Modulation Operation
Giga-tronics 2500B Series Microwave Signal Generators
Page 54
Operation Manual, Part Number 34737, Rev C, June 30, 2011
5.7
Generate an Externally Phase Modulated Signal
The procedure in this section describes how to generate a phase-modulated (ΦM) signal from the 2500B using an
external phase modulation source connected to the 2500B. The ΦM signal is set up to have the following characteristics:
Carrier frequency = 4.00 GHz
Carrier power = 1.00 dBm
Deviation = 1 rad
Rate of phase modulation = 1 kHz
Modulating waveform = sine wave
Equipment and Materials
External phase modulation source (see specifications in Table 52 on page 95)
Cables and connectors for connecting the ΦM modulation source to the 2500B
Cables and connectors for connecting the device to be tested to the 2500B RF Output
Table 24: Generate an Externally Phase Modulated Signal
Generate an Externally Phase Modulated Signal
Step
Action
1.
Verify that the RF output is NOT energized by checking the RF on/off indicator on the front of the
2500B (see Figure 3 on page 11). If the indicator is lit, press the
button to de-energize
the RF output.
2.
Connect the RF output on the 2500B as needed.
3.
On the rear of the 2500B, locate the FM/ΦM IN connector (see Figure 6 on page 19).
4.
Connect the external ΦM modulation source to the FM/ΦM IN connector.
5.
Press the
menu button.
6.
In the CW menu, select 4.00 GHz for the frequency of the ΦM signal:
4.
Press
Frequency.
5.
On the numeric keypad on the front panel of the 2500B, enter 4.
6.
Press the GHz Units button (next to the numeric keypad) to enter the new frequency.
NOTE:
You can also use the
keys and
to change the frequency.
In the CW menu, select 1 dBm for the power level of the ΦM signal:
4.
Press
Power.
5.
On the numeric keypad on the front panel of the 2500B, enter 1.
6.
Press the GHz (nSec/dBm) Units button (next to the numeric keypad) to enter the new power
level.
NOTE:
You can also use the
keys and
to change the power level.
14.
Press the
Menu button. The FM Main Menu opens in the display.
FM
Soft Button
Soft Button
CW
RF ON