CN211239807U - Signal synthesizer - Google Patents

Abstract

The application discloses a signal synthesis device, which comprises a PCB, wherein a pulse filtering module, a direct current filtering module and an isolation module are arranged on the PCB; the pulse filtering module is used for performing waveform smoothing and noise reduction processing on the received first pulse signal to obtain a second pulse signal; the direct current filtering module is used for carrying out noise reduction processing on the received first direct current signal to obtain a second direct current signal; the isolation module is respectively connected with the pulse filtering module and the direct current filtering module and outputs a synthesized signal of the second pulse signal and the second direct current signal. According to the method, the overshoot of the second pulse signal in the output composite signal is small through the waveform smoothing and noise reduction processing of the pulse filtering module; and the integration arrangement of the pulse filtering module, the direct current filtering module and the isolation module is realized through the PCB, the size is small, and the structure is simple.

Description

Signal synthesizer

Technical Field

The application belongs to the field of power electronics, and particularly relates to a signal synthesis device.

Background

The regulation and control of the superconducting qubit depend on high-precision regulation and control signals, and for the superconducting qubit, the required regulation and control signals mainly comprise pulse signals and direct-current signals; when the superconducting qubit is controlled, the two types of signals need to be applied simultaneously, and meanwhile, in order to reduce the number of signal transmission lines, the signals need to be synthesized in one channel and then transmitted to the superconducting qubit.

The multi-port coupling devices commonly used for pulse signal and direct current signal synthesis all adopt complex active modules or passive couplers to realize high-isolation signal synthesis. In consideration of the environmental requirements of the superconducting qubit in operation, the operating temperature is generally in a very low temperature environment of 10mk-4K, and the superconducting qubit has extremely high requirements on the precision of the applied control signal, and needs to have the characteristics of low noise, low power consumption and low overshoot. If the active multi-port coupling device or module which is widely applied at present is adopted, extra power supply and signal input are needed, the power consumption is large, and the normal work in the extremely low temperature environment cannot be realized; if a passive coupling device is adopted, the volume is large, and the overshoot index of the coupled pulse signal cannot meet the signal index requirement on superconducting qubit regulation.

SUMMERY OF THE UTILITY MODEL

The purpose of the present application is to provide a signal synthesis device, so as to solve the deficiencies in the prior art, and it can perform waveform smoothing and filtering processing on a first pulse signal through a pulse filtering module, so that the waveform overshoot of a second pulse signal in an output synthesis signal is small; the second pulse signal and the second direct current signal in the output composite signal have high isolation degree through the isolation module; meanwhile, the PCB is integrated with a pulse filtering module, a direct current filtering module and an isolation module which are used for processing signals, and the PCB is small in size and simple in structure.

The technical scheme adopted by the application is as follows:

a signal synthesis device comprises a PCB, wherein a pulse filtering module, a direct current filtering module and an isolation module are arranged on the PCB;

the pulse filtering module is used for performing waveform smoothing and noise reduction processing on the received first pulse signal to obtain a second pulse signal;

the direct current filtering module is used for carrying out noise reduction processing on the received first direct current signal to obtain a second direct current signal;

the isolation module is respectively connected with the pulse filtering module and the direct current filtering module and used for isolating the second pulse signal from entering the direct current filtering module, isolating the second direct current signal from entering the pulse filtering module and outputting a synthesized signal of the second pulse signal and the second direct current signal.

Further, the pulse filtering module comprises a first attenuator, a low-pass filter and a second attenuator;

the first attenuator is used for carrying out noise reduction and signal reflection reduction processing on the received first pulse signal to obtain a first pulse sub-signal;

the low-pass filter is connected with the first attenuator and is used for performing waveform smoothing processing on the first pulse sub-signal to obtain a first smooth pulse sub-signal;

and the second attenuator is connected with the low-pass filter and used for carrying out noise reduction and signal reflection reduction on the first smooth pulse sub-signal to obtain the second pulse signal.

Further, the first attenuator and the second attenuator both comprise a pi-type resistance attenuation circuit and a T-type resistance attenuation circuit.

