A calibration and control unit configured to be integrally connected to at least one measuring unit, and to be interconnected between an analyzer unit and said at least one measuring unit by connectors capable for RF signal transmission, and to be connected to the analyzer unit via a data transmitting connector (C2, C4), the calibration and control unit comprising: at least three calibration load terminals (J2, J4, J5) of known RF reflection coefficients, a memory utility storing recorded data indicative of the known RF reflection coefficients of said at least three calibration load terminals and recorded data indicative of RF transfer coefficients of the calibration and control unit, a switch comprising first and second connection ports (J1, J3) for connecting to the measuring unit and to the analyzer unit respectively, and at least three connection ports for connecting to said at least three calibration load terminals, the switch thereby having at least four switching states enabling selective connection of each one of said at least three calibration load terminals and each of said at least one measuring unit to the analyzer unit, and a controller utility characterised by: the controller utility being, configured for controlling operation of said memory utility and said switch to thereby: carry out a first off-line stage of a calibration procedure, carried out before integrating said calibration and control unit with said measuring unit, said off-line stage comprising measuring and recording in the memory utility said recorded data indicative of said known RF reflection coefficients of said at least three calibration load terminals and indicative of said RF transfer coefficients of the calibration and control unit, and transfer said recorded data from said memory utility to said analyzer unit, during a second on-line stage of the calibration procedure carried out when said calibration and control unit is integrated with said measuring unit and is connected to said analyzer unit, to be used for calibrating each of said at least one measuring unit, thereby enabling calculation of an RF response of each of said at least one measuring unit while said at least one measuring unit remains integral with the calibration and control unit and said calibration and control unit remains connected to the analyzer unit. at least three calibration load terminals (J2, J4, J5) of known RF reflection coefficients, a memory utility storing recorded data indicative of the known RF reflection coefficients of said at least three calibration load terminals and recorded data indicative of RF transfer coefficients of the calibration and control unit, a switch comprising first and second connection ports (J1, J3) for connecting to the measuring unit and to the analyzer unit respectively, and at least three connection ports for connecting to said at least three calibration load terminals, the switch thereby having at least four switching states enabling selective connection of each one of said at least three calibration load terminals and each of said at least one measuring unit to the analyzer unit, and a controller utility characterised by: the controller utility being, configured for controlling operation of said memory utility and said switch to thereby: carry out a first off-line stage of a calibration procedure, carried out before integrating said calibration and control unit with said measuring unit, said off-line stage comprising measuring and recording in the memory utility said recorded data indicative of said known RF reflection coefficients of said at least three calibration load terminals and indicative of said RF transfer coefficients of the calibration and control unit, and transfer said recorded data from said memory utility to said analyzer unit, during a second on-line stage of the calibration procedure carried out when said calibration and control unit is integrated with said measuring unit and is connected to said analyzer unit, to be used for calibrating each of said at least one measuring unit, thereby enabling calculation of an RF response of each of said at least one measuring unit while said at least one measuring unit remains integral with the calibration and control unit and said calibration and control unit remains connected to the analyzer unit. carry out a first off-line stage of a calibration procedure, carried out before integrating said calibration and control unit with said measuring unit, said off-line stage comprising measuring and recording in the memory utility said recorded data indicative of said known RF reflection coefficients of said at least three calibration load terminals and indicative of said RF transfer coefficients of the calibration and control unit, and transfer said recorded data from said memory utility to said analyzer unit, during a second on-line stage of the calibration procedure carried out when said calibration and control unit is integrated with said measuring unit and is connected to said analyzer unit, to be used for calibrating each of said at least one measuring unit, thereby enabling calculation of an RF response of each of said at least one measuring unit while said at least one measuring unit remains integral with the calibration and control unit and said calibration and control unit remains connected to the analyzer unit.