Based on the theory of the passive hydrogen maser, along with the technology of frequency modulation and modulation transfer spectroscopy, the theoretical expression of the single frequency modulation for the passive ...Based on the theory of the passive hydrogen maser, along with the technology of frequency modulation and modulation transfer spectroscopy, the theoretical expression of the single frequency modulation for the passive hydrogen maser and the function of the cavity and H line error signals separation are derived, which are basically coincident with the experiment. The absorption and dispersion spectrum curves with different resonance widths show that the cavity and hydrogen transition serve as discriminators, and the two error signals can be separated. Through the calculations of the two error signals in the passive hydrogen maser, it analyzes the traditional method of the two error signals separation, and then describes a new improved method for the passive hydrogen servo loops consisting in the use of a single modulation frequency and frequency discrimination. A null interaction of the two error signals for the new selection of the phase setting is deduced theoretically and validated by the simulation. The preliminary experimental result confirms the feasibility of this new approach, which can reduce the influence from the cavity frequency variety on the crystal oscillator and contribute significantly to the long term performance of the passive hydrogen maser.展开更多
Based on the operating principle and the electric property design of the passive hydrogen maser, the technology and test results of its space adaptability are carried out under the special launch conditions and space ...Based on the operating principle and the electric property design of the passive hydrogen maser, the technology and test results of its space adaptability are carried out under the special launch conditions and space environment. The various perturbations affecting the output frequency of such a standard used for the navigation satellite system are specified, such as magnetic field change, vibration, thermal vacuum and radiation. Through the adaptability technology in the aspects above, the security and reliability of the space passive hydrogen maser sufficiently fulfill the requirements of space operation. At present, the space passive hydrogen maser is working normally on board, indicating that the space adaptability satisfies the design requirement.展开更多
To obtain frequency-temperature compensation in a sapphire loaded cavity for hydrogen maser, a dielectric named SrTiO3 is employed whose temperature coefficient of permittivity is opposite to that of sapphire. Based o...To obtain frequency-temperature compensation in a sapphire loaded cavity for hydrogen maser, a dielectric named SrTiO3 is employed whose temperature coefficient of permittivity is opposite to that of sapphire. Based on theoretical analysis and computer simulation, a TE011 mode of a sapphire loaded cavity associated with two small rings of SrTiO3 with different thickness is solved, and the useful parameters that influence the temperature coefficient of cavity are calculated. Finally an experiment is brought forward and its results are very close to the computing results. When the thickness of SiTiO3 dielectric is 7 mm and the diameter is 17 mm in configuration b, the temperature coefficient of cavity is decreased from -58.8 kHz/K to -8.2 kHz/K and the quality factor is 40248.展开更多
基金supported by the Next Generation of Beidou Navigation Satellite(GFZX0301020104)
文摘Based on the theory of the passive hydrogen maser, along with the technology of frequency modulation and modulation transfer spectroscopy, the theoretical expression of the single frequency modulation for the passive hydrogen maser and the function of the cavity and H line error signals separation are derived, which are basically coincident with the experiment. The absorption and dispersion spectrum curves with different resonance widths show that the cavity and hydrogen transition serve as discriminators, and the two error signals can be separated. Through the calculations of the two error signals in the passive hydrogen maser, it analyzes the traditional method of the two error signals separation, and then describes a new improved method for the passive hydrogen servo loops consisting in the use of a single modulation frequency and frequency discrimination. A null interaction of the two error signals for the new selection of the phase setting is deduced theoretically and validated by the simulation. The preliminary experimental result confirms the feasibility of this new approach, which can reduce the influence from the cavity frequency variety on the crystal oscillator and contribute significantly to the long term performance of the passive hydrogen maser.
基金supported by the Next Generation of Beidou Navigation Satellite(the Space Passive Hydrogen Maser Technology,GFZX0301020104)
文摘Based on the operating principle and the electric property design of the passive hydrogen maser, the technology and test results of its space adaptability are carried out under the special launch conditions and space environment. The various perturbations affecting the output frequency of such a standard used for the navigation satellite system are specified, such as magnetic field change, vibration, thermal vacuum and radiation. Through the adaptability technology in the aspects above, the security and reliability of the space passive hydrogen maser sufficiently fulfill the requirements of space operation. At present, the space passive hydrogen maser is working normally on board, indicating that the space adaptability satisfies the design requirement.
文摘To obtain frequency-temperature compensation in a sapphire loaded cavity for hydrogen maser, a dielectric named SrTiO3 is employed whose temperature coefficient of permittivity is opposite to that of sapphire. Based on theoretical analysis and computer simulation, a TE011 mode of a sapphire loaded cavity associated with two small rings of SrTiO3 with different thickness is solved, and the useful parameters that influence the temperature coefficient of cavity are calculated. Finally an experiment is brought forward and its results are very close to the computing results. When the thickness of SiTiO3 dielectric is 7 mm and the diameter is 17 mm in configuration b, the temperature coefficient of cavity is decreased from -58.8 kHz/K to -8.2 kHz/K and the quality factor is 40248.
