8540C 电路图.pdf

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1、. Certified Product ISO 9001.Certified Process Registrar: BSI, Certification No. FM 34226 Registered 04 June 1996 Amended on 01 March 2000 Giga-tronics Incorporated 4650 Norris Canyon Road San Ramon, California 94583 925.328.4650 or 800.726.4442 925.328.4700 (Fax) 800.444.2878 (Customer Service) 925

2、.328.4702 (Fax) Manual Part Number: Revision: Print Date: Operation see Appendix B for Power Sensor Specifications. 1.1.8Tools and Test Equipment No special tools are required to operate the 8540C. Test equipment required for calibration or performance verification is described in Chapter 4. 1.1.9Co

3、oling No cooling is required if the instrument is operated within its specified operating temperature range (0 to 50 C). Introduction Manual 30280, Rev. J, September 20001-3 1.1.10Cleaning The front panel can be cleaned using a cloth dampened with a mild detergent; wipe off the detergent residue wit

4、h a damp cloth and dry with a dry cloth. Solvents and abrasive cleaners should not be used. 1.1.11Installation and Preparation for Use The instrument is shipped in an operational condition and no special installation procedures are required. 1.1.12Receiving Inspection Use care in removing the instru

5、ment from the carton and check immediately for physical damage, such as bent or broken connectors on the front and rear panels, dents or scratches on the panels, broken extractor handles, etc. Check the shipping carton for evidence of physical damage and immediately report any damage to the shipping

6、 carrier. Each Giga-tronics instrument must pass rigorous inspections and tests prior to shipment. Upon receipt, its performance should be verified to ensure that operation has not been impaired during shipment. The performance verification procedure is described in Chapter 5 of this manual. 1.1.13P

7、reparation for Reshipment Follow these instructions if it is necessary to return the product to the factory. To protect the instrument during reshipment, use the best packaging materials available. If possible use the original shipping container. If this is not possible, a strong carton or a wooden

8、box should be used Wrap the instrument in heavy paper or plastic before placing it in the shipping container. Completely fill the areas on all sides of the instrument with packaging material. Take extra precautions to protect the front and rear panels. Seal the package with strong tape or metal band

9、s. Mark the outside of the package “FRAGILE FRAGILE FRAGILE FRAGILE DELICATE INSTRUMENTDELICATE INSTRUMENTDELICATE INSTRUMENTDELICATE INSTRUMENT”. If corresponding with the factory or local Giga-tronics sales office regarding reshipment, please reference the full model number and serial number. If t

10、he instrument is being reshipped for repair, enclose all available pertinent data regarding the problem that has been found. NOTE: If you are returning an instrument to Giga-tronics for service, first contact Giga-tronics Customer Service at 800.444.2878 or Fax at 925.328.4702 so that a return autho

11、rization number can be assigned. You can also contact Customer Service via our e-mail address . Series 8540C Universal Power Meters 1-4Manual 30280, Rev. J, September 2000 1.2Safety Precautions This instrument has a 3-wire power cord with a 3-terminal polarized plug for connection to the power sourc

12、e and safety-ground. The ground (or safety ground) is connected to the chassis. If a 3-to-2 wire adapter is used, connect the ground lead from the adapter to earth ground. Failure to do this can cause the instru- ment to float above earth ground, posing a shock hazard. The 8540C is designed for inte

13、rnational use with source voltages of 100, 120, 220, or 240 Vac, 10% at 50 to 400 Hz. The 8540C uses an internationally approved connector that includes voltage selection, fuse, and filter for RFI protection (see Figure 1-1). The instrument can be damaged if connected to a source voltage with the li

14、ne voltage selector set incorrectly. Before connecting the instrument to power, make sure that the line voltage selector is set for the correct source voltage. 1.2.1Line Voltage and Fuse Selection The instrument is shipped in an operational condition and no special installation procedures are requir

15、ed except to check and/or set the operating voltage and fuse selection as described in the following. When the instrument is shipped from the factory, it is set for a power line voltage (120 Vac for domestic destinations). The power line fuse for this setting is 0.50 A Slo-Blo. If the source voltage

16、 is to be 220 to 240 Vac, the fuse must be changed to 0.35 A Slo-Blo (see Figure 1-1). Figure 1-1: Voltage Selector and Fuse Holder WARNING CAUTION 110 120 VOLTAGE SELECTION WHEEL COVER FUSE AND FUSE HOLDER AC POWER INPUT Introduction Manual 30280, Rev. J, September 20001-5 The voltage selector and

17、fuse holder are both contained in the covered housing directly above the AC power connector on the rear panel. To gain access to them, use a small screwdriver or similar tool to snap open the cover and proceed as follows: 1.To change the voltage setting: Use the same tool to remove the voltage selec