Further, the low-pass filter comprises a plurality of order resonators which are connected in sequence; and a coupler is connected in series between the resonators of two adjacent stages.

Further, the resonator comprises a first resistor and a first capacitor which are connected in sequence;

one end of the first capacitor far away from the first resistor is connected to the ground;

one end of the first resistor, which is far away from the first capacitor, is connected with the coupler.

Further, each of the couplers includes a second resistor and a first inductor connected in parallel;

the same ends of the second resistor and the first inductor are respectively connected to two adjacent resonators.

Further, the direct current filter module comprises a multi-order RC filter circuit which is connected in sequence;

the RC filter circuit of the first stage receives the first direct current signal, and the RC filter circuit of the last stage is connected with the isolation module.

Further, the isolation module includes a second capacitor and a third resistor;

the second capacitor is connected with the pulse filtering module and is used for inhibiting the second direct current signal from flowing to the pulse filtering module;

the third resistor is connected with the direct current filtering module and used for inhibiting the second pulse signal from flowing to the direct current filtering module.

Furthermore, the pulse filtering module, the direct current filtering module and the isolation module are all passive devices.

Furthermore, the signal synthesis device also comprises a closed shell; the PCB is arranged in the sealed shell.

Compared with the prior art, the intelligent power supply device comprises a PCB, wherein a pulse filtering module, a direct current filtering module and an isolation module are arranged on the PCB; the pulse filtering module is used for processing the received first pulse signal to smooth the waveform and reduce the noise to obtain a second pulse signal; the direct current filtering module is used for carrying out noise reduction processing on the received first direct current signal to obtain a second direct current signal; the isolation module is respectively connected with the pulse filtering module and the direct current filtering module and used for isolating the second pulse signal from entering the direct current filtering module, isolating the second direct current signal from entering the pulse filtering module and outputting a synthesized signal of the second pulse signal and the second direct current signal. According to the method, the overshoot of the second pulse signal in the output synthesized signal is small through the waveform smoothing and noise reduction processing of the pulse filtering module, and meanwhile the second pulse signal and the second direct current signal in the synthesized signal are high in mutual isolation degree through the isolator; and the integration arrangement of the pulse filtering module, the direct current filtering module and the isolation module is realized through the PCB, the size is small, and the structure is simple.

Drawings

FIG. 1 is a functional block diagram of the present application;

FIG. 2 is a schematic diagram of a first pulse signal smoothing process according to the present application;

FIG. 3 is a block diagram of the pulse filter module of the present application;

FIG. 4 is a diagram of the low pass filter of FIG. 1;

FIG. 5 is a block diagram of the low pass filter of the present application shown in FIG. 2;

FIG. 6 is a block diagram of the DC filter module of the present application;

FIG. 7 is a block diagram of the isolated module of the present application.

Detailed Description

The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

The embodiment of the present application provides a signal synthesizing apparatus, as shown in fig. 1, including a PCB1, wherein the PCB1 is provided with a pulse filtering module 11, a dc filtering module 13 and an isolation module 12.

The pulse filtering module 11 is configured to perform waveform smoothing and noise reduction processing on the received first pulse signal to obtain a second pulse signal; the dc filtering module 13 is configured to perform noise reduction processing on the received first dc signal to obtain a second dc signal; the isolation module 12 is connected to the pulse filtering module 11 and the dc filtering module 13, and configured to isolate the second pulse signal from entering the dc filtering module 13, isolate the second dc signal from entering the pulse filtering module 11, and output a synthesized signal of the second pulse signal and the second dc signal.

When the superconducting quantum bit isolation device is specifically implemented, the pulse filtering module 11, the direct current filtering module 13 and the isolation module 12 are integrally arranged on the PCB1, are small in size and suitable for providing a composite signal of a pulse signal and a direct current signal for a plurality of superconducting quantum bits.

