626 research outputs found
A fully balanced first order high-pass filter
The topic of this article is the design of a fully balanced first-order high-pass filter and its two circuits. The first circuit is a fully balanced current-tunability first-order high-pass filter consisting of four NPN transistors and a single capacitor, which is a simple design and quite compact. The pole frequency can be adjusted with a bias current. The results of the first circuit shows the phase and gain responses, the phase and gain responses when adjusted with a bias current, the time-domain response, and the harmonic spectrum. However, this circuit found a flaw in the temperature that affects the pole frequency, and total harmonic distortion is relatively high. Therefore, the second circuit improves defects by the CAPRIO technique to reduce the total harmonic distortion, and the resistors in the circuit are added to the design to replace the resistance and the effect of temperature on the properties of the transistor. This circuit consists of four NPN transistors, four resistors, and a single capacitor. The resistors in this circuit can be adjusted to change the pole frequency and voltage gain. The results of the second circuit show the gain and phase responses of the proposed circuits, the phase and gain responses when adjusted to the value of the resistor, the phase and gain responses at various temperatures, as well as their time-domain responses and total harmonic signal distortion. The all-pass filter is also made using the filter introduced in the second circuit because of its voltage gain-adjustable property. So, if the suggested circuit is constructed in combination with a buffer circuit to make it feasible to function as an all-pass filter, the result will be an all-pass filter. In accordance with the results of this study, we have introduced a design for a high-pass filter to reduce total harmonic distortion and the effect of temperatur
A miniature tunable quadrature shadow oscillator with orthogonal control
This article presents a new design of a quadrature shadow oscillator. The oscillator is realized using one input and two outputs of a second-order filter cell together with external amplifiers in a feedback configuration. The oscillation characteristics are controlled via the external gain without disturbing the internal filter cell, following the concept of the shadow oscillator. The proposed circuit configuration is simple with a small component-count. It consists of, two voltage-different transconductance amplifiers (VDTAs) along with a couple of passive elements. The frequency of oscillation (FO) and the condition of oscillation (CO) are controlled orthogonally via the dc bias current and external gain. Moreover, with the addition of the external gain, the frequency range of oscillation can be further extended. The proposed work is verified by computer simulation with the use of 180 nm complementary metal–oxide–semiconductor (CMOS) model parameters. The simulation gives satisfactory results of two sinusoidal output signals in quadrature with some small total harmonic distortions (THD). In addition, a circuit experiment is performed using the commercial operational transconductance amplifiers LM13700 as the active components. The circuit experiment also demonstrates satisfactory outcome which confirms the validity of the proposed circuit
Switchable wideband receiver frontend for 5G and satellite applications
Modern day communication architectures provides the requirement for interconnected
devices offering very high data rate (more than 10 Gbps), low latency,
and support for multiple service integration across existing communication generations
with wideband spectrum coverage. An integrated satellite and 5G architecture
switchable receiver frontend is presented in this thesis, consisting of
a single pole double throw (SPDT) switch and two low noise amplifiers (LNAs)
spanning X-band and K/Ka-band frequencies. The independent X-band LNA
(8-12 GHz) has a gain of 38 dB at a centre design frequency of 9.8 GHz, while
the K/Ka-band (23-28 GHz) has a gain of 29 GHz at a centre design frequency
of 25.4 GHz. Both LNAs are a three-stage cascaded design with separated gate
and drain lines for each transistor stage.
The broadband high isolation single pole double throw (SPDT) switch based on
a 0.15 μm gate length Indium Gallium Arsenide (InGaAs) pseudomorphic high
electron transistor (pHEMT) is designed to operate at the frequency range of
DC-50 GHz with less than 3 dB insertion loss and more than 40 dB isolation.
The switch is designed to improve the overall stability of the system and the
gain. A gain of about 25 dB is achieved at 9.8 GHz when the X-band arm is
turned on and the K/Ka-band is turned off. A gain of about 23 dB is achieved
at 25.4 GHz when the K/Ka-band arm is turned on and the X-band arm is
off. This presented switchable receiver frontend is suitable for radar applications,
5G mobile applications, and future broadband receivers in the millimetre wave
frequency range
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Conformable transistors for bioelectronics
The diversity of network disruptions that occur in patients with neuropsychiatric disorders creates a strong demand for personalized medicine. Such approaches often take the form of implantable bioelectronic devices that are capable of monitoring pathophysiological activity for identifying biomarkers to allow for local and responsive delivery of intervention. They are also required to transmit this data outside of the body for evaluation of the treatment’s efficacy.