18、tor (a small barrel-shaped component marked with voltage settings). Rotate the selector so that the desired voltage faces outward and replace the selector back in its slot. Close the housing cover; the appropriate voltage should be visible through the window (see Figure 1-1). 2.To replace the fuse:

19、Pull out the small drawer on the right side of the housing (marked with an arrow) and remove the old fuse. Replace with a new fuse, insert the drawer and close the housing cover (see Figure 1-1). 1.2.2Power Sensor Precautions Power sensor safety precautions, selection, specifications, and calibratio

20、n are detailed in Appendix B to this manual. Series 8540C Universal Power Meters 1-6Manual 30280, Rev. J, September 2000 1.38540C System Specifications 1.3.1Power Meter Frequency Range:10 MHz to 40 GHz1 Power Range:-70 dBm to +47 dBm (100 pW to 50 Watt)1 Single Sensor Dynamic Range: CW Power Sensors

21、:90 dB1 Peak Power Sensors:40 dB Peak, 50 dB CW Modulation Sensors:87 dB CW; 80 dB MAP/PAP; 60 dB BAP Display Resolution:User-selective from 1 dB to 0.001 dB in Log mode and from 1 to 4 digits of display resolution in Linear mode. 1.3.2Accuracy CalibratorPower Sweep calibration signal to dynamically

22、 linearize the sensors Frequency:50 MHz nominal Settability:The 1 mW (0.0dBm) level in the Power Sweep Calibrator is factory set to 0.7% traceable to National Institute of Standards and Technology. Measure with 15 seconds of setting calibrator to 0.0 dBm. 0.0dBm Accuracy:1.2% worst case for one year

23、 over a temperature range of 5 to 35 C Connector:Type N, 50 VSWR:33 dB) System Linearity at 50 MHz for Standard Sensors:0.02 dB over any 20 dB range from -70 to +16 dBm 0.02 dB 0.05 dB/dB from +16 to +20 dBm 0.04 dB from -70 to +16 dBm Temperature Coefficient of Linearity:0.3%/ C temperature change

24、following Power Sweep Calibration. 24-hour warm-up required. Zeroing Accuracy (CW (Standard Sensors): Zero Set50 pW2 100 pW with 80400A and 80600A Series Modulation Power Sensors Zero Drift100 pW during 1 hour 2, 3 200 pW with 80400A and 80600A Series Sensors Noise50 pW measured over any 1 minute in

25、terval. Three standard deviations.2 100 pW with 80400A and 80600A Series Sensors Notes: 1.Depending on sensor used (see Power Sensor details in Appendix B). 2.Specifications applies at -50 dBm for 803XXA Standard sensors. When measuring power levels Po other than -50 dBm, divide noise and zero speci

26、fications by (10 -Po/10)/(10-5). For other 80300 Series CW Sensors, specification applies at 20 dB above the minimum specified reading level. For Peak Sensors, see Appendix B and the 80350A Series Peak Power Sensor Data Sheet. Specified performance applies with Maximum averaging and 24 hour warm-up

27、temperature vision 3015 Swift Mode, Continuous or Buffered, Bus/TTL triggered175N/A Swift Mode, Continuous or Buffered, Free-run triggered 200N/A Fast Buffered Mode, Buffered Data, Time Interval = 0 2600N/A Fast Modulated Mode, Continuous Single Readings N/A30 3 2 1 0 -1 -2 -3 80301A 80310A 80320A 8

28、0321A 80322A 80325A 80330A 80401A (CW) 80401A (MAP , PAP) 80401 (BAP) 80601 (CW) 80601 (MAP , PAP) 80601 (BAP) -70 -64 -60 -50 -40 -40 -30 -67 -60 -60 -55 -40 -33 -27 -21 -15 -9 -33 9 15 20 -60 -54 -50 -40 -30 -30 -20 -57 -50 -50 -45 -50 -44 -40 -30 -20 -20 -10 -47 -40 -40 -35 -40 -34 -30 -20 -10 -1

29、0 0 -37 -30 -30 -25 -30 -24 -20 -10 0 0 10 -27 -20 -20 -15 -20 -14 -10 0 0 10 20 -17 -10 0 -5 -10 -4 0 10 20 20 -7 0 10 5 0 6 10 20 20 30 3 10 20 15 10 16 20 30 40 40 13 20 20 26 30 40 44 50 Input (dBM) SENSORS Typical Error (dB) -40 -33 -27 -21 -15 -9 -33 9 15 20 Series 8540C Universal Power Meters

30、 1-8Manual 30280, Rev. J, September 2000 Individual data points are read immediately after measurement in the Normal mode. The Normal mode and the Swift mode both slow down at low power levels (200 readings per second in the free-run Swift mode, 800 readings per second in the Fast Modulated mode, an

31、d 2,000 readings per second in the Fast Buffered mode. Three Swift mode triggering controls are available: Fast free-run, bus triggered, and TTL triggered modes. Bus and TTL allow triggering control of individual measurement points. Data can be stored in an internal data buffer or read immediately.

