skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Frequency and Bandwidth Tunable mm-Wave Hairpin Bandpass Filters Using Microfluidic Reconfiguration With Integrated Actuation
Title: Frequency and Bandwidth Tunable mm-Wave Hairpin Bandpass Filters Using Microfluidic Reconfiguration With Integrated Actuation
Microfluidically reconfigurable radio-frequency (RF) devices in general have been found attractive for low-loss, wide-frequency tunability and high-power-handling capabilities. Recently, integrated actuation of the microfluidically reconfigurable devices has been proposed for compact mm-wave device applications. This article for the first time introduces microfluidically reconfigurable frequency- and/or bandwidthtunable bandpass filters (BPFs) operated at the mm-wave band with integrated actuation. The BPFs consist of coupled hairpin resonators. Frequency tuning is achieved by capacitively loading the resonators. Bandwidth tuning is achieved by creating varying capacitive loading among the resonators to control the interresonator couplings. The capacitive loading mechanisms are realized using the selectively metallized plates (SMPs) that can be repositioned within the microfluidic channels. The microfluidic channels are located directly above the stationary metallizations of the filter. Piezoelectric bending actuators placed under the filter’s ground plane provide the SMP motion capability. The BPFs perform with the worst-case insertion loss of 3.1 dB. Frequency-tuning capable filters operate within 28–38-GHz band. Fractional bandwidth tunability varies from 7.8% to 16.7% at 38 GHz and 7.6% to 12.5% at 28 GHz for the filter that is capable of both tuning mechanisms. The filters are characterized to handle 5 W of the continuous RF power without needing thick ground planes or heat sinks. In addition, the frequency-tuning speed is characterized to be 285 MHz/ms.  more » « less
Award ID(s):
1920926 1351557
PAR ID:
10186228
Author(s) / Creator(s):
;
Date Published:
Journal Name:
IEEE Transactions on Microwave Theory and Techniques
Volume:
68
Issue:
9
ISSN:
0018-9480
Page Range / eLocation ID:
1 to 1
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; (, Microwave and Optical Technology Letters)
    Abstract We report a novel approach for realizing tunable/reconfigurable terahertz (THz) mesh filters on the basis of micromachined mesa‐array structures. In this approach, different filter patterns are generated virtually using photogenerated free carriers in a semiconducting mesa‐array structure to achieve superior tunability and reconfigurability. Micromachined mesa‐array structures enable the formation of high fidelity, optically generated mesh filter structures for THz frequencies. To evaluate the proposed filter designs, the optically patterned spatial modulation properties of mesa‐array structures were first evaluated. Reconfigurable mesh filter prototypes were then designed and simulated using silicon mesa arrays with 50 × 50 μm2square mesa unit cells. Simulations show that reconfigurable bandpass filters (BPFs) operating in the frequency range of 108–489 GHz with insertion losses of 0.82–1.13 dB can be achieved. By employing smaller unit cells, the frequency tuning range and filtering performance can be further improved. In addition to BPFs, other filter functionalities can also be realized utilizing the proposed approach. The wide tuning range and reconfigurability of the mesh filters demonstrate that the proposed approach is promising for developing tunable/reconfigurable circuits and components for advanced THz sensing, imaging, and communications. 
    more » « less
  2. ; ; (, International journal of microwave and wireless technologies)
    The design of mixed-technology quasi-reflectionless planar bandpass filters (BPFs), bandstop filters (BSFs), and multi-band filters is reported. The proposed quasi-reflectionless filter architectures comprise a main filtering section that determines the power transmission response (bandpass, bandstop, or multi-band type) of the overall circuit network and auxiliary sections that absorb the reflected radio-frequency (RF) signal energy. By loading the input and output ports of the main filtering section with auxiliary filtering sections that exhibit a complementary transfer function with regard to the main one, a symmetric quasi-reflectionless behavior can be obtained at both accesses of the overall filter. The operating principles of the proposed filter concept are shown through synthesized first-order BPF and BSF designs. Selectivity-increase techniques are also described. They are based on: (i) cascading in-series multiple first-order stages and (ii) increasing the order of the filtering sections. Moreover, the RF design of quasi-reflectionless multi-band BPFs and BSFs is discussed. A hybrid integration scheme in which microstrip-type and lumped-elements are effectively combined within the filter volume is investigated for size miniaturization purposes. For experimental validation purposes, two quasi-reflectionless BPF prototypes (one- and two-stage architectures) centered at 2 GHz and a second-order BSF prototype centered at 1 GHz were designed, manufactured, and measured. 
