PowerXpert™ Help : Using the MA24105A : Basic Power Measurement
Basic Power Measurement
This section provides steps and information to make basic power measurements with the MA24105A power sensor and PowerXpert. To perform a power measurement:
1. Connect the sensor to a computer or Anritsu Master™ series instrument as shown in Figure: Measurement Setup.
2. Open the Anritsu PowerXpert application.
3. Zero the sensor as described below in Zeroing the Sensor.
Do not apply power greater than the power sensor specifications or permanent damage may result. Connect a fixed attenuator to the output connector when power exceeds +20 dBm.
Before connecting the power sensor to a another device, read the Instrument Care and Preventive Maintenance.
4. Connect the load to the RF OUT port of the sensor. Connecting the load first protects the power sensor as well as the source/DUT from excessive mismatch.
5. Connect the RF source to the RF IN port of the power sensor.
6. Read the power measurement from the Anritsu PowerXpert application window (power readings are continuous with the default setting).
Measurement Setup
RF In: N type Connector (Torque connector at 12 lbf·in [1.35 N·m])
RF Out: N type Connector (Torque connector at 12 lbf·in [1.35 N·m])
PC with Anritsu PowerXpert Application
USB Cable to PC
USB to Spectrum Analyzer
USB to Spectrum Analyzer
Connecting the Sensor
RF signal connections are made to the Type N female RF connectors, which have a 50 Ω characteristic impedance. The input port is labeled RF IN and the output port is labeled RF OUT.
When connecting to the Type N female connector of the MA24105A to a Type N connector, observe the following proper practice for tightening the connection:
1. While holding the body of the N connector in one hand, turn the Type N Male connector nut to finger tighten the connection. Do not turn the body of the MA24105A as this will cause excessive wear to the connector.
2. Back off the connection by turning the connector nut counter clockwise ¼ turn.
3. Tighten the connection (clockwise) using a 12 in-lb torque wrench (Anritsu part number: 01-200).
The Sensor has a USB 2.0 interface with a USB Type Micro-B port. The MA24105A can be remotely programmed over this USB interface. In addition to programming, the MA24105A is powered by the USB. The interface is USB 2.0 compatible, but with an interface speed of 12 Mbps.
Zeroing the Sensor
Zero the sensor before making power measurements. If frequent low-level measurements are being made, check the sensor zeroing often and repeat as necessary. If the sensor goes into sleep mode, the sensor must be re-zeroed before taking measurements. Before zeroing the sensor, connect it to the DUT (device under test) test port and remove RF power from the connection to a level 20 dB below the noise floor of the power sensor. For the MA24105A power sensor, this level is less than –20 dBm. Leave the sensor connected to the DUT test port so that ground noise and thermal EMF (electro-magnetic fields) are zeroed out of the measurement. The sensor may also be connected to a grounded connector on the DUT or disconnected from any signal source.
To zero the sensor, click the Zero button on the application. If the sensor fails the zeroing operation, the message box states “Sensor zero failed” and “ZERO_ERROR” will be displayed on the application screen until the problem is corrected. If RF is detected, a reminder message will pop up asking to remove the RF source.
Applying a Calibration Factor Correction
The MA24105A power sensor has an internal EEPROM containing correction and calibration factors that were programmed into the sensor at the factory. The power sensor has an internal temperature sensor that reports its readings periodically to the microprocessor. The sensor makes all of the required calculations on the measurement once the measurement frequency has been entered by the user.
The signal channel/analog signal acquisition hardware is integrated along with the RF front end of the power sensor. All of the necessary frequency and temperature corrections take place within the sensor. Therefore, there is no need for a reference calibration with the MA24105A.