Rf frontend and vna measurement system

A radio frequency (RF) frontend for a vector network analyzer (VNA) measurement system, the RF frontend comprising:

• at least one port being connectable to a device under test;
• at least one measurement path that is connected to the at least one port;
• and
• a first frontend portion and a second frontend portion,
• wherein the first frontend portion comprises a first directional unit being connected to the at least one measurement path and being configured to couple an RF signal traveling towards the at least one port out of the at least one measurement path, wherein the first frontend portion further comprises a second directional unit being connected to the at least one measurement path and being configured to couple an RF signal traveling away from the at least one port out of the at least one measurement path,
• wherein the second frontend portion comprises a frequency combining unit and a switching stage,
• wherein the switching stage comprises an input port, a common port, an output port, a first signal path, and a second signal path,
• wherein the switching stage has a first switching state, wherein the switching stage is configured to forward a stimulus RF signal received by the input port to the common port via the first signal path in the first switching state,
• wherein the switching stage has a second switching state, wherein the switching stage is configured to forward an RF signal received by the common port to the output port via the second signal path in the second switching state,
• wherein the frequency combining unit is connected to the at least one measurement path, wherein the frequency combining unit comprises a common port that is connected to the common port of the switching stage, wherein the frequency combining unit is configured to couple the stimulus RF signal into the at least one measurement path, and wherein the frequency combining unit is configured to couple an RF signal traveling away from the at least one port out of the at least one measurement path, such that the RF signal is forwarded to the common port of the frequency combining unit, and
• wherein the second frontend portion comprises a first amplifier that is arranged within the second signal path, wherein the first amplifier is configured to amplify the RF signal received from the measurement path via the frequency combining unit, wherein the second frontend portion is configured to obtain an output signal based on the RF signal received from the measurement path via the frequency combining unit.