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Quartzlock NEW A7-A Frequency, Phase and Phase Noise Measurement System

Quartzlock NEW A7-A Frequency, Phase and Phase Noise Measurement System. Richard Percival May 2003. New Quartzlock Product for measuring a wide range of frequency standards, isolation amplifiers, frequency multipliers and dividers, and passive devices.

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Quartzlock NEW A7-A Frequency, Phase and Phase Noise Measurement System

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  1. Quartzlock NEW A7-AFrequency, Phase and Phase Noise Measurement System Richard Percival May 2003

  2. New Quartzlock Product for measuring a wide range of frequency standards, isolation amplifiers, frequency multipliers and dividers, and passive devices. Complete redesign using phase locked multipliers Metrology capability (higher resolution) of a full time domain analysis through data acquisition from the frequency counter. Production/Calibration oriented moving coil meter for rapid, unambiguous display between two sources of: a)      Fractional Frequency Difference or b)      Relative Phase Difference A7 Overview

  3. High Resolution (50fs) & Low Noise (5E-14 @ t =1s) Real-Time moving coil display on front panel Optional PC Counter and Stability software Time domain to frequency domain conversion (t<1s) Optional fitted 4-output distribution amplifier OR rubidium Measurement of Masers, Cs & Rb freq. Standards to 1E-12 offset using t=100ms Manual calibration of variety of frequency standards Complete solution for stability characterisation Calculation of close to carrier phase noise Convenient integrated total solution A7 Features and Benefits (1)

  4. Optional 24V Battery Back up Selectable IF filters (sets measurement bandwidth) Accepts wide variety of input stabilities Selectable measurement resolution Easy to use Glitch less switching upon mains power failure Phase Noise Filtering of noisy sources Enables measurements of VCXO’s & OCXO’s Optimisation of measurement on both high and low stability sources Unskilled technician operation A7 Features and Benefits (2)

  5. Manual Adjustment of fractional frequency offset - accuracy Measurement of phase residuals and calculation of frequency and time stabilities Calculation of ‘close to the carrier’ Phase Noise A7 Measurement Capabilities

  6. In Frequency mode the moving coil meter on the front panel shows the fractional freq. difference between inputs Easy to manually adjust/calibrate the fractional freq. difference (accuracy) of any standard Setting resolution improvement possible by using an external counter configured as a frequency counter. The typical RMS resolution (def: standard deviation of 1000 phase measurements/1s) achieved with the A7 is better than 5 parts in 1014 for a 1 second gate time (t) Accuracy can be set to 1E-12 (t = 100ms) Manual Adjustment of Accuracy

  7. In Phase mode, the moving coil meter on the front panel shows the relative phase difference between inputs External counter will be configured as a time interval counter – (collection of phase residuals) A7-A improves counter resolution by multiplying very small phase differences by 10000 Single shot time resolution 50fs Essential for short term stability characterisation and comparison of highly stable frequency standards Stability software allows computation of all frequency and time stability statistics (from Phase Residuals) Frequency Stability Characterisation

  8. A7-A is only instrument where gate times (t) of <1s are possible Conversion of time domain phase residuals into frequency domain allows calculation of ‘close to the carrier’ Phase Noise Only Instrument where this is possible Useful additional capability, eliminating need for expensive dedicated phase test sets Calculation of ‘close to the carrier’ Phase Noise

  9. Noise Floor of A7-M (t= 1ms to t= 4.64s)

  10. Noise Floor of A7-M (t= 10s to t= 10000s)

  11. Gate time A7-M CH1-75A Active Maser CH1-76A Passive Maser A8-M GPS Rb Agilent 5071A Cesium High perf. 10-B Rubidium 1s 5E-14 2E-13 8E-13 1E-11 5E-12 3E-11 10s 1E-14 3E-14 1.6E-13 2E-12 3.5E-12 1E-11 100s 2E-15 7E-15 6E-14 4E-13 8.5E-13 3E-12 1000s 5E-16 2.2E-15 2E-14 2E-13 2.7E-13 1E-12 Why the A7-M noise floor is important Table 1: Comparison of A7-M Noise Floor against variety of atomic frequency standards. The noise floor of a measurement system must be at least 3….10 times lower than the reference standard. It shows why the low noise of the A7-M is so critical today (lower even than the extreme short term stability of CH1-75 2003 AHM)

  12. i) A7-A - Frequency & Phase Measurement System (Base Unit): Standard Resolution Production/Calibration oriented A7-M – Frequency & Phase Measurement System (includes options 1 or 17, 0, 32, 33, 34 and 36 as bundle): High Resolution Metrology Oriented Ordering Instructions

  13. 0 - 24V DC Battery Backup 1 - 4 output distribution amplifier 17 - P1000D Rb Oscillator (ask for details of others) 18/19 - 3/5 year warranties 32 - Frequency stability software 33 - PC based counter card 34 - Computer and printer 35 - Low noise splitter (for Noise Floor measurements) 36 - Training A7 Options

  14. Spare Slides if needed

  15. INPUTS a) Reference & Measurement 5 or 10MHz sine wave ±50x10-6 b) Input levels: +0dBm to +13dBm into 50Ohm c) Max Freq difference (Filter off)Low resolution ±10x10-6(Fractional Frequency difference x = 103) High resolution ±100x10-9 (Fractional Frequency difference x = 105) OUTPUTS (All CMOS/TTL) a) Counter A channel 100kHz square wave (freq. mode) 10ms pulse (phase mode) b) Counter B channel 10ms pulse (phase mode) c) Counter external reference 10MHz FILTER Selectable Bandwidth IF filter reduces measurement noise Nominal 3dB Bandwidths 200Hz, 60Hz, 10Hz Specifications 1

  16. Measurement Resolution Using an external frequency/ time interval counter a) Frequency difference mode: High resolution 1x10-13/gate time Low resolution 1x10-12/gate time Gate times 1ms to 3200s b) Phase difference mode: (High resolution: filter off) c) RMS resolution (single shot): 50fs d) Short-term stability: 5x10-11t=1ms, 5x10-12t=10ms, 5x10-13t=100ms, 5x10-14t=1s, 1x10-14t=10s, 2x10-15t=100s, 5x10-16t=1000s, 1x10-16t=10000s e) Sampling interval: 1ms to 1000s in decade steps f) Drift: <1ps/hr typical at constant ambient temp <5ps/day typical at constant ambient temp g) Drift with temperature: <2ps per °C Specifications 2

  17. Measurement Resolution Using internal moving coil meter a) Frequency difference mode: Full scale ranges ±1x10-7 to ±1x10-12 in decade steps Time constant 20ms to 10s linked to range Displayed noise <2x10-13 peak Zero drift <2x10-13/ hour b) Phase difference mode: Full scale ranges ±10ms to ±100ps in decade steps Displayed noise TBD Zero drift TBD MECHANICAL 2U full rack unit POWER SUPPLY 120/240V AC 50W (max 24V DC opt. battery back up with auto switching. Current consumption 1A (add 2A for Rb & 1A dist. Amplifier) Specifications 3

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