This work presents the design of an additively manufactured W-band bandpass filter and a subtractively manufactured W-band diplexer in order to demonstrate the use of admittance inverter sequences for the ease of manufacture at millimetre-wave frequencies. Contrary to typical impedance inverters (E-plane and H-plane irises), the use of admittance inverters (E-plane and H-plane stubs) allow for larger dimensions to be specified and ultimately do not impede the general waveguide path. The proposed bandpass filter is designed with all E-plane stubs, while the diplexer is designed with one branch utilizing both E-plane and H-plane stubs as an arbitrary sequence, and the second branch utilizing all H-plane irises. The additively manufactured bandpass filter is fabricated using the most elementary level stereolithography (SLA) based methods, demonstrating that a hobbyist-type SLA printer and metallization method can procure exceptional results for millimeterwave filter designs. The subtractively manufactured diplexer is fabricated using high-precision computer numerical control (CNC) milling in order to highlight the use of arbitrary inverter sequences in a more complex and robust design profile, while the dispersive transmission zeros that are caused by over-moding of the inverter stubs is utilized to demonstrate unique isolation characteristics in the upper W-band region. The design concepts, fabrication profiles, simulations and measurements which are presented in this work highlight a viable option for overcoming miniaturized dimensions in millimetre and sub-millimetre-wave applications.
A new class of compact, high-Q, tunable coaxial filters is presented in this paper based on a novel inset resonator concept. The tuning concept is based on the displacement of movable resonators inside a properly modified metallic housing which features wide tuning capabilities and stable high Qfactor performance with minimum variation throughout the tuning window. Various prototypes are designed and implemented to demonstrate and validate the proposed concept. A single tunable inset resonator is first designed and measured showing distinctive results of a 43% tuning range, stable high-Q of 4100±4%, spurious-free band up to 3.8•f0, and volume-saving up to 50% when compared to the conventional combline and halfwavelength structures. The design procedure for constant absolute bandwidth (CABW) tunable filters is then presented, and two different tunable inset filters are designed and implemented. Firstly, a manually tunable four-pole filter is demonstrated with the merits of a wide 39.3% tuning range, while maintaining a constant bandwidth of 116 MHz±6%, and a stable high-Q of 1820±6%. Next, an automatically tunable 3rd-order inset filter is designed and measured using high-accuracy piezomotors. Similarly, the measured results exhibit a wide 1.3 GHz tuning range from 2.65 GHz -3.95 GHz with a stable insertion loss that is less than 0.35 dB, a return loss that is better than 15 dB, and a good spurious performance up to 2.8•f0. To our own knowledge, the proposed tuning technique and tunable components represent state-of-the-art tuning range and stable high-Q with minimal variation when compared with similar loaded-waveguide designs.
This paper introduces a new so-called "inset" resonator configuration for fixed and tunable microwave filter applications. The proposed configuration has many attractive advantages in comparison with conventional structures, including miniaturized size, enhanced spurious performance, and wide tuning capabilities with the least deterioration in unloaded quality factor throughout the tuning window. For proof of concept purposes, a single inset resonator and a two-pole filter are designed, manufactured, and measured. The measurements agree very well with simulations. The measured prototypes demonstrate a wide spurious-free band, volume saving up to 50%, a wide tuning range > 41%, and a high Qu of 4004±2.4% with minimum variation throughout the tuning range.
In this letter, triangular-cavity bandpass filters are investigated in stackable multi-layer technologies in order to achieve highly compact designs with reduced fabrication complexity. The triangular-shaped cavities are first introduced in the form of singlets and then expanded on as a novel method for achieving a quasi-triplet filter response, where the filter's input and output irises are utilized as resonating means for two additional passband poles. Exploitation of this advanced singlet scheme exemplifies innovative use of resonant irises for achieving highly compact filters that can be manufactured with simple multi-layer fabrication steps for use in future terahertz applications.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.