    more » « less
  3. ; ; ; ; ; ; ; (, IEEE)
    F-band substrate-integrated waveguides (SIWs) are designed, fabricated, and characterized on a SiC wafer, along with SIW-based filters, impedance standards, and transitions to grounded coplanar waveguides (GCPWs). The GCPW-SIW transitions not only facilitate wafer probing, but also double as resonators to form a 3-pole band-pass filter together with an SIW resonator. The resulted filter exhibits a 1.5-dB insertion loss at 115 GHz with a 34-dB return loss and a 19-GHz (16%) 3-dB bandwidth. The size of the filter is only 63% of previous filters comprising three SIW resonators. These results show the feasibility for monolithic integration of highquality filters with high-efficiency antennas and amplifiers in a single-chip RF frontend above 110 GHz, which is particularly advantageous for 6G wireless communications and nextgeneration automobile radars. 
    more » « less
  4. ; ; ; ; (, Journal of Fluids Engineering)
    Microfluidic-based techniques have been shown to address limitations of reconfigurable radio frequency (RF) antennas and filters in efficiency, power handling capability, cost, and frequency tuning. However, the current devices suffer from significant integration challenges associated with packaging, actuation, and control. Recent advances in reconfigurable microfluidics that utilize the motion of a selectively metalized plate (SMP) for RF tuning have demonstrated promising RF capabilities but have exposed a need for an accurate fluid actuation model. This research presents a model for the mechanical motion of a moving plate in a channel to relate the SMP size, microfluidic channel size, velocity, and inlet pressure. This model facilitates understanding of the actuation response of an RF tuning system based on a moving plate independent of the actuation method. This model is validated using a millimeter-scale plate driven by a gravitational pressure head as a quasi-static pressure source. Measurements of the prototyped device show excellent agreement with the analytical model; thus, the designer can utilize the presented model for designing and optimizing a microfluidic-based reconfigurable RF device and selecting actuation methods to meet desired outcomes. To examine model accuracy at device scale, recent papers in the microfluidics reconfigurable RF area have been studied, and excellent agreement between our proposed model and the literature data is observed. 
    more » « less
  5. ; ; (, IEEE Transactions on Microwave Theory and Techniques)
    A coupling-matrix approach for the theoretical design of a type of input-reflectionless RF/microwave bandpass filters (BPFs) and bandstop filters (BSFs) is presented. They are based on diplexer architectures with arbitrary-order bandpass and bandstop filtering channels that feature complementary transfer functions. The transmission behavior of these reflectionless filters is defined by the channel that is not loaded at its output, whereas the input-signal energy that is not transmitted by this branch is completely dissipated by the loading resistor of the other channel. Analytical formulas for the coupling coefficients for the first-to-fourth-order filter designs are provided and validated through several synthesis examples. This theoretical design methodology, along with an optimization step, is also exploited to design input-quasi-reflectionless quasielliptic- type BPFs with a transmission-zero-(TZ)-generation cell in their bandpass filtering channel. In addition, the application of the proposed input-reflectionless BPF and BSF networks to input-quasi-reflectionless multiplexer design is approached. It is shown that a single resistively terminated multi-band BSF branch can absorb the input-signal energy not transmitted by the multiplexer channels in their common stopband regions to achieve quasi-reflectionless characteristics at its input. Moreover, experimental microstrip prototypes consisting of 2-GHz third-order BPF and BSF circuits, a 2-GHz sharp-rejection thirdorder BPF with two close-to-passband TZs, and a second-order diplexer device with channels centered at 1.75 and 2.1 GHz are developed and measured. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email