A microwave ablation antenna assembly (10) including a coaxial cable (14) terminating in a radiating section (16), a first tubular member (18) circumscribing the coaxial cable (14) and spaced therefrom to permit fluid flow therebetween, and a second tubular member (20) circumscribing the first tubular member (18) and spaced therefrom to permit fluid flow therebetween. The microwave ablation antenna assembly (10) further includes a hub (26) configured to receive the coaxial cable (14), first tubular member (18), and second tubular member (20), the hub (26) including a fluid inflow chamber (36) and a fluid outflow chamber (38) and an integrated hub divider (40) and hub cap (28) separating the fluid inflow chamber (36) from the fluid outflow chamber (38) and prohibiting fluid flow between the inflow chamber (36) and outflow chamber (38) except via the spacing between the coaxial cable (14) and the first tubular member (18) and between the first tubular member (18) and the second tubular member (20).
