| 1. |
- Chvojka, Petr, et al.
(author)
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Expanded Multiband Super-Nyquist CAP Modulation for Highly Bandlimited Organic Visible Light Communications
- 2020
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In: IEEE Systems Journal. - 1932-8184 .- 1937-9234. ; 14:2, s. 2544-2550
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Journal article (peer-reviewed)abstract
- In this article, we experimentally demonstrate a novel expanded nonorthogonal multiband super-Nyquist carrier-less amplitude and phase (m-ESCAP) modulation for bandlimited organic visible light communication (VLC) systems. The proposed scheme has the same bandwidth requirement as the conventional m-CAP while breaking the orthogonality between subcarriers by purposely overlapping them. We compare m-ESCAP with the conventional m-CAP and a compressed nonorthogonal version of m-CAP (m-SCAP) in terms of measured bit error rate (BER) performance, bit rates, and spectral efficiencies. We show that the m-ESCAP system offers improvement in the bit rate of $\sim$10% and 20% compared to the m-CAP and m-SCAP, respectively, and in the spectral efficiency of $\sim$20% compared to m-CAP. These gains are achieved at the cost of increased BER, which, however, remains below the 7% forward error correction limit.
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| 2. |
- Eriksson, Klas, 1983, et al.
(author)
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InP DHBT Distributed Amplifiers With Up to 235-GHz Bandwidth
- 2015
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In: IEEE Transactions on Microwave Theory and Techniques. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9480 .- 1557-9670. ; 63:4, s. 1334-1341
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Journal article (peer-reviewed)abstract
- Three wideband amplifiers in double-heterojunction bipolar transistor technology have been designed and measured. The amplifiers use different types of distributed amplifier (DA) topologies, all based on cascode gain cells. A single-stage DA design achieves 7.5-dB gain and 192-GHz bandwidth and a two-cascaded single-stage DA achieves an average gain of 16 dB with a bandwidth of 235 GHz. The third circuit is a conventional DA with more than 10-dB gain from 70 kHz up to 180 GHz. To the authors' best knowledge, the single-stage DA and the two-cascaded single-stage DA are the widest band amplifiers in any technology reported to date. Furthermore, the conventional DA has a record bandwidth for circuits in conventional DA topology with gain from near dc.
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| 3. |
- Eriksson, Klas, 1983, et al.
(author)
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InP DHBT wideband amplifiers with up to 235 GHz bandwidth
- 2014
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In: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781479938698 ; , s. Art. no. 6848436-
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Conference paper (peer-reviewed)abstract
- Two wideband amplifier MMICs are designed and tested. Both designs employ InP double-heterojunction bipolar transistor technology. The amplifiers are designed using cascode cells, in a distributed amplifier topology, with simple on-chip resistive bias circuitry. A single stage design achieves 7.5 dB gain and 192 GHz bandwidth and a 2-cascaded distributed amplifier achieves gain in excess of 16 dB and with bandwidth exceeding 235 GHz, thus being the widest band amplifiers reported to date.
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| 4. |
- Giannakopoulos, Stavros, 1989, et al.
(author)
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Transimpedance amplifiers with 133 GHz bandwidth on 130 nm indium phosphide double heterojunction bipolar transistors
- 2019
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In: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 55:9, s. 521-522
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Journal article (peer-reviewed)abstract
- In this work, the authors present two transimpedance amplifier (TIA) circuits designed for fibre optical interconnect systems. They compare a common base (CB) topology with a common emitter (CE) shunt shunt feedback topology in terms of frequency response, power consumption, noise, and input impedance. The two TIAs are designed on a 130 nm indium phosphide double heterojunction bipolar transistor technology from Teledyne Scientific Company (TSC) with an 1 f(t)/f(max). of 520 GHz/1.15 TED and are measured in the frequency and time domains. They exhibit a transimpedance gain of 42 dBS2 with a 133 GHz bandwidth, the highest bandwidth reported in the literature and power consumption of 32.3 nikV tqr the C13 and 25.5 mW for the CE. Eye diagram measurements were conducted up to 64 Ghps and input referred noise density was measured at 30.2 pAh/root Hz for the CB and 13.9 pA.root Hz for the CE.
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| 5. |
- Haigh, Paul Anthony, et al.
(author)
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Experimental demonstration of staggered cap modulation for low bandwidth red-emitting polymer-LED based visible light communications
- 2019
-
In: 2019 IEEE International Conference on Communications Workshops, ICC Workshops 2019 - Proceedings.
