Compound semiconductor detectors such as CdTe, CdZnTe, HgI2 and TlBr are known to exhibit large variations in their charge collection times. This paper considers the effect of such variations on the measurement of induced charge pulses by using resistive feedback charge-sensitive preamplifiers. It is shown that, due to the finite decaytime constant of the preamplifiers, the capacitive decay dur...

The main objective of this dissertation is to optimize system performance at the photodetection end. Since the optical signal is typically at its weakest power level when it arrives at the receiver, it is important to account for the various noise mechanisms which affect the signal-to-noise ratio (SNR) and degrade the fidelity of the communicated waveform. This chapter presents a brief discussi...

Different application fields require the development of charge preamplifiers to be coupled with dedicated radiation detectors. In view fast prototyping and targeting a medium number readout channels, there are several advantages in use operational amplifiers (OpAmps) for forward gain stage shaping filters. this paper we present feasibility study, design qualification an OpAmp-based, preamplifie...

In this paper, a four-point characterization method is developed for samples that have either capacitive or ohmic contacts. When capacitive contacts are used, capacitive current- and voltage-dividers result in a capacitive scaling factor not present in four-point measurements with only ohmic contacts. From a circuit equivalent of the complete measurement system, one can determine both the measu...

The tuning and matching conditions of rf circuits, as well as the properties of the transmission lines connecting these to the preamplifier, have direct consequences for NMR probe sensitivity and as for the optimum delivery of rf power to the sample. In addition, tuning/matching conditions influence radiation damping effects, which manifest themselves as fast signal flip-back and line broadenin...

Biopotential signal recording is often affected by noise during recording. There is a large body of literature on noise removal techniques for every class of biopotential signals. However, obtaining clean recording is preferable to cleaning a noisy recording. An instantaneous quality measure of the signal to noise ratio during recording would be invaluable in correcting a defective recording si...

So effectively, you can say that the capacitor acts as a low-pass filter when it in a transistor circuit, it blocks the DC and acts as a low impedance path for AC. Official Full-Text Publication: Single Transistor Active Filters: What is Possible and The results presented here fill both a circuit-theoretic gap and an application-oriented gap related to single a case is the low-pass filter numbe...

Cortical layering is a hallmark of the mammalian neocortex and a major determinant of local synaptic circuit organization in sensory systems. In motor cortex, the laminar organization of cortical circuits has not been resolved, although their input-output operations are crucial for motor control. Here, we developed a general approach for estimating layer-specific connectivity in cortical circui...

We report on the fabrication and characterization of solid-state thermal neutron detectors with detection areas up to 16 cm that require only a single preamplifier for data acquisition. These detectors consist of a honeycomb-like micro-structured Si diode with boron-10 filled deep holes. A continuous p–n junction formed over the entire surface of the microstructure helps to achieve a low leakag...

HAL25 is a mixed low noise, low power consumption and radiation hardened ASIC intended for the Silicon Strip Detectors (SSD) read out in the ALICE tracker. It is designed in a 0.25 micron CMOS process. It contains 128 analogue channels, consisting each of a preamplifier, a shaper and a storage capacitor. The analogue data is sampled by an external logic signal and then is serially read out thro...