Design of a Microwave Quadrature Hybrid Coupler with Harmonic Suppression Using Artificial Neural Networks

Figure 1

Three steps of creating the basic LPF. (a) The initial structure of the basic LPF. (b) The frequency response for the LPF in step 1, in which the basic LPF only consists of an open-stub and a high impedance line located in a T-shaped structure. The structures and frequency responses for the designed basic LPF in step 2 and step 3 are shown in subfigures (c)–(f). In steps 2 and 3, the middle high impedance line is bended, resulted in size reduction and also performance improvement of the LPF.

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