A Novel Integrated Power Module
with Solid-State Diode at THz
Frequency—The Concept and a Possible
Way to Realize It
Subal Kar
Abstract The basic concept and possible way to realize a novel power module with
device and antenna integrated in the same structure using IMPATT diode has been
proposed that might have useful applications at THz frequency. The power module
judiciously used the idea of resonant-cap cavity for oscillator design normally used
at microwave and millimetre–wave frequency, slotted disc for broadband operation
and an improvised circular microstrip patch antenna integrated in the same structure.
The structure is realizable with fully planer technology with some added steps in the
device fabrication process. Since there is no need for transmission line or waveguide
to connect the antenna with the oscillator, the transmission loss is minimized and
the integrated structure will also lead to size miniaturization. The integrated power
module is expected to have many applications especially at THz frequency regime.
1 Introduction
From the beginning of twenty-first century THz signal generation, detection [1] and
its application for security purposes in concealed weapon detection and standoff
detection of explosives and abusive drugs [2–4] and medical purposes for early
detection of skin and breast cancer [5] including that in pharmaceutical industry [6]
have proliferated exponentially. However, till the end of twentieth century, the ‘THz
gap’, vide Fig. 1, was the most neglected chunk of electromagnetic spectrum with
very few applications for space and Earth science studies [1].
Nowadays, we have various techniques for THz signal generation including
optical heterodyning [7], quantum cascade laser [8], free-electron laser [9] and so
forth. Initially, it was observed that tube and solid-state devices used in the generation of microwave/millimetre-wave signal are limited for THz signal generation,
as they are controlled by transit time of the charge carriers via the device causing
lower output power and bandwidth of operation. But with the availability of device
fabrication materials like GaN for high power devices and better fabrication facility,
S. Kar (B)
Institute of Radio Physics and Electronics, University of Calcutta, Kolkata, India
e-mail: subal.kar@fulbrightmail.org
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
A. Biswas et al. (eds.), Emerging Trends in Terahertz Engineering and System
Technologies, https://doi.org/10.1007/978-981-15-9766-4_1
1
with Solid-State Diode at THz
Frequency—The Concept and a Possible
Way to Realize It
Subal Kar
Abstract The basic concept and possible way to realize a novel power module with
device and antenna integrated in the same structure using IMPATT diode has been
proposed that might have useful applications at THz frequency. The power module
judiciously used the idea of resonant-cap cavity for oscillator design normally used
at microwave and millimetre–wave frequency, slotted disc for broadband operation
and an improvised circular microstrip patch antenna integrated in the same structure.
The structure is realizable with fully planer technology with some added steps in the
device fabrication process. Since there is no need for transmission line or waveguide
to connect the antenna with the oscillator, the transmission loss is minimized and
the integrated structure will also lead to size miniaturization. The integrated power
module is expected to have many applications especially at THz frequency regime.
1 Introduction
From the beginning of twenty-first century THz signal generation, detection [1] and
its application for security purposes in concealed weapon detection and standoff
detection of explosives and abusive drugs [2–4] and medical purposes for early
detection of skin and breast cancer [5] including that in pharmaceutical industry [6]
have proliferated exponentially. However, till the end of twentieth century, the ‘THz
gap’, vide Fig. 1, was the most neglected chunk of electromagnetic spectrum with
very few applications for space and Earth science studies [1].
Nowadays, we have various techniques for THz signal generation including
optical heterodyning [7], quantum cascade laser [8], free-electron laser [9] and so
forth. Initially, it was observed that tube and solid-state devices used in the generation of microwave/millimetre-wave signal are limited for THz signal generation,
as they are controlled by transit time of the charge carriers via the device causing
lower output power and bandwidth of operation. But with the availability of device
fabrication materials like GaN for high power devices and better fabrication facility,
S. Kar (B)
Institute of Radio Physics and Electronics, University of Calcutta, Kolkata, India
e-mail: subal.kar@fulbrightmail.org
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
A. Biswas et al. (eds.), Emerging Trends in Terahertz Engineering and System
Technologies, https://doi.org/10.1007/978-981-15-9766-4_1
1