Multifunctional reconfigurable filter based on principle of signal interference

Abstract

The invention discloses a novel multifunctional reconfigurable filter based on a principle of signal interference. The multifunctional reconfigurable filter comprises an upper micro-strip structure, an intermediate dielectric plate, and a lower grounded metal, wherein the upper micro-strip structure comprises two input / output feeder lines, five microstrip lines, one pair of parallel coupling lines, six blocking capacitors, five biasing resistors, five PIN pipes and four short circuit grounded through holes. By adding a switch for controlling on-off in a transmission line, selection of path of the transmission line can be controlled, and thus multiple filter modes which are switchable can be achieved. The achieved filter modes comprise an ultra-wideband band-pass filter mode (UWB-BPF), a narrow-band band-pass filter mode (NB-BPF) and an ultra-wideband band stop filter mode (UWB-BSF) respectively. A pass band mode is formed by leading a transmission zero into a terminal short-circuit resonator; a stop band mode is formed by forming a wide stop band through superposition and subtraction of two-way signals according to the principle of signal interference. All the three modes can be achieved and adjusted, the structures are simple, features are good, and integration of circuits and packaging of systems can be easily achieved.

Description

technical field [0001] The invention relates to the field of reconfigurable circuit theory, in particular to a multifunctional reconfigurable filter based on signal interference theory. Background technique [0002] Modern wireless communication systems tend to open up more and more spectrum resources, which leads to wider operating bandwidth and more frequency bands. Therefore, there is a great demand for devices that can realize more functions in a limited space. For multiband wireless systems, tunable and switchable filters enable reconfiguration to adapt to changing electromagnetic environments, leaving the desired signal while eliminating unwanted interference. Tunability or switchability of the filter can be achieved by controlling the natural frequency of the coupled resonators. In planar filters, this can be achieved by inserting variable reactive elements such as PIN transistors, Schottky transistors, varactor diodes or microelectromechanical systems (MEMS) in the...

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Problems solved by technology

In recent years, many scholars have been working on reconfigurable filters with good stability, such as literature 1 "Deng P H, Tsai JT, Liu R C. Design of a Switchable Microstrip Dual-Band Lowpass-Bandpass Filter. IEEE Microwave & Wireless Components Letters, vol.24, no.9, pp.599–601, Sep.2014.”), and literature 2 “Y.-H.Cho, G.-M.Rebeiz 0.7–1.0-GHz reconfigurablebandpass to-bandstop filter With selectable 2-and 4-pole responses, IEEETrans.Microw.Theory Techn., vol.62, no.11, pp.2626–2632, Nov.2014") introduced several reconfigurable filters in more detail The structure of the filter, the shortcomings of the reconfigurable filter structure designed in the past are: 1) the circuit is complex and the volume is large; 2) the influence of active devices makes the performance not stable enough

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