Based on the multi-port resistive loading technique, this article introduces an effective and simple method for designing a new class of harmonic absorption antenna (HAA). Compared to the traditional harmonic reflection antenna (HRA), the proposed HAA features a favorable harmonic absorption capacity. Additionally, the proposed HAA evidently differs from the absorptive filtering antenna (AFA) due to a much higher and broader absorptive band as well as a more compact structure. In this article, a multi-port network model is established to represent the resistive loading antenna. Based on the generalized S parameters defined by power waves, concise and accurate expressions for calculating radiation efficiency (RE) and power absorption ratio (PAR) are derived and verified by simulation. After that, an HAA with no feedlines is presented with a detailed explanation of resistor loading positions. The resistance values are determined in a simple and fast manner without the need for multiple full-wave simulations. Measured results of the final prototype verify the absorption capacity for up to 4f₀ (operating frequency). Due to the additional merits of compactness and removal of feedlines, the proposed HAA can be a good candidate for modern communication systems.