Modulation Operation
Giga-tronics 2500B Series Microwave Signal Generators
Page 52
Operation Manual, Part Number 34737, Rev C, June 30, 2011
5.6
Generate an Externally Modulated FM Signal
The procedure below describes how to generate an FM signal that uses an external FM modulation source connected to
the 2500B. An FM signal is created with the following characteristics:
Carrier frequency = 1.00 GHz
Carrier power = 1.00 dBm
Deviation = 1.00 kHz
Rate of FM modulation = 50 kHz
Modulating waveform = sine wave
NOTE:
The example procedure in this section uses specific parameters to illustrate how to setup the 2500B. You can use
this procedure for real-life situations by simply changing the parameters to fit your needs.
Equipment and Materials
External FM modulation source (see specifications in Table 52 on page 95)
Cables and connectors for connecting the FM modulation source to the 2500B
Cables and connectors for connecting device to be tested to the 2500B RF Output
Table 23: Generate an Externally Modulated FM Signal
Generate an Externally Modulated FM 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 FM modulation source to the FM/ΦM IN connector (see specifications in Table
5.
Press the
menu button.
6.
In the CW menu, select 1.00 GHz for the frequency of the FM signal:
1.
Press
Frequency.
2.
On the numeric keypad on the front panel of the 2500B, enter 1.
3.
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.
7.
In the CW menu, select 1.00 dBm for the power level of the FM signal:
1.
Press
Power.
2.
On the numeric keypad on the front panel of the 2500B, enter 1.
3.
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.
Soft Button
Soft Button
CW
RF ON
