Yiannis Kokolakis
Broadcom
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Publication
Featured researches published by Yiannis Kokolakis.
IEEE Journal of Solid-state Circuits | 2003
Iason Vassiliou; Kostis Vavelidis; Theodore Georgantas; Sofoklis Plevridis; Nikos Haralabidis; George Kamoulakos; Charalambos Kapnistis; Spyros Kavadias; Yiannis Kokolakis; Panagiotis Merakos; Jacques C. Rudell; Akira Yamanaka; Stamatis Bouras; Ilias Bouras
The drive for cost reduction has led to the use of CMOS technology in the implementation of highly integrated radios. This paper presents a single-chip 5-GHz fully integrated direct conversion transceiver for IEEE 802.11a WLAN systems, manufactured in 0.18-/spl mu/m CMOS. The IC features an innovative system architecture which takes advantage of the computing resources of the digital companion chip in order to eliminate I/Q mismatch and achieve accurately matched baseband filters. The integrated voltage-controlled oscillator and synthesizer achieve an integrated phase noise of less than 0.8/spl deg/ rms. The receiver has an overall noise figure of 5.2 dB and achieves sensitivity of -75 dBm at 54-Mb/s operation, both referred to the IC input. The transmit error vector magnitude is -33 dB at -5-dBm output power from the integrated power-amplifier driver amplifier. The transceiver occupies an area of 18.5 mm/sup 2/.
IEEE Journal of Solid-state Circuits | 2008
Iason Vassiliou; Kostis Vavelidis; Nikos Haralabidis; Aris Kyranas; Yiannis Kokolakis; Stamatis Bouras; George Kamoulakos; Charalambos Kapnistis; Spyros Kavadias; Nikos Kanakaris; Emmanouil Metaxakis; Christos Kokozidis; Hamed Peyravi
This paper presents a direct conversion, multistandard TV tuner implemented on a 65 nm digital CMOS process occupying less than 7 . The tuner is compliant with several digital terrestrial, fixed and mobile TV standards, including DVB-T, DVB-H, T-DMB, and ISDB-T. It achieves a 3/3.2/3.5 dB noise figure at VHF, UHF, and L-band, respectively, while the measured sensitivity at UHF for the QPSK-frac12 DVB-T mode is at the PCB connector. The implemented RF front-ends support both single-ended and differential inputs. An integrated - fractional-N synthesizer operating from 1.2 to 1.8 GHz achieves less than 1 integrated phase error, thus enabling a maximum SNR in excess of 37 dB for VHF and UHF. Multistandard capability is also enabled by programmable channel-select filters. Power consumption is less than 140 mW in DVB-T mode for all three bands.
international solid-state circuits conference | 2003
J. Bouras; Stamatis Bouras; Theodore Georgantas; Nikos Haralabidis; G. Kamoulakos; Charalampos Kapnistis; S. Kavadias; Yiannis Kokolakis; P. Merakos; Jacques C. Rudell; Sofoklis Plevridis; Iason Vassiliou; Kostis Vavelidis; A. Yamanaka
This transceiver achieves a transmit 1dB output compression point of +15dBm, and the overall receiver noise figure is 5dB. A power gain range of >45dB/65dB for transmit/receive and a PLL synthesizer frequency range of 4.9 to 5.85GHz with -79dBc/Hz phase noise at 10kHz offset have been measured. The IC is realized in 0.5/spl mu/m SiGe BICMOS technology and occupies 17mm/sup 2/.
IEEE Journal of Solid-state Circuits | 2004
Kostis Vavelidis; Iason Vassiliou; Theodore Georgantas; Akira Yamanaka; S. Kavadias; George Kamoulakos; Charalambos Kapnistis; Yiannis Kokolakis; Aris Kyranas; P. Merakos; Ilias Bouras; Stamatis Bouras; Sofoklis Plevridis; Nikos Haralabidis
A single-chip dual-band 5.15-5.35-GHz and 2.4-2.5-GHz zero-IF transceiver for IEEE 802.11a/b/g WLAN systems is fabricated on a 0.18-/spl mu/m CMOS technology. It utilizes an innovative architecture including feedback paths that enable digital calibration to help eliminate analog circuit imperfections such as transmit and receive I/Q mismatch. The dual-band receive paths feature a 4.8-dB (3.5-dB) noise figure at 5.25 GHz (2.45 GHz). The corresponding sensitivity at 54 Mb/s operation is -76 dBm for 802.11a and -77 dBm for 802.11g, both referred at the input of the chip. The transmit chain achieves output 1-dB compression at 6 dBm (9 dBm) at 5 GHz (2.4 GHz) operation. Digital calibration helps achieve an error vector magnitude (EVM) of -33 dB (-31 dB) at 5 GHz (2.4 GHz) while transmitting -4 dBm at 54Mb/s. The die size is 19.3 mm/sup 2/ and the power consumption is 260 mW for the receiver and 320 mW (270 mW) for the transmitter at 5 GHz (2.4 GHz) operation.