Specifically, the first pulse signal may be provided by a signal source such as an arbitrary waveform generator and a vector microwave signal source; the first dc signal may be provided by a dc current source, a voltage source, or other signal source device. It should be noted that, particularly in the field of quantum measurement and control, when a superconducting qubit is regulated, a pulse signal and a direct current signal need to be applied simultaneously; the operating environment of the superconducting qubit requires extremely low temperature, while various pulse signal sources and direct current signal sources can only be set in room temperature environment, and the pulse signals and direct current signals transmitted to the superconducting qubit are ensured to meet the requirements of low noise, low power consumption and low overshoot through a signal transmission line and a series of signal processing devices.

The pulse filtering module 11 is arranged to receive the first pulse signal generated by the pulse signal source, specifically, the first pulse signal is a waveform with a specific pulse shape, such as a square waveform; the requirements for the pulse signal regulated by the superconducting qubit specifically include:

overshoot: less than or equal to 2 percent;

delayed overshoot: less than or equal to 1 percent.

Wherein, the overshoot refers to the peak pulse that the pulse signal exceeds the set value at the peak value or the peak valley, and the tip pulse is shown; the sharp pulse can directly influence the regulation precision of the superconducting qubit; therefore, when the superconducting qubit is controlled by applying the composite signal including the second pulse signal, smoothing processing needs to be performed on a waveform of the second pulse signal in the composite signal, which may be specifically understood as smoothing processing on a rising edge and a falling edge of a waveform of the second pulse signal.

The pulse filtering module 11 performs smoothing and noise reduction processing on the received first pulse signal, so that the output second pulse signal has extremely low overshoot; as shown in fig. 2, a first curve in the graph, that is, a waveform curve of the first pulse signal, can be seen that there is an obvious overshoot phenomenon at a rising edge and a falling edge of the waveform curve; the second curve in the figure is a waveform curve of the second pulse signal output after the smoothing and filtering process is performed by the pulse filtering module.

The direct current filtering module 13 is further configured to receive the first direct current signal generated by the direct current signal source, and perform noise reduction processing on the first direct current signal to obtain the second direct current signal; the second pulse signal output by the pulse filter module 11 and the second dc signal output by the dc filter module 13 are transmitted to the isolator 12 together; the pulse filter module 11 and the dc filter module 13 are isolated by the isolator 12 to prevent the second pulse signal from entering the dc filter module 13 and the second dc signal from entering the pulse filter module 11; and outputs a composite signal of the second pulse signal and the second dc signal through the isolator 12.

The pulse filtering module 11 is arranged to perform waveform smoothing and noise reduction processing on the first pulse signal, so that overshoot of the second pulse signal in the output synthesized signal is small, and the isolator 12 is used to ensure that the isolation between the second pulse signal and the second direct current signal in the synthesized signal is high; and the integration of the pulse filtering module 11, the direct current filtering module 13 and the isolation module 12 is realized through the PCB, the size is small, and the structure is simple.

As shown in fig. 3, in this embodiment, the pulse filtering module 11 may include a first attenuator 111, a low pass filter 112, and a second attenuator 113;

the first attenuator 111 is configured to perform noise reduction and signal reflection reduction processing on the received first pulse signal to obtain a first pulse sub-signal;

the low-pass filter 112 is connected to the first attenuator 111, and configured to perform waveform smoothing on the first pulse sub-signal to obtain a first smooth pulse sub-signal;

the second attenuator 113 is connected to the low-pass filter 112, and configured to perform noise reduction and signal reflection reduction processing on the first smooth pulse sub-signal to obtain the second pulse signal.

Specifically, in order to ensure that the superconducting qubit can work normally, the applied second pulse signal needs to be very weak and much weaker than the first pulse signal generated by the pulse signal source, so the first attenuator 111 needs to be arranged to attenuate the first pulse signal, and simultaneously, the noise signal carried by the first pulse signal is attenuated; in addition, the first attenuator 111 can improve impedance matching and reduce the reflected signal generated by the first pulse signal through the low-pass filter 112, so as to avoid crosstalk with the first pulse sub-signal and affect the accuracy of the first pulse sub-signal.

