Proceedings published in Dept. of ETE http://103.99.128.19:8080/xmlui/handle/123456789/72 2026-04-19T10:39:58Z 2026-04-19T10:39:58Z Hossain, Md. Azad Chowdhury, Piyas Hossain, Quazi Delwar Goopta, Rubell Sen Rahman, Muhammad Asad http://103.99.128.19:8080/xmlui/handle/123456789/416 2024-03-25T07:44:06Z 2013-11-21T00:00:00Z

Linear Polarization Switchable Patch Array Antenna using Magic-T Bias Circuit and Orthogonal Feed Hossain, Md. Azad; Chowdhury, Piyas; Hossain, Quazi Delwar; Goopta, Rubell Sen; Rahman, Muhammad Asad In this paper, a linear polarization switchable patch array antenna is proposed. The orthogonal feed circuit and magic-T circuit is introduced to realize the proposed array antenna. The advantage of the magic-T circuit is the excellent isolation between the RF signal and the switching bias signal. The microwave integration technology is effectively employed to realize proposed linear polarization switchable array antenna. The proposed array antenna consists of four patch elements and 16 PIN diodes. In order to realize the ±45º polarization switching, four switching diodes are integrated with each patch elements. Using the ON/OFF condition of the diodes, the polarization axis can be easily switched to ±45º. The array antenna is realized in very simple and compact structure as all the antenna elements, feeding circuit and bias circuit are arranged on both sides of a dielectric substrate. The ability of the proposed array antenna to switch the polarization axis at ±45º at 10 GHz (X band) is confirmed by the experimental investigation.

2013-11-21T00:00:00Z Rupom, Arif Istiaque Patwary, Adnan Basir http://103.99.128.19:8080/xmlui/handle/123456789/314 2021-10-25T05:57:33Z 2019-02-07T00:00:00Z

P300 Speller Based ALS Detection Using Daubechies Wavelet Transform in Electroencephalograph Rupom, Arif Istiaque; Patwary, Adnan Basir The Brain is the main controller of the human body consisting of neurons which generate electrical signals to control the body. Different neurological diseases can cause brain abnormalities such as ALS that affect the electrical activity of the brain which can be seen in the EEG signal. Therefore, these abnormalities can be detected by analyzing the EEG signal. As the Alpha and Beta waves are recorded during the active state of the brain, the effect of abnormalities can be seen in the waves. This study proposes a technique to detect the brain abnormalities and detect ALS syndromes based on Alpha and Beta waves. In this study, the Alpha and Beta waves are extracted from the raw EEG signal by discrete wavelet transformation. Here, the raw EEG signal is divided into several orthogonal wavelets using Doubechis 4 wavelet transform; Alpha and Beta wave frequency components are selected and reconstructed. Then these waves can be compared between different types of ALS patients and normal people based on amplitude and event related potential. The result showed great variation in amplitude as well as event related potential for different ALS patients and normal people. The proposed technique could be used in detecting abnormalities and their severity. It could also help in detecting ALS at a primary stage.

2019-02-07T00:00:00Z Patwary, Adnan Basir Abedin, Sabrina Hossain, Md. Azad http://103.99.128.19:8080/xmlui/handle/123456789/300 2021-09-30T04:17:04Z 2019-02-07T00:00:00Z

Design of a Ladybug Shaped Circular Polarized Microstrip Antenna at 5.8 GHz as Microwave Power Transmitter to a MAV Patwary, Adnan Basir; Abedin, Sabrina; Hossain, Md. Azad This paper is based on a circular polarized microstrip patch antenna which is designed for microwave power transmission with resonating frequency of 5.8 GHz. The radiating patch of the antenna is based on a dual feed elliptical patch which is modified by adding quarter wavelength resonators and circular slots. The resultant patch resembles to a ladybug and hence the name “Ladybug antenna”. The designed antenna has a gain of 6.88 dB and return loss of 25dB. It has 0.48 dB axial ratio at 5.8 GHz which shows that it has good circular polarization. The Ladybug antenna has omnidirectional radiation pattern which is suitable for short range MPT operation of Micro Aerial Vehicles (MAV).

2019-02-07T00:00:00Z Mumu, Mumtahina Khan Chowdhury, Piyas Hossain, Md. Azad http://103.99.128.19:8080/xmlui/handle/123456789/284 2021-09-21T08:34:54Z 2019-02-07T00:00:00Z

A Star-Fish Shaped Compact Dual band Antenna for Millimeter Wave Band Applications Mumu, Mumtahina Khan; Chowdhury, Piyas; Hossain, Md. Azad In this paper a star fish shaped microstrip patch antenna is proposed and its design procedure and characteristics are analyzed. The shape of the antenna patch is similar to a star fish, therefore the antenna is called Star fish antenna.The proposed antenna is able to provide dual band operation in V band (40-52 GHz) and W band (77-95 GHz) which lie in the range of millimeter wave frequency. The proposed antenna has 8 branches of unequal length in order to achieve wide bandwidth in millimeter wave range. Each of the branch resonates at different frequency which ultimately results in a wide bandwidth of 30 GHz with an efficient gain of 7.9026 dBi and highly reduced return loss. Designed antenna has a very compact dimensions of 9x9x2.03 mm3, thus it can be easily fabricated with small handset devices.

2019-02-07T00:00:00Z