IQ mixer, quantum measurement and control system and quantum computing device

Abstract

The utility model discloses an IQ mixer, a quantum measurement and control system and quantum computing equipment, which are used in the technical field of mixing. According to the utility model, one of the two opposite side surfaces of the cavity of the IQ mixer is provided with the in-phase port and the quadrature phase port, and the other side surface is provided with the local oscillator port and the radio frequency port. According to the invention, extrusion of ports between side surfaces of adjacent IQ mixers can be avoided, and a plurality of IQ mixers can be compactly arranged on a signal transmission module of a quantum measurement and control system.

Description

Technical Field

[0001] The utility model relates to the technical field of frequency mixing, and in particular to an IQ mixer, a quantum measurement and control system, and a quantum computing device. Background Art

[0002] In the field of wireless microwaves, IQ mixers are often used for frequency shifting; IQ mixers are a commonly used wireless transmission device that achieves the transmission and processing of signals of different frequencies through frequency conversion and phase adjustment. They play an important role in wireless communication systems, software radio, and signal processing. For example, for an up-conversion IQ mixer, two orthogonal in-phase intermediate frequency signals (I-channel signals) and quadrature-phase intermediate frequency signals (Q-channel signals) can be mixed with a local oscillator signal to output an RF signal.

[0003] The current IQ mixers are generally divided into two shapes: a cross-shaped IQ mixer and a π-shaped IQ mixer. Both IQ mixers have four ports: an in-phase port, a quadrature-phase port, a local oscillator port, and a radio frequency port. For a cross-shaped IQ mixer, these four ports are located on the four sides of the IQ mixer cavity, and for a π-shaped IQ mixer, these four ports are located on the three sides of the IQ mixer cavity. However, when the IQ mixer is applied to the signal transmission module of a quantum measurement and control system (such as a signal transmission module or a signal receiving module), the port layout of these two IQ mixers makes it easy for the ports between the adjacent IQ mixer sides to be squeezed, which easily leads to the space between the IQ mixers on the signal transmission module being limited, which is not conducive to the miniaturization and integration of the system. Utility Model Content

[0004] The utility model provides an IQ mixer, a quantum measurement and control system, and a quantum computing device, which can enable multiple IQ mixers to be compactly arranged on a signal transmission module of the quantum measurement and control system.

[0005] The utility model provides an IQ mixer, wherein a cavity of the IQ mixer includes a circuit board and an IQ mixer chip;

[0006] An in-phase port and an orthogonal phase port are arranged on one side of the cavity opposite to the two side surfaces, and a local oscillator port and a radio frequency port are arranged on the other side surface;

[0007] The IQ mixer chip is arranged on the circuit board, the in-phase pin of the IQ mixer chip is connected to the in-phase port, the quadrature-phase pin of the IQ mixer chip is connected to the quadrature-phase port, the local oscillator pin of the IQ mixer chip is connected to the local oscillator port, and the radio frequency pin of the IQ mixer chip is connected to the radio frequency port; wherein a heat sink is installed on the circuit board.

[0008] In some embodiments, a ground hole is provided on the circuit board, and the empty pins of the IQ mixer chip are grounded through the ground hole of the circuit board.

[0009] In some embodiments, the in-phase pin and the quadrature-phase pin of the IQ mixer chip are respectively connected to the corresponding in-phase port and the quadrature-phase port through microstrip lines, the local oscillator pin of the IQ mixer chip is connected to the local oscillator port through a local oscillator microstrip line, and the RF pin of the IQ mixer chip is connected to the RF port through a RF microstrip line.

[0010] In some embodiments, the impedance values ​​of the local oscillator microstrip line and the radio frequency microstrip line are determined based on the isolation of the local oscillator signal input at the local oscillator port from leaking to the radio frequency port, and the corresponding conversion loss of the IQ mixer.

[0011] In some embodiments, the microstrip line in the cavity is welded to a port on a side surface of the cavity through a welding pad, and an absorbing material is provided at the welding pad.

[0012] In some embodiments, the cavity further comprises a base;

[0013] The circuit board is provided with a mounting hole, and the circuit board is mounted on the base through the mounting hole; wherein, the mounting hole is provided with an absorbing material.

[0014] In some embodiments, the cavity further includes a base and a cover;

[0015] The base is provided with a groove corresponding to the circuit board, the circuit board is installed in the groove, and the cover plate is fittedly installed on the end surface of the opening of the groove.

