Manuel d'utilisation / d'entretien du produit 8510 du fabricant Agilent Technologies
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Agilent Specifying Calibration Standards for the Agilent 8510 Network Analyzer Application Note 8510-5B Discontinued Product Information — For Support Reference Only — Information herein, may refer to products/services no longer supported. We regret any inconvenience caused by obsolete information.
2 3 3 3 4 5 5 7 7 8 9 9 9 11 12 12 12 14 14 15 16 16 17 17 17 18 18 18 18 19 19 19 19 19 20 20 20 21 21 22 22 22 23 23 26 29 Introduction Measurement errors Measurement calibration Calibration kit Sta.
3 Introduction This product note co vers measurement calibration requirements for the Agilent 8510B/C network analyzer . All of t he capabilities described in this note also apply to the A gilent 8510.
4 The array coeff icients are computed by measuring a set of “kno wn” devices connected at a f ixed point and solving as the vector difference betw een t he modeled and measured response. The full 2-port er ror model sho wn in F igure 1 is an example of onl y one of t he measurement calibra- tions available with the 8510.
5 Standard definition Standard def inition is the process of mathematical- ly modeling the electrical characteristics (delay , attenuation and impedance) of each calibration standard.
6 T able 1. Standard definitions table T able 2. Standard class assignments.
7 Modification procedure Calibration kit modification provides the capability to adapt to measurement calibrations in ot her con- nector types or to generat e more precise error models from existing kits.
8 Define standards A glossar y of standard definition paramet ers used with t he Agilent 8510 is included in t his section. Each parameter is described and appropriate con- versions are listed f or implementation wit h the 8510. T o illustrat e, a calibration kit f or WR -62 rec- tangular waveguide (operating frequency range 12.
9 Each standard is described using the St andard Definition Table in accordance with t he 1- or 2- port model. The St andard Definition t able for a wav eguide calibration kit is shown in Table 1. Each standard type (shor t, open, load, thr u, and arbi- trar y impedance) ma y be def ined by the parame- ters as specif ied belo w .
10 It is not possible to remov e fringing capacit ance, but the result ant phase shift can be modeled as a function of frequency using C 0 through C 3 (C 0 +C l x f + C 2 x f 2 + C 3 x f 3 ,with units.
11 Note In some cases (when the phase response is linear with respect t o frequency) the response of an open can be modeled as an equivalent “incremental” length. This method will serve as a first order appro xima- tion only , but can be useful when dat a or stan- dards f or t he abo ve modeling techniques are not available.
The inductance as a function of frequency can be modeled by specifying the coeff icients of a third- order polynomial (L 0 + L 1 x f + L 2 x f 2 + L 3 x f 3 ), with units of L 0 (nH), L 1 (10 -24 H/Hz), L 2 (10 -33 H/Hz 2 ) and L 3 (10 -42 H/Hz 3 ). F or t he wav eguide example, the induct ance of the offset shor t circuits is negligible.
13 The convention f or def inition of offset delay in wav eguide requires entr y of t he dela y assuming no dispersion. F or waveguide transmission line, the Agilent 8510 calculat es the ef f ects of .
14 µ r = relative permeability constant of t he medium (equal to 1.0 in air) ε r = relative permittivity constant of t he medium (equal to 1.000649 in air) D = inside diameter of outer conduct or d .
15 Therefore, f or the WR -62 wav eguide st andard defi- nition table, of fset loss of zero ohm/sec is entered for all f our standards. Lower/minimum frequency Lo wer frequency defines t he minimum frequency at which the st andard is to be used for the purposes of calibration.
16 Upper/maximum frequency This specifies t he maximum frequency at which the st andard is valid. In broadband applications, a set of banded standards may be necessary t o pro- vide constant response. For exam ple, coaxial of fset standards (i.e., 1 / 4 λ offset shor t) are generally spec- ified over bandwidths of an octav e or less.
17 Note Mathematical operations on measurements (and display ed dat a) aft er calibration are not corrected for dispersion. Enter W A VEGUIDE int o the st andard definition table for all f our st andards. Standard labels Labels are entered through t he title menu and ma y contain up t o 10 characters.
18 S 11 A,B,C and S 22 A,B,C S 11 A, B,C and S 22 A,B,C correspond t o the S 11 and S 22 ref lection calibrations for port 1 and por t 2 respectivel y. These t hree classes are used by the Agilent 8510 t o solv e for the systematic er rors; directivity , source match, and ref lection tracking.
