Suspended rubidium spectral lamp and control circuit
By designing a suspended rubidium spectral lamp and its control circuit, the problem of limited operating temperature of the rubidium lamp was solved, the luminous intensity of the rubidium lamp and the frequency stability of the rubidium atomic clock were improved, and higher luminous intensity and better temperature control were achieved.
Patent Information
- Application Number
- CN202421742331.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-23
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2034-07-23
AI Technical Summary
The maximum operating temperature of existing rubidium spectral lamps is limited, preventing them from achieving higher luminous intensity and affecting the frequency stability and phase noise of rubidium atomic clocks.
The design employs a suspended structure, which separates the rubidium bulb from the constant temperature bath and the excitation coil through a heat insulation ring. The heat insulation ring increases the thermal resistance, allowing the rubidium bulb to operate in an environment with a temperature higher than that of the constant temperature bath. The control circuit stabilizes the RF signal power.
It significantly improved the maximum operating temperature and luminous intensity of rubidium lamps, and enhanced the frequency stability and phase noise performance of rubidium atomic clocks.
Smart Images
Figure CN223540722U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of atomic frequency standard technology, specifically providing a suspended rubidium spectral lamp and its control circuit. Background Technology
[0002] The rubidium spectral lamp is a key component of the spectral rubidium atomic clock. The intensity of the rubidium isotope characteristic spectral lines (i.e., effective light intensity) that are useful for the operation of the rubidium atomic clock can affect the rubidium frequency discrimination intensity, which in turn affects the signal-to-noise ratio of the rubidium frequency discrimination signal, and ultimately affects the frequency stability and phase noise of the rubidium atomic clock.
[0003] As is well known, the effective luminous intensity of a rubidium spectral lamp is primarily determined by the saturated vapor pressure of rubidium inside the bulb. This saturated vapor pressure, in turn, depends on the bulb's actual operating temperature. In other words, the effective luminous intensity of a rubidium spectral lamp is essentially dependent on the temperature of the cold end (the coldest part of the bulb). Therefore, in practical applications, rubidium bulbs typically need to operate above +110°C, and in some designs, above +125°C or even higher, to ensure optimal luminous intensity. In existing rubidium spectral lamp structures, to achieve good thermal stability and consequently good luminous intensity stability, the bulb and the thermostatic bath are generally designed for efficient heat conduction.
[0004] For example, such as Figure 1 As shown, the rubidium bulb is tightly bonded to the thermostat bath. Due to its very low thermal resistance, the thermal gradient between them is small, and the cold junction temperature of the rubidium bulb is essentially equal to the temperature of the thermostat bath. Its temperature stability is also essentially equivalent to that of the thermostat bath. In practical rubidium atomic clock designs, to improve heating efficiency, transistors are typically used to heat the thermostat bath to which the rubidium bulb is bonded. However, to improve the reliability of the transistors, their junction temperatures need to be dated. The dated transistor casing temperature has an upper limit, directly restricting the maximum temperature of the thermostat bath and thus limiting the operating temperature of the rubidium bulb, preventing it from achieving higher luminous intensity.
[0005] Accordingly, a new solution is needed in this field to address the aforementioned problems. Utility Model Content
[0006] In order to overcome the above-mentioned defects, this utility model is proposed to provide a solution or at least a partial solution to the problem of the limited maximum operating temperature of rubidium bulbs in the design of conventional rubidium spectral lamps.
[0007] In a first aspect, the present invention provides a suspended rubidium spectral lamp, the rubidium spectral lamp comprising: a constant temperature bath, a rubidium bulb disposed inside the constant temperature bath, an excitation coil disposed around the rubidium bulb, and a heat insulation ring disposed between the constant temperature bath and the rubidium bulb;
[0008] The heat insulation ring is used to fix the rubidium bulb so that the rubidium bulb is disconnected from the excitation coil and the constant temperature bath.