[0016] In some embodiments, the in-phase port, the quadrature-phase port, the local oscillator port, the radio frequency port, and the cavity form an H-type IQ mixer.

[0017] In some embodiments, the IQ mixer chip includes a first double-balanced mixer, a second double-balanced mixer, and a 90-degree hybrid bridge;

[0018] Wherein, the input end of the 90-degree hybrid bridge is connected to the local oscillator pin of the IQ mixer chip, and the isolation end of the 90-degree hybrid bridge is grounded;

[0019] The 0 degree end of the 90 degree hybrid bridge is connected to the local oscillator end of the first double balanced mixer, and the 90 degree end of the 90 degree hybrid bridge is connected to the local oscillator end of the second double balanced mixer;

[0020] The intermediate frequency end of the first double-balanced mixer is connected to the in-phase pin of the IQ mixer chip, and the intermediate frequency end of the second double-balanced mixer is connected to the orthogonal phase pin of the IQ mixer chip;

[0021] After the radio frequency end of the first double-balanced mixer is connected to the radio frequency end of the second double-balanced mixer, the radio frequency end is connected to the radio frequency pin of the IQ mixer chip.

[0022] In some embodiments, the first double-balanced mixer includes: a first transformer, a second transformer, and a balanced bridge;

[0023] Wherein, the primary winding of the first transformer is connected to the 0 degree end of the 90 degree hybrid bridge, and the secondary winding of the first transformer is connected to the first diagonal line of the balanced bridge;

[0024] The second diagonal of the balanced bridge is connected to the primary winding of the second transformer, and the midpoint of the primary winding of the second transformer is connected to the in-phase pin of the IQ mixer chip;

[0025] The secondary winding of the second transformer is connected to the radio frequency end of the second double-balanced mixer.

[0026] The utility model also provides a quantum measurement and control system, wherein a plurality of the above-mentioned IQ mixers are arranged on a signal transmission module of the quantum measurement and control system; wherein the in-phase port and the orthogonal phase port of the IQ mixer are respectively connected to the signal transmission port on the signal transmission module of the quantum measurement and control system.

[0027] In some embodiments, the signal transmission module includes a signal transmission module, which is used to transmit radio frequency signals to quantum bits to perform quantum gate operations; the signal transmission module is an edge transmission module or a vertical transmission module; and the IQ mixer is arranged on the signal transmission module.

[0028] In some embodiments, the signal transmission module includes a signal acquisition module, which is used to receive an output signal from a quantum bit to obtain a quantum state of the quantum bit; the signal acquisition module is an edge acquisition module or a vertical acquisition module; and the IQ mixer is arranged on the signal acquisition module.

[0029] The utility model also provides a quantum computing device, including a quantum processor and a quantum measurement and control system connected to the quantum processor, the quantum processor includes a quantum bit, the quantum measurement and control system is used to provide a radio frequency signal to the quantum bit to perform a quantum gate operation, and is used to receive a radio frequency signal output from the quantum bit to obtain the quantum state of the quantum bit, wherein the quantum measurement and control system is the above-mentioned quantum measurement and control system.

[0030] It can be seen from the above technical solutions that the utility model has the following advantages:

[0031] The cavity of the IQ mixer includes a circuit board and an IQ mixer chip; an in-phase port and an orthogonal phase port are arranged on one side of the two opposite sides of the cavity, and a local oscillator port and a radio frequency port are arranged on the other side; the IQ mixer chip is arranged on the circuit board, the in-phase pin and the orthogonal phase pin of the IQ mixer chip are respectively connected to the corresponding in-phase port and the orthogonal phase port, the local oscillator pin of the IQ mixer chip is connected to the local oscillator port, and the radio frequency pin of the IQ mixer chip is connected to the radio frequency port.

