| 摘要 |
A broadband high frequency device is capable of determining linear combinations of broadband high frequent signals, in particular determining a differential signal, from input signals, being applied substantially simultaneously. One embodiment is based on a plurality of broadband microwave structures, arranged such that symmetry properties can be exploited. The output signal of this differential coupler is proportional to the difference of 2 input ports. This signal is made using a hybrid structure. A pair of broadband impedances are used to scale the 2 incoming signals with 2 complex coefficients. A symmetric structure of two identical broadband directional couplers and a symmetric power combiner are used afterwards to obtain the differential signal. The high bandwidth of both the terminations, the directional couplers and the power combiner make it possible to obtain a differential coupling factor and a common mode rejection ratio which is frequency insensitive over several decades.
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