Abstract
This brief reports on the electromagnetic (EM) design and the practical development of frequency-reconfigurable quasi-reflectionless bandpass filters (BPFs) using substrate integrated coaxial (SIC) resonators. The filter concept is based on in-series-cascaded quasi-reflectionless stages that are shaped by a first-order bandpass section and two resistively-terminated first-order bandstop sections. For the first time, we explore the realization of these filters using tunable SIC resonators that exhibit high quality factor ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${Q}$ </tex-math></inline-formula> ) and can be widely tuned with commercially-available linear piezoelectric actuators. Synthesized examples alongside various EM design and practical integration aspects are discussed in detail. The concept is experimentally validated at S-band through the manufacturing and testing of two reconfigurable (one-stage and two-stage) prototypes.
Highlights
INTRODUCTIONDESPITE in their infancy, reflectionless or absorptive bandpass filters (BPFs) are recently being explored as a compact reflection cancellation mechanism for multi-stage RF front-ends (e.g., in instrumentation systems [1] and in harmonic radars [2]) in which reflected RF signals deteriorate the dynamic range of the overall RF system by creating spurs, standing waves, and unwanted oscillations [3]
DESPITE in their infancy, reflectionless or absorptive bandpass filters (BPFs) are recently being explored as a compact reflection cancellation mechanism for multi-stage RF front-ends in which reflected RF signals deteriorate the dynamic range of the overall RF system by creating spurs, standing waves, and unwanted oscillations [3]
Reflectionless BPFs are typically constructed by adding resistively-terminated bandstop filtering networks at their input ports [7]-[10]
Summary
DESPITE in their infancy, reflectionless or absorptive bandpass filters (BPFs) are recently being explored as a compact reflection cancellation mechanism for multi-stage RF front-ends (e.g., in instrumentation systems [1] and in harmonic radars [2]) in which reflected RF signals deteriorate the dynamic range of the overall RF system by creating spurs, standing waves, and unwanted oscillations [3]. Substrate-integrated-coaxial-(SIC)-resonator-based filters have been attracting significant interest due to their compact size and the potential for frequency tuning These concepts have been widely explored as reflective BPFs [18]-[21], bandstop filters (BSFs) [22]-[23], and multi-band filters [24], yet there is no reported work on SIC-resonatorbased reflectionless BPFs. Considering the aforementioned limitations, this brief reports on the design and practical development of frequency-. The details of the quasi-reflectionless SIC-resonator-based BPF concept are shown in Fig. 1 through the conceptual 3D drawing (and EM simulation model) of a single-stage configuration and its corresponding normalized coupling routing diagram (CRD) It is based on three sections, namely a bandpass section that comprises one resonator (resonant node 2) and two inverters KA, and two resistively-terminated bandstop sections that each consists of one resonator (resonant node 4 or 7) and three inverters KB and KC. 2(b), BW control can be obtained by altering KA
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