[0032] It can be seen that in the utility model, by arranging an in-phase port and an orthogonal phase port on one side of the two opposite sides of the cavity of the IQ mixer, and arranging a local oscillator port and a radio frequency port on the other side, when the IQ mixer is applied to the signal transmission module of the quantum measurement and control system, it is possible to avoid squeezing of ports between adjacent IQ mixer sides, and enable multiple IQ mixers to be compactly arranged on the signal transmission module of the quantum measurement and control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solution in the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0034] Figure 1 is a schematic diagram of the layout of an existing edge-transmitting module;

[0035] Figure 2 A schematic diagram of the layout of an existing vertical launch module;

[0036] Figure 3 It is a three-dimensional structural schematic diagram of an IQ mixer disclosed in the utility model;

[0037] Figure 4 A schematic diagram of a new layout of an edge-emitting module disclosed in the utility model;

[0038] Figure 5 A schematic diagram of a new layout of a vertical launch module disclosed in the utility model;

[0039] Figure 6 for Figure 3 An exploded schematic diagram of the IQ mixer is shown;

[0040] Figure 7 for Figure 6The layout of the circuit board module of the IQ mixer is shown;

[0041] Figure 8 for Figure 7 A schematic diagram of the circuit structure of an IQ mixer chip on the circuit board module shown;

[0042] Fig. 9 for Figure 8 The circuit structure diagram of a double-balanced mixer of the IQ mixer chip shown is shown. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0044] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] The current IQ mixers are generally divided into two shapes: cross-shaped IQ mixers and π-shaped IQ mixers. Both types of IQ mixers have four ports: an in-phase port, a quadrature-phase port, a local oscillator port, and a radio frequency port. For the π-shaped IQ mixer, these four ports are located on three sides of the IQ mixer cavity, where the in-phase port and the quadrature-phase port are located on the same side, and the local oscillator port and the radio frequency port are located on two opposite sides.

[0047] Among them, when the signal transmission module of the quantum measurement and control system is an edge transmission module, the π-type IQ mixer is applied to the edge transmission module, such as Figure 1 As shown in the figure, IFT is the intermediate frequency transmitting end of the transmitting module, such as the same-phase intermediate frequency transmitting end (I-path signal end) or the orthogonal-phase intermediate frequency transmitting end (Q-path signal end); when the signal transmission module of the quantum measurement and control system is a vertical transmitting module, the π-type IQ mixer is applied to the vertical transmitting module, such as Figure 2 As shown; it can be seen that Figure 1 as well as Figure 2 For π-type IQ mixers, the ports between the sides of adjacent IQ mixers are prone to squeezing, that is, there is physical assembly interference, which easily leads to the space between the IQ mixers on the antenna transmitting module being limited. In addition, the local oscillator port and the radio frequency port located on the two opposite sides of the IQ mixer also need to be connected with cables to communicate with other modules through the cables. On the one hand, the cables are connected from the side, occupying space and not easy to route. On the other hand, these cables are needed to be connected to other modules, resulting in the entire quantum measurement and control system and the quantum computing device composed of the IQ mixer being bloated, which is not conducive to miniaturization and integration. It can be understood that the signal transmission module of the quantum measurement and control system can also be a signal acquisition module. When the π-type IQ mixer is applied to the signal acquisition module, there are similar problems, which will not be described in detail here.

[0048] In order to avoid the space between the IQ mixers on the signal transmission module being limited and to arrange multiple IQ mixers compactly on the signal transmission module, the present application proposes a new design scheme, such as Figure 3 As shown, the port layout of the IQ mixer is changed to: an in-phase port 303 and an orthogonal phase port 304 are arranged on one side of the two opposite sides of the cavity 310 of the IQ mixer, and a local oscillator port 305 and a radio frequency port 306 are arranged on the other side.

[0049] At this time, the in-phase port 303 and the quadrature-phase port 304, the local oscillator port 305 and the radio frequency port 306 are respectively located on two opposite sides of the IQ mixer cavity 310, wherein the in-phase port 303, the quadrature-phase port 304, the local oscillator port 305, the radio frequency port 306 and the cavity 310 can form an H-type IQ mixer. When the H-type IQ mixer is applied to an edge transmitting module, such as Figure 4 or, when the H-type IQ mixer is applied to the vertical transmission module, as shown in Figure 5As shown; whether it is an edge emission module or a vertical emission module, the newly designed IQ mixer can be well matched and connected therewith, and can avoid squeezing of ports between the sides of adjacent H-type IQ mixers, so that multiple IQ mixers can be compactly arranged on the signal transmission module of the quantum measurement and control system, and the H-type IQ mixer can be highly densely integrated in the signal transmission module of the quantum measurement and control system to meet the high-density installation requirements of the signal transmission module; in addition, no additional cables are required to be connected, or cables are required to be connected, no additional space is occupied, and wiring is easy, which is conducive to the miniaturization and integration of the quantum computing device composed of the entire quantum measurement and control system and the IQ mixer.

