194:
121:
42:
31:
265:
is also sensitive to temperature, and thus they require temperature stabilization, especially as the laser beam heats up the crystal. Additionally fast retuning of the crystal is often employed. For this application, the crystal and the thermistor need to be in very close contact and both must have
147:
circuit is used to control the power to the heater and ensure that the oven is maintained at the precise temperature desired. Because the oven operates above ambient temperature, the oscillator usually requires a warm-up period after power has been applied to reach its operating temperature. During
205:
Because of the power required to run the heater, OCXOs require more power than oscillators that run at ambient temperature, and the requirement for the heater, thermal mass, and thermal insulation means that they are physically larger. Therefore, they are not used in battery-powered or miniature
151:
The temperature selected for the oven is that at which the slope of the crystal's frequency vs. temperature curve is zero, further improving stability. AT- or SC-cut (stress-compensated) crystals are used. The SC-cut has a wider temperature range over which near-zero temperature coefficient is
701:"Tutorial Precision Frequency Generation Utilizing OCXO and Rubidium Atomic Standards with Applications for Commercial, Space, Military, and Challenging Environments IEEE Long Island Chapter March 18, 2004"
77:, where "XO" is an old abbreviation for "crystal oscillator"). This type of oscillator achieves the highest frequency stability possible with a crystal. They are typically used to control the frequency of
210:. However, in return, the oven-controlled oscillator achieves the best frequency stability possible from a crystal. The short-term frequency stability of OCXOs is typically 1
198:
139:. Since other electronic components in the circuit are also vulnerable to temperature drift, usually the entire oscillator circuit is enclosed in the oven. A
625:
163:. Their power output is proportional to the current, rather than the square of the current, which linearizes the gain of the control loop.
197:
Some of the earliest crystal ovens. These precision 100 kHz oven-controlled crystal oscillators at the US Bureau of
Standards (now
808:
654:
842:
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as low a heat capacity as possible. To avoid breaking the crystal, large temperature variations in short times must be avoided.
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vibrates depends on its physical dimensions. A change in temperature causes the quartz to expand or contract due to
243:
461:
239:
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124:
94:
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132:
58:
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Miniature crystal oven used to stabilize the frequency of a vacuum-tube mobile radio transmitter
117:, temperature changes are still the major cause of frequency variation in crystal oscillators.
412:
310:
227:
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144:
106:
78:
35:
816:
665:
436:
258:
231:
850:
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136:
222:) per year by aging of the crystal. Achieving better stability requires switching to an
262:
235:
54:
880:
809:"ETH - IfE-Wearable Computing - Miniature pocket-worn motion sensor with DCF77 clock"
781:
849:. Institute of Electrical and Electronics Engineers. pp. 33–46. Archived from
578:. Institute of Electrical and Electronics Engineers. pp. 33–46. Archived from
223:
177:
Most standard commercial crystals are specified to an environmental temperature of
120:
727:
254:), a GPSDO can maintain oscillation stability of 10 for extended periods of time.
782:"URSI/IEEE XXIX Convention on Radio Science, Espoo, Finland, November 1-2, 2004"
490:
41:
246:). Using a GPS receiver that can generate stable time signals (down to within
153:
140:
85:, military communications equipment, and for precision frequency measurement.
66:
30:
546:
110:
102:
98:
82:
62:
238:. Another cheaper alternative is to discipline a crystal oscillator with a
214:
10 over a few seconds, while the long-term stability is limited to around 1
148:
this warm-up period, the frequency will not have the full rated stability.
113:
of the signal produced by the oscillator. Although quartz has a very low
695:
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871:
17:
494:
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29:
201:) served as the frequency standard for the United States in 1929.
843:"Fifty years of progress in quartz crystal frequency standards"
572:"Fifty years of progress in quartz crystal frequency standards"
872:
febo.com - Frequency
Stability and Accuracy in the Real World
251:
61:
at a constant temperature, in order to prevent changes in the
257:
Crystal ovens are also used in optics. In crystals used for
135:
enclosure containing the crystal and one or more electrical
545:. Time and Frequency Division, NIST. 2008. Archived from
53:
is a temperature-controlled chamber used to maintain the
728:"Time and Frequency - Precisely the Way You Need It"
242:
time signal, creating a GPS-disciplined oscillator (
27:
Temperature-controlled chamber for a quartz crystal
101:produced. The frequency at which a quartz crystal
181:, industrial versions are usually specified to
152:achieved and thus reduces warmup time. Power
65:due to variations in ambient temperature. An
8:
344:Microcomputer-compensated crystal oscillator
156:are usually used for the heaters instead of
847:Proc. 1996 IEEE Frequency Control Symposium
755:"GPS Time and Frequency Reference Receiver"
576:Proc. 1996 IEEE Frequency Control Symposium
166:A common temperature for a crystal oven is
565:
563:
363:Oven-controlled crystal oscillator (OCXO)
324:Temperature-compensated crystal oscillator
273:
601:"Temperature Controller for Crystal Oven"
270:Comparison with other frequency standards
655:"IQXO-350, -350I Commercial Oscillator"
527:
170:, but the temperature may vary between
533:
531:
7:
93:Quartz crystals are widely used in
413:Rubidium atomic frequency standard
278:
71:oven-controlled crystal oscillator
25:
626:"Oven for Nonlinear Crystals TK7"
437:Caesium atomic frequency standard
115:coefficient of thermal expansion
284:
1:
34:An OCXO inside an HP digital
841:Marvin E., Frerking (1996).