[0009] In one technical solution of the above-mentioned suspended rubidium spectral lamp, the rubidium bulb, the heat insulation ring, and the excitation coil are all placed inside the constant temperature bath, which is used to heat the rubidium bulb and provide a stable temperature working environment for the rubidium bulb.
[0010] In one technical solution of the above-mentioned suspended rubidium spectrometer lamp, the lower end of the heat insulation ring is configured as an open shape with a bevel, which is used to bond with the rubidium bulb so that the rubidium bulb is disengaged from the excitation coil and the bottom of the constant temperature bath;
[0011] The upper end of the heat insulation ring is configured as a sealed cylindrical shape to house the tail of the rubidium bulb, so that the tail of the rubidium bulb is in a sealed environment and is not in contact with the constant temperature bath.
[0012] In one technical solution of the above-mentioned suspended rubidium spectral lamp, the excitation coil is fixed to the coil support frame, and the coil support frame is arranged around the rubidium bulb in the constant temperature bath.
[0013] In one technical solution of the above-mentioned suspended rubidium spectral lamp, the heat insulation ring is provided with a groove at the position where it contacts the coil support frame.
[0014] In one technical solution of the above-mentioned suspended rubidium spectral lamp, the rubidium bulb contains rubidium element and ignition gas, and the excitation coil is placed outside the rubidium bulb and connected to the control circuit;
[0015] The rubidium bulb and the excitation coil are further configured as follows:
[0016] After the control circuit controls the excitation coil to generate a radio frequency signal, the radio frequency signal provides radio frequency energy to the rubidium bulb to excite the rubidium bulb to emit light and heat.
[0017] In one technical solution of the above-mentioned suspended rubidium spectral lamp, the heat insulation ring is made of a thermal insulation material.
[0018] In a second aspect, the present invention provides a control circuit, the control circuit comprising:
[0019] An excitation circuit is used to control the excitation coil of the suspended rubidium spectral lamp of any of the first aspects above to generate a radio frequency signal.
[0020] A power detection circuit is used to detect the amplitude of the radio frequency signal;
[0021] An automatic gain controller is used to control the power of the radio frequency signal to stabilize at a preset value based on the detection result of the power detection circuit.
[0022] In one technical solution of the above control circuit, the power detection circuit is further used for:
[0023] Acquire the signal amplitude of the radio frequency signal;
[0024] A detection voltage is generated based on the signal amplitude.
[0025] In one technical solution of the above control circuit, the automatic gain controller includes an analog-to-digital converter and a controller:
[0026] The analog-to-digital converter is used to acquire the detected voltage, compare the detected voltage with a preset voltage value, and generate a digital signal based on the comparison result.
[0027] The controller is used to control the analog-to-digital converter to acquire the detection voltage, and to adjust the voltage or current applied to the excitation circuit according to the digital signal of the analog-to-digital converter.
[0028] The above-described technical solutions of this utility model have at least one or more of the following beneficial effects:
[0029] In implementing the technical solution of this utility model, a suspended rubidium spectral lamp is provided, comprising: a constant temperature bath, a rubidium bulb disposed inside the constant temperature bath, an excitation coil disposed outside the rubidium bulb, and a heat insulation ring disposed between the constant temperature bath and the rubidium bulb; wherein, the heat insulation ring is used to de-contact the rubidium bulb with both the excitation coil and the constant temperature bath. By introducing a heat insulation ring between the constant temperature bath and the rubidium bulb, the thermal resistance between the constant temperature bath and the rubidium bulb is increased. Thus, when the rubidium bulb is heated using radio frequency heating, a temperature difference exists between the constant temperature bath and the rubidium bulb, allowing the rubidium bulb to operate at an ambient temperature higher than that of the constant temperature bath. Without additional power or constant temperature bath temperature, the maximum operating temperature of the rubidium lamp is significantly increased, and the maximum luminous intensity of the rubidium bulb is improved. Attached Figure Description
[0030] The disclosure of this utility model will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. Furthermore, similar numbers in the drawings are used to denote similar components, wherein:
[0031] Figure 1 This is a schematic diagram of the cross-sectional structure of a rubidium spectral lamp based on existing technologies.
