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S. J. Mukhopadhyay et al.
4.1 Effect of Optical Illumination
The influence of photo-irradiation on the noise characteristics of Si IMPATT sources
has been studied by Acharyya et al. [22]. Top-mount (TM) and flip chip (FC) configurations of IMPATT diodes were considered for that study (see Fig. 5). It was observed
that the optical illumination causes significant degradation in the noise performance
of the source; however, this degradation is observed to be less in FC arrangement
than the TM (Fig. 5).
4.2 Influence of Magnetic Field
Influence of steady transverse magnetic field on the noise characteristics of Si
IMPATT sources was studied by Banerjee et al. [23]. It was found that the noise
performance deteriorated due to this effect (see Fig. 6).
4.3 Effect of Reduced Impact Ionization Rate
The influence of reduced ionization rates as a consequence of the energy loss of charge
carriers due to of inter-carrier collisions on noise properties of DDR Si IMPATT
sources has been studied by Bandhyopadhyay et al. [24]. It was reported that the
noise performance of the source slightly deteriorated as a result of this effect (see
Fig. 7).
5 Noise Characterizes of 3C-SiC IMPATT Sources
Noise performance of 3C-SiC-based IMPATT sources have been investigated by
using the simulation method described earlier in this chapter. The most important
performance-evaluating parameters associated with the avalanche noise, i.e., noise
measure of the above-mentioned sources, are calculated and those are compared with
the same parameters of Si and diamond IMPATT sources. The noise measure values
of Si, 3C-SiC, and diamond IMPATT sources obtained from fifteen trial simulation
runs have been plotted against frequency (Fig. 8). The noise measures of WBG
semiconductor (i.e., 3C-SiC and diamond)-based sources are found to be significantly
higher than those of usual Si-based IMPATT oscillators. Wider multiplication zones
of WBG IMPATT sources (see Fig. 8 of the earlier chapter) are responsible for higher
noise in those as compared to the Si IMPATTs. Moreover, 3C-SiC IMPATTs possess
slightly broader avalanche zones than the diamond IMPATTs (see Fig. 8 of the earlier
S. J. Mukhopadhyay et al.
4.1 Effect of Optical Illumination
The influence of photo-irradiation on the noise characteristics of Si IMPATT sources
has been studied by Acharyya et al. [22]. Top-mount (TM) and flip chip (FC) configurations of IMPATT diodes were considered for that study (see Fig. 5). It was observed
that the optical illumination causes significant degradation in the noise performance
of the source; however, this degradation is observed to be less in FC arrangement
than the TM (Fig. 5).
4.2 Influence of Magnetic Field
Influence of steady transverse magnetic field on the noise characteristics of Si
IMPATT sources was studied by Banerjee et al. [23]. It was found that the noise
performance deteriorated due to this effect (see Fig. 6).
4.3 Effect of Reduced Impact Ionization Rate
The influence of reduced ionization rates as a consequence of the energy loss of charge
carriers due to of inter-carrier collisions on noise properties of DDR Si IMPATT
sources has been studied by Bandhyopadhyay et al. [24]. It was reported that the
noise performance of the source slightly deteriorated as a result of this effect (see
Fig. 7).
5 Noise Characterizes of 3C-SiC IMPATT Sources
Noise performance of 3C-SiC-based IMPATT sources have been investigated by
using the simulation method described earlier in this chapter. The most important
performance-evaluating parameters associated with the avalanche noise, i.e., noise
measure of the above-mentioned sources, are calculated and those are compared with
the same parameters of Si and diamond IMPATT sources. The noise measure values
of Si, 3C-SiC, and diamond IMPATT sources obtained from fifteen trial simulation
runs have been plotted against frequency (Fig. 8). The noise measures of WBG
semiconductor (i.e., 3C-SiC and diamond)-based sources are found to be significantly
higher than those of usual Si-based IMPATT oscillators. Wider multiplication zones
of WBG IMPATT sources (see Fig. 8 of the earlier chapter) are responsible for higher
noise in those as compared to the Si IMPATTs. Moreover, 3C-SiC IMPATTs possess
slightly broader avalanche zones than the diamond IMPATTs (see Fig. 8 of the earlier