international solid-state circuits conference | 2006
Iason Vassiliou; Kostis Vavelidis; Stamatis Bouras; S. Kavadias; Yiannis Kokolakis; G. Kamoulakos; Aris Kyranas; Charalampos Kapnistis; Nikos Haralabidis
A 0.18mum CMOS direct-conversion dual-band DVB-H receiver occupies 9.7mm2 and achieves a 4dB/5dB NF at UHF/L-band, eliminating the need for an external LNA. By using a fractional-N synthesizer, the 470 to 890MHz and 1.4 to 1.8GHz bands are supported while achieving an integrated phase noise of <-41dBc. 6th-order LPF support channel bandwidths from 4 to 10 MHz. The overall power consumption is 295mW/280mW for continuous operation in the UHF/L-band, respectively
european solid-state circuits conference | 2007
Kostis Vavelidis; Iason Vassiliou; Nikos Haralabidis; Aristeidis I. Kyranas; Yiannis Kokolakis; Stamatis Bouras; Georgios S. Kamoulakos; Charalampos Kapnistis; S. Kavadias; Nikos Kanakaris; E. Metaxakis; Christos Kokozidis; Hamed Peyravi
A direct conversion, 65 nm CMOS multi-standard TV tuner is presented, which is compliant with several digital terrestrial, fixed and mobile TV standards (DVB-T, DVB-H, T-DMB and ISDB-T, including 1-3 segment). The tuner achieves a 3/3/2.8 dB NF at VHF, UHF and L-band respectively, while consuming less than 140 mW in DVB-T mode. By using integrated transformers, both single-ended and differential RF inputs are supported. Multi-standard capability is enabled by programmable channel-select filters and a Sigma-Delta fractional-N synthesizer.
european solid-state circuits conference | 2003
Kostis Vavelidis; Iason Vassiliou; T. Georgantas; A. Yamanaka; S. Kavadias; Georgios S. Kamoulakos; Charalampos Kapnistis; Yiannis Kokolakis; Aristeidis I. Kyranas; P. Merakos; I. Bouras; Stamatis Bouras; S. Plevridis; Nikos Haralabidis
A dual band, 5.15GHz-5.35GHz, 2.4GHz-2.5GHz, zero-IF transceiver is fabricated on a 0.18/spl mu/m CMOS process. The fully integrated synthesizer and VCO achieve an integrated phase error of 0.8/spl deg/ at 5GHz. The transmitter achieves -33dB EVM, while the receiver features a 5.2dB noise figure (NF) at 5.25GHz and 3.5dB NF at 2.45GHz. An architecture including feedback paths enables digital calibration, which help eliminate I/Q mismatch and achieve accurately matched baseband filter tuning.
radio and wireless symposium | 2006
Iason Vassiliou; Kostis Vavelidis; Nikos Haralabidis; S. Kavadias; Stamatis Bouras; Georgios S. Kamoulakos; Charalampos Kapnistis; Yiannis Kokolakis; Aristeidis I. Kyranas; E. Metaxakis; Sofoklis Plevridis; P. Merakos; Kosmas Tsilipanos
A zero-IF, 4.9-5.95 GHz, 2.3-2.5 GHz, transceiver is fabricated on a 0.18 /spl mu/m CMOS process. By using a fractional-N synthesizer, an integrated phase error of 0.6/spl deg/ (0.7/spl deg/) at 5 GHz (2.4 GHz) is achieved, while supporting fine frequency resolution. Digital calibration eliminates I/Q mismatch and achieves accurately matched baseband filters. The transceiver is compliant to 802.11a/b/g, while programmable bandwidth filters and an EVM of -35 dB in both transmit and receive, make it suitable for applications based on 802.16d/e.
custom integrated circuits conference | 2004
Nikos Haralabidis; Kostis Vavelidis; Iason Vassiliou; Theodore Georgantas; Akira Yamanaka; Spyros Kavadias; George Kamoulakos; Charalampos Kapnistis; Yiannis Kokolakis; Aris Kyranas; P. Merakos; Ilias Bouras; Stamatis Bouras; Sofoklis Plevridis
A single-chip 2.4 GHz, zero-IF transceiver for IEEE 802.11 b/g WLAN systems is fabricated on a 0.18 /spl mu/m CMOS technology. Based on an innovative system architecture using digital calibration, analog circuit imperfections are eliminated. The transceiver features enhanced phase noise performance with the use of a fractional-N synthesizer. A switched configuration allows for the same filters to be used on both TX/RX paths, thus minimizing area. It features a NF of 3.5 dB while the sensitivity is -78 dBm at 54 Mb/s operation, referred at the input of the chip. The transmit output 1 dB compression point is 9 dBm. Digital calibration helps achieve an EVM of -31 dB while transmitting -4 dBm at 54 Mb/s.
radio frequency integrated circuits symposium | 2014
Sofoklis Plevridis; Kostis Vavelidis; Nikos Haralabidis; Theodore Georgantas; Stamatis Bouras; Charalampos Kapnistis; Eleni Kytonaki; Yiannis Kokolakis; Theodoros Chalvatzis; S. Kavadias; Hamed Peyravi; Nikos Kanakaris; Christos Kokozidis; Spyridon Liolis; Kosmas Tsilipanos; Aris Kyranas; Chrysostomos Xesternos; Panagiotis Betzios; Ilias Bouras; Maryam Rofougaran
Last mile residential connectivity and the demand for increased indoor coverage and capacity in 3G cellular systems has led to the commercial introduction of femtocell (Home Node B) base stations. To achieve higher component integration, support additional functionality, and decrease power, there is a need to minimize component count, PCB area and power consumption without sacrificing performance, while also preserving backwards-compatibility with legacy 2G systems. In this paper, we present a 65nm CMOS 3G/HSPA+ femtocell transceiver with 350mW power consumption that eliminates the need for Tx SAW filters. The proposed solution supports 10 TX (Downlink) and 10+10 (Downlink+Uplink) RX UMTS bands from Band I to Band VI and Band VIII to Band XI, quad-band GSM sniffing and GPS band receive capability for soft GPS operation.