1.0 THz GaN IMPATT Source: Effect of Parasitic Series Resistance

1.0–10.0 THz Radiation from Graphene Nanoribbon Based Avalanche Transit Time Sources

“…Therefore, it is quite clear that the primary limitation of already developed solid‐state terahertz generators is the output power which is limited up to few microwatts. However, two‐terminal IMPATT sources based on some wide bandgap (WBG) semiconductors such as Wz‐GaN, 4H‐SiC, type‐IIb diamond, etc., have immense potentiality to deliver terahertz power in milliwatt range . But, no researcher able to fabricate WBG semiconductor based terahertz IMPATT diode till date, due to the lack of mature process technology of the materials under consideration for the dimensions in the order of sub‐micrometers (<1 µm) required for fabricating terahertz diodes.…”

Terahertz wave radiation from mutually injection locked multi‐element graphene nanoribbon avalanche transit time sources

“…In the same figure the simulated and experimentally measured power outputs of IMPATT sources based on Si, GaAs, InP, type-IIb diamond and Wurtzite (Wz)-GaN are also shown. [39][40][41][42][43][44][45][46][47][48] It is interesting to observe from Figure 13 that the power output of ten-element mutually injection locked G-IMPATT source exceeds the power output of most promising Wz-GaN IMPATT source when the frequency of operation increases up to 5.0 THz. Therefore, mutually injection locked N-element (N ≥ 10) G-IMPATT sources operating in PCPC mode is the best choice for generating THz frequencies greater than 5.0 THz.…”

Three‐Terminal Graphene Nanoribbon Tunable Avalanche Transit Time Sources for Terahertz Power Generation

“…The RF power output of the sources is observed to be increased due to the application of nonzero V G ; it is illustrated in Figure a–c. Variations of RF power output of standalone IMPATT sources based on conventional semiconductors such as Wz‐GaN, 4H‐SiC, type‐IIb diamond, GaAs, InP, and Si with frequency obtained from simulation and/or experiments (where available) have been shown in Figure a . RF power outputs achieved from PCPC G‐IMPATT sources ( N = 10) operating at different millimeter‐wave and THZ frequencies have been compared with the RF power outputs obtained from the IMPATT sources based on conventional semiconductors as mentioned earlier in Figure a.…”

“…The RF power output of the sources is observed to be increased due to the application of nonzero V G ; it is illustrated in Figure 9a-c. Variations of RF power output of standalone IMPATT sources based on conventional semiconductors such as Wz-GaN, 4H-SiC, type-IIb diamond, GaAs, InP, and Si with frequency obtained from simulation and/or experiments (where available) have been shown in Figure 9a. [25][26][27][108][109][110][111][112][113][114] RF power outputs achieved from PCPC G-IMPATT sources (N ¼ 10) operating at different millimeter-wave and THZ frequencies have been compared with the RF power outputs obtained from the IMPATT sources based on conventional semiconductors as mentioned earlier in Figure 9a. It has already been concluded by the author in his earlier report that up to 1.0 THz frequency, 4H-SiC is the best material for IMPATT sources in terms of RF power delivering capability; however, G-IMPATT sources operating in PCPC mode have the potentiality to overtake the performance of Wz-GaN IMPATT sources in terms of RF power output especially at and above 5.0 THz.…”

“…Since last decade, several researchers have explored the potentialities of wide‐bandgap material‐based impact avalanche transit time (IMPATT) oscillators as THz frequency radiators . Especially, two wide band gap (WBG) semiconductor materials, i.e., 4H‐SiC and Wurtzite‐GaN (Wz‐GaN) have attracted the attention of the researchers due to the possibilities of appreciably high THz power (in the order of milliwatts (mW)) generation from the IMPATT sources based on those materials . However, lack of mature technology is acting as a barrier for the implementation of THz IMPATT sources based on 4H‐SiC and Wz‐GaN.…”