Cokeva
11940C
Operation Note
10
Figure
7.
Testing
an
Enclosure
Seam
8.
a
Coaxial
Cable
Page 1: ...Operation Note 11940C Close Field Probe Part No CK 11940 90007 Printed in USA Jan 2013 ...
Page 2: ...ation please contact us at Cokeva Inc 9000 Foothills Blvd Roseville CA 95747 USA www cokeva com sales cokeva com Tel 1 916 462 6000 Business hours Mon Fri 8 00 AM 4 30 PM Pacific Standard Time In any correspondence or telephone conversation please refer to your instrument by its model number and full serial number Cokeva Inc 2013 All Rights Reserved Reproduction adaptation or translation without p...
Page 3: ...mming instructions when properly installed on that instrument Cokeva Inc does not warrant that the operation of the instrument or software or firmware will be uninterrupted or error free LIMITATION OF WARRANTY The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance or calibration by Buyer or by vendors not approved by Cokeva Buyer supplied software or in...
Page 4: ...ation 3 3 2 Theory of Operation 3 3 4 Antenna Factors 3 3 8 Power Density and Electric Field Calculations 5 3 10 Localized Field Source 5 3 12 Test Setups 6 3 17 Measurement Techniques 8 4 1 Operation Verification 8 4 4 Return Loss Measurement Test 9 5 1 SMA Rotary Joint Installation Procedure 12 Contents 1 ...
Page 5: ...es are denotes a haza rmed or adher nstrument Do itions are fully denotes a haz rmed or adher yond a WARNI et LS and in the inst rument nstrument will to refer to the amage Locatio y use of this sym present Be ex ard It calls atte red to could re o not proceed understood an zard It calls att red to could re NG sign until t trument Fam be marked wi instruction ma on of pertinen mbol in the tab xtre...
Page 6: ...ter Coaxial Straight Male BNC Female SMA 1 8120 4811 Cable Assembly Coaxial 1 CK 11940 90007 Operation Note 1 1 4 Initial Inspection 1 5 If the shipment contents are incomplete or damaged notify the Cokeva office If the shipping container is damaged or the cushioning material shows signs of stress notify the carrier as well as the Cokeva office Keep the shipping materials for the carrier s inspect...
Page 7: ...Cokeva 11940C Operation Note 2 Table 1 Cokeva 11940C Specifications Figure 1 Cokeva 11940C Characteristic Antenna Factors 30 MHz 1 GHz ...
Page 8: ... frequency information and is ideally suited for use with a spectrum analyzer The Cokeva 11940C circuitry is passive and therefore only contributes thermal noise to any measurement system Inspect the probe tip for damage before using Figure 2 Magnetic Field Orientation for Maximum Coupling 3 4 Antenna Factors 3 5 The Cokeva 11940C is supplied with a calibration table mounted on its side The table ...
Page 9: ...Bµ V me 0C Antenna F gain in dB betw ve value if loss e 1 for interpol e 30 MHz and ab c antenna fact Cokeva 11940C C easured on an Factor in dB µ ween 11940C a negative valu ating antenna bove 1000 MH tors below 30 M Characteristic Cokeva 1 alyzer µA m µV and spectrum a e if gain factors betwe z without calib MHz Antenna Facto 1940C O analyzer en the five cal bration and wit ors below 30 MH Opera...
Page 10: ...0 MHz measured VSA 60 3 dBµV Let K 0 and AF 44 dB µA m µV then E dB µV m 60 3 44 51 5 155 8 dBµV m 61 7 V m S dB mW cm2 60 3 44 104 3 0 dB mW cm2 1 mW cm2 3 10 Localized Field Source 3 11 The probe can also be used as a localized magnetic field source for locating susceptibility problems on an electronic circuit It is a reciprocal device that is a voltage fed into the unit will create a magnetic f...
Page 11: ... Em The relative sh s response tech e the enclosure rmation See Se C ized magnetic and test setup ment that satis hen used as a p analyzer If a p level the probe has to the probe a where a potent basic configura missions Test hielding effectiv hniques See F e under test w ection 3 17 for Cokeva 1 field probe or ps for the probe sfies the critica probe be sure preamplifier is a characterist and or ...
Page 12: ...or susceptibility testing of electronic circuits For broadband susceptibility testing use the probe with a swept or tracking source See Figure 6 for an example of the basic localized field source test setup Power applied to the probe must not exceed the maximum input power listed in Table 1 or damage to the probe will result Figure 6 Source Test Setup ...
Page 13: ...n the probe tip as shown in Figure 8 The side of the probe with the calibration label should be facing away from the cable being measured 3 19 The probe may be used as a source in susceptibility testing as described in Section 3 11 and Paragraph 3 16 In this application hold the probe within 1 cm of the electronic circuit component being tested 4 1 OPERATION VERIFICATION 4 2 Operation Verification...
Page 14: ...nts Any equipment that satisfies the following critical specifications for the test setup may be substituted for the recommended equipment Frequency Range 200 MHz Test Port Match 22 dB Return Loss Equipment Network Analyzer HP 8754A Transmission Reflection Test Set HP 8502A Storage Normalizer Optional HP 8750A Adapters Type N m to SMA f HP 1250 1250 Type SMA m to SMA m HP 1250 1159 Type SMA f Coax...
Page 15: ...Cokeva 11940C Operation Note 10 Figure 7 Testing an Enclosure Seam Figure 8 Testing a Coaxial Cable ...
Page 16: ...he normalizer s gain and position controls for the proper display on the network analyzer Refer to the HP 8750A Operation and Service Manual for the adjustment procedure 3 Set the HP 8754A controls as follows CH 1 REF POSITION ON POLAR CENTER OFF START ON TUNING 30 MHz SWEEP WIDTH 50 MHz SWEEP AUTO FAST OUTPUT 10 dBm EXT FREQUENCY DOUBLER OFF Channel 1 A R ON 10 dB DIV ON REFERENCE 00 dB POLAR A R...
Page 17: ...ive to the short 7 If an HP 8750A Storage Normalizer is used press the following keys on the HP 8750A CH 1 INPUT STORE INPUT and INPUT MEM The displayed reference line will shift to the middle of the screen Errors in the reflection test set will now be normalized 8 Remove the SMA Coaxial Short and replace it with the Cokeva 11940C probe The displayed trace should be 16 dB or more below the referen...
Page 18: ... with respect to the body of the Rotary Joint The other connector is fixed to the body Cover two or three end threads of the fixed end connector with a small amount of Loctite 222 3 Screw the rotating end of the Rotary Joint clockwise onto the probe s SMA Connector see Figure 11 4 Using a 9 32 torque wrench tighten the Rotary Joint to 24 inch pounds 5 When attaching a cable to the Rotary Joint hol...
Page 19: ...Printed in USA January 2013 For Cokeva Internal Reference Only Cokeva Part Number CK 11940 90007 ...
