Terahertz Radiators Based on Silicon Carbide Avalanche Transit …
39
Fig. 1 a Schematic showing the reflection technique adopted by Hines [3] for realizing amplifier by
using a negative-resistance diode, b corresponding equivalent circuit, and c circuit for calculating
noise current
of IMPATT devices can be obtained if reliable ionization rate and drift velocity data
are taken into consideration. Some important results of his study have been shown
in Fig. 3. Etla and Haddad [8] in 1978 reported the existence of a clear trade-off
between noise level and power output for MITATT mode operation.
In the year 1996, noise simulation of MITATT devices was reported [9]. Design
of low-noise IMPATT diode having a noise measure of around 6.7 dB was achieved
from the simulation studies [10]. Recently, the authors carried out studies on the influence of parasitic series resistance on the noise characteristics of DDR Si IMPATTs
operating at W-band [11, 12]. Noise characteristics of 94 GHz DDR MITATT devices
based on Si ~ Si 1−x Ge x heterostructure were investigated by Banerjee et al. [13] in
2012. They showed that the avalanche noise in IMPATTs can be significantly reduced
by using anisotype Si ~ Si 1−x Ge x heterojunctions for which the preferred structure
was also suggested see Fig. 4).
39
Fig. 1 a Schematic showing the reflection technique adopted by Hines [3] for realizing amplifier by
using a negative-resistance diode, b corresponding equivalent circuit, and c circuit for calculating
noise current
of IMPATT devices can be obtained if reliable ionization rate and drift velocity data
are taken into consideration. Some important results of his study have been shown
in Fig. 3. Etla and Haddad [8] in 1978 reported the existence of a clear trade-off
between noise level and power output for MITATT mode operation.
In the year 1996, noise simulation of MITATT devices was reported [9]. Design
of low-noise IMPATT diode having a noise measure of around 6.7 dB was achieved
from the simulation studies [10]. Recently, the authors carried out studies on the influence of parasitic series resistance on the noise characteristics of DDR Si IMPATTs
operating at W-band [11, 12]. Noise characteristics of 94 GHz DDR MITATT devices
based on Si ~ Si 1−x Ge x heterostructure were investigated by Banerjee et al. [13] in
2012. They showed that the avalanche noise in IMPATTs can be significantly reduced
by using anisotype Si ~ Si 1−x Ge x heterojunctions for which the preferred structure
was also suggested see Fig. 4).