[0032] Figure 2 This is a schematic diagram of the main cross-sectional structure of a suspended rubidium spectral lamp according to an embodiment of the present invention;
[0033] Figure 3 This is a schematic diagram of the main cross-sectional structure of a suspended rubidium spectral lamp according to another embodiment of the present invention;
[0034] Figure 4 This is a schematic diagram of the control circuit according to an embodiment of the present invention.
[0035] List of reference numerals :
[0036] 11: Thermostatic bath; 12: Rubidium lamp; 13: Excitation coil; 14: Heat insulation ring; 15: Coil support frame; 16: Groove; 101: Excitation circuit; 102: Power detection circuit; 103: Automatic gain controller. Detailed Implementation
[0037] Some embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.
[0038] In the description of this utility model, "module" and "processor" can include hardware, software, or a combination of both. A module can include hardware circuitry, various suitable sensors, communication ports, and memory, and may also include software components, such as program code, or a combination of software and hardware. A processor can be a central processing unit, microprocessor, image processor, digital signal processor, or any other suitable processor. The processor has data and / or signal processing capabilities. The processor can be implemented in software, in hardware, or a combination of both. Non-transitory computer-readable storage media includes any suitable medium capable of storing program code, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, etc. The term "A and / or B" means all possible combinations of A and B, such as only A, only B, or A and B. The terms "at least one A or B" or "at least one of A and B" have a similar meaning to "A and / or B" and can include only A, only B, or A and B. The singular terms "a" or "this" can also include plural forms.
[0039] The following is combined Figure 2 and Figure 3 The suspended rubidium spectral lamp of the present invention will be described in detail below.
[0040] See appendix Figure 2 , Figure 2This is a schematic diagram of the main cross-sectional structure of a suspended rubidium spectral lamp according to an embodiment of the present invention. Figure 2 As shown, the suspended rubidium spectral lamp in this embodiment includes: a constant temperature bath 11, a rubidium bulb 12 disposed inside the constant temperature bath, an excitation coil 13 disposed around the rubidium bulb, and a heat insulation ring 14 disposed between the constant temperature bath and the rubidium bulb.
[0041] In this embodiment, the constant temperature bath 11 is a temperature control body with high temperature control accuracy, used to maintain a stable temperature environment for the rubidium lamp. The constant temperature bath 11 is generally a metal with a high thermal conductivity, such as aluminum alloy or copper, and includes a heating device and a temperature sensing element, while the control components can be located outside the temperature control body.
[0042] In one implementation, such as Figure 2 As shown, the rubidium bulb 12, the heat insulation ring 14, and the excitation coil 13 are all placed inside the constant temperature bath 11. The constant temperature bath is used to heat the rubidium bulb and provide a stable working environment for the rubidium bulb.
[0043] In this embodiment, the rubidium lamp 12 is a special electrodeless lamp, generally made of special glass material. Excited by a radio frequency signal, it emits atomic characteristic spectral lines and serves as the light source component of the rubidium atomic clock's optical pumping system. The tail of the rubidium lamp can generally be bonded to a metal frame, forming a "cold end." This not only collects excess rubidium atoms at the tail but also allows for adjustment of the lamp's light intensity by controlling the temperature of this cold end, thereby optimizing the overall performance of the rubidium atomic clock.
[0044] In practical applications, the rubidium bulb 12 is typically filled with rubidium and ignition gas to emit light under radio frequency energy excitation and operates in a plasma state. At high temperatures, the bulb is filled with rubidium vapor, with excess rubidium condensing at the cold end. The actual operating temperature of the bulb affects the saturated vapor pressure of the rubidium, thus influencing the effective luminous intensity of the bulb.