The low-pass filter 112 is provided, connected to the first attenuator 111, and filters the first pulse sub-signal generated after passing through the first attenuator 111, thereby smoothing an overshoot portion of a rising edge and a falling edge of the waveform of the first pulse sub-signal. When the rising edge and the falling edge of the pulse waveform are subjected to smoothing processing, the effect of the Gaussian filter is better, so that the first smooth pulse sub-signal with the optimal waveform spike smoothing effect is obtained by adopting the Gaussian low-pass filter. The smoothing effect of the rising edge and the falling edge of the first smooth pulse sub-signal can refer to the waveform shown by the second curve in fig. 2, and the overshoot index of the pulse waveform of the second curve is less than or equal to 1%, which is much smaller than the requirement index of the superconducting qubit for the pulse signal, and less than or equal to 2%.

The first smoothed pulse sub-signal obtained after the smoothing processing by the low-pass filter 112 already has the requirement index of pulse waveform overshoot, considering that the first smoothed pulse sub-signal still has the influence of signal reflection, pulse waveform distortion and the like due to impedance matching among modules in the transmission process; therefore, the second attenuator 113 is arranged behind the low-pass filter 112, so that signal reflection and pulse waveform distortion can be effectively avoided, the fidelity of the first smooth pulse sub-signal is higher, and the second pulse signal required by the superconducting qubit test is guaranteed.

The peaks of the rising edge and the falling edge of the pulse waveform of the first pulse sub-signal are smoothed by the low-pass filter 112, so as to meet the technical index requirement of the overshoot; the first attenuator 111 and the second attenuator 113 are respectively arranged in front of and behind the low-pass filter 112 to reduce noise and signal reflection, so that the second pulse signal output by the pulse filtering module 11 has the characteristics of low noise and low overshoot, and a pulse signal with higher precision is further provided for the superconducting qubit regulation.

In this application, the first attenuator 111 and the second attenuator 113 may include a pi-type resistance attenuation circuit and a T-type resistance attenuation circuit.

In the field of communication and radio frequency, the attenuator is widely applied, is used for adjusting signal intensity and improving impedance matching, and has the types of coaxial attenuators, pi-type resistance attenuation circuits, T-type resistance attenuation circuits and the like; in specific implementation, the size and the cost can be effectively reduced by adopting the pi-type resistance attenuation circuit and/or the T-type resistance attenuation circuit.

As shown in fig. 4, the low pass filter 112 according to the present application may include a plurality of order resonators 1121 connected in sequence; a coupler 1122 is connected in series between the resonators of two adjacent stages.

The low pass filter 112 belongs to a microwave device, and can be designed to have a specific cut-off frequency and stop-band rejection to achieve the filtering and smoothing effects on the first pulse sub-signal. For example, when the method is specifically applied to superconducting qubit regulation, the overshoot is required to be less than or equal to 2%, the cut-off frequency reaches 200MHz, the suppression degree to 600MHz reaches 40dB, and the suppression degree to 2GHz reaches 80 dB; the resonators 1121 are designed to match the cutoff frequency index, and the couplers 1122 are designed to match the stop band rejection index and the overshoot index. The number of the resonators 1121 is determined by the stop-band suppression degree index, and is set to 4 as embodied in the present application, and the number of the couplers 1112 is determined to be 3. By setting a certain number of the resonators 1121 and the couplers 1122, the low-pass filter 112 having a certain specification is achieved.

As shown in fig. 5, the resonator 1121 according to the present application may include a first resistor 11211 and a first capacitor 11212 connected in sequence; it should be noted that the relative positions of the first resistor 11211 and the first capacitor 11212 may be interchanged, that is, the coupler 1122 may be connected through one end of the first resistor 11211, or the coupler 1122 may be connected through one end of the first capacitor 11212; as an example, the end of the first resistor 11211 away from the first capacitor 11212 is connected to the coupler 1122; an end of the first capacitor 11212 remote from the first resistor 11211 is connected to ground.

Specifically, each of the couplers 1122 of the present application may include a second resistor 11221 and a first inductor 11222 connected in parallel; the same ends of the second resistor 11221 and the inductor 11222 are connected to two adjacent resonators 1121, respectively.

