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We overview the technology of superconducting Hot-Electron Bolometer mixers in the field of terahertz heterodyne detection. HEB mixer performance is analyzed vs competing technologies and application fields, with emphasize on radio astronomy. We discuss materials which have been reported in the past to be used for such devices with both phonon-substrate and electron-diffusion cooling mechanisms. It...
The maximum clock rate of continuous-time ΔΣ modulators has increased dramatically over the past several years, showing that continuous-time systems can operate at higher rates than their discrete-time counterparts. This paper outlines the circuits and architectures that have led to these improvements and presents an analysis of the maximum clock rate of continuous-time ΔΣ modulators when limited...
This paper introduces filter bank multicarrier (FBMC) as a potential candidate in the application of massive MIMO communication. It also points out the advantages of FBMC over OFDM (orthogonal frequency division multiplexing) in the application of massive MIMO. The absence of cyclic prefix in FBMC increases the bandwidth efficiency. In addition, FBMC allows carrier aggregation straightforwardly. Self-equalization,...
We demonstrate robust error-free transmission of 51.56 Gbit/s PAM-4 over multiple examples of 100m of multimode fiber with 905nm VCSELs. We further demonstrate the need to include level dependent RIN when assessing impairments and predicting performance of PAM-4 MMF links.
We proposed optimal design of the post filter taps, for post filter + sequence detector receiver. The design is verified by detecting 56GBaud PDM-QPSK generated by commercial CMOS DACs with 11GHz analog bandwidth. Only 2.6dB@1e-2 penalty is observed.
Non-Coherent receivers are attractive for IR-UWB systems and are preferred over its coherent counterpart, because of its implementation simplicity and non-requirement of channel state information (CSI). UWB systems have a low Power Spectral Density (PSD) which limits it from achieving a wide coverage and high data rate despite, providing an adequate system performance. Hence, cooperative diversity...
An operational amplifier is described which uses separate loops to control the output voltage and the error voltage between its inputs. To a large extent this architecture combines the high-speed characteristics of “current feedback” amplifiers with the low input referred errors of precision architectures. The technique has been applied to produce an amplifier with precision characteristics comparable...
A novel completely inverter-based ADC driver is proposed that relaxes the gain and unity gain bandwidth requirements of the negative feedback loop by making it not see the closed loop gain. This ADC driver has a built-in first order anti alias filter and uses a passive amplifier to provide a rail-to-rail sampled output signal. This design exploits the linearity of current mirrors and achieves 65dB...
Method for calculation of maximum permissible field strength at fixed radio monitoring station site is suggested. If the field strength of the radio stations situated near radio monitoring station does not exceed the calculated value, then they do not cause radio interferences to the radio monitoring station.
In this paper, a distributed amplifier (DA) with a feed forward path is presented to reduce noise effects of input matching termination at the output. The proposed active termination (AT) technique also improves the amplifier gain without increasing its power consumption. To validate the introduced method, a four-stage wideband actively terminated DA (ATDA) is designed in a 0.18μm CMOS technology...
It is well known that rising anthropogenic underwater noise has chronic impacts on marine fauna. Since the contribution of navigation is particularly important to this kind of noise, areas near big harbors can be critically affected. One case of great environmental concern is the Port of Santos, the largest harbor in Latin America that, additionally, is expected to be expanded. The port is located...
This paper describes the implementation and the experimental performance of a spectrum sensing scheme, based on a Constant False Alarm Rate (CFAR) algorithm, for cognitive radio in TV white space (TVWS) operation. We use various signal profiles, representing an incumbent or primary user (PU) in the channel, along with a physical testbed to experimentally measure the detection of a PU signal over the...
Auditory evoked potentials (AEPs) are typically acquired at rates that facilitate their study as segregated by epochs relative to stimulus onset: early (ABR, 1.5–15 ms), middle (MLR, 15–60 ms), and late (LAEP, ≥60 ms) potentials. In particular, late AEPs are often acquired with stimulus repetition rates between 0.1 Hz and 1 Hz, and are bandpass filtered to contain information only within 1–30 Hz....
A low power, low noise implantable neural recording interface for use in a Radio-Frequency Identification (RFID) is presented in this paper. A two stage neural amplifier and 8 bit Pipelined Analog to Digital Converter (ADC) are integrated in this system. The optimized number of amplifier stages demonstrates the minimum power and area consumption; The ADC utilizes a novel offset cancellation technique...
We present the design and characterization of a broadband, low-noise transimpedance amplifier (TIA) with adjustable gain-peaking, implemented in 65-nm CMOS. The TIA exhibits 40-GHz bandwidth, 20-dB gain and consumes 107 mW power. An additional continuously-tunable 12-dB gain-peaking near 40 GHz is available through a simple yet effective tuning mechanism, consuming only 14% more power. The adjustable...
A low power, low noise implantable neural recording interface for use in a power harvested inductive coupling system is presented in this paper. A two stage neural amplifier, selective reference thresholder and a serial communication interface form the neural data logger. The midband gain of neural amplifier is 59.1dB with a 3dB bandwidth from 0.45 to 8 kHz. Input-referred noise and total power consumption...
This paper presents the design and characterization of a high gain, high-speed differential transimpedance amplifier (TIA) to be used as the front-end interface for optical receiver applications. The TIA is realized in a standard 0.18-µm digital CMOS technology and it dissipates 25.4mW from a single 1.8 V supply. The objective of the design is to maximize the bandwidth. The main contribution of this...
An area-efficient and low-power low-noise amplifier with adjustable parameters for bio-potential recording applications is presented. This amplifier replaces traditional analog filters using large AC coupling capacitor with the proposed DC offset suppression block based on Differential Difference Amplifier (DDA) structure, which allows the system to obtain good high pass characterization without using...
Ultra-wideband capacitively coupled phased array antennas for low and mid frequency radio astronomy are presented. Two distinct and novel broadband techniques are employed for the candidate current sheet models. One of the arrays is designed to operate from 250 MHz to 1.3 GHz while the other functions from 50 MHz to 400 MHz. The radiating arrays comprise synthetic periodic aperture of fractal plates,...
Since 2010 we have been developing a quantum-voltage-calibrated Johnson noise thermometer at NIM to measure the Boltzmann constant k. With recent improvements in grounding and shielding of the electronics, and matching of the noise sources and transmission lines, the effects of electromagnetic interference and variations of fitting parameters with different bandwidths were greatly reduced. By combining...
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