| 1. |
- Amin, Yasar, et al.
(författare)
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Performance-optimized Printed Wideband RFID Antenna and Environmental Impact Analysis
- 2024
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Ingår i: ETRI Journal. - Korea : ETRI. - 1225-6463 .- 2233-7326.
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents performance optimized RFID tag antenna, developed by using commercially accessible paper substrates and advanced inkjet printing process to guarantee mechanical flexibility and ultra-low production costs. The proposed antenna structure can endure the variations which emerge in electromagnetic properties of paper substrate due to varying environmental effects. Hole-matching technique is implemented to eliminate the matching network for reducing the consumption of conductive ink. The proposed structure is uniquely evaluated by demonstrating, sustainability and environmental impact analysis that validate the potential for ultra-low cost mass production of RFID tags for future generation of organic electronics. The antenna performance is assessed for cardboard cartons exclusively containing metal cans and water bottles. The experimental characterization of the proposed antenna endorses the wider bandwidth to cover UHF RFID ISM band (860-960MHz), which empowers its usage throughout the globe for supply chain applications. The improved design effectuates return loss of better than -15dB over a wide frequency range while exhibiting outstanding readability from 10.1 meters.
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| 2. |
- Le, Minh-Ha, et al.
(författare)
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Certificate-Based Signcryption Scheme without Pairing : Directly Verifying Signcrypted Messages Using a Public Key
- 2016
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Ingår i: ETRI Journal. - : John Wiley & Sons. - 1225-6463 .- 2233-7326. ; 38:4, s. 724-734
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Tidskriftsartikel (refereegranskat)abstract
- To achieve confidentiality, integrity, authentication, and non-repudiation simultaneously, the concept of signcryption was introduced by combining encryption and a signature in a single scheme. Certificate-based encryption schemes are designed to resolve the key escrow problem of identity-based encryption, as well as to simplify the certificate management problem in traditional public key cryptosystems. In this paper, we propose a new certificate-based signcryption scheme that has been proved to be secure against adaptive chosen ciphertext attacks and existentially unforgeable against chosen-message attacks in the random oracle model. Our scheme is not based on pairing and thus is efficient and practical. Furthermore, it allows a signcrypted message to be immediately verified by the public key of the sender. This means that verification and decryption of the signcrypted message are decoupled. To the best of our knowledge, this is the first signcryption scheme without pairing to have this feature.
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| 3. |
- Lee, Jong-Ho, et al.
(författare)
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Array pattern synthesis using semidefinite programming and a bisection method
- 2019
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Ingår i: ETRI Journal. - : WILEY. - 1225-6463 .- 2233-7326. ; 41:5, s. 619-625
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we propose an array pattern synthesis scheme using semidefinite programming (SDP) under array excitation power constraints. When an array pattern synthesis problem is formulated as an SDP problem, it is known that an additional rank-one constraint is generated inevitably and relaxed via semidefinite relaxation. If the solution to the relaxed SDP problem is not of rank one, then conventional SDP-based array pattern synthesis approaches fail to obtain optimal solutions because the additional rank-one constraint is not handled appropriately. To overcome this drawback, we adopted a bisection technique combined with a penalty function method. Numerical applications are presented to demonstrate the validity of the proposed scheme.
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| 4. |
- Ramazan, Rashad, 1971-, et al.
(författare)
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Wideband Low Reflection Transmission Lines for Bare Chip on Multilayer PCB
- 2011
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Ingår i: ETRI Journal. - Daejeon, Korea : Electronics and Telecommunications Research Institute. - 1225-6463 .- 2233-7326. ; 33:3, s. 335-343
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Tidskriftsartikel (refereegranskat)abstract
- The pad pitch of modern RF ICs is in order of few tens of micrometers. Connecting the large number of high speed I/Os to outside world with good signal fidelity and low cost is extremely challenging. To cope with this requirement, we need reflection-free transmission lines from on-chip pad to on-board SMA connectors. Such a transmission line is very hard to design due to the difference in on-chip and on-board feature size and the requirement for extremely large bandwidth. In this paper, we propose the use of narrow tracks close to chip and wide tracks away from the chip. This narrow to wide transition in width results in impedance discontinuity. A step change in substrate thickness is utilized to cancel the effect of the width discontinuity, thus achieving a reflection-free microstrip. To verify the concept several microstrips were designed on multilayer FR4 PCB without any additional manufacturing steps. The TDR measurements reveal that impedance variation is less then 3Ω for 50Ω microstrip when the width changes from 165μm to 940μm and substrate thickness changes from 100μm to 500μm. The Sparameter measurement on same microstrip shows S11 better then -9dB for the frequency range 1-6GHz.
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| 5. |
- Yoo, S. J., et al.
(författare)
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A highly linear CMOS baseband chain for wideband wireless applications
- 2004
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Ingår i: ETRI Journal. - : Wiley. - 1225-6463 .- 2233-7326. ; 26:5, s. 486-492
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Tidskriftsartikel (refereegranskat)abstract
- The emergence of wide channel bandwidth wireless standards requires the use of a highly linear, wideband integrated CMOS baseband chain with moderate power consumption. In this paper, we present the design of highly linear, wideband active RC filters and a digitally programmable variable gain amplifier. To achieve a high unity gain bandwidth product with moderate power consumption, the feed-forward compensation technique is applied for the design of wideband active RC filters. Measured results from a 0.5 mum CMOS prototype baseband chain show a cutoff frequency of 10 MHz, a variable gain range of 33 dB, an in-band IIP3 of 13 dBV, and an input referred noise of 114 muVrms while dissipating 20 mW from a 3 V supply.
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