MARCONI 6970 Ops 电路图.pdf

Operating Manual i RF POWER METER 6970 IFR Ltd. 2000 No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, or recorded by any information storage or retrieval system, without permission in writing by IFR Ltd. Printed in the UK Manual part no. 46882-182 Issue 12 23 February 2000 RadioFans.CN 收音机爱 好者资料库 46882-182 App-A-1 Appendix A POWER MEASUREMENT ERROR ANALYSIS CONTENTS Page INTRODUCTION.A-1 ERROR SOURCES.A-1 Instrumentation Error.A-1 Mismatch Error.A-1 Power reference uncertainty .A-2 Calculating measurement uncertainty.A-2 Typical uncertainty calculations.A-3 INTRODUCTION The 6970 uses the customary technique of power measurement of a sensor element at the power source with a remote signal processing unit. By using a microcontroller and digital signal processing techniques, sensor correction, calibration and zeroing factors can be used to give the best enhancement of measurement accuracy. RF power measurements are never free from uncertainties. These can be due to instrumentation error, mismatch uncertainty and sensor calibration uncertainty. Significant measurement errors are possible unless these uncertainties are reduced to a minimum. ERROR SOURCES Instrumentation Error The instrumentation error comes from component tolerances and calibration uncertainty of the power meter. The total instrumentation accuracy of 6970 is typically 0.5 %. Mismatch Error Large uncertainties can arise from either sensor or source mismatches. The first effect of these mismatches is to cause a transmission loss, i.e. the sensor does not receive the maximum available power from the source. The second effect is multiple reflections occurring between the source and the sensor causing unpredictable transmission losses. RadioFans.CN 收音机爱 好者资料库 POWER MEASUREMENT ERROR ANALYSIS App-A-2 46882-182 Power reference uncertainty When the power reference is used to calibrate the power meter and the power sensor together, the accuracy of the reference oscillator becomes part of the overall measurement uncertainty. Calculating measurement uncertainty For a source and load having complex reflection coefficients of S and L respectively, the ratio of transmitted power to maximum available power is as follows:- P PO SL SL L = 1 2 1 2 1 2 This has a maximum of: () 1 2 1 2 1 2 SL SL and a minimum of: () 1 2 1 2 1 2 + SL SL Uncertainty is usually quoted as a percentage uncertainty. From the previous formula:- Positive uncertainty () =+ 1001 2 1 SL % Negative uncertainty () = 1001 2 1 SL % The positive and negative uncertainties are essentially the same for low reflection coefficients, but as the reflection coefficients increase the positive uncertainty increases more rapidly than the negative uncertainty. If the source and load matches are quoted as VSWRs then they may be converted to reflection coefficients by the following simple formula:- = + S S 1 1 where S is the VSWR If the reflection coefficients are small, typically less than 0.15, the positive and negative uncertainties can be taken to be equal and the uncertainty can be approximated by:- Percentage uncertainty =200 SL RadioFans.CN 收音机爱 好者资料库 POWER MEASUREMENT ERROR ANALYSIS 46882-182 App-A-3 Typical uncertainty calculations (1) Calculate the mismatch uncertainty for a source reflection coefficient of 0.33 and a sensor reflection coefficient of 0.05. Positive uncertainty = 100 (1 + 0.33 0.05) 2 1) = 100 (1 + 0.0165) 2 1) = 100 (1.0333 1) = 3.33% Negative uncertainty = 100 (1 - 0.33 0.05) 2 1) = 100 (1 - 0.0165) 2 1) = 100 (0.9673 1) = 3.27% (2) Calculate the uncertainties for the source VSWR of 1.3:1 and a sensor VSWR of 1.05:1. The VSWRs must first be turned in to reflection coefficients. S = + = 1 3 1 1 3 1 0 3 2 3 0 130 . . . . . L = + = 1 05 1 1 05 1 0 05 2 05 0 024 . . . . . As both the source and sensor reflection coefficients are low we can apply the approximation formula described previously. Percentage uncertainty = 200 0.13 0.024 = 0.624% ii 46882-182 CONTENTS PRECAUTIONS Chapter 1 GENERAL INFORMATION Chapter 2 INSTALLATION Chapter 3 OPERATION Chapter 4 TECHNICAL DESCRIPTION Chapter 5 ACCEPTANCE TESTING Appendix A POWER MEASUREMENT ERROR ANALYSIS INDEX 46882-182 iii PRECAUTIONS WARNINGS, CAUTIONS and NOTES These terms have specific meanings in this manual: WARNINGS contain information to prevent personal injury. CAUTIONS contain information to prevent damage to the equipment. Notes contain important general information. HAZARD SYMBOLS The meaning of hazard symbols appearing on the equipment is as follows: Symbol Nature of hazard Toxic hazard Class II supply Static sensitive component GENERAL CONDITIONS OF USE This product is designed