19 TRL Thru TRL Thru cor responds to t he measurement of the S-parameters of a zero-length or shor t thr u connec- tion between port 1 and por t 2. The Thru, Ref lect and Line classes are used ex clusively f or t he three steps of the TRL 2-PORT calibration.
20 Each adapter is specif ied as a single delay/thr u standard and up to seven standards numbers can be specified int o the adapter class. Standard Class labels Standard Class labels are entered t o facilitat e menu-driven calibration.
21 Again, cal kit labels should be chosen t o best describe the calibration devices. The “B.1” default suff ix corresponds t o the kit’s mechanical revision (B) and mathematical revision (1).
22 User modified cal kits and Agilent 8510 specifications As noted previously , the result ant accuracy of t he 8510 when used with any calibration kit is depend- ent on ho w well its standards are defined and is verified through measurement of a device with traceable frequency response.
23 Appendix A Calibration kit entry procedure Calibration kit specifications can be ent ered into the A gilent 8510 using the 8510 disk drive, a disk drive connected to the syst em bus, by fr ont panel entr y , or through program control b y an ext ernal controller .
24 Front panel procedure: (P -band waveguide example) 1. Prior to modifying or generating a cal kit, store one or both of t he cal kits in the 8510’s non- volatile memory to a disk. 2. Select CAL menu, MORE. 3. Prepare to modify cal kit 2: press MODIFY 2.
25 4. Change the class label for S 11 A: LABEL CL ASS, S 11 A, ERASE TITLE. 5. Enter the label of PSHORT 1 by using the knob, the SELECT sof t ke y and t he SP ACE soft k ey.
26 Appendix B Dimensional considerations in coaxial connectors This appendix describes dimensional considera- tions and required conventions used in determin- ing the physical offset length of calibration standards in sexed coaxial connector families.
27 Female type-N Male type-N 7 mm Coaxial connector T ype-N coaxial connector interface The location of the “calibration plane” in T ype-N standards is the outer conductor mating surfaces as shown below . Note: 1.0mm, 1.85mm and 2.4mm connectors not shown, but similar to 3.
28.
29 Appendix C Cal coefficients model Offset devices like offset shorts and of fset opens c an be modeled by the follo wing signal f low graph : Figure 1 Signal flow graph model of offset devices The offset por tion of the open or shor t, is modeled as a perfectly unif or m lossy air dielectric transmis- sion line.
30 Their first order appro ximations, R is small and G=0, are: Equation 3 Since Equation 4 F or coaxial devices.
31 then: Equation 5 Equation 6 If the Of fset delay=0, then the coeff icient of ref lection, Γ = Γ L ..
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Un point important après l'achat de l'appareil (ou même avant l'achat) est de lire le manuel d'utilisation. Nous devons le faire pour quelques raisons simples:
Si vous n'avez pas encore acheté Agilent Technologies 8510 c'est un bon moment pour vous familiariser avec les données de base sur le produit. Consulter d'abord les pages initiales du manuel d'utilisation, que vous trouverez ci-dessus. Vous devriez y trouver les données techniques les plus importants du Agilent Technologies 8510 - de cette manière, vous pouvez vérifier si l'équipement répond à vos besoins. Explorant les pages suivantes du manuel d'utilisation Agilent Technologies 8510, vous apprendrez toutes les caractéristiques du produit et des informations sur son fonctionnement. Les informations sur le Agilent Technologies 8510 va certainement vous aider à prendre une décision concernant l'achat.
Dans une situation où vous avez déjà le Agilent Technologies 8510, mais vous avez pas encore lu le manuel d'utilisation, vous devez le faire pour les raisons décrites ci-dessus,. Vous saurez alors si vous avez correctement utilisé les fonctions disponibles, et si vous avez commis des erreurs qui peuvent réduire la durée de vie du Agilent Technologies 8510.
Cependant, l'un des rôles les plus importants pour l'utilisateur joués par les manuels d'utilisateur est d'aider à résoudre les problèmes concernant le Agilent Technologies 8510. Presque toujours, vous y trouverez Troubleshooting, soit les pannes et les défaillances les plus fréquentes de l'apparei Agilent Technologies 8510 ainsi que les instructions sur la façon de les résoudre. Même si vous ne parvenez pas à résoudre le problème, le manuel d‘utilisation va vous montrer le chemin d'une nouvelle procédure – le contact avec le centre de service à la clientèle ou le service le plus proche.