[0050] Specifically, Figure 6 As shown: In the utility model, the cavity of the IQ mixer includes: a circuit board module. The circuit board module includes a circuit board 301 (PCB) and an IQ mixer chip 302. Among them, an in-phase port 303 (I-path port) and an orthogonal phase port 304 (Q-path port) are set on one side of the two opposite sides of the cavity, and a local oscillator port 305 (LO port) and a radio frequency port 306 (RF port) are set on the other side; wherein, the port set on the cavity can be an SMA antenna seat or an IPX antenna seat, which is not specifically limited here. It can be understood that when the IQ mixer performs up-conversion, the IQ mixer is applied to the signal transmission module of the quantum measurement and control system, and the in-phase port 303 (I-channel port) and the quadrature-phase port 304 (Q-channel port) of the IQ mixer respectively input (IN) the in-phase intermediate frequency signal and the quadrature-phase intermediate frequency signal transmitted by the signal transmission module, and the in-phase intermediate frequency signal and the quadrature-phase intermediate frequency signal are signals with a phase difference of 90 degrees; at the same time, the local oscillator port 305 (LO port) inputs the local oscillator signal, and the IQ mixer mixes the in-phase intermediate frequency signal and the quadrature-phase intermediate frequency signal with the local oscillator signal, and outputs (OUT) the radio frequency signal through the radio frequency port 206 (RF port). At the same time, when the H-type IQ mixer performs down-conversion, the IQ mixer is applied to the signal acquisition module of the quantum measurement and control system, and the in-phase port 303 and the orthogonal phase port 304 of the IQ mixer are connected to the receiving port of the signal acquisition module. At this time, the IQ mixer can also be integrated into the signal acquisition module with high density, that is, the IQ mixer can perform high-density up and down conversion. It can be understood that the above-mentioned signal transmission module can be a signal transmission array, and the above-mentioned signal acquisition module can be a signal acquisition array, which will not be repeated below.

[0051] The IQ mixer chip 302 is arranged on the circuit board 301, and the in-phase pin and the quadrature-phase pin of the IQ mixer chip 302 are connected to the corresponding in-phase port 303 and the quadrature-phase port 304 respectively through, for example, but not limited to, a microstrip line 307 (microwave source cable). The local oscillator pin of the IQ mixer chip is connected to the local oscillator port 305 through, for example, but not limited to, a local oscillator microstrip line; the radio frequency pin of the IQ mixer chip is connected to the radio frequency port 306 through, for example, but not limited to, a radio frequency microstrip line. A heat sink is installed on the circuit board 301. The heat sink is used to dissipate heat from the circuit board 301 when the IQ mixer is working. The heat sink can be a graphite sheet or a brass sheet, which is not specifically limited here.

[0052] It can be seen that in the utility model, by arranging an in-phase port and an orthogonal phase port on one side of the two opposite sides of the cavity of the IQ mixer, and arranging a local oscillator port and a radio frequency port on the other side, when the IQ mixer is applied to the signal transmission module of the quantum measurement and control system, it is possible to avoid squeezing of ports between adjacent IQ mixer sides, and enable multiple IQ mixers to be compactly arranged on the signal transmission module of the quantum measurement and control system.

[0053] In addition, after a large number of experiments and studies, the inventor found that when the local oscillator port and the RF port are set on the same side of the IQ mixer, the distance between the local oscillator microstrip line connected to the local oscillator port and the RF microstrip line connected to the RF port is relatively close, which easily increases the signal radiation between the local oscillator signal transmitted on the local oscillator microstrip line and the RF signal transmitted on the RF outer band line, and the local oscillator signal and the RF signal are coupled with each other to produce crosstalk, which affects the normal use of the IQ mixer. Therefore, the utility model further provides an IQ mixer that can avoid adverse effects such as crosstalk between the local oscillator signal and the RF signal in the IQ mixer while allowing multiple IQ mixers to be compactly arranged in the signal transmission module of the quantum measurement and control system. The following will be described in detail:

[0054] In the present invention, the IQ mixer chip 302 on the IQ mixer is a passive mixer chip, such as Figure 8As shown, the IQ mixer chip includes a first double-balanced mixer N1, a second double-balanced mixer N2, and a 90-degree hybrid bridge 90°HYBRID; wherein, the input end of the 90-degree hybrid bridge is connected to the local oscillator pin (LO pin) of the IQ mixer chip, and the isolation end of the 90-degree hybrid bridge is grounded; the 0-degree end of the 90-degree hybrid bridge is connected to the local oscillator end of the first double-balanced mixer N1, and the 90-degree end of the 90-degree hybrid bridge is connected to the local oscillator end of the second double-balanced mixer N2; the intermediate frequency end of the first double-balanced mixer N1 is connected to the in-phase pin IF1 of the IQ mixer chip, and the intermediate frequency end of the second double-balanced mixer N2 is connected to the orthogonal phase pin IF2 of the IQ mixer chip; the RF end of the first double-balanced mixer N1 is connected to the RF end of the second double-balanced mixer N2, and then connected to the RF pin of the IQ mixer chip. In the figure, GND is a ground pin, and NIC is an empty pin.

[0055] The circuit structure of the first double balanced mixer is similar to that of the second double balanced mixer. Fig. 9 As shown, it includes: a first transformer T1, a second transformer T2 and a balanced bridge; the balanced bridge is composed of a plurality of diodes D1, D2, D3 and D4 connected in series.

[0056] Among them, the primary winding of the first transformer T1 is connected to the 0 degree end of the 90 degree hybrid bridge, that is, one end of the primary winding of the first transformer T1 is the local oscillator end of the first double balanced mixer, and the secondary winding of the first transformer T1 is connected to the first diagonal of the balanced bridge; the second diagonal of the balanced bridge is connected to the primary winding of the second transformer, the midpoint of the primary winding of the second transformer T2 is connected to the in-phase pin of the IQ mixer chip, and the midpoint of the primary winding of the second transformer T2 is the intermediate frequency end of the first double balanced mixer; the secondary winding of the second transformer T2 is connected to the RF end of the second double balanced mixer, that is, one end of the secondary winding of the second transformer T2 is the RF end of the first double balanced mixer.

[0057] When the IQ mixer chip performs up-conversion, the local oscillator signal (LO signal) is divided into two local oscillator signal components with a phase difference of 90 degrees through a 90-degree hybrid bridge. These two local oscillator signal components are mixed with the in-phase signal (I-path signal) input by the in-phase pin and the orthogonal phase signal (Q-path signal) input by the orthogonal phase pin in the double-balanced mixer, and then added to obtain the output radio frequency signal (RF signal).

[0058] In the present invention, after a large number of experiments, it is found that grounding the empty pin NIC of the IQ mixer chip can effectively suppress the signal radiation between the local oscillator signal transmitted on the local oscillator microstrip line and the radio frequency signal transmitted on the radio frequency outer band line, thereby improving the isolation degree from the local oscillator signal to the radio frequency port; Figure 7As shown, a ground hole 3011 is provided on the circuit board 301, and the empty pin NIC of the IQ mixer chip 302 can be grounded through the ground hole 3011 of the circuit board 301; by grounding all the empty pins NIC of the IQ mixer chip 302, the signal radiation between the local oscillator signal transmitted on the local oscillator microstrip line and the radio frequency signal transmitted on the radio frequency outer band line can be further reduced, the isolation of the local oscillator signal to the radio frequency port is improved, and the adverse effects such as crosstalk between the local oscillator signal and the radio frequency signal in the IQ mixer can be avoided.

[0059] In one feasible method, in order to further reduce the signal radiation between the local oscillator signal transmitted on the local oscillator microstrip line and the radio frequency signal transmitted on the radio frequency outer band line, it is necessary to determine the optimal impedance value of the local oscillator microstrip line and the radio frequency microstrip line based on the worst isolation of the local oscillator signal input at the local oscillator port leaking to the radio frequency port and the conversion loss (up-conversion loss or down-conversion loss) of the IQ mixer.

