Spectrum analyzers advantages

Other demonstrated prototype devices include optical gyroscopes (144), broadband acoustic spectrum analyzers (145), 1x2 Y-fed directional couplers (146) and polarization-insensitive electrooptic modulators (147,148). For long-haul telecommimication applications, it is difficult to maintain polarization control thus, a need exists for polarization-insensitive modulators. Indeed, polarization insensitivity was one of the advantages claimed for gallium arsenide elec-troabsorptive modulators. By using different poling schemes, overall polarization insensitivity has been achieved for polymeric modulators (147,148). 

MAX/MIN A display mode on some spectrum analyzers that shows the maximum and minimum signal levels at alternate frequency points, its advantage is its resemblance to an analog display. 

This paper reports preliminary experiment where the human body was measured by a new experimental system. The previous experimental system consisted of a general-purpose spectrum analyzer that only measured amplitude of input signal in a certain frequency range. The new measurement system, introduced in this paper, consisted of a GNU Radio compliant peripheral and GNU Radio software. GNU Radio is an open source project where user can build special purpose receiver and transmitter in conjunction with a simplified peripheral. The measurement results indicated advantages of the new experimental system with GNU Radio. 

Advantages of the GNU Radio measurement system were discussed in comparison with the former system that consisted of generic spectrum analyzer. 

The term Q/TOF is used to describe a type of hybrid mass spectrometer system in which a quadrupole analyzer (Q) is used in conjunction with a time-of-flight analyzer (TOP). The use of two analyzers together (hybridized) provides distinct advantages that cannot be achieved by either analyzer individually. In the Q/TOF, the quadrupole is used in one of two modes to select the ions to be examined, and the TOF analyzer measures the actual mass spectrum. Hexapole assemblies are also used to help collimate the ion beams. The hybrid orthogonal Q/TOF instrument is illustrated in Figure 23.1. 

The advantages of this type of detector are that even a noisy photodiode can easily be turned into a quantum limited detector and that the spectrum of the source can be analyzed precisely. 

The ion-trap mass spectrometer uses three electrodes to trap ions in a small volume. The mass analyzer consists of a ring electrode separating two hemispherical electrodes. A mass spectrum is obtained by changing the electrode voltages to eject the ions from the trap. The advantages of the ion-trap mass spectrometer include compact size and the ability to trap and accumulate ions thus increasing the signal-to-noise ratio of a measurement [534,535,551, 553]. 

This spectrum is relatively simple compared to the absorption spectrum of the same molecule and therefore easy to analyze (see Fig. 5). The main advantage is that single lines can be resolved even with medium-resolution instruments and the quantum numbers of the levels involved can often be determined from a preliminary spectrum analysis using a fast monochromator run. 

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