and tested to comply with the requirements of IEC/EN61010-1 Safety requirements for electronic measuring apparatus, for Class III hand-held equipment and is for use in a pollution degree 2 environment. The equipment is designed to operate from an installation Category I supply. Equipment should be protected from the ingress of liquids and precipitation such as rain, snow, etc. When moving the instrument from a cold to a hot environment, it is important to allow the temperature of the instrument to stabilise before it is connected to the supply to avoid condensation forming. The instrument must only be operated within the environmental conditions specified in Chapter 1, Performance Data. This product is not approved for use in hazardous atmospheres or medical applications. If the equipment is to be used in a safety-related application, e.g. avionics or military applications, the suitability of the product must be assessed and approved for use by a competent person. WARNING - TOXIC HAZARDS Some of the components used in this equipment may include resins and other materials which give off toxic fumes if incinerated. Take appropriate precautions, therefore, in the disposal of these items. iv 46882-182 WARNING - NICKEL CADMIUM A Nickel-cadmium battery is used in this equipment. Do not crush or otherwise mutilate, as corrosive electrolyte can be released. Do not incinerate as they may explode or release toxic fumes. WARNING - POWER ADAPTER The supplied power adapter has been designed and tested in accordance with BS EN 60950 (IEC 950) Safety of information technology equipment, including electrical business equipment, and meets the SELV requirements of products with low voltage DC supply inputs. The adapter conforms with IEC safety Class II incorporating double insulation in its construction, and does not require a protective ground connection. No user serviceable parts are contained within the adapter and no attempt should be made to open the case. Where a supply lead is fitted to adapters incorporating an integrally fused plug ensure that the fuse rating is commensurate with the current requirements of the adapter. See under Performance data in Chapter 1 for power requirements. CAUTION - LCD HANDLING When using this equipment take care not to depress the front of the display module, as this may damage the liquid crystal elements. CAUTION - STATIC SENSITIVE COMPONENTS This equipment contains static sensitive components which may be damaged by handling - refer to the Maintenance part of the Service Manual for handling precautions. CAUTION - PRECISION CONNECTOR The precision Type N connector fitted to this instrument (Option 001 only) may be damaged by mating with a non-precision type. Damage to the connector may also occur if the connector interface parameters are not within specification. The connector should be checked with the appropriate gauging tool. CAUTION - SUITABILITY FOR USE This equipment has been designed and manufactured by IFR Ltd. to for making power measurements in the range 0.1 nW to 25 W over a wide range of frequencies using the IFR 6900 series of power sensors. IFR Ltd. has no control over the use of this equipment and cannot be held responsible for events arising from its use other than for its intended purpose. 46882-182 v PRECAUTIONS WARNINGS, CAUTIONS et NOTES Les termes suivants ont, dans ce manuel, des significations particulires: WARNINGS contient des informations pour viter toute blessure au personnel. CAUTIONS contient des informations pour viter les dommages aux quipements. Notes contient dimportantes informations dordre gnral. SYMBOLES SIGNALANT UN RISQUE La signification des symboles lis cet quipement est la suivante: Symbole Nature du risque Danger produits toxiques Class II supply CONDITIONS GENERALES DUTILISATION Ce produit e t conu et test pour tre conforme aux exigences des normes CEI/EN61010-1 Spcifications des conditions de scurit pour instruments de mesure lectronique , pour des quipements Classe III qui tiennent dans la main et pour une utilisation dans un environnement de pollution de niveau 2. Cet quipement est conu pour fonctionner partir dune alimentation de catgorie I. Cet quipement doit tre protg de lintroduction de liquides ainsi que des prcipitations deau, de neige, etc. Lorsquon transporte cet instrument dun environnement chaud vers un environnement froid, il est important de laisser linstrument se stabiliser en temprature avant de le connecter une alimentation afin dviter toute formation de condensation. Linstrument doit tre utilis uniquement dans les conditions denvironnement spcifies dans le chapitre 1 Performances du manuel dutilisation. Ce produit