| 摘要 |
In theory, one can design an in-phase hybrid coupler having any arbitrary signal division ratio k/t as a function of frequency. The resulting network, as disclosed in the prior art, comprises a pair of frequency insensitive 3db hybrid couplers interconnected by means of two identical, reverse-connected antimetric networks. The problem, however, is that parasitics often make it difficult, if not impossible, to realize the required antimetric networks at the higher operating frequencies. This application discloses that any in-phase hybrid coupler can be synthesized as a tandem array of a plurality of in-phase hybrid couplers where each frequency-sensitive coupler circuit in the array contains a preselected simplified antimetric network that is more readily realizable over the frequency band of interest. In particular, the simplified network can be designed to incorporate component parasitics into the network itself, thus further extending the useful operating range. |
