Design of High Frequency Passive Reconfigurable Circuits

The group has acquired experience and acknowledgement in a new R&D line that is a key point in the development of high frequency communications systems with reconfigurable characteristics (front-ends for RF radio systems defined by software, tunable wireless communications and reconfigurable satellite payloads). Thus, future passive components (especially filters and multiplexers) with fully reconfigurable electric characteristics (type of response, central frequencies and operational bandwidths) must be developed.

In this R&D line, progress is made in the design of circuits in planar and SIW technology (essentially filters, see pictures) with passband response of reconfigurable characteristics (central frequency and bandwith). Electronic devices are used as tuning elements, such as varactors (continuous tuning elements), p-i-n diodes and micro-electro-mechanical systems (MEMS) used as switches (discrete tuning elements). The use of new advanced materials (ferroelectrics, quartz crystals and ferrites) with controllable electric and magnetic properties is also investigated.

Among the main results of this R&D line, it should be pointed out that a national and international patent has been requested of a “Microwave tunable filter in surface mounted technology based on substrate integrated coaxial resonant cavities”, with Ref. PCT/ES2012/070649

The development of this promising R&D line makes use of the group facilities mentioned before, such as full-wave EM simulation laboratory, manufacture and integration of components in planar and hybrid technology, as well as the experimental characterization systems for these high frequency devices.

Tunable MEMs-SIW filter	Tunable Varactor-SIW filter