36results about How to "Improve spurious-free dynamic range" patented technology

The invention provides a multi-octave microwave transmission device, which includes: a light source, a signal modulation unit, an optical polarizer, an optical fiber and a photodetector; the light source is used to generate and output an optical carrier; the signal modulation unit It is used to receive the optical carrier and the microwave signal to be transmitted, and modulate the microwave signal to be transmitted onto the optical carrier in the state of suppressing the single sideband of the carrier to form a modulated optical signal; the optical polarizer is used to receive the modulated optical signal , and perform polarization processing on the modulated light signal to form a polarized light signal; the optical fiber is used to transmit the polarized light signal to the photodetector; the photodetector is used to convert the polarized light signal into electric signal. The invention also provides a multi-octave microwave transmission method. The invention can carry out long-distance transmission with high linearity to multi-octave microwave signals, and can overcome the power attenuation problem caused by optical fiber dispersion in microwave signal transmission.

The invention relates to the field of wireless monitoring, in particular to a broadband receiver nonlinear blind recognition and compensation method. In the method, a distorted signal is compensated for to obtain a mixed signal, a cost function of short-time energy information of distortion components in the mixed signal is worked out, the compensation parameter corresponding to the minimum distortion compensation is worked out, compensation parameters in the compensation model are updated, the steps are carried out repeatedly until the distortion components are well inhibited, and therefore the spurious-free dynamic range of the receiver is expanded, and the weak-signal extraction ability is improved as well.

The present invention provides a pipelined successive approximation analog-to-digital converter and conversion method, including: a first-stage successive approximation analog-to-digital conversion module, a second-stage successive approximation analog-to-digital conversion module and a digital code error correction logic module; wherein, the first The stage successive approximation analog-to-digital conversion module includes a first capacitor array unit, an amplification unit, a latch comparison unit, a first register logic control unit and a control switch, and the amplification unit is multiplexed as a residual amplifier and a first-stage successive approximation analog-to-digital converter pre-amplifier for the comparator. The present invention completely eliminates the input offset voltage mismatch existing between the two by multiplexing the residual amplifier pre-amplifier, stabilizes the input swing of the residual amplifier, improves the linearity of the residual amplifier, and saves chip area ; and the gain error is obtained by multiplexing the second-stage successive approximation analog-to-digital conversion module, which reduces the gain error of the residual amplifier and improves the conversion accuracy of the entire pipelined successive approximation analog-to-digital converter.

The invention provides a new microwave photonic link SFDR (Spurious Free Dynamic Range) enlarging method. According to the method, an automatic light gain control function is additionally increased in front of a photodetector of a link, light power entering into the photodetector is traced and tuned, so that the total power of third-order cross modulation is less than a noise bottom, furthermore fundamental frequency item power greater than the noise bottom is ensured, and thus, the purpose of enlarging the SFDR is achieved. The automatic gain link is composed of a light beam splitter, a circulator, a fiber bragg grating, the photodetector, a voltage conversion module and a light intensity modulator, wherein the received light is split into two beams by the light beam splitter, one light beam serves as monitoring light, after carrier wave is filtered out by the grating, the monitoring light is subjected to photoelectric conversion, so that a control voltage signal is formed. The control voltage is injected into the direct current bias input port of the light intensity modulator in front of the photodetector, the intensity of the other light beam is controlled by use of the optical interference theory, and the automatic light gain control function is achieved, so that the SFDR of the whole link is enlarged.

The invention relates to an N-bit digital-to-analog conversion apparatus, which is used for receiving a digital signal and a clock signal. The clock signal is switched between a first state and a second state. Besides, the N-bit digital-to-analog conversion apparatus comprises a decoder, a random number generator and a conversion module. More specifically, the decoder is used for converting a digital signal into a multi-bit thermometer code. The random number generator is used for outputting a reset signal in a random number state; the rest signal has a plurality of bits that are arranged alternatively and randomly, wherein the arrangement mode is changed at different time; and in the reset signal, the number of the bits that are in a logic high level is equal to the number of the bits that are in a logic low level. When the clock signal is in the first state, the conversion module converts the thermometer code into an analog voltage relating to the digital signal; and when the clock signal is in the second state, the conversion module enables the analog voltage to be reduced to zero according to the reset signal. According to the invention, a spurious free dynamic range can be enlarged.

The present invention relates to a method for improving the spurious-free dynamic range based on single sideband modulation, comprising: step 1: the laser emits an optical carrier S1; step 2: the radio frequency input signal S2 modulates the optical signal S1 output by the laser through a phase modulator, thereby Obtain and output the phase modulation signal S3; Step 3: After the phase modulation signal S3 passes through the third-order intermodulation distortion suppressor, output the SSB phase modulation signal S4 with a certain carrier-to-sideband ratio; Step 4: The photodetector demodulates the signal S4 The suppression of the third-order intermodulation distortion in the output radio frequency signal S5 is realized, and the output signal of the optical band detector is input into a spectrum analyzer for analysis. Wherein, the third-order intermodulation distortion suppressor obtains the SSB signal of the optical carrier and the +2nd-order sideband amplitude 1:9 after the amplitude-frequency processing of the signal, and extracts the signal by the photodetector in the step 4 , used to increase the spurious-free dynamic range of a spurious-free dynamic range link.

The invention discloses a nonlinear correction method and device for improving the stray-free dynamic range of an analog-to-digital converter, including a training signal generation module, a network parameter detection and extraction unit, an analog-to-digital converter and a nonlinear correction processing unit. The present invention realizes the nonlinear correction of the analog-to-digital converter by setting the network parameter detection and extraction unit and the nonlinear correction processing unit, effectively suppressing the nonlinear distortion of the analog-to-digital converter such as harmonics, intermodulation, and high-order correlation spurs, At the same time, the non-linear distortion and spurs generated by quantization such as DNL and INL are also greatly suppressed, which significantly improves the spurious-free dynamic range of the analog-to-digital converter.

The invention discloses a graphene Mach-Zehnder intensity modulator and its linearization method, comprising a first modulation arm, a second modulation arm, a first positive electrode, a second positive electrode, a negative electrode and a substrate layer, the first The modulation arm and the second modulation arm are graphene ridge waveguides, and the two modulation arms constitute a Mach-Zehnder interference structure; the graphene ridge waveguide includes a first ridge, a graphene layer, a second Ridge; the first ridge is isolated from the graphene layer by the first isolation layer, and the second ridge is isolated from the graphene layer by the second isolation layer; the first positive electrode and the second positive electrode are respectively located in the first modulation arm and on the graphene layer extending from the graphene ridge waveguide of the second modulation arm, the negative electrode is located on the first isolation layer extending from the graphene ridge waveguide; the light wave of the TE mode of the input incident constant power changes the modulation arm The bias voltage is used to measure the output optical power of the modulator, and the curve of the transmitted optical power of the modulator as a function of the bias voltage is obtained.