Abstract
In this paper, we report the development of the design verification model (DVM) of Rb atomic frequency standard for the Indian Regional Navigational Satellite System (IRNSS) programme. Rb atomic clock is preferred for the space applications as it is light-weight and small in size with excellent frequency stability for the short and medium term. It has been used in all other similar navigation satellite systems including GPS, GLONASS Galileo etc. The Rb atomic frequency standard or clock has two distinct parts. One is the physics package where the hyperfine transitions produce the clock signal in the integrated filter cell or separate filter cell configuration and the other is the electronic circuits which include frequency synthesizer for generating the resonant microwave hyperfine frequency, phase modulator and phase sensitive detector. In this paper, the details of the Rb physics package and the electronic circuits are given. The reasons for the mode change in Rb lamp have been revisited. The effect of putting the photo detector inside the microwave cavity is studied and reported with its effect on the resonance signal profile. The Rb clock frequency stability measurements have also been discussed.
Highlights
A rubidium frequency standard is a very versatile atomic clock with excellent short-term frequency stability and it is relatively small in dimensions and light in weight
The atomic resonance serves as a discriminator and produces an error signal that varies in magnitude and phase as a function of the difference in frequencies between the applied RF excitation derived from the VCXO and the atomic hyperfine transitions
The core of the physics package consists of the rubidium bulb, integrated filter cell and the microwave cavity
Summary
A rubidium frequency standard is a very versatile atomic clock with excellent short-term frequency stability and it is relatively small in dimensions and light in weight. The atomic resonance serves as a discriminator and produces an error signal that varies in magnitude and phase as a function of the difference in frequencies between the applied RF excitation derived from the VCXO and the atomic hyperfine transitions. This error voltage is obtained and processed by a servo amplifier, which generates a voltage that controls the frequency of the crystal oscillator. First phase of the programme only Rb atomic clocks will be used to achieve an accuracy of 20 m over India and 1500 km around it
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