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Conference paper (peer-reviewed)abstract
- © 2019 IEEE. In this paper we experimentally demonstrate, for the first time, staggered carrier-less amplitude and phase (sCAP) modulation for visible light communication systems based on polymer light-emitting diodes emitting at ∼639 nm. The key advantage offered by sCAP in comparison to conventional multiband CAP is its full use of the available spectrum. In this work, we compare sCAP, which utilises four orthogonal filters to generate the signal, with a conventional 4-band multi-CAP system and on-off keying (OOK). We transmit each modulation format with equal energy and present a record un-coded transmission speed of ∼6 Mb/s. This represents gains of 25% and 65% over the achievable rate using 4-CAP and OOK, respectively.
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| 6. |
- Haigh, Paul Anthony, et al.
(author)
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Hybrid Super-Nyquist CAP Modulation based VLC with Low Bandwidth Polymer LEDs
- 2019
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In: IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC. ; 2019-September
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Conference paper (peer-reviewed)abstract
- Visible light communication systems often suffer from high frequency attenuation when transmitting out-of-band. This effect has been ameliorated by multi-band modulations such as multi-band carrier-less amplitude and phase (m-CAP), which minimises the effect of decreased high frequency magnitude and maximises signal-to-noise ratio-per-sub-band. On the other hand, in the pass-band region, super-Nyquist CAP (SCAP) can offer throughput improvements with no additional complexity at the receiver, at the cost of bit error rate. We propose, for the first time, a new hybrid SCAP modulation format that takes advantageous of both SCAP (i.e. overlapped sub-bands within the modulation bandwidth) and conventional m-CAP (orthogonally spaced bands outside the modulation bandwidth) while maintaining isolation between noise sources. We show higher baud rates within the passband region whilst supporting out-of-band transmission at lower error vector magnitudes.
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| 7. |
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| 8. |
- Nopchinda, Dhecha, 1991, et al.
(author)
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Dual Polarization Coherent Optical Spectrally Efficient Frequency Division Multiplexing
- 2015
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In: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 28:1, s. 83-86
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Journal article (peer-reviewed)abstract
- A new optical spectrally efficient frequency division multiplexing technique, utilizing coherent detection and polarization division multiplexing, is proposed and demonstrated. The proposed system uses non-orthogonal and overlapping subcarriers to provide a significant reduction in both the electrical and optical bandwidth of up to 33%, relative to dual polarization orthogonal frequency division multiplexing (DP-OFDM), with an implementation penalty
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| 9. |
- Odedeyi, Temitope, et al.
(author)
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InP DHBT Single-Stage and Multiplicative Distributed Amplifiers for Ultra-Wideband Amplification
- 2020
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In: IEEE Transactions on Circuits and Systems I: Regular Papers. - 1549-8328 .- 1558-0806. ; 67:11, s. 3804-3814
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Journal article (peer-reviewed)abstract
- This paper highlights the gain-bandwidth merit of the single stage distributed amplifier (SSDA) and its derivative multiplicative amplifier topologies (i.e. the cascaded SSDA (C-SSDA) and the matrix SSDA (M-SSDA)), for ultra-wideband amplification. Two new monolithic microwave integrated circuit (MMIC) amplifiers are presented: An SSDA MMIC with 7.1dB average gain and 200GHz bandwidth; and the world's first M-SSDA, which has a 12dB average gain and 170GHz bandwidth. Both amplifiers are based on an Indium Phosphide DHBT process with 250nm emitter width. To the authors best knowledge, the SSDA has the widest bandwidth for any single stage amplifier reported to date. Furthermore, the three tier M-SSDA has the highest bandwidth and gain-bandwidth product for any matrix amplifier reported to date.
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| 10. |
- Odedeyi, Temitope, et al.
(author)
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Single-stage and multiplicative distributed amplifiers for 200GHz+ amplification
- 2019
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In: Asia-Pacific Microwave Conference Proceedings, APMC. ; 2019-December, s. 640-642
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Conference paper (peer-reviewed)abstract
- In this paper, we review the merit of the single stage distributed amplifier (SSDA) and consider the potential of its derivative multiplicative amplifier topologies (the cascaded and the matrix SSDA) for ultra-wideband amplification. We highlight the significant bandwidth advantage that the SSDA topology offers and the higher gain potential of multiplicative DAs compared to the conventional multi-stage DA. Furthermore, we describe how available design trade-offs may be used to offset inherent noise performance limitations of this family of distributed amplifiers. We also report a new SSDA MMIC with 7.1 dB gain at 200 GHz bandwidth and a high frequency gain tuning range of 5 dB to 12 dB, based on an Indium Phosphide DHBT process with 250 nm emitter width.
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