Instrument Description
Coaxial RF Power Standards Instruction and Service Manual
1-3
Description of Equipment
Functional Description
These Coaxial RF Power Standards are designed for the precise measurement of microwave power
in the 100 kHz to 26.5 GHz frequency range. These units are highly accurate, stable with time
and temperature, and are designed for use as a standard for the transfer of calibration factors to
other sensors. Each unit is supplied with calibration points traceable to National Institute of
Standards and Technology (NIST). These standards are configured in Reference and Working
Standard configurations. The Working RF Power Standard (or Feedthrough RF Power Standard) is
a thermistor mount power splitter combination employed as a feedthrough standard for the
calibration of terminating power sensors such as bolometer mounts and power meters. This
standard was designed for use in the TEGAM System II Power Sensor Calibration System (Figure
1.4). The Reference RF Power Standard (or Terminating RF Power Standard) is a terminating
thermistor mount used for the calibration of feedthrough standards (Figure 1.6) and applications
that require direct measurement of RF power (Figure 1.5).
Physical Description
Refer to Table 1.1 for the general specifications for the RF Power Standards. The Working RF
Power Standards feature a SENSOR, RF INput, BIAS VOLTAGE and TEMPerature connectors on
the front panel. The Reference RF Power Standards feature an RF INput connector on the front
and BIAS VOLTAGE and TEMPerature connectors in the rear. The Working RF Power Standards
can be mounted in any cabinet or rack designed according to EIA RS-310 and MIL-STD-189 using
the appropriate hardware.
Specifications
Table 1.1 lists the general specifications for all the RF Power Standards. Tables 1.2 through 1.4
list specifications unique to each model.
Table 1.1 General Specifications
Power Range
0.01 to 25 mW (-20 to +14 dBm)
RF Impedance
50 Ohms nominal
Power Linearity
<0.1% from 0.1 to 10 mW
Calibration Factor Drift
<0.5% per year
Individual calibrations traceable to NIST
supplied at the following frequencies:
100, 200, 300, 455, 500 kHz
1, 1.25, 3, 5 MHz
10 to 100 MHz in 10 MHz steps
0.1 to 2 GHz in 50 MHz steps
2 GHz to 4 GHz in 100 MHz steps
4 to 12.4 GHz in 200 MHz steps
12.75 to 18 GHz in 250 MHz steps
18 to 26 GHz in 1 GHz steps
26.5GHz
Thermistor DC Bias Power
30 +/-0.7 mW
Thermistor Resistance at Bias
200 Ohms
Thermistor Power Sensitivity
Approximately 13 Ohms/mW
Temperature
Operating
Storage
+12° to +40° C (+54° to +104° F)
-55° to +75° C (-67° to +167° F)
Warm up time
2 hours minimum
