Mushtaq Alqaisy
@aliraqia.edu.iq
Computer Engineering Department/College of Engineering
Al-iraqia University
EDUCATION
PhD Communication Engineering-wireless communication
RESEARCH INTERESTS
Microwave and Microstrip Filter design
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Bashar Bahaa Qas Elias, Ahmed Mushtaq Alqaisy, and Jack Soh Ping
Faculty of Philology, University of Belgrade
Mushtaq Alqaisy
IEEE
A tunable dual-band dual-mode microwave bandpass filter (BPF) with compact size is suggested using meander stepped impedance square loop resonator (SIR). A new scheme exhibited miniaturization more than 58 % compared to Euclidean microstrip loop resonator. A small patch was attached in one corner of a square loop resonator to degenerate dual mode configurations. On the other hand, a step impedance technique was utilized to tune the second band of the suggested BPF. Dual mode dual band responses are located at the medical applications (2.45 GHz) with -40 dB as a return loss and two transmission zeroes for sharp skirt response as a first band and also a tunable band from (4-5 GHz) for LTE applications with return loss less than -10 dB as a second band. To validate this structure design and analysis, CST computer simulation package was used. The dual mode simulation results have been extracted and compared with the literature which finding closed to each other. So that, CST simulator certified and can be adopted it for extracting a tunable dual-band results which have been achieved using a mentioned simulator.
Ghadah M. faisal and Mushtaq A. Alqaisy
IEEE
Multi band antenna with miniature volume is of more requests for the ever growing wireless communication industry. In this paper, a double-layers and five-bands of microstrip patch antenna is designed. The S-parameter as well as radiation pattern are investigated. On the other hand, the proposed antenna is suggested to be employed in a handset mobile phone that covers five frequency bands as follows; GSM 900 (889– 960) GSM 1800 DCS 1800, (1710–1885)W-CDMA (Wideband Code Division Multiple Access), IMT 2000 (International Mobile Telecommunication)1885–2200, Wi-Fi/WLAN (IEEE 802.11 b/g/n) ISM 2450 (Industrial, Scientific and Medical) (2400–2500) and WiMax (Worldwide Interoperability for Microwave access) which have been established by the IEEE 802.16 working group. The proposed square patch antenna has been gained return loss of −33dB at 2.0924 GHz, −25dB at 2.67 GHz, −20.5 dB at 1.745 GHz and −20dB at 2.44GHz and −18dB at 0. 94GHz frequencies. Design and simulation of the presented structure was based on CST software package. Finally, five frequency bands are produced and the antenna shows encouraged results for WLAN applications.
Mushtaq Alqaisy, Chandan K. Chakrabraty, Jawad K. Ali, Adam Reda Alhawari, and Tale Saeidi
Cambridge University Press (CUP)
In this manuscript, serial-shunt of square ring resonators with step-impedance open circuited stub resonators to produce a new on-off switchable bandpass to bandstop response in the same ultra-wideband microstrip filter structure is proposed. The closed ring of series-shunt square ring resonators with a combine stubs are introduced to excite the bandpass response while bandstop characteristic excited when gaps are embedded in the corners of the square ring resonators. The main advantage of this microstrip filter is its capability to switch from bandpass-to-bandstop operation using open-short gap, respectively. A microwave simulator is utilized to show the switchable case by replacing Skyworks radio frequency diodes (RF-PIN) instead of those gaps. The entire filter models have been simulated using the computer simulation technology (CST) Microwave Studio. The computed results for the proposed filters were compared with the measured results of the both prototype structures (bandpass- and bandstop-filter). The codes also showed good agreement between them. Other advantages include being small in size, and low in effective cost.
Mushtaq A. Alqaisy, Mahmoud T. Yassen, F. Sh. Khalifa, and Ali J. Salim
IEEE
A Filter block has been highly attention due to it's highly importance in wireless communication systems. High harmonic level normally companies with the performance of the filter block. The use of both low-pass or band-stop filter and the step-impedance lines methods to reduce the spurious characteristics of the filter are not a practical solutions since that adds more complexity and large in size. On the other hand, multiband components are preferable in most modern wireless system applications. In this paper, a single unit cell of a complementary split ring resonator designed on the ground plane of the conventional five pole bandpass filter has been proposed and considered as more practical method to excite the second bandpass frequency band and to solve the important filter problem in terms of third order harmonic characteristic suppression (3fo). The final structure has been simulated using the CST Microwave Studio. The simulated result for the proposed construction was extracted and displayed together with the measured result of the conventional five pole prototype structure. The outputs showed good agreement between them also return loss enhancement is very clear through the combination between the complementary split ring resonators and band pass filter. Other advantages no complexity adds, and low in effective cost.
