output of electrical phase shifter 6 is connected to the second electrical drive port 72 of QPSK modulator 7; bias voltage source 8 is connected to the voltage bias port 73 of QPSK modulator 7; bias voltage source 9 is connected to the voltage bias port 74 of QPSK modulator 7; bias voltage source 10 is connected to the voltage bias port 75 of QPSK modulator 7; and the output of continuous wave laser 2 and the optical output of QPSK modulator 7 are connected to the input of balanced photodetector 11. In channel 2, the output of continuous wave laser 12 is connected to the optical input of QPSK modulator 18; and the output of RF signal source 14... The output terminal is connected to the input terminal of the power amplifier 15. The output terminal of the power amplifier 15 is connected to the input terminal of the power divider 16. The output port 161 of the power divider 16 is connected to the first electrical drive port 181 of the QPSK modulator 18. The output port 162 of the power divider 16 is connected to the input terminal of the phase shifter 17. The output terminal of the phase shifter 17 is connected to the second electrical drive port 182 of the QPSK modulator 18. The bias voltage source 19 is connected to the voltage bias port 183 of the QPSK modulator 18. The bias voltage source 20 is connected to the voltage bias port 184 of the QPSK modulator 18. The bias voltage source 21 is connected to the voltage bias port 185 of the QPSK modulator 18. The output terminal of the continuous wave laser 13 and the optical output terminal of the QPSK modulator 18 are connected to the input terminal of the balanced photodetector 22. The output terminals of the balanced photodetector 11 and the balanced photodetector 22 are connected to the input terminal of the electrical adder 23. The output terminal of the electrical adder 23 is connected to an oscilloscope.

[0057] In channel 1, the bias phase shift introduced by bias voltage source 10 in QPSK modulator 7 is π, and the bias phase shift introduced by bias voltage source 8 and bias voltage source 9 is equal; in channel 2, the bias phase shift introduced by bias voltage source 21 in QPSK modulator 18 is π, and the bias phase shift introduced by bias voltage source 19 and bias voltage source 20 is equal.

[0058] In channel 1, the power and wavelength of continuous-wave laser 1 are set to 4 dBm and 1553.33 nm, respectively, and the linewidth of continuous-wave laser 1 is set to 1 MHz. The power and wavelength of continuous-wave laser 2 are also set to 4 dBm and 1553.33 nm, respectively, and the linewidth of continuous-wave laser 2 is set to 1 MHz. The insertion loss and half-wave voltage of QPSK modulator 7 are set to 5 dB and 3.14 V, respectively, and the extinction ratio is set to 100 dB. A bias phase shift is introduced by bias voltage source 8. The phase of the electrical phase shifter 6 is Φ1 = 0.9664 rad. The modulation coefficient of the QPSK modulator 7 is m1 = 2.4. The frequency of the RF signal source 3 is set to 10 GHz. The power and wavelength of the continuous wave laser 12 in channel 2 are set to 5.5 dBm and 1552.52 nm, respectively, and the linewidth of the continuous wave laser 12 is set to 1 MHz. The power and wavelength of the continuous wave laser 13 are set to 5.5 dBm and 1552.28 nm, respectively, and the linewidth of the continuous wave laser 13 is set to 1 MHz. The insertion loss and half-wave voltage of the QPSK modulator 18 are set to 5 dB and 3.14 V, respectively, and the extinction ratio is set to 100 dB. The bias phase shift introduced by the bias voltage source 19... The phase of the phase shifter 17 is Φ2 = 0.0267 rad. The modulation coefficient of the QPSK modulator 18 is m2 = 2.8. The frequency of the RF signal source 14 is set to 10 GHz. The time-domain plot of the oscilloscope output signal is shown below. Figure 5 As shown.

[0059] Example 5

[0060] An adjustable symmetrical triangular waveform generator based on channelized frequency synthesis is characterized in that: the arbitrary waveform generator includes two channels; channel 1 includes a continuous wave laser 1, a continuous wave laser 2, an RF signal source 3, an electrical amplifier 4, an electrical power divider 5, an electrical phase shifter 6, a QPSK modulator 7, a bias voltage source 8, a bias voltage source 9, a bias voltage source 10, and a balanced photodetector 11; channel 2 includes a continuous wave laser 12, a continuous wave laser 13, an RF signal source 14, an electrical amplifier 15, an electrical power divider 16, an electrical phase shifter 17, a QPSK modulator 18, a bias voltage source 19, a bias voltage source 20, a bias voltage source 21, a balanced photodetector 22, and an electrical adder 23; the specific connection method is as follows:

[0061] In channel 1, the output of continuous wave laser 1 is connected to the optical input of QPSK modulator 7; the output of RF signal source 3 is connected to the input of electrical amplifier 4; the output of electrical amplifier 4 is connected to the input of electrical power divider 5; the output port 51 of electrical power divider 5 is connected to the first electrical drive port 71 of QPSK modulator 7; the output port 52 of electrical power divider 5 is connected to the input of electrical phase shifter 6; the output of electrical phase shifter 6 is connected to the second electrical drive port 72 of QPSK modulator 7; bias voltage source 8 is connected to the voltage bias port 73 of QPSK modulator 7; bias voltage source 9 is connected to the voltage bias port 74 of QPSK modulator 7; bias voltage source 10 is connected to the voltage bias port 75 of QPSK modulator 7; and the output of continuous wave laser 2 and the optical output of QPSK modulator 7 are connected to the input of balanced photodetector 11. In channel 2, the output of continuous wave laser 12 is connected to the optical input of QPSK modulator 18; and the output of RF signal source 14... The output terminal is connected to the input terminal of the power amplifier 15. The output terminal of the power amplifier 15 is connected to the input terminal of the power divider 16. The output port 161 of the power divider 16 is connected to the first electrical drive port 181 of the QPSK modulator 18. The output port 162 of the power divider 16 is connected to the input terminal of the phase shifter 17. The output terminal of the phase shifter 17 is connected to the second electrical drive port 182 of the QPSK modulator 18. The bias voltage source 19 is connected to the voltage bias port 183 of the QPSK modulator 18. The bias voltage source 20 is connected to the voltage bias port 184 of the QPSK modulator 18. The bias voltage source 21 is connected to the voltage bias port 185 of the QPSK modulator 18. The output terminal of the continuous wave laser 13 and the optical output terminal of the QPSK modulator 18 are connected to the input terminal of the balanced photodetector 22. The output terminals of the balanced photodetector 11 and the balanced photodetector 22 are connected to the input terminal of the electrical adder 23. The output terminal of the electrical adder 23 is connected to an oscilloscope.

[0062] In channel 1, the bias phase shift introduced by bias voltage source 10 in QPSK modulator 7 is π, and the bias phase shift introduced by bias voltage source 8 and bias voltage source 9 is equal; in channel 2, the bias phase shift introduced by bias voltage source 21 in QPSK modulator 18 is π, and the bias phase shift introduced by bias voltage source 19 and bias voltage source 20 is equal.

[0063] In channel 1, the power and wavelength of continuous-wave laser 1 are set to 13 dBm and 1553.33 nm, respectively, and the linewidth of continuous-wave laser 1 is set to 1 MHz. The power and wavelength of continuous-wave laser 2 are also set to 13 dBm and 1553.33 nm, respectively, and the linewidth of continuous-wave laser 2 is set to 1 MHz. The insertion loss and half-wave voltage of QPSK modulator 7 are set to 5 dB and 3.14 V, respectively, and the extinction ratio is set to 100 dB. A bias phase shift is introduced by bias voltage source 8. The phase of the electrical phase shifter 6 is Φ1 = 0.9966 rad. The modulation coefficient of the QPSK modulator 7 is m1 = 2.4. The frequency of the RF signal source 3 is set to 10 GHz. The power and wavelength of the continuous wave laser 12 in channel 2 are set to 5 dBm and 1552.52 nm, respectively, and the linewidth of the continuous wave laser 12 is set to 1 MHz. The power and wavelength of the continuous wave laser 13 are set to 5 dBm and 1552.28 nm, respectively, and the linewidth of the continuous wave laser 13 is set to 1 MHz. The insertion loss and half-wave voltage of the QPSK modulator 18 are set to 5 dB and 3.14 V, respectively, and the extinction ratio is set to 100 dB. The bias phase shift introduced by the bias voltage source 19... The phase of the phase shifter 17 is Φ2 = 0.8690 rad. The modulation coefficient of the QPSK modulator 18 is m2 = 2.8. The frequency of the RF signal source 14 is set to 10 GHz. The time-domain plot of the oscilloscope output signal is shown below. Figure 6 As shown.

[0064] Example 6

[0065] An adjustable symmetrical triangular waveform generator based on channelized frequency synthesis is characterized in that: the arbitrary waveform generator includes two channels; channel 1 includes a continuous wave laser 1, a continuous wave laser 2, an RF signal source 3, an electrical amplifier 4, an electrical power divider 5, an electrical phase shifter 6, a QPSK modulator 7, a bias voltage source 8, a bias voltage source 9, a bias voltage source 10, and a balanced photodetector 11; channel 2 includes a continuous wave laser 12, a continuous wave laser 13, an RF signal source 14, an electrical amplifier 15, an electrical power divider 16, an electrical phase shifter 17, a QPSK modulator 18, a bias voltage source 19, a bias voltage source 20, a bias voltage source 21, a balanced photodetector 22, and an electrical adder 23; the specific connection method is as follows:

