248 Keysight E8357D/67D & E8663D PSG User’s Guide
GPS Modulation (Option 409)
Real Time GPS
The real-time GPS signal is now available at the signal generator RF OUTPUT
connector.
shows what the signal generator display
should like after all steps have been completed. Notice the
GPS
,
I/Q
, and
RF
ON
annunciators are on and the parameter settings for the signal are displayed
in the status area of the signal generator display.
This procedure sets up a GPS signal that incorporates a subframe structure
using 10 words, each with 24 raw data bits and 6 parity bits computed from the
data source. The signal generator created this subframe structure when you
selected Enc as the data mode and a PN15 sequence as the data type. The
PN15 sequence was encoded with the C/A code at 50 bps. Using factory
preset settings, the C/A chip rate is 1.023 Mcps with a clock reference of 10.23
Mcps. A 2.5 kHz doppler shift simulates the relative motion of the satellite with
respect to the receiver. For more information on the GPS option, refer to
.
Figure 8-6
Real Time GPS Setup with Internal Clock
Configuring the External Reference Clock
1.
Access the real-time GPS personality (
Mode
>
More(1 of 2)
>
GPS
>
Real
Time GPS
).
2.
Press
More (1 of 2)
>
GPS Ref Clk Ext Int
to Ext.
3.
Press
GPS Ref (f0)
>
11.03
>
kcps.
4.
Connect the external reference clock source to the DATA CLOCK INPUT
connector.
The maximum clock rate for this input connector is 50 MHz with a voltage
range of
−
0.5 to 5.5 V.
5.
Set the external reference clock source to the chip rate value entered in
.
