NDLI: A rubidium frequency standard based on unreal time control approach

Content Provider	IEEE Xplore Digital Library
Author	Hui Zhou Wei Zhou Bayi Qu Zongqiang Xuan
Copyright Year	2005
Description	Author affiliation: Dept. of Meas. & Instrum., Xidian Univ., Xi'an (Hui Zhou; Wei Zhou; Bayi Qu; Zongqiang Xuan)
Abstract	In conventional rubidium frequency standard and some passive atomic frequency standards the voltage control crystal oscillator VCOCXO exporting the frequency signal of the standards is real time controlled. Because in the locking loop there are frequency transformation circuits, servo amplifier, testing circuits, and physics package, although the output signal of the standards is very accurate and with a good long-term performance, its short-term stability and phase noise performance are poorer than those of VCOCXO. There have been some techniques to filter or control the servo noise, but it is difficult to obtain both good long-term and short-term specifications at the same time. Because a highly stable crystal oscillator not only has a good short-term stability, but also can keep the high accuracy in certain period. Therefore, as an accurate assistant frequency source, the frequency of VCOCXO does not have to be controlled in real time. The unreal time control approach means the servo voltage from the servo amplifier following physics package does not control the frequency of VCOCXO directly. Based on the ability of VCOCXO to keep the accuracy in certain period the control signal can keep unchanged, the good short-term performance of VCOCXO in the standard is taken advantage. In the new rubidium frequency standard, we use microprocessor and I/O units (A/D and D/A converters). This microprocessor can provide the capability of both processing and isolating. It can compare the mean value of output voltage signals of servo amplifier with former voltage signals that control the VCOCXO. The noise of output voltage of servo amplifier can be eliminated through the software processing. The difference between the output voltage signals and the current control voltage signals is related to the regulation value to VCOCXO. The regulation is completed evenly in step according to the least voltage stepping adjusting value in a given adjusting period. This method can guarantee the original stability of VCOCXO and even frequency locking. The rubidium frequency standard can show 1 ~ 2 times $10^{-12}/s$ stability and better than 5 $times10^{-11}/month$ drift. It is possible to improve its performances further
Starting Page	594
Ending Page	597
File Size	161650
Page Count	4
File Format	PDF
ISBN	0780390539
DOI	10.1109/FREQ.2005.1574000
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	2005-08-29
Publisher Place	Canada
Access Restriction	Subscribed
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Frequency Servomechanisms Voltage control Stability Circuit testing Physics Packaging Microprocessors Atomic clocks Voltage-controlled oscillators
Content Type	Text
Resource Type	Article

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

An ultra-miniature rubidium frequency standard with two-cell scheme

Design of a VCO for rubidium atomic frequency standard

Radioactive Counting Clocks

The Phase Stabilities of the Servo Circuit in a Rubidium Vapor Cell Frequency Standard

An ultra-miniature rubidium frequency standard

Investigation on physics package with slotted-tube microwave cavity for rubidium atomic frequency standard

Application of lock-in amplifier in the rubidium atomic frequency standard

Evaluation of a Rubidium Standard for Satellite Application

A New Compact Cesium Beam Frequency Standard

A rubidium frequency standard based on unreal time control approach

Similar Documents

An ultra-miniature rubidium frequency standard with two-cell scheme

Design of a VCO for rubidium atomic frequency standard

Radioactive Counting Clocks

The Phase Stabilities of the Servo Circuit in a Rubidium Vapor Cell Frequency Standard

An ultra-miniature rubidium frequency standard

Investigation on physics package with slotted-tube microwave cavity for rubidium atomic frequency standard

Application of lock-in amplifier in the rubidium atomic frequency standard

Evaluation of a Rubidium Standard for Satellite Application

A New Compact Cesium Beam Frequency Standard

A rubidium frequency standard based on unreal time control approach