[0060] It is understandable that the IQ mixer needs to input the local oscillator signal from the local oscillator port whether it is up-converting or down-converting. The isolation degree of the local oscillator signal input from the local oscillator port leaking to the RF port is specifically the ratio of the power of the local oscillator signal leaking to the RF port to the input power of the local oscillator signal, in dB. The greater the isolation degree, the lower the signal radiation between the local oscillator signal transmitted on the local oscillator microstrip line and the RF signal transmitted on the RF outer band line; and when the impedance value of the local oscillator microstrip line and the RF microstrip line changes, the isolation degree of the local oscillator signal input from the local oscillator port leaking to the RF port also changes accordingly. In order to achieve the optimal isolation while minimizing the conversion loss of the IQ mixer, the worst isolation of the local oscillator signal input from the local oscillator port leaking to the RF port and the corresponding conversion loss of the IQ mixer can be obtained when the local oscillator microstrip line and the RF microstrip line have multiple different impedance values; for example, the impedance value of the microstrip line can be adjusted by adjusting the diameter of the microstrip line, that is, the wider the diameter of the microstrip line, the smaller the impedance value, and the narrower the diameter of the microstrip line, the larger the impedance value; and the corresponding worst isolation and conversion loss of the IQ mixer can be detected, as shown in Table 1:

[0061] Table 1

[0062] Microstrip line impedance value-Ω Conversion loss-dB Worst isolation -dB A 7.1 33.7 B 6.1 34.8 C 11.1 33.5

[0063] In Table 1, A < B < C; based on the worst isolation and the corresponding conversion loss, the impedance values of the local oscillator microstrip line and the radio frequency microstrip line can be determined from multiple different impedance values. For example, by matching the impedance values with the conversion loss and the worst isolation, it can be known that when the impedance value of the microstrip line is BΩ, the conversion loss of the IQ mixer is the lowest and the worst isolation is the largest. That is, the impedance values of the local oscillator microstrip line and the radio frequency microstrip line can be determined as BΩ; so that while improving the isolation, the conversion loss is also reduced as much as possible, and further reducing the signal radiation between the local oscillator signal transmitted on the local oscillator microstrip line and the radio frequency signal transmitted on the radio frequency outer strip line.

[0064] Furthermore, as Figure 7 shown, in the present utility model, the microstrip line 307 in the cavity of the IQ mixer is welded to the port on the side of the cavity through the pad 3012. At this time, an absorbing material can be provided at the pad 3012; the absorbing material can be a graphene-based absorbing material, ferrite, SiC ceramic or Si3N4 ceramic material, etc., and specific details are not limited here. That is, an absorbing material can be provided near the port to absorb the signal radiation of the local oscillator signal and the radio frequency signal, and further improve the isolation from the local oscillator signal to the radio frequency port.

[0065] Combined with Figure 6 shown, furthermore, the cavity of the IQ mixer further includes a base 308; wherein, the circuit board 301 is provided with mounting holes 3013, and the circuit board 301 can be mounted on the base 308 through the mounting holes 3013; wherein, an absorbing material can be provided in the mounting holes 3013 to further reduce the signal radiation of the local oscillator signal and the radio frequency signal.

[0066] Furthermore, the cavity of the IQ mixer can further include a base 308 and a cover plate 309; the circuit board 301 is disposed between the base 308 and the cover plate 309, and a groove 3081 corresponding to the circuit board 301 is provided on the base 308, that is, the volume of the groove 3081 matches the volume of the circuit board 301, and the circuit board 301 can be embedded and installed in the groove 3081; the cover plate 309 is fitted and installed on the end surface at the opening of the groove 3081. Among them, the cover plate 309 can be installed by screws through threaded holes or buckled by buckles, and specific details are not limited here. By installing the circuit board 301 in the groove 3081 and fitting and installing the cover plate 309 on the end surface at the opening of the groove 3081, the circuit board 301 can be made airtight and seamless with the base 308 and the cover plate 309, that is, the cavity structure of the IQ mixer is airtight and seamless, reducing the reflection of electromagnetic microwaves (local oscillator signal and radio frequency signal) in the cavity to reduce the signal radiation of the local oscillator signal and the radio frequency signal. Among them, the ground hole of the circuit board 301 is in good conduction with the base 308 to ensure good grounding of the empty pins of the IQ mixer chip.

[0067] It can be seen that through the above embodiments, the signal radiation of the local oscillator signal and the radio frequency signal can be continuously further reduced, and the isolation from the local oscillator signal to the radio frequency port can be maintained above 40 dB, effectively avoiding crosstalk between the local oscillator signal and the radio frequency signal in the IQ mixer.