[0045] In this embodiment, the excitation coil 13 is generally a loop-shaped wire, usually made of copper. When current passes through the excitation coil, a radio frequency electromagnetic field is generated inside the coil to produce a radio frequency signal. The radio frequency signal can radiate radio frequency energy to the rubidium bulb 12, causing the rubidium bulb 12 to light up and generate heat.
[0046] In one implementation, see Appendix Figure 3 , Figure 3 This is a schematic diagram of the main cross-sectional structure of a suspended rubidium spectral lamp according to another embodiment of the present invention. Figure 3 As shown, the suspended rubidium spectral lamp provided in this embodiment may also include a coil support frame 15.
[0047] Specifically, the excitation coil 13 is fixed to the coil support frame 15, which is located around the rubidium bulb 12 inside the constant temperature bath 11.
[0048] In this embodiment, the coil support frame 15 can be used to fix the excitation coil 13, so that the excitation coil 13 and the rubidium bulb 12 are no longer in contact. Since the temperature of the rubidium bulb is higher than that of the excitation coil, this can reduce the heat loss of the rubidium bulb to the surrounding excitation coil.
[0049] In other embodiments, the gap between the rubidium bulb 12 and the excitation coil 13 can be increased so that the rubidium bulb 12 can fully receive the radio frequency energy radiated by the excitation coil 13 to emit light and heat.
[0050] In this embodiment, the heat insulation ring 14 can be a ring-shaped structure, which is used to bond to the tail of the rubidium bulb 12 so that the rubidium bulb is suspended and detached from the constant temperature bath 11.
[0051] In one embodiment, the heat insulation ring is made of a thermally insulating material.
[0052] In this embodiment, the thermal insulation material is a material that impedes heat transfer and may include plastics and glass fibers, etc. In practical applications, the heat insulation ring 14 is used to increase the thermal resistance between the rubidium bulb 12 and the constant temperature bath 11. Thus, the maximum operating temperature of the rubidium bulb can be significantly increased relative to the maximum temperature that the constant temperature bath can reach, and the increase in temperature is related to the thermal resistance value between the rubidium bulb 12 and the constant temperature bath 11.
[0053] In one implementation, it can be as follows Figure 2 As shown, the lower end of the heat insulation ring 14 is configured as an open shape with a bevel, which is used to bond with the rubidium bulb 12 so that the rubidium bulb 12 is not in contact with the excitation coil 13 and the bottom of the constant temperature bath 11; the upper end of the heat insulation ring 14 is configured as a sealed cylinder, which is used to place the tail of the rubidium bulb 12 so that the tail of the rubidium bulb 12 is in a sealed environment and is not in contact with the constant temperature bath 11.
[0054] In one implementation, such as Figure 3 As shown, the heat insulation ring 14 has a groove 16 at the position where it contacts the coil support frame 15.
[0055] Specifically, the groove 16 can be used to increase the distance between the heat insulation ring 14 and the excitation coil 13, and reduce... Figure 3 Heat is lost from the space formed by the heat insulation ring 14 and the coil support frame 15, which in turn increases the temperature difference between the rubidium bulb 12 and the constant temperature bath 11.
[0056] The suspended rubidium spectral lamp provided in this embodiment increases the thermal resistance between the rubidium lamp and the excitation coil by introducing a heat insulation ring between the thermostatic bath and the rubidium bulb, thus isolating the rubidium bulb from contact with the excitation coil and the thermostatic bath. As a result, when the rubidium bulb is heated using radio frequency heating, a temperature difference exists between the thermostatic bath and the rubidium bulb, allowing the rubidium bulb to operate at an ambient temperature higher than that of the thermostatic bath. Without increasing the power or the temperature of the thermostatic bath, the maximum operating temperature of the rubidium lamp is significantly increased, as is its maximum luminous intensity.
[0057] See appendix Figure 4 , Figure 4 This is a schematic diagram of the control circuit according to one embodiment of the present invention. Figure 4 As shown, this utility model also proposes a control circuit, including: an excitation circuit 101, a power detection circuit 102, and an automatic gain controller 103.