Mushtaq A. Alqaisy, C. Chakrabraty, J. Ali, A. R. H. Alhawari, and Tale Saeidi
Informa UK Limited
ABSTRACT Four square ring resonators together with an L-shaped uniform open tuning stub is the base of an ultra-wide bandpass filter. Based on the bandpass-coupled edge, a small gap was created in the feed lines of the proposed bandpass filter to obtain a second lower band. This study introduces a dual-band bandpass filter. The main advantage of this bandpass filter is its capability to reconfigure bandwidth and tune the center frequency of a dual-band bandpass filter function. The microstrip bandpass filter is reconfigured into a dual band when varactor diodes are fixed on the head of each uniform stub. The roll-off is characterized by sharp edges of 81.325 and 80.165 GHz/dB, which provided this filter with high selectivity in the transmission band, a wide stopband of more than 2 GHz in both sides, and a rejection band of up to 32 dB. Results show better performance of S21, which fluctuated from 4 to 1.5 dB within the transmission band from 8.327 to 13.942 GHz. All the reported filters were modeled, and their corresponding responses were assessed by using CST Microwave Studio (CST, 2010). Measured and simulated results of the proposed bandpass filters were compared, and the results indicate good agreement.
Hayder S. Ahmed, Ali J. Salim, Jawad K. Ali, and Mushtaq A. Alqaisy
IEEE
Bandstop filters (BSFs) are highly required in modern wireless communication and electromagnetic compatibility related applications. In this paper, a fractal based dual-mode microstrip BSF has been proposed as a compact resonator structure with high selectivity. Filter miniaturization results from the application of Minkowski fractal geometry on the conventional triangle dual-mode resonator. Performance evaluation of the proposed filter design has been performed using the commercially available EM simulator; Sonnet. Parametric study reveals that the application of Minkowski fractal geometry results in BSFs offering both a compact size and high selectivity stopband responses. The results show that the proposed BSF over performs those reported in the literature in both the size reduction and the realized selectivity.
Mushtaq Alqaisy, Chandan Chakrabraty, Jawad Ali, and Adam R.H. Alhawari
Cambridge University Press (CUP)
In this paper, a fractal-based complementary split-ring resonator (CSRR) has been introduced as a defected ground structure (DGS) in the ground plane of a dual-mode microstrip bandpass filter to produce a new compact filter with dual-band response. The conventional double square ring resonator structure is modified such that its inner ring is made with a fractal shape instead of a square. Measured and simulation results show that the resulting filter offers a dual passband response; the higher passband is attributed to the dual-mode microstrip ring structure, whereas the lower passband is as a result of the embedded CSRR DGS structure. In addition, the results show that the position of the lower passband could be varied, to a certain extent, without affecting the position of the higher passband by applying higher fractal iteration levels to the inner split ring. These features, together with the compact size the proposed filter offers, make it suitable for use in a wide variety of dual-band communication applications. Measured results, carried out on filter prototypes, have been found in agreement with those theoretically predicted.
Ahmed Hameed Reja, Mushtaq A. Alqaisy, Syed Naseem Ahmed, and Abdul Kareem Kasim Abdul Raheem
IEEE
In this paper, stepped-impedance microwave low-pass filters (LPFs) are presented. A conventional stepped-impedance LPF with cutoff frequency (fc) of 1.9GHz is proposed. Replacing rectangular split ring resonator (SRR) structure instead of low-impedance lines in conventional design to get compact, low insertion loss (IL), sharp cutoff, and high selectivity LPF. The effect of etching rectangular complementary split ring resonators (CSRRs) or etching square CSRRs in the ground of microstrip line to get new metamaterial microwave LPFs is also presented. The new filters have better results compared to conventional filter. The simulated results indicate that the proposed filters achieve a flat pass-band without ripples, corresponding to numbers of unit cells of CSRR structures. Reduction in size up to 29% of the filter has been achieved by using square CSRRs. The group delay values of LPFs approximate to 0.5 ns in the pass-band interval in all designs. Numerical results for the stepped-impedance microwave LPFs are obtained. The filters are then simulated by the computer aided design software (Ansoft HFSS) commonly used in microwave applications which has been implemented on the Roger RO3210 substrate with dielectric constant er = 10.2, substrate height h = 1.27mm, and thickness of microstrip conductor t = 0.035mm.