As shown in fig. 6, the dc filter module 13 includes a multi-stage RC filter circuit 131 connected in sequence; the RC filter circuit 131 receives the first dc signal in the first stage, and the RC filter circuit 131 is connected to the isolation module in the last stage.

Specifically, the multi-stage RC filter circuit 131 performs filtering processing on the received first dc signal according to the principle of capacitor charging and discharging to reduce amplitude fluctuation of the first dc signal, so that the second dc signal output by the RC filter circuit 131 in the last stage has small fluctuation and high precision, and further provides guarantee for the synthesized signal provided by the superconducting qubit.

It should be added that, the embodiment of the present application only describes the form of a 3-order RC filter circuit, and the RC filter circuit can also be 4-order, 5-order or even more-order; specifically according to the spatial layout of the PCB.

As shown in fig. 7, the isolation module 12 according to the present application includes a second capacitor 121 and a third resistor 122; the second capacitor 121 is connected to the pulse filtering module 11, and is configured to suppress the second direct current signal from flowing to the pulse filtering module 11; the third resistor 122 is connected to the dc filtering module 13, and is configured to suppress the second pulse signal from flowing to the dc filtering module 13.

Specifically, the second capacitor 121 is connected to the second attenuator 113 in the pulse filtering module 11, and the third resistor 122 is connected to the last stage of the RC filtering circuit 131 in the dc filtering module 13;

since the second capacitor 121 has a characteristic of blocking direct current and alternating current, on the one hand, the second direct current signal can be prevented from flowing to the pulse filter module 11; on the other hand, the amplitude of the second pulse signal can be adjusted by adjusting the capacitance of the second capacitor 121. Specifically, when the second capacitor 121 passes through the pulse signal, the capacitive reactance of the second capacitor 121:

Zc＝1/2πfc

where f is the frequency of the second pulse signal, and c is the capacitance of the second capacitor 121; the amplitude value of the second pulse signal after passing through the second capacitor 121 is further changed by changing the value of the capacitive reactance by adjusting the value of the second capacitor 121.

When it is necessary to suppress the second pulse signal from flowing to the dc filtering module 13, an inductor or a resistor may be used; however, when the superconducting qubit is controlled, the required current value of the dc signal is extremely small, usually less than 10mA, and therefore, the current limiting function needs to be considered, so that the resistor, i.e., the third resistor 122 is adopted; by setting the resistance value of the third resistor 122 to a high resistance value, on one hand, the second pulse signal can be inhibited from flowing to the dc filter module 13, and on the other hand, the current value of the output second dc signal can be adjusted to meet the current requirement for adjusting and controlling the superconducting qubit.

The pulse filtering module 11, the direct current filtering module 12 and the isolation module 13 are passive devices.

In the field of power electronics, the pulse filtering module 11, the dc filtering module 12, and the isolation module 13 may all realize their functions through active devices or passive devices. When the method is specifically applied to the field of quantum measurement and control, the environmental requirement of superconducting quantum bit work is considered, the working temperature is generally in an extremely low temperature environment of 10mk-4K, and a common active device cannot normally work at the extremely low temperature; in addition, the active device needs additional power supply and signal input, which directly increases power consumption. Therefore, the pulse filtering module 11, the direct current filtering module 12 and the isolation module 13 are realized by using passive devices, so that the power consumption is low, and the regulation and control precision of the superconducting qubits is improved.

The signal synthesis device further comprises a closed shell; the PCB1 is disposed within the hermetic housing.

When the signal synthesis device is specifically applied to the field of quantum measurement and control, a closed shell can be further arranged and used for fixing the PCB1, and compared with the direct fixation of the PCB1, the closed shell is easier to fix and convenient to detach; meanwhile, the PCB1 is arranged in the closed shell, so that signal crosstalk can be effectively prevented; and a plurality of connectors are arranged on the closed shell and used for connecting the signal source, the signal synthesis device and the superconducting qubit, so that the stability is better.

