Actually, medical microwave imaging, MW, through electromagnetic radiation is being applied to detect, discover and diagnosis cardiovascular diseases, brain strokes as well as cancerous tumors breast. This technique is based on the dielectric changes in the human tissue, as an alternative viable and less expensive respect to magnetic resonance imaging (MRI) which is expensive, not available and not easy access to the people for treatment in the majority of health centers. In most MI equipment uses antennas which operate in the 1–10 GHz, which size is not small and with certain resolution, so, in order to further improve and increase the detection level and image resolution, this work proposes a miniature Yagi array antenna operating at 3.5 GHz, low cost, small dimensions, area and volume, saving space within the microwave imaging device.