4-12.
PULSE MODULATION RISE AND FALL TIME (Cont’d)
2. Set up the HP 8012B Pulse Generator as follows:
OFFSET
OFF
POLARITY
OUTPUT
NORMAL
INT LOAD
IN
PULSE PERIOD slide switch
1~t
in
TRANSITION TIME
slide switch
minimum (Sn)
AMPLITUDE slide switch
top position (S.0)
PULSE DOUBLE/NORMAL
NORMAL
PULSE
DELAY slide switch
minimum
Pulse
Delay
VERNIER
fully CCW
LEADING EDGE control
fully CCW
PULSE WIDTH
slide switch
lOn—ip
TRAILING EDGE control
fully CCW
3. Set both oscilloscope channels A and B for SO ohm input. Set the oscilloscope to view the pulse
generator output waveform. Adjust the HP 8012B pulse width VERNIER for a 100 nanosecond
pulse. Adjust the pulse period VERNIER for a 10 microsecond period.
Adjust the amplitude VERNIER for about a 3V pulse amplitude (TTL level). Set the oscilloscope to
trigger on this pulse (trigger on channel B).
4. Press [INSTRPRESET] on both the DUT and the LO. On the DUT, press [CW] [1] [GHz] and the
[PULSE]modulation key. On the LO, press [CW]
[.] [9] [5]
[GHz].The IF frequency is then 50
MHz. Set the LO for +10 dBin or maximum leveled output. The DUT’s RF power should be 0 dBm.
NOTE
For best accuracy in this test, the Local Oscillator drive to the mixer
should be
= +4
dBm.
5. Set the oscilloscope horizontal sweep to SO nanoseconds/division and select channel A input
only. Adjust the channel A (pulsed IF input signal) vertical gain and position so that the pulse OFF
is at the 0% graticule line and the pulse ON is at
1000/a
graticule line. Select the horizontal MAG
X1O. The oscilloscope is now calibrated for S nanoseconds/division. Adjust the horizontal position
control to position the modulation envelope so that the 10% point of the envelope rise time is at the
center vertical graticule line similar to Figure 4-14.
4-60
Performance Tests
HP 8340B/41B