在微波集成电路(MIC)中使用的带线环行器,一般可看作是铁氧体平面电路(二维电路)中的一种。在本文中,我们研究了宽频带工作的平面环行器的最佳形状,发现电路设计中这种平面结构有更大的自由性。用有效边界积分法设计出的宽带平面环行器是一种三角形形状,它的边缘稍向内凹,其20dB隔离的相对带宽约为50%。 Band line circulators used in microwave integrated circuits (MICs) are generally considered as one of ferrite planar circuits (two-dimensional circuits). In this paper, we study the optimal shape of a planar circulator operating in a wide band and find that this planar structure has greater freedom in circuit design. The wideband planar circulator designed by the effective boundary integral method is a triangular shape whose edge is slightly concave and the relative bandwidth of 20dB isolation is about 50%.