User’s Guide
HP V8486A Power Sensor
Serial Number Prefix:
US3901
HP Part No. 08486-90131
Printed in USA
January 1999
© Copyright 1999 Hewlett-Packard Company
HP V8486A Power Sensor
ii User’s Guide
Contents
1. HP V8486A Power Sensor
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Calibration Factor (CF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Initial Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Storage and Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Operating Environment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Operating Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Power Meter Calibrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Power Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Operating Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Modulation Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Linearity Correction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Performance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Replaceable Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Repair and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
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Contents
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1 HP V8486A Power Sensor
1
HP V8486A Power Sensor
User’s Guide
Figure 1-1 HP V8486A Power Sensor with Accessories and Hardware
2 Chapter 1
HP V8486A Power Sensor
User’s Guide
General Information
This Operating Manual contains information about initial inspection and
operation of the HP V8486A Power Sensor.
Warranty
The Power Sensor is warranted and certified as indicated on the last
page of this manual. Do not open the Power Sensor. Any attempt to
disassemble the Power Sensor will void warranty.
Description
The HP V8486A is a diode-based power sensor. It measures power levels
in a range from −30 dBm to +20 dBm. (Specifications for the Power
Sensor are in Table 1-1.) The HP V8486A measures at frequencies from
50 GHz to 75 GHz.
The power is determined from the ac voltage developed across the
waveguide termination from the microwave source. The diodes convert
this ac voltage to dc. The dc voltage produced is proportional to the
square of the ac voltage. The dc voltage thus generated is a very low-level
voltage and requires amplification before it can be transferred via the
sensor cable to the power meter.
The amplification is provided by an input amplifier assembly which
consists of a chopper (sampling gate) and an input amplifier. The dc
voltage is routed to the chopper circuit which converts the low-level dc
voltage to an ac voltage. The chopper is driven by a square wave
generated by the power meter. The result is an ac output signal
proportional to the dc input. The ac signal is then amplified by the input
amplifier . The relatively high-level ac signal output can now be routed by
standard cables.
Chapter 1 3
HP V8486A Power Sensor
User’s Guide
NOTE The HP V8486A Power Sensor is compatible with the following power
meters:
HP 435B HP E1416A
HP 436A HP E4418A/B
HP 437B HP E4419A/B
HP 438A HP 70100A
To obtain optimum accuracy for power measurements above +10 dBm,
when used with the HP E4418A and HP E4419A power meters, a
firmware upgrade will be required. Refer to your HP E4418A and
HP E4419A power meter’s user’s guide for instructions on how to obtain
the revision of the firmware currently installed in the unit. The firmware
revision required is A1.03.00 (or above) for the HP E4418A and A2.03.00
(or above) for the HP E4419A. Contact your local HP Sales and Service
Office for more information.
In application, the Power Sensor is connected between a microwave
source and a compatible power meter. The Power Sensor provides a
matched load for the microwave source for very low SWR. The power
meter indicates the power dissipated in the load in µW, mW or in dBm.
CAUTION Do not disassemble the Power Sensor. The Power Sensor is extremely
static-sensitive and can be easily damaged.
Accessories
Included is a hex ball driver plus the waveguide mounting screws. Refer
to Figure 1-1 for a visual check of what should be included with your
power sensor.
4 Chapter 1
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