近年来，微波加热以其高效性和内部加热等优点在各领域得到广泛应用。然而，微波加热的不均匀性限制了其大规模工业应用的发展。高均匀性和高效率是微波加热领域研究的重点。效率低会造成能源 的浪费，而不均匀加热会导致加热品质差、甚至热失控等现象。本文提出一种双端口选频加热方法，通过在腔体中内置两个正交极化天线方式进行馈电。并且利用扫频来分析各频点的加热效率以及不同频率对加热效 果的影响。最后选择性地对其中高效率的频点进行选频加热，使其在维持加热高效率的前提下提高加热的均匀性。

In recent years, microwave heating has been widely used in various fields due to its high efficiency and internal heating. However, the uniformity of microwave heating limits the development of its large-scale industrial application. High uniformity and high efficiency are the focus of microwave heating research. Low efficiency will cause the waste of energy and non-uniform heating will lead to poor heating quality and even thermal runaway. In this paper, a method of frequency-selected heating with dual-port is proposed and the power is fed by two orthogonal polarized antennas in the cavity. Then, the heating efficiency of each frequency point and the influence of different frequencies on the heating effect are analyzed by using sweep frequency. Finally, frequency-selected heating is carried out on the frequency point with high efficiency, so as to improve the heating uniformity under the premise of maintaining high heating efficiency.