The paper presents verification of a peak detection method cooperating with infrared radiation detector module applications. The work has been divided into parts including SPICE simulations and presentation of results obtained with the constructed prototype. The design of the peak detector dedicated to applications with very short pulses requires a different approach than that for standard solutions. It is mainly caused due to the ratio of pulse width and time period. In the described application this ratio is less than 10%. The paper shows testing of an analogue circuit which is capable to be inserted in these applications.
The paper presents a low noise voltage FET amplifier for low frequency noise measurements. It was built using two stages of an op amp transimpedance amplifier. To reduce voltage noise, eight-paralleled low noise discrete JFETs were used in the first stage. The designed amplifier was then compared to commercial ones. Its measured value of voltage noise spectral density is around 24 nV/√ Hz, 3 nV/√ Hz, 0.95 nV/√Hz and 0.6 nV/√ Hz at the frequency of 0.1, 1, 10 and 100 Hz, respectively. A −3 dB frequency response is from ∼ 20 mHz to ∼ 600 kHz.
The paper is a review of analog and digital electronics dedicated to monitor nanosecond pulses. Choosing the optimal peak detector construction depends on many factors for example precision, complexity, or costs. The work shows some virtues and limitations of selected peak detection methods, for example standard peak detector with rectifier, sample and hold circuit with triggering units and ADC fast acquisition. However, the main attention is paid to problems of results from effective triggering signal for sample and hold operation. The obtained results allow for designing a peak detector construction as an alternative for costly and very complex fast acquisition systems based on ADC and FPGA technologies.
This paper presents some construction analysis and test results of a Free Space Optics system operating at the wavelength of 9.35 μm. In the system, a quantum cascade laser and a photoreceiver with mercury cadmium telluride photodetectors were used. The main parameters of these elements were discussed taking into account a data link operation. It also provides to determine a data range for various weather conditions related to scattering and scintillation. The results of numerical analyses defined the properties of currently available FSO technologies working in the near infrared or in the short infrared range of spectrum versus the performances of the developed system. The operation of this system was verified in three different test environments. The obtained results may also contain important issues related to the practical application of any FSO system.