[0066] In channel 1, the output of continuous wave laser 1 is connected to the optical input of QPSK modulator 7; the output of RF signal source 3 is connected to the input of electrical amplifier 4; the output of electrical amplifier 4 is connected to the input of electrical power divider 5; the output port 51 of electrical power divider 5 is connected to the first electrical drive port 71 of QPSK modulator 7; the output port 52 of electrical power divider 5 is connected to the input of electrical phase shifter 6; the output of electrical phase shifter 6 is connected to the second electrical drive port 72 of QPSK modulator 7; bias voltage source 8 is connected to the voltage bias port 73 of QPSK modulator 7; bias voltage source 9 is connected to the voltage bias port 74 of QPSK modulator 7; bias voltage source 10 is connected to the voltage bias port 75 of QPSK modulator 7; and the output of continuous wave laser 2 and the optical output of QPSK modulator 7 are connected to the input of balanced photodetector 11. In channel 2, the output of continuous wave laser 12 is connected to the optical input of QPSK modulator 18; and the output of RF signal source 14... The output terminal is connected to the input terminal of the power amplifier 15. The output terminal of the power amplifier 15 is connected to the input terminal of the power divider 16. The output port 161 of the power divider 16 is connected to the first electrical drive port 181 of the QPSK modulator 18. The output port 162 of the power divider 16 is connected to the input terminal of the phase shifter 17. The output terminal of the phase shifter 17 is connected to the second electrical drive port 182 of the QPSK modulator 18. The bias voltage source 19 is connected to the voltage bias port 183 of the QPSK modulator 18. The bias voltage source 20 is connected to the voltage bias port 184 of the QPSK modulator 18. The bias voltage source 21 is connected to the voltage bias port 185 of the QPSK modulator 18. The output terminal of the continuous wave laser 13 and the optical output terminal of the QPSK modulator 18 are connected to the input terminal of the balanced photodetector 22. The output terminals of the balanced photodetector 11 and the balanced photodetector 22 are connected to the input terminal of the electrical adder 23. The output terminal of the electrical adder 23 is connected to an oscilloscope.

[0067] In channel 1, the bias phase shift introduced by bias voltage source 10 in QPSK modulator 7 is π, and the bias phase shift introduced by bias voltage source 8 and bias voltage source 9 is equal; in channel 2, the bias phase shift introduced by bias voltage source 21 in QPSK modulator 18 is π, and the bias phase shift introduced by bias voltage source 19 and bias voltage source 20 is equal.

[0068] In channel 1, the power and wavelength of continuous-wave laser 1 are set to 10 dBm and 1553.33 nm, respectively, and the linewidth of continuous-wave laser 1 is set to 1 MHz. The power and wavelength of continuous-wave laser 2 are also set to 10 dBm and 1553.33 nm, respectively, and the linewidth of continuous-wave laser 2 is set to 1 MHz. The insertion loss and half-wave voltage of QPSK modulator 7 are set to 5 dB and 3.14 V, respectively, and the extinction ratio is set to 100 dB. The bias phase shift introduced by bias voltage source 8... The phase of the electrical phase shifter 6 is Φ1 = 1.3924 rad. The modulation coefficient of the QPSK modulator 7 is m1 = 2.4. The frequency of the RF signal source 3 is set to 10 GHz. The power and wavelength of the continuous wave laser 12 in channel 2 are set to 14 dBm and 1552.52 nm, respectively, and the linewidth of the continuous wave laser 12 is set to 1 MHz. The power and wavelength of the continuous wave laser 13 are set to 14 dBm and 1552.28 nm, respectively, and the linewidth of the continuous wave laser 13 is set to 1 MHz. The insertion loss and half-wave voltage of the QPSK modulator 18 are set to 5 dB and 3.14 V, respectively, and the extinction ratio is set to 100 dB. The bias phase shift introduced by the bias voltage source 19... The phase of the phase shifter 17 is Φ2 = 1.5510 rad. The modulation coefficient of the QPSK modulator 18 is m2 = 2.8. The frequency of the RF signal source 14 is set to 10 GHz. The time-domain plot of the oscilloscope output signal is shown below. Figure 7 As shown.

