Browsing by Author "Hammer, Andreas"
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- A compact low-power 140-GHz low-noise amplifier with 19-dB gain and 7-dB NF
A4 Artikkeli konferenssijulkaisussa(2021) Ryynänen, Kaisa; Stadius, Kari; Hammer, Andreas; Varonen, Mikko; Forsten, Henrik; Kiuru, Tero; Viikari, Ville; Ryynänen, JussiThis paper describes the design of a 140-GHz low-noise amplifier in 130-nm SiGe BiCMOS technology. The circuit is aimed for a high integration-density imaging radiometer, where several receivers are integrated on the same die. Thus, we particularly focus on minimizing the die area and power consumption. The two-stage amplifier is composed of cascode stages with gain boosting base resonators. The performance of a single cascode stage is optimized by correctly sizing the base resonator to avoid instability and optimizing the compact transistor layout without typically used interstage matching between the cascode stages. The circuit features gain of 19 dB at 140 GHz, and noise figure of 7 dB, while consuming only 15 mW with the supply voltage of 2 V and occupying a die area of 0.1 mm2 - A Configurable Hysteresis Comparator for Asynchronous Sigma-Delta Modulators
A4 Artikkeli konferenssijulkaisussa(2018-12-13) Olabode, Olaitan; Unnikrishnan, Vishnu; Kempi, Ilia; Hammer, Andreas; Kosunen, Marko; Ryynänen, JussiThis paper describes a configurable hysteresis comparator for asynchronous sigma-delta modulators (ASDM). The proposed comparator provides coarse and fine tuning options for configuring the loop delay and hence the frequency of an ASDM. The post-layout simulation of the comparator implemented in a 28 nm FDSOI process shows that the comparator provides hysteresis voltage range of ±(1 to 15.3) mV while consuming 36.8 nW to 4.4 uW from 0.7 V supply, which enables configurable ASDM center-frequency in the range of 100 kHz to 6 MHz. - D-band balun suunnittelu, mallintaminen ja simuloiminen
Sähkötekniikan korkeakoulu | Bachelor's thesis(2021-05-16) Häkkinen, Micke - LDO-regulaattorin operaatiovahvistin- ja kompensaatiosuunnittelu
Sähkötekniikan korkeakoulu | Bachelor's thesis(2017-12-28) Räbinä, Henry - LDO-regulaattorin toiminta ja piirisuunnittelu
Sähkötekniikan korkeakoulu | Bachelor's thesis(2021-05-16) de Wit, Alvar - Nanolankatransistori
Sähkötekniikan korkeakoulu | Bachelor's thesis(2015-05-15) Hammer, Andreas - Power Management for Neural Signal Acquisition IC
Sähkötekniikan korkeakoulu | Master's thesis(2017-05-22) Hammer, AndreasWireless biosignal measurement is a growing opportunity to increase the efficiency of medical procedures: An integrated circuit (receiver) is implanted inside human tissue and it’s output can be read wirelessly with a transmitter that also provides energy for the implant. This method requires RFID technology, where wireless data is transmitted in the RF-band back-and-forth between the receiver and transmitter. The receiver can be implemented either as an active design, where a local power supply is required inside the receiver, or as a passive design without internal energy storage. However, as the modern CMOS process is fairly advanced and the power consumption is low - passive designs are the most common. In the passive design the power for the receiver is drawn from the electromagnetic field transmitted to the chip, generally with electromagnetic induction. A design and implementation of an 860 MHz UHF-band RFID power system is presented in this work and its performance evaluated. The system was designed for a wireless EEG (electroencephalography) reader that can be implanted under the skalp – but the design principles can be expanded upon any RF-band RFID system. The final system works with an input power of -6.8 dBm with a startup time of slightly below 40 µs with specifications of 700 mV to 150 µA load. The LDO line regulation achieves a -51 dB level at DC with the full bandwidth covered. The RF Rectifier uses the design principles of a cross-coupled rectifier and a 63% conversion efficiency is achieved with the proposed matching circuitry. The reference circuitry is designed with the Betamultiplier architecture and expanded slightly to improve the current consumption in the circuit. The reference current is set at 100 nA and reference voltage at 400 mV. - Radiotaajuuksinen induktiivinen tehonsiirto ja impedanssisovitus
Sähkötekniikan korkeakoulu | Bachelor's thesis(2017-12-04) Huynh, Jin-Long - Resilient flow control for wireless data streaming in inductively coupled medical implants
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2020-02-01) Kempi, Ilia; Ahmed, Nouman; Hammer, Andreas; Olabode, Olaitan; Unnikrishnan, Vishnu; Kosunen, Marko; Ryynänen, JussiThis paper describes the hardware implementation of a custom communication protocol tailored for low power telemetry data streaming over an inductive link. An efficient transceiver design is achieved by adapting only the essential physical layer features of a typical RFID baseband processor and optimizing the flow control logic for continuous and reliable data transfer. For the external near-field reader, we provide a logical model for receiver operation and suggest a simple forward error correction (FEC) mechanism. The benefit of FEC in the context of developed communication system is demonstrated by simulations, and projections of design scalability are also presented. The proposed communication system was implemented in 28nm CMOS process. Place-and-route (PNR) results occupy only 0.0048 mm2 of core area, and the transient simulations show a power consumption of 306 nW at 0.5 V supply and a master clock of 845.7 kHz. The implementation provides an uplink rate of 12 kbit/s, sufficient for reliable transmission of a 1-channel 1 kS/s 12-bit sample recording. - RF-to-Digital kommunikaatiometodit SoC applikaatioille
Sähkötekniikan korkeakoulu | Bachelor's thesis(2019-05-12) Hirvonen, Elias - Sub-1 V output-capacitor-less low-dropout regulator with two compensation amplifiers for enhanced power supply rejection
A4 Artikkeli konferenssijulkaisussa(2020) Hammer, Andreas; Kempi, Ilia; Olabode, Olaitan; Kosunen, MarkoIn this paper we propose two methods to boost the power supply rejection (PSR) of an output-capacitor-less low-dropout regulator (LDO). Our LDO is targeted for low-power system-on-chip applications, such as medical electronics, RFIDs, and IoT devices, where applied energy harvesting techniques induce large voltage ripple to supply line, thus requiring high PSR out of the LDO. The regulator utilizes a feed-forward path through the amplifier power supply rail to pass-transistor gate. Furthermore it includes a feed-forward amplifier to improve the frequency response and a feedback amplifier to stabilize the LDO, eliminating the need for an area consuming compensation capacitor. The proposed LDO is implemented in 28-nm CMOS technology. It supplies 700-mV output level with a current range of 0-5 mA and a 100-mV dropout voltage. The three amplifiers within our LDO consume only a total of 13 μA, thus regardless of increased complexity, high current efficiency of 99.74% is maintained. At the nominal load of 1 mA, low-frequency PSR reaches a value of -97 dB and at the high-frequency range of 1-20 MHz PSR is boosted to remain below -20 dB and the region of 3-10 MHz below -30 dB.