[0068] In an operative manner, when the pins of the IQ mixer chip are connected to the ports of the IQ mixer through a microstrip line, the microstrip line will introduce environmental noise, and the microstrip line will attenuate the microwave signal when transmitting the microwave signal (local oscillator signal or radio frequency signal), so that the corresponding function of the IQ mixer is limited when it is used in the quantum measurement and control system, and the signal-to-noise ratio of the measurement and control is reduced. By reducing the signal radiation of the local oscillator signal and the radio frequency signal through the above embodiment, the environmental noise introduced by the microstrip line can be effectively reduced, and the signal-to-noise ratio of the measurement and control can be effectively improved.

[0069] The utility model also provides a quantum measurement and control system (not shown), in which a plurality of the above-mentioned IQ mixers are arranged on a signal transmission module of the quantum measurement and control system; wherein the in-phase port and the orthogonal phase port of the IQ mixer are respectively connected to the signal transmission port on the signal transmission module of the quantum measurement and control system.

[0070] When the signal transmission module of the quantum measurement and control system is a signal transmission module, the signal transmission module can be an edge transmission module or a vertical transmission module, which is not limited here; the in-phase port and the orthogonal phase port of the IQ mixer are connected to the transmission port of the transmission module. At this time, the IQ mixer performs up-conversion, converts the in-phase signal and the orthogonal phase signal output by the signal transmission module of the transmission module into radio frequency signals, and outputs the radio frequency signal to transmit the radio frequency signal to the quantum bit for quantum state manipulation.

[0071] When the signal transmission module of the quantum measurement and control system is a signal acquisition module, the signal acquisition module can be an edge acquisition module or a vertical acquisition module, which is not limited here; the in-phase port and the orthogonal phase port of the IQ mixer are connected to the receiving port of the signal acquisition module. At this time, the IQ mixer performs down-conversion and converts the RF signal received by the RF port of the IQ mixer into an in-phase intermediate frequency signal and an orthogonal phase intermediate frequency signal and transmits them to the signal acquisition module to realize the acquisition of the RF signal from the quantum bit and obtain the state of the quantum bit.

[0072] The utility model also provides a quantum computing device (not shown), which includes a quantum processor (not shown) and a quantum measurement and control system connected to the quantum processor, the quantum processor includes a quantum bit, the quantum measurement and control system is used to provide a radio frequency signal to the quantum bit to perform a quantum gate operation, and is used to receive a radio frequency signal output from the quantum bit to obtain the quantum state of the quantum bit, wherein the quantum measurement and control system is the quantum measurement and control system described in any one of the above embodiments.

[0073] The IQ mixer disclosed in the present invention is applied to the above-mentioned quantum measurement and control system, for example. However, the IQ mixer can also be applied to other suitable electronic devices. The present application does not limit this. As long as the IQ mixer is made based on the creative concept of the present application, it should fall within the protection scope of the present application.

[0074] In the present invention, the terms "first", "second", "third", and "fourth" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more, unless otherwise clearly defined.

[0075] The above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it; although the utility model is described in detail with reference to the above embodiments, those skilled in the art should understand that: it is still possible to modify the technical solutions recorded in the above embodiments, or to replace some or all of the technical features therein by equivalent; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of each embodiment of the utility model, and they should all be included in the scope of the claims and specifications of the utility model. If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk and other media that can store program codes.

Claims

1. An IQ mixer, characterized in that: The cavity of the IQ mixer includes a circuit board and an IQ mixer chip; An in-phase port and an orthogonal phase port are arranged on one side of the cavity opposite to the two side surfaces, and a local oscillator port and a radio frequency port are arranged on the other side surface; The IQ mixer chip is arranged on the circuit board, the in-phase pin of the IQ mixer chip is connected to the in-phase port, the quadrature-phase pin of the IQ mixer chip is connected to the quadrature-phase port, the local oscillator pin of the IQ mixer chip is connected to the local oscillator port, and the radio frequency pin of the IQ mixer chip is connected to the radio frequency port; wherein a heat sink is installed on the circuit board.

2. The IQ mixer according to claim 1, characterized in that The circuit board is provided with a ground hole, and the empty pins of the IQ mixer chip are grounded through the ground hole of the circuit board.