nest pas garanti pour fonctionner dans des atmosphres dangereuses ou pour un usage mdical. Si lquipement doit tre utilis pour des applications en relation avec la scurit, par exemple des applications militaires ou aronautiques, la compatibilit du produit doit tre tablie et approuve par une personne comptente. WARNING - DANGER PRODUITS TOXIQUES Certains composants utiliss dans cet appareil peuvent contenir des rsines et dautres matires qui dgagent des fumes toxiques lors de leur incinration. Les prcautions dusages doivent donc tre prises lorsquon se dbarrasse de ce type de composant. vi 46882-182 WARNING - NICKEL CADMIUM Une batterie au cadmium nickel est utilise dans cet quipement. Ne pas lcraser ou la broyer, llectrolyte contenu est corrosif. Ne pas lincinrer cela risque de provoquer lexplosion et le dgagement de fumes toxiques. WARNING - ADAPTATEUR SECTEUR Ladaptateur secteur fourni avec lappareil a t conu et test en conformit avec la norme BSEN 60950 (CE 950) “Scurit de quipements de technologie de linformation et quipements lectriques industriels” et suit les recommandations “SELV” des produits comportant des entre continues faible voltage. Ladaptateur possdant dorigine une double isolation conformment la norme CEI “Scurit Classe II”, ne require pas de retour la masse. Ladaptateur ne contient pas de composants rparables et il faut absolument viter douvrir la prise. Lorsque le cble dalimentation connect ladaptateur contient un fusible, il faut vrifier quil soit bien dimensionn. Voir chapitre 1 “Performance data” pour la consommation. 46882-182 vii VORSICHTSMASSNAHMEN WARNINGS, CAUTIONS und NOTES Diese Hinweise haben eine bestimmte Bedeutung in diesem Handbuch: WARNINGS dienen zur Vermeidung von Verletzungsrisiken. CAUTIONS dienen dem Schutz der Gerte. Notes enthalten wichtige Informationen. GEFAHRENSYMBOLE Die Gefahrensymbole auf den Gerten sind wie folgt: Symbol Gefahrenart Warnung vor giftigen Substanzen Class II supply ALLGEMEINE HINWEISE ZUR VERWENDUNG Dieses Produkt wurde entsprechend den Anforderungen von IEC/EN61010-1 Sicherheitsanforderungen fr elektronische Megerte , Klasse III, fr Betrieb in der Hand zur Verwendung in einer Grad 2 verunreinigten Umgebung, entwickelt und getestet. Dieses Gert ist fr Netzversorgung Klasse I zugelassen. Das Megert sollte vor dem Eindringen von Flssigkeiten sowie vor Regen, Schnee etc. geschtzt werden. Bei Standortnderung von kalter in wrmere Umgebung sollte das Megert wegen der Kondensation erst nach Anpassung an die wrmere Umgebung mit dem Netz verbunden werden. Das Megert darf nur in Umgebungsbedingungen wie in Kapitel 1 Leistungsdaten (Performance data) der Bedienungsanleitung beschrieben, betrieben werden. Dieses Produkt ist nicht fr den Einsatz in gefhrlicher Umgebung (z.B. Ex-Bereich) und fr medizinische Anwendungen geprft. Sollte das Gert fr den Einsatz in sicherheitsrelevanten Anwendungen wie z.B. im Flugverkehr oder bei militaerischen Anwendungen vorgesehen sein, so ist dieser von einer fr diesen Bereich zustndigen Person zu beurteilen und genehmigen. WARNING - WARNUNG VOR GIFTIGEN SUBSTANZEN In einigen Bauelementen dieses Gerts knnen Epoxyharze oder andere Materialien enthalten sein, die im Brandfall giftige Gase erzeugen. Bei der Entsorgung mssen deshalb entsprechende Vorsichtsmanahmen getroffen werden. viii 46882-182 WARNING - NICKEL CADMIUM Eine Nickel-Cadmium-Batterie ist in diesem Gert eingebaut. Das Gert nicht beschdigen oder verbrennen, da tzende Elektrolyte freigesetzt wird. Die Batterie kann dabei explodieren oder giftige Gase freisetzen. WARNING - NETZADAPTER Der mitgelieferte Netzadapter ist entsprechend der Norm BS EN 60950 (IEC 950) fr die Sicherheit datentechnischer Anlagen, inklusive elektrischer Bromaschinen, ausgelegt und getestet worden. Er entspricht den “SELV” Richtlinien fr Gerte mit niedrigen Gleichspannungsversorgungen. Der Adapter entspricht mit doppelter Isolation der IEC Sicherheitsklasse II und bentigt keinen Masse-Schutzleiter. Der Adapter enthlt keine reparier- oder austauschbaren Teile und darf nicht geffnet werden. Falls ein Netzkabel und ein Stecker mit eingebauter Sicherung verwendet werden, beachten Sie bitte, da die Sicherung den elektrischen Werten des Adapters entspricht. Weiter Information zur Leistungsaufnahme finden Sie unter “Leistungsdaten” in Kapitel 1. 46882-182 ix PRECAUZIONI WARNINGS, CAUTIONS e NOTES Questi termini vengono utilizzati in questo manuale con significati specifici: WARNINGS riportano informazioni atte ad evitare possibili pericoli alla persona. CAUTIONS riportano informazioni per evitare possibili pericoli allapparecchiatura. Notes riportano importanti informazioni di carattere g