Session: TU4D | Advanced Applications of Transmission Line Elements |
Chair: | George E. Ponchak, NASA Glenn Research Center |
Co-Chair: | Barry E. Spielman, Washington University |
Abstract: | This session is concerned with advanced applications of transmission line elements. The first paper presents a volumetric left-handed structure while the second paper uses a left-handed phenomenon to realize RFID applications. The third paper discusses an application of periodic structure in CMOS environment. The fourth paper demonstrates a water-based rectangular waveguide high-power switch, and the last paper uses a spurline filter structure for suppressing harmonics in Wilkinson power divider. |
| | TU4D-01 | Fully Printed Volumetric Negative-Refractive-Index Transmission-Line Slabs Using A Stacked Shunt-Node Topology |
1185 | J. Zhu, G. V. Eleftheriades, University of Toronto, Toronto, Canada |
| A volumetric negative-refractive-index transmission-line (NRI-TL) slab is proposed using a stacked shunt-node topology. The slab is analyzed using multiconductor transmission line (MTL) theory and verified by Ansoft’s HFSS. A fully printed design employing interdigital capacitors and spiral inductors is derived from the lumped-element counterpart and demonstrates low-loss and broadband properties. A strategy for placing some of the required vias is introduced which dramatically simplifies the fabrication process while still suppressing the parallel-plate waveguide (PPW) parasitic mode. Using these innovations, a volumetric NRI-TL slab lens is fabricated and the focusing experimental results show that the proposed slab lens can overcome the diffraction limit by more than a factor of two. |
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TU4D-02 | Performance Evaluation of Left-Handed Delay Lines for RFID Backscatter Applications |
1172 | M. Schüßler, C. Damm, M. Maasch, R. Jakoby, TU Darmstadt, Darmstadt, Germany |
| The operation principle of a passive RFID tag on the basis of periodically LC loaded delay lines is presented. The system requirements in terms of bandwidth, operation frequency and left- or right-handed lumped element line are analysed. Additionally, limitations due to the dispersion properties of left-handed lines and the maximum number of usable cells are discussed. In conclusion, an expression relating the maximal number of usable bits for the tag impulse response to system parameters like bandwidth, centre frequency etc. is given. A proof of concept is realized with a 100 cell four bit backscatter tag. The set up of the tag is described and the performance analysed. |
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TU4D-03 | Millimeter-Wave CMOS Digital Controlled Artificial Dielectric Differential Mode Transmission Lines for Reconfigurable ICs |
1510 | T. R. LaRocca, S. Tam, D. Huang, Q. Gu, E. Socher, W. Hant, F. Chang, University of California, Los Angeles, Los Angeles, United States |
| Digital control of the effective dielectric constant of a differential mode transmission line is shown up to 60GHz in standard CMOS technology. The effective dielectric constant is shown to increase from 5 to over 50 for the fixed artificial dielectric case. The digital controlled artificial dielectric transmission line (DiCAD) uses MOS switches to dynamically control the phase. DiCAD achieves 50% of the physically available tuning range with effective dielectric constant varying between 7 and 28. Measured results favorably agree with full-wave electromagnetic simulations. |
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TU4D-04 | A Ka-band Waveguide Water-Based Absorptive Switch with an Integrated Micropump |
1634 | C. Chen, D. Peroulis, Purdue University, West Lafayette, United States |
| A new water-based waveguide absorptive switch is developed and reported. The switch functions by controllably inserting water inside a conventional Ka-band waveguide. In particular, three Teflon-made circular cylinders with a diameter of 1.59-mm are placed inside a 50-mm-long waveguide section at an angle of 75 degree and can be filled with water by micropumps. The water-filled tubes offer a measured isolation of 18 and 28 dB at 26.5 and 40 GHz respectively. When water is removed the total insertion loss is measured at less than 0.5 dB across the whole band. This number includes the effects of a) the 50-mm long waveguide section, b) the holes for inserting the teflon tubes, and c) the tubes themselves. In addition, the measured switch return loss is greater than 18 dB at both states from 26.5 to 40 GHz. Water can be inserted and removed at a simulated speed of less than 50 ms. The proposed design requires approximately 40% less volume than conventional waveguide absorptive switches. |
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TU4D-05 | Harmonics Suppression of Wilkinson Power Divider Using Spurlines with Adjustable Rejection Bands |
1070 | H. Liu1, R. Cao2, M. Wu2, 1Chinese Academy of Sciences, Chengdu, China, 2East China Research Institute of Electronic Engin, Hefei, China |
| A newly asymmetrical spurline structure is presented in this letter. Its dual-bandgap characteristics are reported and can be adjusted by changing the length difference between spurlines. Then, a simple circuit model is set up for the spurline structure by using two LCR-resonators and the circuit parameters can be extracted from EM simulations. Moreover, a Wilkinson power divider using the proposed spurlines was designed, fabricated, and measured. Experimental results verify that 27-dB suppression for the second harmonic and 30-dB suppression for the third harmonic are obtained, respectively. In addition, the reflection coefficient are -3.5 dB ± 0.3dB below 3.8 GHz and -3.7 dB at the operating frequency 3.12 GHz. |
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