In the “High Forward Dynamic Range Configuration” (option
the Port 2 coupler is reversed to
optimize dynamic range in the forward measurement direction. Because the b2 sampler is connected
to the coupler through path instead of the coupled arm, there is less isolation between the b2 sampler
and Port 2, and the b2 power level will be higher than bl. This configuration is better for wide dynamic
range or reciprocal devices or components like filters, cables, or antennas, where
is generally not
measured. However, as a result of the lower isolation between the test port and the sampler, “sampler
bounce,” appearing as an occasional spurious response related to the
frequency, can be
noticeable in this “asymmetrical” test set.
The HP 8512A reflection/transmission test set uses one coupler for signal separation. The standard
HP 8512A has:
l
three RF to IF converters, for making reflection (S,,) and transmission (S,,) measurements,
l
no step attenuators to internally change the incident power level,
l
no bias tees to apply external DC bias to the test port center conductors.
Tables 1 and list additional characteristics of the HP85148 and
respectively. Figure l-2
shows the HP 8514B in a typical measurement set-up.
INTERCONNECT
T E S T S E T
TEST SET H P
ANALYZER
O R
SYNTHESIZE0
Figure 1-2. Typical
Measurement Set-up
HP
Test Sets General Information
1-3