Giga-tronics 8650B Series, Operation Manual

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Power Sensors
Publication 31470-001, Rev C, November 2, 2017 B-1
Appendix B Power Sensors
B.1 Introduction
This appendix contains the selection, specifications and calibration data for the Giga-tronics power sensors used
with the Series 8650B Universal Power Meters. This appendix is divided into the following sections:
• Power Sensor Selection
• Modulated Sensor Specifications
• Peak Power Sensor Selection
• Directional Bridges
• Remote Calibration of Sensors
All Giga-tronics power sensors contain balanced zero-biased Schottky diodes for power sensing.
CAUTION
Input power in excess of +23 dBm (200 mW, which is the 100% average for
standard and pulse sensors) can degrade or destroy these diodes. Diodes
degraded or destroyed in this manner will not be replaced under warranty.
Destructive signal levels are higher for high power, true rms, and low VSWR
sensors. When connecting power sensors to other devices, do not turn the body
of the sensor in order to tighten the RF connection. This can damage the
connector mating surfaces.
B.2 Power Sensor Selection
Standard sensors include the 80300A and 81300A series for CW signals, the 80350A series for Peak or CW
power, the 80400A, 80600A and 80700A series for modulated and CW signals, the 80500 series CW Return Loss
Bridges, and the 80330A series True RMS sensors.
Giga-tronics True RMS sensors are recommended for applications such as measuring quadrature modulated
signals, multi-tone receiver intermodulation distortion power, noise power, or the compression power of an
amplifier. These sensors include a pad to attenuate the signal to the RMS region of the diode’s response. This
corresponds to the -70 dBm to -20 dBm linear operating region of Standard CW Sensors. The pad improves the
input VSWR to <1.15 at 18 GHz.
High Power (1, 5, 25 and 50 Watt) and Low VSWR sensors are also available for use with the 8650B Power
Meters. Table B-1 lists the Giga-tronics power sensors used with the 8650B. Refer to applicable notes on page B-
7. See Figure B-1 or Figure B-2 for modulation-induced measurement uncertainty.