Multiport interferometer techniques for innovative transceiver applications

This paper presents and reviews basic concepts and emerging development of our proposed multi-port interferometer techniques and demonstrates their applications in the design of carrier-based, impulse ultra-wideband and cognitive transceivers at microwave and millimeter-wave frequencies. Such innovative techniques can be extended to the design of transceivers over terahertz and optical ranges. Various architectures of multiport circuits are discussed with respect to different applications. Practical implementations under different technological platforms are described with simulated and measured results for QAM, UWB and tunable multiband applications. In particular, the equivalence between the multiport junction and mixing circuit is highlighted with respect to the concept of interferometers for direct frequency conversion and translation. It is shown that such multiport techniques are very promising and flexible for the low-cost design of integrated microwave, millimeter-wave and photonic systems such as software-defined radio, cognitive radio and radar systems as well as photonic transceivers.