A system for ablating target tissue within a patient, the system comprising: a catheter (20, 20', 20") having a proximal region and a distal region; a main antenna (43, 43') comprising a monopole, the main antenna disposed at the distal region of the catheter and configured to emit energy to ablate the target tissue and to measure a radiometer temperature generated as a result of the energy emission; a reference termination (48, 48', 48") disposed at the distal region of the catheter, the reference termination configured to measure a reference temperature at the distal region; and a processor operatively coupled to the main antenna and the reference termination, the processor configured to: cause the main catheter to measure radiometer temperature and the reference termination to measure reference temperature in an alternating manner via a switch (42, 42', 42") electrically coupled to the main antenna and the reference termination; and calculate a target tissue temperature based on the measured radiometer temperature and the measured reference temperature, wherein the monopole comprises a proximal radiating element (44a, 44a', 44a") and a distal radiating element (44b, 44b', 44b"), a proximal end of the proximal radiating element comprising a short configured to defeat a choke action of the proximal radiating element. a catheter (20, 20', 20") having a proximal region and a distal region; a main antenna (43, 43') comprising a monopole, the main antenna disposed at the distal region of the catheter and configured to emit energy to ablate the target tissue and to measure a radiometer temperature generated as a result of the energy emission; a reference termination (48, 48', 48") disposed at the distal region of the catheter, the reference termination configured to measure a reference temperature at the distal region; and a processor operatively coupled to the main antenna and the reference termination, the processor configured to: cause the main catheter to measure radiometer temperature and the reference termination to measure reference temperature in an alternating manner via a switch (42, 42', 42") electrically coupled to the main antenna and the reference termination; and calculate a target tissue temperature based on the measured radiometer temperature and the measured reference temperature, wherein the monopole comprises a proximal radiating element (44a, 44a', 44a") and a distal radiating element (44b, 44b', 44b"), a proximal end of the proximal radiating element comprising a short configured to defeat a choke action of the proximal radiating element. cause the main catheter to measure radiometer temperature and the reference termination to measure reference temperature in an alternating manner via a switch (42, 42', 42") electrically coupled to the main antenna and the reference termination; and calculate a target tissue temperature based on the measured radiometer temperature and the measured reference temperature, wherein the monopole comprises a proximal radiating element (44a, 44a', 44a") and a distal radiating element (44b, 44b', 44b"), a proximal end of the proximal radiating element comprising a short configured to defeat a choke action of the proximal radiating element.