Setting Up the Signal Generator

You can set up the signal generator while in the Spectrum Analyzer mode from the Setup menu. For more detailed information on the signal generator setup and operation, refer to "Using the Signal Generator"
CAUTION: The maximum power for the RF In (Port 1) and RF Out/SWR (Port 2) ports is +20 dBm (100 mW). When using the 8481A/8482A Power Sensors, the maximum input power applied to the Power Sensor is +24 dBm (300 mW). When using the 8481D Power Sensor, the maximum input power is +20 dBm (100 mW). When directly coupled to a base station (BTS) or Access Network (AN), the test set can be damaged by excessive power applied to any of these three ports.

To prevent damage in most situations when you directly couple the test set to a base station, use the high power attenuator between the test set and the BTS.
NOTE: The lowest level the signal generator can go to is -90 dBm. In order to achieve a lower level, you must use an external attenuator. You can compensate for the attenuator in the RF Out Loss.

Step
 		Notes
1
 		[Setup]
2
 		[Sig Gen]
3
 		[Freq/Chan]
4
 		[Frequency] or [Channel]
5
 		Enter the channel or frequency using the numeric keypad.

6
  • For channel select [Rev] or [Fwd]
  • For frequency select [GHz], [MHz], [kHz], or [Hz],

7
 		[Mod Format]
8
 		Select the channel standard from the list using the up and down arrow buttons.
9
 		[Select]
10
 		Set the RF output amplitude
  1. [Amplitude]
  2. Enter the amplitude value using the numeric keypad.
  3. [dBm].
You may also enter a new value for amplitude by turning the rotary knob until the desired value is displayed or using the up and down arrow keys.
11
 		If you have previously stored RF Out Loss from an insertion loss measurement, go to the next step.

Or

Press [RF OUT Loss] to select On and enter the RF Out Loss value.
 		For information on the effects of the RF Out Loss function on the amplitude, refer to "Using the RF OUT Loss field' below.
Each time you press this softkey, the selected option changes.
12
 		Connect to the base station.

13
 		On [Enable Sig Gen] select On.
Each time you press this softkey, the selected option changes.
14
 		On [RF] select On.
Each time you press this softkey, the selected option changes.

Using the RF OUT Loss field

The RF OUT Loss field is used when it is necessary to test the receiver sensitivity of a typical base station. The test set's source will typically go down to -95 dBm. In order to reach -113 dBm for sensitivity testing, you must use an external attenuator. The measured value of the attenuator and connecting cables are entered into this field. This value is then used when this field is set to On. When this field is set to On, the test set will set the RF generator level to the correct level offset by the external attenuator/cabling. When you set the RF Generator to -113 dBm (with the RF OUT Loss field turned On and the external attenuator/cabling loss value entered) the output at the end of the RF test cabling is -113 dBm.
 Example: If you want to set the signal generator to -113 dBm, the attenuator and RF cabling measures 42.51 dB (measured with the 2 port insertion loss measurement screen prior to this test), the RF OUT Loss field is turned On (with the 42.51 dB loss value entered). The actual RF output of the signal generator is -70.49 dBm, the attenuator and RF cabling attenuated the signal to the desired level; so the RF signal at the end of the test cable/attenuator is -113 dBm. This also points out the importance of accurately measuring the loss of the attenuator and connecting cables.