[0058] The excitation circuit 101 is used to control the excitation coil 13 of the suspended rubidium spectral lamp described in the above embodiment to generate radio frequency signals.
[0059] The power detection circuit 102 is used to detect the power of the radio frequency signal.
[0060] The automatic gain controller 103 is used to control the power of the radio frequency signal to stabilize at a preset value based on the detection result of the power detection circuit 102.
[0061] Specifically, since the temperature of the constant-temperature bath used to heat the rubidium bulb in the above embodiment is controlled and constant, the actual temperature of the bulb will not change if the power of the radio frequency signal remains constant. However, since the power of the radio frequency signal may be affected by factors such as ambient temperature, voltage, and current, which in turn affect the operating temperature of the rubidium bulb, it is necessary to change the voltage or current output by the excitation circuit 101 when the power of the radio frequency signal changes, so that the power of the radio frequency signal input to the excitation coil remains constant.
[0062] In one embodiment, the excitation circuit 101 may specifically include an oscillator 1011 and an amplifier 1012. Specifically, the oscillator 1011 is used to generate a stable radio frequency signal. The amplifier 1012 is used to amplify the power of the signal to an appropriate level after the stable radio frequency signal is generated by the oscillator.
[0063] In this embodiment, by controlling the magnitude of the voltage or current applied to the oscillator 1011 in the excitation circuit 101, the power of the radio frequency signal output by the oscillator 1011 can be controlled.
[0064] In specific application scenarios, the oscillator 1011 in the excitation circuit can typically operate at around 100MHz, and can radiate about 1 watt (W) of radio frequency energy to the rubidium lamp through the excitation coil 13.
[0065] In specific application scenarios, the excitation circuit 101 can also be designed as an integrated structure with the constant temperature bath to form an integrated rubidium spectral lamp.
[0066] In one embodiment, the power detection circuit 102 may be further used to:
[0067] Acquire the signal amplitude of the radio frequency signal;
[0068] The detection voltage is generated based on the signal amplitude.
[0069] In one embodiment, the power detection circuit 102 may further include a detector. The detector can be used to detect the amplitude information of the signal and generate a DC voltage signal.
[0070] In practical applications, the power detection circuit 102 can be specifically a diode detector, which can detect the peak value of the radio frequency signal, convert it into DC voltage, and send it to the analog-to-digital converter in the automatic gain controller 103 for sampling.
[0071] In one embodiment, the automatic gain controller 103 may include an analog-to-digital converter 1031 and a controller 1032:
[0072] The analog-to-digital converter 1031 is used to acquire the detection voltage, compare the detection voltage with a preset voltage value, and generate a digital signal based on the comparison result.
[0073] The controller 1032 is used to control the analog-to-digital converter 1031 to acquire the detection voltage signal, and to adjust the voltage or current applied to the excitation circuit 101 according to the digital signal of the analog-to-digital converter 1031.
[0074] In this embodiment, the analog-to-digital converter 1031, also known as an analog-to-digital converter (A / D converter), is used to convert analog signals into digital signals. In some embodiments, after the power detection circuit 101 generates a detection voltage, the detection voltage can be directly transmitted to the analog-to-digital converter 1031 in signal form.
[0075] In one embodiment, the analog-to-digital converter 1031 may include a voltage comparator and a register. The register is used to store a preset voltage value, and the voltage comparator is used to compare the detected voltage with the preset voltage value and output a digital signal. The preset voltage value may be the voltage value required by the excitation circuit 101 for the rubidium spectral lamp to operate stably and meet preset requirements.
[0076] In practical applications, the controller 1032 can be a micro controller unit (MCU), and the A / D converter can also be integrated onto the controller chip to reduce the size occupied by the automatic gain controller 103.