Claims

1. A tunable symmetrical triangular waveform generator based on channelized frequency synthesis, characterized by: The adjustable symmetrical triangular waveform generator comprises two channels, and the channel 1 comprises a first continuous wave laser (1), a second continuous wave laser (2), a first radio frequency signal source (3), a first electric amplifier (4), a first electric power divider (5), a first electric phase shifter (6), a first QPSK modulator (7), a first bias voltage source (8), a second bias voltage source (9), a third bias voltage source (10), and a first balanced photodetector (11); the channel 2 comprises a third continuous wave laser (12), a fourth continuous wave laser (13), a second radio frequency signal source (14), a second electric amplifier (15), a second electric power divider (16), a second electric phase shifter (17), a second QPSK modulator (18), a fourth bias voltage source (19), a fifth bias voltage source (20), a sixth bias voltage source (21), a second balanced photodetector (22), and an electric adder (23); and the specific connection mode is as follows: The output end of the first continuous wave laser (1) in the channel 1 is connected with the optical input end of the first QPSK modulator (7), the output end of the first radio frequency signal source (3) is connected with the input end of the first electric amplifier (4), the output end of the first electric amplifier (4) is connected with the input end of the first electric power divider (5), the first output port (51) of the first electric power divider (5) is connected with the first electric drive port (71) of the first QPSK modulator (7), the second output port (52) of the first electric power divider (5) is connected with the input end of the first electric phase shifter (6), the output end of the first electric phase shifter (6) is connected with the second electric drive port (72) of the first QPSK modulator (7), the first bias voltage source (8) is connected with the first voltage bias port (73) of the first QPSK modulator (7), the second bias voltage source (9) is connected with the second voltage bias port (74) of the first QPSK modulator (7), the third bias voltage source (10) is connected with the third voltage bias port (75) of the first QPSK modulator (7), the output end of the second continuous wave laser (2) and the optical output end of the first QPSK modulator (7) are connected with the input end of the first balanced photoelectric detector (11); the output end of the third continuous wave laser (12) in the channel 2 is connected with the optical input end of the second QPSK modulator (18), the output end of the second radio frequency signal source (14) is connected with the input end of the second electric amplifier (15), the output end of the second electric amplifier (15) is connected with the input end of the second electric power divider (16), the first output port (161) of the second electric power divider (16) is connected with the first electric drive port (181) of the second QPSK modulator (18), the second output port (162) of the second electric power divider (16) is connected with the input end of the second electric phase shifter (17), the output end of the second electric phase shifter (17) is connected with the second electric drive port (182) of the second QPSK modulator (18), the fourth bias voltage source (19) is connected with the first voltage bias port (183) of the second QPSK modulator (18), the fifth bias voltage source (20) is connected with the second voltage bias port (184) of the second QPSK modulator (18), the sixth bias voltage source (21) is connected with the third voltage bias port (185) of the second QPSK modulator (18), the output end of the fourth continuous wave laser (13) and the optical output end of the second QPSK modulator (18) are connected with the input end of the second balanced photoelectric detector (22), the output end of the first balanced photoelectric detector (11) and the output end of the second balanced photoelectric detector (22) are connected with the input end of the electric adder (23), and the output end of the electric adder (23) is connected with the oscilloscope.

2. A tunable symmetrical triangular waveform generator based on channelized frequency synthesis according to claim 1, characterized in that: The value of the bias phase shift introduced by the third bias voltage source (10) in the first QPSK modulator (7) in channel 1 is π , the values of the bias phase shifts introduced by the first bias voltage source (8) and the second bias voltage source (9) are equal; the value of the bias phase shift introduced by the sixth bias voltage source (21) in the second QPSK modulator (18) in channel 2 is π , the values of the bias phase shifts introduced by the fourth bias voltage source (19) and the fifth bias voltage source (20) are equal.

3. A tunable symmetrical triangular waveform generator based on channelized frequency synthesis according to claim 1, characterized in that: The bias phase shifts introduced by the first bias voltage source (8) and the second bias voltage source (9) in the channel 1 are equal and are represented by φ 1, in the range -2.8016 rad ≤ φ 1≤ 3.1416 rad; the modulation factor is set to m 1= πV RF / 2V π = 2.4, where V π Vπ represents the half-wave voltage of the modulator, the signal amplitude output by the first radio frequency signal source (3) being adjusted to V RF = 1.528 V π ; the phase of the first electric phase shifter (6) is Φ1, in the range 0.9664 rad ≤ Φ1 ≤ 1.3924 rad; the bias phase shifts introduced by the fourth bias voltage source (19) and the fifth bias voltage source (20) in the channel 2 are equal and are represented by φ 4, in the range -3.1416 ad ≤ φ 4≤ 3.1416 rad; the modulation factor is set to m 2= πV RF / 2V π = 2.8, the signal amplitude output by the second radio frequency signal source (14) being adjusted to V RF = 1.783 V π ; the phase of the second electric phase shifter (17) is Φ2, in the range 0.0267 rad ≤ Φ2 ≤ 1.5510 rad.

4. A tunable symmetrical triangular waveform generator based on channelized frequency synthesis according to claim 1, characterized in that: The triangular waveforms with the symmetry factor of 0%-100% can be generated, wherein the symmetry factor is defined as the ratio of the time experienced by the rising edge of the waveform to the whole period.

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