Calibration system and calibration method for a vector network analyzer with a remote vector analyzer frontend

A calibration method for a measurement system,

• the measurement system comprising a vector network analyzer (VNA), at least one remote frontend, and a cable connection connecting the remote frontend to the VNA,
• wherein the remote frontend includes at least one dedicated calibration circuit connected between at least one directive element and the at least one measurement port, and the at least one dedicated calibration circuit provides calibration standards for calibrating the measurement system,
• the calibration method comprising:
• connecting, to at least one measurement port of the remote frontend, a device under test (DUT);
• generating, by at least one signal source of the VNA, a radio frequency (RF) signal and providing the RF signal via the cable connection and via the directive element of the at least one remote frontend to the at least one measurement port;
• transmitting the RF signal to the DUT via the at least one measurement port;
• the at least one directive element coupling out a transmitted portion of the RF signal and a reflected portion of the RF signal received at the at least one measurement port for measuring the transmitted portion and the received portion of the RF signal;
• and
• controlling, by a control circuit of the measurement system, the dedicated calibration circuit in a calibration mode, in which the dedicated calibration circuit provides the calibration standards for calibrating the measurements system,
• controlling, by the control circuit, the at least one dedicated calibration circuit in at least a first calibration mode, in which the control circuit consecutively selects a respective calibration standard from the calibration standards provided by the at least one dedicated calibration circuit,
• the control circuit switches the at least one dedicated calibration circuit into the first calibration mode to control the at least one dedicated calibration circuit in the first calibration mode after at least one of a predetermined time interval has elapsed and a predetermined number of measurement cycles is reached,
• the control circuit generates and outputs a message via an output interface for prompting the control circuit to switch the at least one dedicated calibration circuit into a second calibration mode to control the at least one dedicated calibration circuit in the second calibration mode,
• wherein either:
• (1) in the second calibration mode, the control circuit controls the dedicated calibration circuit to establish a direct connection between the at least one directive element and the at least one measurement port, and in the second calibration mode, the control circuit controls measuring external calibration standards connected to the at least one measurement port, or
• (2) the control circuit switches the at least one dedicated calibration circuit into the first calibration mode more often than the control circuit switches the at least one dedicated calibration circuit into the second calibration mode.

A measurement system comprising a vector analyzer (VNA), at least one remote frontend arranged within outside a climate cell, and a cable connection connecting the remote frontend to the VNA,

• the VNA comprises at least one signal source generating a radio frequency (RF) signal and providing the RF signal via the cable connection to the remote frontend;
• the remote frontend includes at least one measurement port for connecting a device under test (DUT) and transmitting the RF signal to the DUT, the DUT arranged in the climate cell to simulate exposure of the DUT to various environmental conditions, and at least one directive element,
• the at least one directive element couples out a transmitted portion of the RF signal and a reflected portion of the RF signal received at the at least one measurement port for measuring the transmitted portion and the reflected portion of the RF signal;
• and
• the remote frontend further includes at least one dedicated calibration circuit connected between the at least one directive element and the at least one measurement port, and
• the at least one dedicated calibration circuit provides calibration standards for calibrating the measurement system.