[0077] As an example, in a practical application scenario, the control circuit can perform the following operations: When the ambient temperature rises, the excitation circuit 101 is affected by the temperature, assuming that the temperature effect ultimately reduces the power of the radio frequency signal. At the same time, the amplitude of the radio frequency signal will also decrease, and the detection voltage value output by the power detection circuit 102 will decrease. After the automatic gain controller 103 acquires the detection voltage, it will increase the voltage or current applied to the excitation circuit 101 to restore the power of the radio frequency signal input to the excitation coil of the excitation circuit 101 to the power value before the ambient temperature rises.
[0078] Furthermore, it should be understood that since the various modules are only provided to illustrate the functional units of the device of this utility model, the physical devices corresponding to these modules may be the processor itself, or a part of the processor's software, a part of its hardware, or a combination of software and hardware. Therefore, the number of modules shown in the figure is merely illustrative.
[0079] Those skilled in the art will understand that the various modules in the device can be adaptively split or combined. Such splitting or combining of specific modules will not cause the technical solution to deviate from the principle of this utility model; therefore, the technical solution after splitting or combining will fall within the protection scope of this utility model.
[0080] The technical solution of this utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.
Claims
1. A suspended rubidium spectral lamp, characterized in that, The rubidium spectral lamp includes: a constant temperature bath, a rubidium bulb disposed inside the constant temperature bath, an excitation coil disposed outside the rubidium bulb, and a heat insulation ring disposed between the constant temperature bath and the rubidium bulb; The heat insulation ring is used to disconnect the rubidium bulb from the excitation coil and the constant temperature bath; the rubidium bulb, the heat insulation ring and the excitation coil are all placed inside the constant temperature bath, which is used to heat the rubidium bulb and provide a stable temperature working environment for the rubidium bulb; The lower end of the heat insulation ring is configured as an open shape with a bevel, which is used to bond with the rubidium bulb so that the rubidium bulb is disconnected from the excitation coil and the bottom of the constant temperature bath; the upper end of the heat insulation ring is configured as a sealed cylinder, which is used to place the tail of the rubidium bulb so that the tail of the rubidium bulb is in a sealed environment and disconnected from the constant temperature bath.
2. The suspended rubidium spectral lamp according to claim 1, characterized in that, The excitation coil is fixed to the coil support frame, which is located around the rubidium bulb inside the constant temperature bath.
3. The suspended rubidium spectral lamp according to claim 2, characterized in that, The heat insulation ring has a groove at the position where it contacts the coil support frame.
4. The suspended rubidium spectral lamp according to claim 1, characterized in that, The rubidium bulb contains rubidium element and ignition gas, and the excitation coil is placed outside the rubidium bulb and connected to the control circuit. The rubidium bulb and the excitation coil are further configured as follows: After the control circuit controls the excitation coil to generate a radio frequency signal, the radio frequency signal provides radio frequency energy to the rubidium bulb to excite the rubidium bulb to emit light and heat.
5. The suspended rubidium spectral lamp according to claim 1, characterized in that, The heat insulation ring is made of a thermal insulation material.
6. A control circuit, characterized in that, The control circuit includes: An excitation circuit for controlling the excitation coil of the suspended rubidium spectral lamp according to any one of claims 1 to 5 to generate a radio frequency signal; A power detection circuit is used to detect the power of the radio frequency signal; An automatic gain controller is used to control the power of the radio frequency signal to stabilize at a preset value based on the detection result of the power detection circuit.
7. The control circuit according to claim 6, characterized in that, The power detection circuit is further used for: Acquire the signal amplitude of the radio frequency signal; The detection voltage is output based on the signal amplitude.
8. The control circuit according to claim 7, characterized in that, The automatic gain controller includes an analog-to-digital converter and a controller: The analog-to-digital converter is used to acquire the detected voltage, compare the detected voltage with a preset voltage value, and generate a digital signal based on the comparison result. The controller is used to control the analog-to-digital converter to acquire the detection voltage, and to adjust the voltage or current applied to the excitation circuit according to the digital signal of the analog-to-digital converter.