Highly Efficient Ultra-Wide Band MIMO Patch Antenna Array …
195
antenna. Otherwise, it will be not possible by using horn antenna, lens antenna, and
Yagi-Uda antenna [8, 9].
If we speak about the previous research, for several terahertz applications several
researchers recorded terahertz antenna. Some of the most generally recognized terahertz antennas, to the best of the author ‘s knowledge, are mentioned here. Several
researchers achieved a high degree of directness and gain by designing lens antenna,
leaky-wave antenna, reflector-based antenna, and Yagi-Uda antenna but at the cost
of a large, voluminous, and complex three-dimensional structure [10–16]. Because
of their large and complicated configurations, compatibility of the these kinds of
antenna with the on-chip processor is thus unlikely. So, the antenna researchers
switch to planar antenna configuration with on-chip integration. Hossein. D and
Behbod. G had developed a highly efficient wideband THz antenna having a bandwidth of 118% (0.434–1.684 THz) and a maximum gain of 5.72 dB [17]. Singh
proposed a multiband antenna using a photonic band structure resonating at the THz
frequency with a peak gain of 10.5 dB [18]. Mittal developed a planar antenna at
0.63 THz frequency by using the polyimide substrate and achieved 7.93 dB gain
for defense applications [19]. Hocini et al. in Ref. [20] developed five THz patch
antennas based on a modified photonic bandgap (PBG) substrate in the frequency
range from 0.5 to 0.8 THz and obtained maximum 9.19 dB gain. Paul et al. proposed
a compact size wideband antenna for THz band using PBG and DGS techniques
at resonating frequency of 0.703 THz for THz applications and achieved a gain of
5.95 dB [21]. Azam et al. investigated the graphene patch antenna at resonating
frequency of 6.8 THz, 6.94 THz, 7.1 THz, and 7.13 THz with a peak gain of 16.7 dB
[22]. Jha et al. proposed a dual-band antenna resonating on 0.6 and 0.8 THz with
peak gain 10.9 dB and bandwidth 11.6% [23]. Kushwaha et al. proposed a dual-band
novel antenna using a photonic crystal with a peak gain of 7.94 dB and 10.1% bandwidth [24]. Zhou et al. [25] presented a tunable compact size antenna at 1.03 THz
by using the graphene as the conducting patch and get 9.7% bandwidth. Anand et al.
[26] proposed the antenna at 0.75 THz by using the graphene nanoribbon wires for
tea hertz applications and achieved 5.09 dB gain with 6.67% bandwidth. Tamagone
et al. [26] presented at reconfigurable THz antenna at resonance 0.8 THz and achieved
radiation efficiency of 93%. Jha et al. [27] proposed a dual-band antenna by using the
double-layer substrate technique with a peak gain of 7.968 dB. Cheng [28] increased
the gain of an antenna by using epsilon-near-zero (ENZ) metamaterial superstrate
and found that the peak gain of the antenna is increased from 5.37 to 7.79 dB.
The numerous methodologies, such as PBG, electronics bandgap (EBG), DGS,
multilayered structures, nanoribbon wires, and complex substrate content, are used to
increase the antenna’s gain, bandwidth, and efficiency performance. From literature,
it is found that mostly antennas are resonating on different bands, didn’t cover the
low loss transmission window. Some are suffering from low gain, narrow bandwidth,
large size. Also, most of the authors developed only the single antenna element for
traditional single input single output communications systems but to realize the highspeed communications in the terahertz regime, there is a need to develop and analyze
the MIMO antenna design.
195
antenna. Otherwise, it will be not possible by using horn antenna, lens antenna, and
Yagi-Uda antenna [8, 9].
If we speak about the previous research, for several terahertz applications several
researchers recorded terahertz antenna. Some of the most generally recognized terahertz antennas, to the best of the author ‘s knowledge, are mentioned here. Several
researchers achieved a high degree of directness and gain by designing lens antenna,
leaky-wave antenna, reflector-based antenna, and Yagi-Uda antenna but at the cost
of a large, voluminous, and complex three-dimensional structure [10–16]. Because
of their large and complicated configurations, compatibility of the these kinds of
antenna with the on-chip processor is thus unlikely. So, the antenna researchers
switch to planar antenna configuration with on-chip integration. Hossein. D and
Behbod. G had developed a highly efficient wideband THz antenna having a bandwidth of 118% (0.434–1.684 THz) and a maximum gain of 5.72 dB [17]. Singh
proposed a multiband antenna using a photonic band structure resonating at the THz
frequency with a peak gain of 10.5 dB [18]. Mittal developed a planar antenna at
0.63 THz frequency by using the polyimide substrate and achieved 7.93 dB gain
for defense applications [19]. Hocini et al. in Ref. [20] developed five THz patch
antennas based on a modified photonic bandgap (PBG) substrate in the frequency
range from 0.5 to 0.8 THz and obtained maximum 9.19 dB gain. Paul et al. proposed
a compact size wideband antenna for THz band using PBG and DGS techniques
at resonating frequency of 0.703 THz for THz applications and achieved a gain of
5.95 dB [21]. Azam et al. investigated the graphene patch antenna at resonating
frequency of 6.8 THz, 6.94 THz, 7.1 THz, and 7.13 THz with a peak gain of 16.7 dB
[22]. Jha et al. proposed a dual-band antenna resonating on 0.6 and 0.8 THz with
peak gain 10.9 dB and bandwidth 11.6% [23]. Kushwaha et al. proposed a dual-band
novel antenna using a photonic crystal with a peak gain of 7.94 dB and 10.1% bandwidth [24]. Zhou et al. [25] presented a tunable compact size antenna at 1.03 THz
by using the graphene as the conducting patch and get 9.7% bandwidth. Anand et al.
[26] proposed the antenna at 0.75 THz by using the graphene nanoribbon wires for
tea hertz applications and achieved 5.09 dB gain with 6.67% bandwidth. Tamagone
et al. [26] presented at reconfigurable THz antenna at resonance 0.8 THz and achieved
radiation efficiency of 93%. Jha et al. [27] proposed a dual-band antenna by using the
double-layer substrate technique with a peak gain of 7.968 dB. Cheng [28] increased
the gain of an antenna by using epsilon-near-zero (ENZ) metamaterial superstrate
and found that the peak gain of the antenna is increased from 5.37 to 7.79 dB.
The numerous methodologies, such as PBG, electronics bandgap (EBG), DGS,
multilayered structures, nanoribbon wires, and complex substrate content, are used to
increase the antenna’s gain, bandwidth, and efficiency performance. From literature,
it is found that mostly antennas are resonating on different bands, didn’t cover the
low loss transmission window. Some are suffering from low gain, narrow bandwidth,
large size. Also, most of the authors developed only the single antenna element for
traditional single input single output communications systems but to realize the highspeed communications in the terahertz regime, there is a need to develop and analyze
the MIMO antenna design.