A microwave antenna assembly (112; 212), comprising: a feed line (120; 220) including an inner conductor (150; 250), an outer conductor (156; 256) and an inner insulator (152; 252) disposed therebetween; an outer insulator (162; 258) disposed over the outer conductor; and a radiating section (118; 218) coupled to the feed line (120; 220), the radiating section including: a dipole antenna (140; 240) having a proximal portion (142; 242) and a distal portion (144; 244) and a feed point (146; 246) therebetween, wherein the feed point includes a dielectric material; and a tubular dielectric loading (190; 290) disposed about the dipole antenna (140; 240) including the feed point, wherein the dielectric permittivity of the tubular dielectric loading is higher than the dielectric permittivity of the dielectric material of the feed point; and the antenna assembly further comprising: a housing (200; 270) that defines a chamber therein, the chamber being dimensioned to house the feed line and the radiating section and configured to circulate a dielectric coolant fluid therethrough externally of the tubular dielectric loading, and wherein the dielectric permittivity of the dielectric coolant fluid is higher than the dielectric permittivity of the dielectric material of the tubular dielectric loading, so that the dielectric permittivity gradually increases as the radial distance from the feedpoint increases, further comprising a choke (160; 260) disposed around at least a portion of the feed line (120; 220), and over the outer insulator wherein the outer insulator extends to any length between a distal end of the choke and the feed point. a feed line (120; 220) including an inner conductor (150; 250), an outer conductor (156; 256) and an inner insulator (152; 252) disposed therebetween; an outer insulator (162; 258) disposed over the outer conductor; and a radiating section (118; 218) coupled to the feed line (120; 220), the radiating section including: a dipole antenna (140; 240) having a proximal portion (142; 242) and a distal portion (144; 244) and a feed point (146; 246) therebetween, wherein the feed point includes a dielectric material; and a tubular dielectric loading (190; 290) disposed about the dipole antenna (140; 240) including the feed point, wherein the dielectric permittivity of the tubular dielectric loading is higher than the dielectric permittivity of the dielectric material of the feed point; and the antenna assembly further comprising: a housing (200; 270) that defines a chamber therein, the chamber being dimensioned to house the feed line and the radiating section and configured to circulate a dielectric coolant fluid therethrough externally of the tubular dielectric loading, and wherein the dielectric permittivity of the dielectric coolant fluid is higher than the dielectric permittivity of the dielectric material of the tubular dielectric loading, so that the dielectric permittivity gradually increases as the radial distance from the feedpoint increases, further comprising a choke (160; 260) disposed around at least a portion of the feed line (120; 220), and over the outer insulator wherein the outer insulator extends to any length between a distal end of the choke and the feed point. a dipole antenna (140; 240) having a proximal portion (142; 242) and a distal portion (144; 244) and a feed point (146; 246) therebetween, wherein the feed point includes a dielectric material; and a tubular dielectric loading (190; 290) disposed about the dipole antenna (140; 240) including the feed point, wherein the dielectric permittivity of the tubular dielectric loading is higher than the dielectric permittivity of the dielectric material of the feed point; and the antenna assembly further comprising: a housing (200; 270) that defines a chamber therein, the chamber being dimensioned to house the feed line and the radiating section and configured to circulate a dielectric coolant fluid therethrough externally of the tubular dielectric loading, and wherein the dielectric permittivity of the dielectric coolant fluid is higher than the dielectric permittivity of the dielectric material of the tubular dielectric loading, so that the dielectric permittivity gradually increases as the radial distance from the feedpoint increases, further comprising a choke (160; 260) disposed around at least a portion of the feed line (120; 220), and over the outer insulator wherein the outer insulator extends to any length between a distal end of the choke and the feed point. a housing (200; 270) that defines a chamber therein, the chamber being dimensioned to house the feed line and the radiating section and configured to circulate a dielectric coolant fluid therethrough externally of the tubular dielectric loading, and wherein the dielectric permittivity of the dielectric coolant fluid is higher than the dielectric permittivity of the dielectric material of the tubular dielectric loading, so that the dielectric permittivity gradually increases as the radial distance from the feedpoint increases, further comprising a choke (160; 260) disposed around at least a portion of the feed line (120; 220), and over the outer insulator wherein the outer insulator extends to any length between a distal end of the choke and the feed point.