基于导纳矩阵的任意端口阻抗等分功分器设计

Design of equal-split power divider with arbitrary port impedances based on admittance matrix

为减小非50Ω功分器电路尺寸,研究了任意端口阻抗等分功分器。理论证明了若等分功分器的输出端口之间只使用电阻连接,不能同时实现任意端口阻抗匹配和输出端口隔离。提出了一种新的任意端口阻抗等分功分器结构。在隔离电阻两端串联不同的微带线,在各端口加载短路/开路短截线。利用此结构同时实现了各端口匹配与输出端口之间的互相隔离。基于导纳矩阵推导了该功分器的设计公式,并据此设计研制了中心频率为1 GHz,端口阻抗分别为30Ω、53Ω、47Ω的等分功分器。该文方法设计的功分器电路尺寸比传统设计方法减小了约66%。测试结果验证了该等分功分器结构简单有效。

To decrease the circuit size of non-fifty Ω port impedances power dividers, equal-split power dividers with arbitrary port impedances are studied. It is theoretically verified that if two output ports of an equal-split power divider are connected by a resistor,the impedance matching of arbitrary ports and output port isolation cannot be realized simultaneously. A new circuit topology of equal-split power divider with arbitrary port impedances is proposed. Different microstrip lines are added in series with the isolation resistor at both ends;short/open stubs are loaded at each port. Impedance matching and output port isolation can be achieved simultaneously by adopting this configuration. The closed design formulae of this equal-split power divider with arbitrary port impedances are derived using an admittance matrix. As an example, an equal-split power divider is designed with 30 Ω, 53 Ω,47 Ω port impedances and operating at 1 GHz. The circuit size designed by the method proposed here decreases by about 66% compared with that of the traditional design method. Experimental results demonstrate the simplicity and effectiveness of the proposed circuit topology of equal-split power divider with arbitrary port impedances.