The Study And Design Of The Multilayer Coupler

Microwave passive components, as one of the core components of the radar systems and wireless communication syetems, has been widely used for its integration and miniaturization, which will help achieve the microwave multi-chips assembled on the same dielectric substrate. As we all know, directional couplers, as one of the most commonly used components, are applied to separate the input signal and output from several channels as designed. Usually, performance of the directional coupler is directly related to the performance of the RF circuit or system.In this theis, two multi-layers directional couplers were designed and simulated based on proposed multi-layer technology, which were multi-layer hybrid coupler and multi-layer Lange coupler.In this theis, the coupler features were introduced by series of formulas with odd-even mode analysis. Multi-layer quadrature hybrid coupler was designed to cover bands from 9.6 GHz to 12.4 GHz, which achieved an amplitude imbalance of 2 dB and a phase error of 4° at the outputs whitin the design frequency range. The Lange coupler was implemented in a multi-layer technology, which avoids some disadvantages of planar technology. The coupler was realized and measured by using 50 Ω terminations. The performances of the coupler was good to be with a coupling lever of 3 dB at the center frequency, a isolation greater than 15 dB and return loss greater than 15 d B too. The designed couplers were compared with other existing designs in the theis, which demonstrated advantages innterms of the wide operating bandwidth and small physical size.In both couplers, the multi-layer quadratuire hybrid coupler was designed at the frequency of 11 GHz. And its volume is only 29.68mm×17.54mm×1.00 mm, which is smaaler and lighter than others. The second one is the multi-layer Lange coupler which was working at the frequency of 2.5GHz. The Lange coulpler has a volume of 4.0mm×25.0mm×1.748 mm.