The invention relates to a miniature patch antenna which is easy to multiply and form into an array, according to the spectrum allocated by the international regulatory body, the FCC, for precocious detection of infra-millimetric tumours in breast cancer, implemented with micro-ribbon technology having a single access provided by a jack-type female connector SMA, which connects the four similar and equidistant structures to a micro-ribbon line having a characteristic impedance of 50Ω. The invention relates to an antenna array with four similar and equidistant radiation elements which are easy to produce. This is a device for emitting and receiving electromagnetic radiation across a wide medical band recommended by the Federal Communications Commission (FCC) for detecting tumours, using a power splitter-combiner that ensures a better gain, a wide bandwidth, a small size, good adaptation in the frequency band ranging from 3.1 GHz to 10.6 GHz, with a low production cost. The antenna array is formed by four rectangular micro-ribbon elements, each of which is connected to the output of the power splitter-combiner. The antenna array is powered in parallel by a micro-ribbon line and allows the input power to be split into four equal fractions. The power supply is connected to a jack-type female connector SMA which interconnects the four similar and equidistant patches (figure 9). A slot is located in the partial mass plane, increasing the gain, the directivity and the bandwidth, and reducing the space occupied by the antenna. The device according to the invention is particularly designed for recent non-invasive and non-ionising radiological applications, which do not require a contrast agent, achieve improved diagnostics and precocious detection of breast cancer, and provide a technology that is better than the existing ones, which emit hazardous X-ray radiation.