570:Marvin E., Frerking (1996).
69:of this type is known as an
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462:Global Positioning System
224:atomic frequency standard
97:to precisely control the
143:temperature sensor in a
735:spectruminstruments.net
127:-mounted OCXO from 2016
887:Electronic oscillators
607:. Free Circuit Diagram
605:freecircuitdiagram.com
206:applications, such as
202:
128:
95:electronic oscillators
83:cellular base stations
46:
38:
196:
123:
44:
33:
174:depending on setup.
145:closed-loop control
133:thermally insulated
59:crystal oscillators
892:Laser applications
662:surplectronics.com
301:Crystal oscillator
203:
129:
79:radio transmitters
47:
39:
516:
515:
491:Radio time signal
421:5 × 10 to 5 × 10
394:2 × 10 to 11 × 10
228:rubidium standard
107:thermal expansion
36:frequency counter
16:(Redirected from
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815:. Archived from
813:wearable.ethz.ch
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289:Aging / 10 year
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259:nonlinear optics
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232:caesium standard
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161:heating elements
137:heating elements
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835:Further reading
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277:Oscillator type
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109:, changing the
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866:External links
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762:leapsecond.com
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263:phase matching
236:hydrogen maser
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131:The oven is a
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57:in electronic
55:quartz crystal
26:
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14:
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10:
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3:
2:
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853:on 2009-05-12
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549:on 2008-09-15
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183:−40 to +85 °C
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855:. Retrieved
851:the original
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821:. Retrieved
817:the original
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792:. Retrieved
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749:
738:. Retrieved
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711:. Retrieved
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673:. Retrieved
666:the original
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638:. Retrieved
634:the original
630:EKSMA OPTICS
629:
620:
609:. Retrieved
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584:. Retrieved
580:the original
575:
551:. Retrieved
547:the original
542:
517:
468:4 × 10 to 10
372:15...100 MHz
355:200 μW
335:100 μW
256:
226:, such as a
218:10 (10
204:
176:
172:30 and 80 °C
165:
150:
130:
92:
74:
70:
51:crystal oven
50:
48:
430:1500...2500
315:20 μW
154:transistors
89:Description
881:Categories
857:2009-03-31
823:2009-11-18
794:2009-11-18
767:2009-11-18
740:2009-11-18
713:2009-11-16
675:2009-11-18
640:2009-11-17
611:2009-11-17
586:2009-03-31
553:2008-08-07
522:References
367:5...10 MHz
352:1...3 ppm
332:2...5 ppm
158:resistance
141:thermistor
67:oscillator
450:25...40 W
446:10 to 10
406:200...500
349:10 to 10
306:10 to 10
295:Mass (g)
283:Stability
189:Stability
111:frequency
103:resonator
99:frequency
63:frequency
543:Glossary
442:10 to 10
425:6...12 W
309:10...20
708:ieee.li
415:(RbXO)
400:1...3 W
346:(MCXO)
326:(TCXO)
208:watches
179:0–70 °C
789:vtt.fi
539:"OCXO"
503:4 × 10
472:
464:(GPS)
384:5 × 10
380:2 × 10
292:Power
248:~30 ns
785:(PDF)
758:(PDF)
731:(PDF)
704:(PDF)
669:(PDF)
658:(PDF)
495:DCF77
303:(XO)
244:GPSDO
234:, or
168:75 °C
358:100
199:NIST
75:OCXO
18:OCXO
484:340
479:4 W
418:10
338:50
329:10
318:20
311:ppm
252:UTC
250:of
240:GPS
220:ppb
125:PCB
883::
845:.
811:.
787:.
760:.
733:.
706:.
684:^
660:.
628:.
603:.
574:.
562:^
541:.
530:^
511:87
507:—
497:)
474:10
285:**
261:,
230:,
185:.
81:,
49:A
860:.
826:.
797:.
770:.
743:.
716:.
678:.
643:.
614:.
589:.
556:.
493:(
279:*
216:×
212:×
73:(
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