3. The IQ mixer according to claim 1, characterized in that The in-phase pin and the quadrature-phase pin of the IQ mixer chip are respectively connected to the corresponding in-phase port and the quadrature-phase port through microstrip lines, the local oscillator pin of the IQ mixer chip is connected to the local oscillator port through a local oscillator microstrip line, and the radio frequency pin of the IQ mixer chip is connected to the radio frequency port through a radio frequency microstrip line.

4. The IQ mixer according to claim 3, characterized in that The impedance values ​​of the local oscillator microstrip line and the radio frequency microstrip line are determined based on the isolation of the local oscillator signal input from the local oscillator port from leaking to the radio frequency port and the corresponding conversion loss of the IQ mixer.

5. The IQ mixer according to claim 3, characterized in that: The microstrip line in the cavity is welded to the port on the side of the cavity through a welding pad, and a wave absorbing material is arranged at the welding pad.

6. The IQ mixer according to claim 1, characterized in that: The cavity also includes a base; The circuit board is provided with a mounting hole, and the circuit board is mounted on the base through the mounting hole; wherein, the mounting hole is provided with an absorbing material.

7. The IQ mixer according to claim 1, characterized in that: The cavity also includes a base and a cover plate; The base is provided with a groove corresponding to the circuit board, the circuit board is installed in the groove of the base, and the cover plate is fittedly installed on the end surface of the opening of the groove of the base.

8. The IQ mixer according to claim 1, characterized in that: The in-phase port, the quadrature-phase port, the local oscillator port, the radio frequency port and the cavity form an H-type IQ mixer.

9. The IQ mixer according to claim 1, characterized in that: The IQ mixer chip includes a first double-balanced mixer, a second double-balanced mixer and a 90-degree hybrid bridge; Wherein, the input end of the 90-degree hybrid bridge is connected to the local oscillator pin of the IQ mixer chip, and the isolation end of the 90-degree hybrid bridge is grounded; The 0 degree end of the 90 degree hybrid bridge is connected to the local oscillator end of the first double balanced mixer, and the 90 degree end of the 90 degree hybrid bridge is connected to the local oscillator end of the second double balanced mixer; The intermediate frequency end of the first double-balanced mixer is connected to the in-phase pin of the IQ mixer chip, and the intermediate frequency end of the second double-balanced mixer is connected to the orthogonal phase pin of the IQ mixer chip; After the radio frequency end of the first double-balanced mixer is connected to the radio frequency end of the second double-balanced mixer, the radio frequency end is connected to the radio frequency pin of the IQ mixer chip.

10. The IQ mixer according to claim 9, characterized in that: The first double-balanced mixer comprises: a first transformer, a second transformer and a balanced bridge; Wherein, the primary winding of the first transformer is connected to the 0 degree end of the 90 degree hybrid bridge, and the secondary winding of the first transformer is connected to the first diagonal line of the balanced bridge; The second diagonal line of the balanced bridge is connected to the primary winding of the second transformer, and the midpoint of the primary winding of the second transformer is connected to the in-phase pin of the IQ mixer chip; The secondary winding of the second transformer is connected to the radio frequency end of the second double-balanced mixer.

11. A quantum measurement and control system, characterized in that: A plurality of IQ mixers according to any one of claims 1 to 10 are arranged on the signal transmission module of the quantum measurement and control system; wherein the in-phase port and the orthogonal-phase port of the IQ mixer are respectively connected to the signal transmission port on the signal transmission module of the quantum measurement and control system.

12. The quantum measurement and control system according to claim 11, characterized in that: The signal transmission module includes a signal transmission module, the signal transmission module is used to transmit a radio frequency signal to a quantum bit to perform a quantum gate operation; the signal transmission module is an edge transmission module or a vertical transmission module; the IQ mixer is arranged on the signal transmission module; or / and, The signal transmission module includes a signal acquisition module, which is used to receive the output signal from the quantum bit to obtain the quantum state of the quantum bit; the signal acquisition module is an edge acquisition module or a vertical acquisition module; the IQ mixer is arranged on the signal acquisition module.

13. A quantum computing device, characterized in that: It includes a quantum processor and a quantum measurement and control system connected to the quantum processor, the quantum processor includes quantum bits, the quantum measurement and control system is used to provide radio frequency signals to the quantum bits to perform quantum gate operations, and is used to receive radio frequency signals output from the quantum bits to obtain the quantum state of the quantum bits, wherein the quantum measurement and control system is the quantum measurement and control system described in any one of claims 11-12.

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