Miniaturized All-Reconfigurable Dual-Mode Dielectric Filter Using Piezomotors for Future Satellite Communications

Abstract

A compact fully-reconfigurable C-band pseudoelliptic bandpass filter for the applications of next-generation flexible satellite systems is introduced. The filter is realized using a dual-mode TM-mode dielectric resonator attributing ultra-high miniaturization and volume saving > 70%. A wide 790 MHz tuning window is obtained from 4.72 -5.51 GHz with a constant bandwidth of 50 MHz. Additionally, two independently reconfigurable transmissions zeros are introduced through the use of a doublet configuration and non-resonating modes. A piezomotor-based fixture is utilized for accurate fine-tuning. The measured results show good agreement with simulations. The prototype filter has demonstrated high-Q measurements across the whole tuning band (> 500) while maintaining a low insertion loss of less than 1 dB and return loss higher than 18 dB.

Widely Tunable TM-Mode Dielectric Filters With Constant Absolute Bandwidth Using Re-Entrant Caps

“…For instance, a 4-pole 180 MHz K-band reconfigurable TE 311 waveguide filter was presented in [29] with 1.74% of frequency tuning and a Q factor from 3100 to 2600 using dielectric plates. To this end, coaxial and dielectric-loaded waveguides have gained more interest in many tunable filter applications due to their advantages of miniaturized structures, high Q, and good power handling capabilities [3], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45], [46], [47], [48], [49]. For example, a CABW tunable coaxial filter was reported in [3] for future agile 5G Base Transceiver Stations (BTSs).…”

“…Also in [41] and [42], our group recently presented 40% tunable CABW coaxial filters with the least variation of Q factor over the tuning window using inset resonators. To provide more compactness and a higher Q factor than the coaxial filters, a couple of tunable dielectric resonator (DR) filters were proposed [43], [44], [45], [46], [47], [48], [49]. A four-pole 65 MHz C-band tunable dielectric combline filter was reported in [47] with a tuning window of 4.9% and a Q factor of 548 to 536.…”

“…A four-pole 65 MHz C-band tunable dielectric combline filter was reported in [47] with a tuning window of 4.9% and a Q factor of 548 to 536. Also, [49] introduced a compact tunable dual-mode C-band filter based on TM-mode dielectric resonators. The filter has a tuning range of 15.4% with a CABW of 50 MHz±10% and a Q factor varies from 1100 to 500.…”

Bandwidth-Reconfigurable Coaxial Bandpass Filter With Multioctave Tuning Using a Single Element

“…In particular, BW reconfigurable cavity-based filters are more desirable than planar structures like [1]- [3] because of their lower loss and ability to handle higher power levels. Accordingly, several BW tunable empty-waveguide and coaxial-loaded filters were presented [4]- [9]. A cascaded lowpass filter and highpass filter configuration was used in Manuscript received XX February 2023; accepted XX March 2023.…”

“…In the case of compact structures with an extended tuning range, a combline S-band BW tunable filter was reported in [8], based on the introduction of additional bandstop resonators. Also, [9] presented a fully reconfigurable miniaturized dual-mode C-band filter using TMmode dielectric resonators. Nevertheless, despite that these two loaded-waveguide designs are compact, they still share the aforementioned limitations of empty-cavity structures, and therefore, there is still an essential need for more efficient BW tuning solutions.…”