Compared with the prior art, the intelligent power supply device comprises a PCB, wherein a pulse filtering module, a direct current filtering module and an isolation module are arranged on the PCB; the pulse filtering module is used for processing the received first pulse signal to smooth the waveform and reduce the noise to obtain a second pulse signal; the direct current filtering module is used for carrying out noise reduction processing on the received first direct current signal to obtain a second direct current signal; the isolation module is respectively connected with the pulse filtering module and the direct current filtering module and used for isolating the second pulse signal from entering the direct current filtering module, isolating the second direct current signal from entering the pulse filtering module and outputting a synthesized signal of the second pulse signal and the second direct current signal. According to the method, the overshoot of the second pulse signal in the output synthesized signal is small through the waveform smoothing and noise reduction processing of the pulse filtering module, and meanwhile the second pulse signal and the second direct current signal in the synthesized signal are high in mutual isolation degree through the isolator; and the integration arrangement of the pulse filtering module, the direct current filtering module and the isolation module is realized through the PCB, the size is small, and the structure is simple.

The construction, features and functions of the present application are described in detail in the embodiments illustrated in the drawings, which are only preferred embodiments of the present application, but the present application is not limited by the drawings, and all equivalent embodiments that can be modified or changed according to the idea of the present application are within the scope of the present application without departing from the spirit of the present application.

Claims (10)

1. A signal synthesis device is characterized by comprising a PCB, wherein a pulse filtering module, a direct current filtering module and an isolation module are arranged on the PCB;

the pulse filtering module is used for performing waveform smoothing and noise reduction processing on the received first pulse signal to obtain a second pulse signal;

the direct current filtering module is used for carrying out noise reduction processing on the received first direct current signal to obtain a second direct current signal;

the isolation module is respectively connected with the pulse filtering module and the direct current filtering module and used for isolating the second pulse signal from entering the direct current filtering module, isolating the second direct current signal from entering the pulse filtering module and outputting a synthesized signal of the second pulse signal and the second direct current signal.

2. The signal synthesizing apparatus of claim 1, wherein the pulse filtering module comprises a first attenuator, a low pass filter, a second attenuator;

the first attenuator is used for carrying out noise reduction and signal reflection reduction processing on the received first pulse signal to obtain a first pulse sub-signal;

the low-pass filter is connected with the first attenuator and is used for performing waveform smoothing processing on the first pulse sub-signal to obtain a first smooth pulse sub-signal;

and the second attenuator is connected with the low-pass filter and used for carrying out noise reduction and signal reflection reduction on the first smooth pulse sub-signal to obtain the second pulse signal.

3. The signal synthesizing apparatus according to claim 2, wherein the first attenuator and the second attenuator each include a pi-type resistance attenuation circuit, a T-type resistance attenuation circuit.

4. The signal synthesizing apparatus according to claim 2, wherein the low-pass filter includes a plurality of order resonators connected in series;

and a coupler is connected in series between the resonators of two adjacent stages.

5. The signal synthesizing apparatus according to claim 4, wherein the resonator includes a first resistor and a first capacitor connected in series;

one end of the first capacitor far away from the first resistor is connected to the ground;

one end of the first resistor, which is far away from the first capacitor, is connected with the coupler.

6. The signal synthesizing apparatus according to claim 4, wherein each of the couplers includes a second resistor and a first inductor connected in parallel;

the same ends of the second resistor and the first inductor are respectively connected to two adjacent resonators.

7. The signal synthesizing apparatus according to claim 1, wherein the dc filter module comprises a plurality of stages of RC filter circuits connected in series;

the RC filter circuit of the first stage receives the first direct current signal, and the RC filter circuit of the last stage is connected with the isolation module.

8. The signal synthesis apparatus of claim 1, wherein the isolation module comprises a second capacitor and a third resistor;

the second capacitor is connected with the pulse filtering module and is used for inhibiting the second direct current signal from flowing to the pulse filtering module;

the third resistor is connected with the direct current filtering module and used for inhibiting the second pulse signal from flowing to the direct current filtering module.

9. The signal synthesis apparatus of claim 1, wherein the pulse filtering module, the DC filtering module and the isolation module are all passive devices.

10. The signal synthesizing apparatus of claim 1 wherein said signal synthesizing apparatus further comprises a hermetic housing;

the PCB is arranged in the sealed shell.

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