Using the Power Sensor
Making Measurements
MA24104A UG
PN: 10585-00016, Rev. A
3-13
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 MA24104A 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 MA24104A 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).
Zeroing the Sensor
Zero the sensor before making power measurements. If frequent low-level measurements are being made, it is
advised to 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 MA24104A power sensor, this level is less than –20 dBm. It is preferable to 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, press 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.
Calibrating the Sensor
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 MA24104A.
Applying a Calibration Factor Correction
The MA24104A 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.
Optimizing the Readings
This section presents information on how to get the fastest readings from the MA24104A power sensor when
using the Anritsu Power Meter application or operating under remote control (refer to Chapter 4 for specific
remote programming command descriptions). Measurement speed depends greatly on the type of
measurement, the power level, and stability of the signal. Stability of a measurement is influenced by noise
and signal modulation. If high resolution is required, averaging must be increased.
Warning: Do not connect the sensor backwards (RF IN and RF OUT reversed) or apply power outside of the
MA24104A specifications or permanent damage may result.
Note: The Sensor has a USB 2.0 interface with a USB Type Mini-B port. The MA24104A can be remotely
programmed over this USB interface. In addition to programming, the MA24104A is powered by the USB.
The interface is USB 2.0 compatible, but with an interface speed of 12 Mbps.