Potentiality of Impact Avalanche Transit
Time Diode as Terahertz Source Based
on Group IV and III–V Semiconducting
Materials
Girish Chandra Ghivela, S. J. Mukhopadhyay, Joydeep Sengupta
and M. Mitra
Abstract Through the numerical approach, we have determined the response time
in avalanche and drift regions of the double drift region (DDR) impact ionization
avalanche transit time (IMPATT) diode based on group IV materials like silicon (Si),
germanium (Ge) and group III–V materials like wurtzite gallium nitride (WzGaN),
gallium arsenide (GaAs) and indium phosphide (InP) at the window frequency of
0.094–30 THz. The study of response time reveals that it has impact on the limitation
on high frequency power generated by the IMPATT as terahertz source. A comparison is being made for all the materials so that diode can be designed with suitable
material as per the requirement for THz applications. Also DC-to-radio frequency
(RF) conversion efficiency for InP, GaAs, Si, Ge and WzGaN is computed through
the numerical technique. The efficiency obtained for all the materials are compared
at the corresponding THz frequency.
Keywords Impact ionization · Avalanche · Drift · Response time · THz ·
Semiconductors
1 Introduction
Impact ionization avalanche transit time (IMPATT) diode is used to generate the
high power at microwave, millimeter wave and sub-millimeter wave regions [1]. It
has high power capability compared to other diodes [2, 3]. Its operation provides
a phase shift through avalanche and drift delays [4–6]. Phase noise due to phase
shift causes a negative resistance in IMPATT. Operations at these regions are highly
disturbed due to phase noise [7]. The negative resistance is arising from these delays
as reported in [4–6, 8–12]. These delays are indirectly affecting the phase noise
through negative resistance, and the phase noise degrades the conversion efficiency.
But, the phase noise and DC-to-RF conversion efficiency mainly depend on base
G. C. Ghivela (B) · J. Sengupta
ECE Department, VNIT, Nagpur 440010, India
e-mail: girishvnit2012@gmail.com
S. J. Mukhopadhyay · M. Mitra
E&TC Department, IIEST, Shibpur, Howrah, India
© Springer Nature Singapore Pte Ltd. 2020
A. Biswas et al. (eds.), Emerging Trends in Terahertz Solid-State Physics and Devices,
https://doi.org/10.1007/978-981-15-3235-1_5
65
Time Diode as Terahertz Source Based
on Group IV and III–V Semiconducting
Materials
Girish Chandra Ghivela, S. J. Mukhopadhyay, Joydeep Sengupta
and M. Mitra
Abstract Through the numerical approach, we have determined the response time
in avalanche and drift regions of the double drift region (DDR) impact ionization
avalanche transit time (IMPATT) diode based on group IV materials like silicon (Si),
germanium (Ge) and group III–V materials like wurtzite gallium nitride (WzGaN),
gallium arsenide (GaAs) and indium phosphide (InP) at the window frequency of
0.094–30 THz. The study of response time reveals that it has impact on the limitation
on high frequency power generated by the IMPATT as terahertz source. A comparison is being made for all the materials so that diode can be designed with suitable
material as per the requirement for THz applications. Also DC-to-radio frequency
(RF) conversion efficiency for InP, GaAs, Si, Ge and WzGaN is computed through
the numerical technique. The efficiency obtained for all the materials are compared
at the corresponding THz frequency.
Keywords Impact ionization · Avalanche · Drift · Response time · THz ·
Semiconductors
1 Introduction
Impact ionization avalanche transit time (IMPATT) diode is used to generate the
high power at microwave, millimeter wave and sub-millimeter wave regions [1]. It
has high power capability compared to other diodes [2, 3]. Its operation provides
a phase shift through avalanche and drift delays [4–6]. Phase noise due to phase
shift causes a negative resistance in IMPATT. Operations at these regions are highly
disturbed due to phase noise [7]. The negative resistance is arising from these delays
as reported in [4–6, 8–12]. These delays are indirectly affecting the phase noise
through negative resistance, and the phase noise degrades the conversion efficiency.
But, the phase noise and DC-to-RF conversion efficiency mainly depend on base
G. C. Ghivela (B) · J. Sengupta
ECE Department, VNIT, Nagpur 440010, India
e-mail: girishvnit2012@gmail.com
S. J. Mukhopadhyay · M. Mitra
E&TC Department, IIEST, Shibpur, Howrah, India
© Springer Nature Singapore Pte Ltd. 2020
A. Biswas et al. (eds.), Emerging Trends in Terahertz Solid-State Physics and Devices,
https://doi.org/10.1007/978-981-15-3235-1_5
65