32、Fast buffered power readings are internally buffered for readout at the completion of the fast buffered interval. Maximum measurement rate is about 2,600 readings per second. Data conversion and GPIB communication time are not included in this figure. The maximum buffer size is 5000 readings, or abo

33、ut 2.1 seconds at the maximum reading rate. Option 02 buffer increases this to 128,000 readings. CW Mode This mode is for measuring an unmodulated Continuous Wave (CW) signal. In this mode the RF signal level must be constant for accurate readings to be made. If the signal level changes, a settling

34、time for the internal digital filter is required in order for measurements to be made to the specified accuracy. The settling time (the time required for a measurement based on an averaging of samples to adapt to a changed condition and become accurate again) is affected by various factors. The maxi

35、mum settling time is equal to 20 ms multiplied by the averaging factor (for example, if the averaging factor is 128, the maximum settling time is 2.56 seconds). In most situations the actual settling time is well below the maximum. PEAK Mode (80350A Peak Power Sensor) The Peak mode is for instantane

36、ous peak measurements of the RF power level of a pulse modulated signal during pulse ON periods. The measurement is based on an instantaneous sample taken at a particular point in time. Sampling is triggered by a pulse rising edge either in the modulated signal itself or in a supplied trigger input

37、signal, followed by a programmable delay. The trigger/delay combination makes it possible for you to specify exactly what part of the pulse is sampled. In the peak mode, each displayed reading can consist of a single sample or of an average of multiple samples, each taken at the exact same time rela

38、tive to the pulses rising edge. If the averaging factor is set to 1, single samples are used. If it is other than 1, the averaging factor will determine the filter settling time over which the multiple samples will be taken and averaged. Because the peak mode measures the RF power instantaneously (a

39、t the top of the pulse, provided that the delay has been set correctly), no assumptions are made about the pulse shape or duty cycle. In fact, it is possible to profile the pulse by sweeping the delay time over a range of values to reveal the pulse shape from start to finish. Peak power measurements

40、 are made by sampling the RF input at a point which is defined by a trigger level, a delay, and a delay offset (see Figure 2-4). The initial triggering event occurs when the power input (or in the case of external triggering, a voltage input) reaches a threshold, which you have defined as the trigge

41、r level. The sample is then taken after a delay, which you have defined. To this delay can be added a positive or negative delay offset. NOTE: In the peak mode the 8540C does not know where the peak is. It samples the pulse where it is told to sample the pulse whether or not the point sampled is rea

42、lly the peak point. This mode is therefore less intelligent than the BAP mode and must be used carefully, but its flexibility makes it a powerful tool for studying modulated signals. Series 8540C Universal Power Meters 2-22Manual 30280, Rev. J, September 2000 The delay offset is not necessary for pe

43、ak measurement, but in some applications it is a convenience. For example, a small offset (even a negative offset) might compensate for the difference between the trigger point and some other point of interest (such as the half-power point) especially in applications where pulse width is being measu

44、red. Or if it is necessary to measure the levels of various pulses within a pulse train, the pulses can be sampled successively by changing the delay offset. A fixed delay insures that each pulse is sampled at the same point in its cycle. Figure 2-4: Delay and Delay Offsets Peak Power, Sampled After

45、 a 120 ns Delay SampleSample 120 ns Delay 120 ns Delay Trigger Point Trigger Point Time Time (Microseconds) Time Trigger Level Trigger Level Power Power Power 10 ns Delay Offset Half-Power Point Peak Power, Sampled After a 120 ns Delay and a 10 ns Delay Offset Peak Power, Sampled With a Fixed Delay

46、But Various Delay Offsets Trigger Sample (No Offset) Delay Offset Delay Offset Sample Sample 2.8 s Offset 024681012141618202224262830 32 (22 s Offset)(11 s Offset) Front Panel Operation Manual 30280, Rev. J, September 20002-23 2.6.10Mode Restrictions In certain modes the 8540C has highly specific re

47、strictions on its operation: In the fast measurement collection modes (swift and fast buffered), it is not possible to make measurements which compare the two channels. In other words, it is possible to make measurements using sensor A, or B, or both, but measurements such as A/B and A-B are not per

48、mitted. In GPIB remote operation, only one reading can be sent over the bus (it can be A, or B, or a comparative measurement such as A/B, but it is not possible for separate measurements of A and B to be sent over the bus). The exception is that in the swift and fast buffered measurement collection

49、modes, it is possible for both A and B to be sent over the bus. 2.6.11When to use CW, MAP and BAP For measuring signals with any kind of modulation, MAP mode should be used. In this mode, the 8540C makes use of its digital signal processing algorithms to ensure that the reading is the correct average power level regardless of modulation t