نتایج جستجو برای: spectrum analyzer
تعداد نتایج: 240765 فیلتر نتایج به سال:
This paper describes the waveform reconstruction method of the electric field emitted by UWB (ultra wideband) device by using the complex antenna factor and observed waveform with an oscilloscope. The waveform radiated by a doubleridged guide horn antenna and an impulse generator was measured by an oscilloscope and was reconstructed by the method. The peak power measurement using a resolution b...
We discuss the fundamental limits of fiber Bragg grating (FBG) wavelength metrology. High-accuracy wavelength measurements are critical for FBG strain sensors because a wavelength measurement uncertainty as small as 1 pm leads to an uncertainty of nearly 1 microstrain. We compare the measurement uncertainties for several common wavelengthmeasurement systems, including tunable laser, optical spe...
Abstract –The propagation path loss models may give different results if they are used in different environment other than in which they were designed. In this paper we compare the different path loss propagation models with measured field data. For comparative analysis we use the log distance path loss model, Stanford University Interim (SUI) Model, Hata model, Okumura’s Model, COST231 Extensi...
Many attempts have been made to automate the process through which vibration signals are analyzed to pinpoint a machine fault. Detailed diagnostic vibration analysis is often performed using portable spectrum analyzers that implement Fast Fourier Transform (FFT) mathematics on the vibration signal. In some instances, only a trained analyst can interpret the vibration data, effectively diagnose ...
The two most common errors in the measuring process are (1) failure to provide adequate isolation between the two input signal generators and proper impedance matching, and (2) insufficient filtering of the two input test signals. Without adequate isolation and matching, interaction between the test generators and the device-under-test may produce significant errors (as high as 20 dB). Without ...
In this paper we are studying the power line channel noise in the frequency domain. The noise is measured using a spectrum analyzer. The channel noise profile is essential when OFDM is applied. Moreover, noise measurements are statistically processed in order to extract the probability density functions of the noise power for more than 120 different frequencies in the frequency range 1.15MHz-30...
Worldwide Interoperability for Microwave Access (WiMAX), based on the IEEE 802.16 standards, is a technology that offers low cost mobile broadband access to multimedia and internet applications for operators and end-users. Similarly to cellular phone or other Radio Frequency devices, WiMAX has to be considered as a possible source of electromagnetic pollution and so monitoring its emission coul...
Future wireless communication systems have to address a number of challenges including the massive growth of traffic volume, number of connected devices and a wide range of new applications and operating conditions. Therefore, adaptability and extensibility at all layers of a communication system is of great importance in order to meet the desired goals. In this demonstration, we showcase a pro...
We demonstrate a novel method for spectral analysis of microwave signals that employs time-domain processing in fiber. We use anomalous dispersion in single-mode fiber to perform a Fresnel transform followed by a matched amount of dispersion-compensating fiber to perform an inverse Fresnel transform of an ultrashort pulse. After the Fresnel-transformed waveform is modulated by the microwave sig...
Stampfli has shown that for a given T £ B(H) there exists a K £ C(H) so that o(T + K) = ow(T). An analogous result holds for the essential numerical range We(T). A compact operator K is said to preserve the Weyl spectrum and essential numerical range of an operator T £ B(H) if o(T + K) = o„(T) and W(T + K)= We(T). Theorem. For each block diagonal operator T, there exists a compact operator K wh...
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