HP 85027A/B/C Performance Tests
Equipment
HP 85027A
HP 85027B
HP 85027C
Sweep oscillator
HP 835013
HP 8350B
HP 8350B
RF plug-in
HP 83592A
HP 83595A
HP 83592A
Scalar network analyzer
HP 8757A
HP 8757A
HP 8757A
Cal. open/short
85021-60021
85037-60001
85032-60001
50 ohm load
909A opt 012
909D
909A opt 012
Adapter*
not req’d
85027-60002
1250-1475
*A second directional bridge is required as a test instrunient in addition to the directional
bridge under test. The adapters recommended are suitable for use with two similar
bridges.
Procedure
1.
Set up the equipment as shown in Figure 4-4, with the calibrated open connected
to the test directional bridge, not the directional bridge under test.
2.
PRESET the analyzer. It should indicate that Input A is on Channel 1. Turn off
Channel 2. The Preset should also preset the sweep oscillator to a sweep time of
200 ms with 27.8 kHz modulation on.
3.
Set the sweep oscillator start and stop frequencies to correspond to the first band
of frequencies in the Performance Test Record (0.01 to 8.4 GHz).
4.
Perform an open/short calibration and store it in memory.
5.
Connect the directional bridge under test to the first directional bridge, test port to
test port with an adapter if necessary. Connect the 50 ohm load to the input port
of the directional bridge under test.
6.
On the HP 8757A turn on the cursor and press the [MAX] softkey to find the
point of minimum return loss (highest point) on the trace. Enter this value on the
Performance Test Record.
7.
Repeat steps 3 through 7 for each frequency band of interest.
8.
If the test results (including uncertainties) are not within specifications as indicated
on the Test Port Match Performance Test Record, refer to the Troubleshooting
section of this manual.
Table 4-2. Test Port Match Performance Test Record
HP 85027A
Frequency
Band (GHz)
Spec.
Test
Result
HP 85027B
0.0 1-8.4
8.4-12.4
12.4-18.0
18.0-20.0
20.0-26.5
Spec.
Test
Result
HP 85027C
>=23
>=
19
>=
17
dB
_______
dB
_______
dB
_______
Spec.
Test
Result
Uncertainity*
>=15
>=
15
>=
15
1dB
dB
_______
dB
_______
dB
_______
dB
_______
dB
>=
19
>=
17
>=1 1
1dB
dB
_______
dB
_______
dB
_______
2dB
4-8
