Option H11 – IF access (continued)
The 85309 LO/IF distribution unit interfaces with the PNA, PNA-X in two different
ways, providing either a 20 MHz IF signal for PNA and PNA-X or an 8.33 MHz for PNA, a
7.606534 MHz for PNA-X and PNA-X measurement receiver IF signal. It is important to
understand the differences in each configuration before setting up your measurement.
85309B with PNA configured with Options 014 and 080 or PNA-X
Option 080
With this setup, the PNA or PNA-X operates in frequency offset mode and the 85309B
must create a 20 MHz IF signal. The receiver is set to 20 MHz and the RF and LO sources
must be offset by 20 MHz. The test and reference signals are inserted through the front
panel links, bypassing the internal coupler. This configuration improves the noise floor
by approximately 10 to 38 dB, depending on frequency. However, operation in frequency
offset modes results in a decrease of frequency stepping speed.
85309B with PNA configured with Options 014, 080, 081, UNL, and
H11
With this setup, the 85309B must create an 8.33 MHz IF signal. The RF and LO sources
must be offset by 8.33 MHz. Normal operation of the PNA automatically offsets the
internal LO 8.33 MHz from the internal RF. Above 20 GHz the PNA switches to 3rd
harmonic mode so that RF – 3 * LO = 8.33MHz. This configuration allows the 85309B
IF output to be connected to the PNA H11 rear panel IF inputs, bypassing the first PNA
mixer. This configuration provides the best sensitivity.
85309B with PNA-X configure with Option 020 and 080
With this setup, the 85309B must create a 7.605634 MHz IF signal. The RF and LO
sources must be offset by 7.605634 MHz. Normal operation of the PNA-X automatically
offsets the internal LO 7.605634 MHz from the internal RF. This configuration allows
the 85309B IF output to be connected to the PNA-X option 020 rear panel IF inputs,
bypassing the first PNA-X mixer. This configuration provides the best sensitivity.
85309B with PNA-X Measurement Receiver
With this setup, the 85309B must create a 7.605634 MHz IF signal. The RF and LO
sources must be offset by 7.605634 MHz. PNA-X measurement receiver option 108 au-
tomatically offsets 7.605634 MHz from the external RF when operates in couple mode.
This configuration allows the 85309B IF output to be connected to the rear panel IF
inputs. This configuration provides the best sensitivity and lower cost.
40 | Keysight | Antenna Test – Selection Guide