Radio frequency fluid warmer

A radio frequency fluid warmer apparatus, comprising:

• a rectangular waveguide wherein an aspect ratio of the rectangular waveguide is greater than two to one including first and second electromagnetic ports, an inlet, and an outlet for receiving a fluid tube that traverses the waveguide;
• a pathway situated inside the rectangular waveguide for routing the fluid tube between the inlet and the outlet, wherein the pathway is configured to position the fluid tube such that a position of the fluid tube is adjusted for a fixed electromagnetic dissipation caused by fluid-absorption along a length of the waveguide;
• a radio frequency generator coupled to the first electromagnetic port;
• and
• a termination coupled to the second electromagnetic port for preserving a matched waveguide condition.

A radio frequency fluid warmer apparatus, comprising:

• a waveguide including first and second electromagnetic ports, an inlet, an outlet for receiving a fluid-carrying tube that traverses the waveguide, and a pathway for positioning the fluid-carrying tube inside the waveguide such that a direction of a fluid flow of the fluid-carrying tube is along a length of the waveguide;
• a radio frequency generator coupled to the first electromagnetic port;
• and
• a resistive termination coupled to the second electromagnetic port for preserving a matched waveguide condition, wherein radio frequency signals propagate along the length of the waveguide.