A radio frequency circuit having error detection capability, comprising: a base plate, having a first surface; an element under test, disposed on the base plate, comprising an output port to output an RF signal (RS, RS1); a transmission line (TL, TL11~TL1N, TL21~TL25), disposed on the first surface of the base plate and electrically connected to the output port of the element under test; a sensing line (SL, SL11~SLIN, SL21~SL23), substantially parallel to the transmission line (TL, TL11~TL1N, TL21~TL25) within a sensing area of the base plate, separated from the transmission line (TL, TL11~TL1N, TL21~TL25) by a first length, and adapted for inducing the RF signal (RS, RS1) on the transmission line (TL, TL11~TL1N, TL21~TL25) to generate an induction signal (SS, SS1); a controller, disposed on the base plate, electrically connected to the sensing line (SL, SL11-SLIN, SL21~SL23), and adapted for determining a state of the element under test according to the induction signal (SS, SS1); characterized in that the radio frequency circuit further comprises a connector (14A, 14B), disposed on the base plate, coupled to the sensing line (SL, SL11~SL1N, SL21~SL23), and adapted for connecting to a sensor (16A, 16B); wherein in response to the connector (14A, 14B) being connected to the sensor (16A, 16B), the sensor (16A, 16B) is adapted for generating a determination signal according to the induction signal (SS, SS1), and the controller determines the state of the element under test according to the determination signal, wherein the connector (14A, 14B) comprises: a first conductive structure, electrically connected to the sensing line (SL, SL11~SL1N, SL21~SL23); and a second conductive structure, electrically connected to a first voltage source on the base plate to receive a first voltage; wherein in response to the connector (14A, 14B) being not connected to the sensor (16A, 16B), the first conductive structure and the second conductive structure are in a clamping state; in response to the connector (14A, 14B) being connected to the sensor (16A, 16B), the first conductive structure and the second conductive structure clamp the sensor (16A, 16B). a base plate, having a first surface; an element under test, disposed on the base plate, comprising an output port to output an RF signal (RS, RS1); a transmission line (TL, TL11~TL1N, TL21~TL25), disposed on the first surface of the base plate and electrically connected to the output port of the element under test; a sensing line (SL, SL11~SLIN, SL21~SL23), substantially parallel to the transmission line (TL, TL11~TL1N, TL21~TL25) within a sensing area of the base plate, separated from the transmission line (TL, TL11~TL1N, TL21~TL25) by a first length, and adapted for inducing the RF signal (RS, RS1) on the transmission line (TL, TL11~TL1N, TL21~TL25) to generate an induction signal (SS, SS1); a controller, disposed on the base plate, electrically connected to the sensing line (SL, SL11-SLIN, SL21~SL23), and adapted for determining a state of the element under test according to the induction signal (SS, SS1); characterized in that the radio frequency circuit further comprises a connector (14A, 14B), disposed on the base plate, coupled to the sensing line (SL, SL11~SL1N, SL21~SL23), and adapted for connecting to a sensor (16A, 16B); wherein in response to the connector (14A, 14B) being connected to the sensor (16A, 16B), the sensor (16A, 16B) is adapted for generating a determination signal according to the induction signal (SS, SS1), and the controller determines the state of the element under test according to the determination signal, wherein the connector (14A, 14B) comprises: a first conductive structure, electrically connected to the sensing line (SL, SL11~SL1N, SL21~SL23); and a second conductive structure, electrically connected to a first voltage source on the base plate to receive a first voltage; wherein in response to the connector (14A, 14B) being not connected to the sensor (16A, 16B), the first conductive structure and the second conductive structure are in a clamping state; in response to the connector (14A, 14B) being connected to the sensor (16A, 16B), the first conductive structure and the second conductive structure clamp the sensor (16A, 16B). a first conductive structure, electrically connected to the sensing line (SL, SL11~SL1N, SL21~SL23); and a second conductive structure, electrically connected to a first voltage source on the base plate to receive a first voltage; wherein in response to the connector (14A, 14B) being not connected to the sensor (16A, 16B), the first conductive structure and the second conductive structure are in a clamping state; in response to the connector (14A, 14B) being connected to the sensor (16A, 16B), the first conductive structure and the second conductive structure clamp the sensor (16A, 16B).