However, the ability to perform these demanding electronic functions in the complex physiological environment with minimum disruption to the biological tissue remains a big challenge. An optimal fully implantable bioelectronic device would require each component from the front-end to the data transmission to be conformable and biocompatible. For this reason, organic material-based conformable electronics are ideal candidates for components of bioelectronic circuits due to their inherent flexibility, and soft nature.
In this work, first an organic mixed-conducting particulate composite material (MCP) able to form functional electronic components and non-invasively acquire high–spatiotemporal resolution electrophysiological signals by directly interfacing human skin is presented. Secondly, we introduce organic electrochemical internal ion-gated transistors (IGTs) as a high-density, high-amplification sensing component as well as a low leakage, high-speed processing unit.
Finally, a novel wireless, battery-free strategy for electrophysiological signal acquisition, processing, and transmission that employs IGTs and an ionic communication circuit (IC) is introduced. We show that the wirelessly-powered IGTs are able to acquire and modulate neurophysiological data in-vivo and transmit them transdermally, eliminating the need for any hard Si-based electronics in the implant
Radiation Tolerant Electronics, Volume II
Research on radiation tolerant electronics has increased rapidly over the last few years, resulting in many interesting approaches to model radiation effects and design radiation hardened integrated circuits and embedded systems. This research is strongly driven by the growing need for radiation hardened electronics for space applications, high-energy physics experiments such as those on the large hadron collider at CERN, and many terrestrial nuclear applications, including nuclear energy and safety management. With the progressive scaling of integrated circuit technologies and the growing complexity of electronic systems, their ionizing radiation susceptibility has raised many exciting challenges, which are expected to drive research in the coming decade.After the success of the first Special Issue on Radiation Tolerant Electronics, the current Special Issue features thirteen articles highlighting recent breakthroughs in radiation tolerant integrated circuit design, fault tolerance in FPGAs, radiation effects in semiconductor materials and advanced IC technologies and modelling of radiation effects
Low Power Memory/Memristor Devices and Systems
This reprint focusses on achieving low-power computation using memristive devices. The topic was designed as a convenient reference point: it contains a mix of techniques starting from the fundamental manufacturing of memristive devices all the way to applications such as physically unclonable functions, and also covers perspectives on, e.g., in-memory computing, which is inextricably linked with emerging memory devices such as memristors. Finally, the reprint contains a few articles representing how other communities (from typical CMOS design to photonics) are fighting on their own fronts in the quest towards low-power computation, as a comparison with the memristor literature. We hope that readers will enjoy discovering the articles within
Integrated Electronics for Wireless Imaging Microsystems with CMUT Arrays
Integration of transducer arrays with interface electronics in the form of single-chip CMUT-on-CMOS has emerged into the field of medical ultrasound imaging
and is transforming this field. It has already been used in several commercial products such as handheld full-body imagers and it is being implemented by commercial and academic groups for Intravascular Ultrasound and Intracardiac Echocardiography. However, large attenuation of ultrasonic waves transmitted through
the skull has prevented ultrasound imaging of the brain. This research is a prime
step toward implantable wireless microsystems that use ultrasound to image the
brain by bypassing the skull. These microsystems offer autonomous scanning
(beam steering and focusing) of the brain and transferring data out of the brain for
further processing and image reconstruction.
The objective of the presented research is to develop building blocks of an integrated electronics architecture for CMUT based wireless ultrasound imaging systems while providing a fundamental study on interfacing CMUT arrays with their
associated integrated electronics in terms of electrical power transfer and acoustic
reflection which would potentially lead to more efficient and high-performance
systems.
A fully wireless architecture for ultrasound imaging is demonstrated for the
first time. An on-chip programmable transmit (TX) beamformer enables phased
array focusing and steering of ultrasound waves in the transmit mode while its
on-chip bandpass noise shaping digitizer followed by an ultra-wideband (UWB)
uplink transmitter minimizes the effect of path loss on the transmitted image data
out of the brain. A single-chip application-specific integrated circuit (ASIC) is de-
signed to realize the wireless architecture and interface with array elements, each
of which includes a transceiver (TRX) front-end with a high-voltage (HV) pulser,
a high-voltage T/R switch, and a low-noise amplifier (LNA). Novel design techniques are implemented in the system to enhance the performance of its building
blocks.
Apart from imaging capability, the implantable wireless microsystems can include a pressure sensing readout to measure intracranial pressure. To do so, a
power-efficient readout for pressure sensing is presented. It uses pseudo-pseudo
differential readout topology to cut down the static power consumption of the sensor for further power savings in wireless microsystems.
In addition, the effect of matching and electrical termination on CMUT array
elements is explored leading to new interface structures to improve bandwidth
and sensitivity of CMUT arrays in different operation regions. Comprehensive
analysis, modeling, and simulation methodologies are presented for further investigation.Ph.D
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