Keysight PD1000A Operating Manual page 14

Figure 2 shows the PD1000A Bias T Networks connected in a typical
measurement setup. Other applications are possible; the general method of
setup and operation is the same.
Figure 2 Typical (simplified) Measurement Setup
14
When an RF cable more than 50 cm (19.6 in.) in length is used, a
50 Ω, 1 dB attenuator should be inserted at the RF Input
Connector.
When a bias voltage is applied to the network, both the RF input
and the RF output terminals must be terminated at 50 Ω to
prevent oscillations.
PD1000A Specifications
Keysight PD1000A Bias T Operating Guide