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Designing a Compact Microstrip Antenna Using the Machine Learning Approach

100%

Sharma K. , Pandey G. P.

tom nr 4

44--52

This paper presents how machine learning techniques may be applied in the process of designing a compact dual-band H-shaped rectangular microstrip antenna (RMSA) operating in 0.75–2.20 GHz and 3.0–3.44 GHz frequency ranges. In the design process, the same dimensions of upper and lower notches are incorporated, with the centered position right in the middle. Notch length and width are verified for investigating the antenna. An artificial neural network (ANN) model is developed from the simulated dataset, and is used for shape prediction. The same dataset is used to create a mathematical model as well. The predicted outcome is compared and it is determined that the model relying on ANN offers better results.

Dual Frequency Triangular Slotted Microstrip Patch Antenna for Ku Band Applications

75%

Samsuzzaman M. , Islam M. T. , Yatim B. , Ali M. A.

tom R. 89, nr 1a

275--279

A single feed, compact, new shaped, dual band microstrip patch antenna has presented in this paper. Here three equilateral triangular slots are introduced in the three edges of the patch and a small feed line has used another edge of the patch to obtain the dual band. The antenna has a condensed structure where patch dimension is about 8.5mm by 7.96mm by 1.905mm leading to good bandwidths covering 13.15 GHz to 13.72 GHz and 16.04 GHz to 16.58GHz. The return loss of -19.00dB is achieved at the first resonant frequency at 13.61 GHz and -28.69dB is at second resonance frequency at 16.33GHz. Stable average peak gain that is observed across the operating band in both lower and higher frequency is almost 3.53dB and 5.562dB respectively .The radiation patterns are nearly omnidirectional with moderate gain in both these operating bands. Good results have been established in dual frequencies at 13.62GHz as downlink and 16.33GHz as uplink. This low profile nature and simple configuration of the proposed antenna show the way to easy fabrication and make it adaptable for the application in wireless and satellite communication.

W artykule przedstawiono dwupasmową prostokątną antenę mikropaskową o jednym doprowadzeniu i nowym kształcie. W trzech rogach znajdują się trzy szczeliny w kształcie trójkąta równobocznego, a w czwartym doprowadzenie linii. Antena posiada pasmo 13,15-13,72GHz oraz 16,04-16,58GHz. Niski profil oraz prosta konfiguracja wskazują na łatwą metodę produkcji oraz możliwość zastosowania w aplikacjach bezprzewodowych i komunikacji satelitarnej.

Quantum structures for multiband photon detection

75%

Perera A. G. U.

tom Vol. 14, No. 2

103-112

The work describes multiband photon detectors based on semiconductor micro- and nano-structures. The devices considered include quantum dot, homojunction, and heterojunction structures. In the quantum dot structures, transitions are from one state to another, while free carrier absorption and internal photoemission play the dominant role in homo or heterojunction detectors. Quantum dots-in-a-well (DWELL) detectors can tailor the response wavelength by varying the size of the well. A tunnelling quantum dot infrared photodetector (T-QDIP) could operate at room temperature by blocking the dark current except in the case of resonance. Photoexcited carriers are selectively collected from InGaAs quantum dots by resonant tunnelling, while the dark current is blocked by AlGaAs/InGaAs tunnelling barriers placed in the structure. A two-colour infrared detector with photoresponse peaks at ~6 and ~17 µm at room temperature will be discussed. A homojunction or heterojunction interfacial workfunction internal photoemission (HIWIP or HEIWIP) infrared detector, formed by a doped emitter layer, and an intrinsic layer acting as the barrier followed by another highly doped contact layer, can detect near infrared (NIR) photons due to interband transitions and mid/far infrared (MIR/FIR) radiation due to intraband transitions. The threshold wavelength of the interband response depends on the band gap of the barrier material, and the MIR/FIR response due to intraband transitions can be tailored by adjusting the band offset between the emitter and the barrier. GaAs/AlGaAs will provide NIR and MIR/FIR dual band response, and with GaN/AlGaN structures the detection capability can be extended into the ultraviolet region. These detectors are useful in numerous applications such as environmental monitoring, medical diagnosis, battlefield-imaging, space astronomy applications, mine detection, and remote-sensing.