| 1. |
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| 2. |
- Deleniv, Anatoli, et al.
(author)
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Modeling gap discontinuity in coplanar waveguide using quazi-static spectral domain method
- 2000
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In: International Journal of RF and Microwave Computer-Aided Engineering. - 1096-4290 .- 1099-047X. ; 10:3, s. 150-158
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Journal article (peer-reviewed)abstract
- An efficient computer technique based on the spectral domain method is presented to solve the problem of modeling coplanar gap discontinuity. Comparison with available published data is done to confirm the accuracy of the method.
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| 3. |
- Aslam, Bilal, et al.
(author)
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A compact implantable RFID tag antenna dedicated to wireless health care
- 2017
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In: International Journal of RF and Microwave Computer-Aided Engineering. - : John Wiley & Sons. - 1096-4290 .- 1099-047X. ; 27:5
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Journal article (peer-reviewed)abstract
- Implantable tag antennas are an integral component of contemporary pervasive patient monitoring setups envisioned to reduce the medical errors and improve the quality of health care facilities. These tags, embedded into the human body, transmit critical patient information to the external equipment via a wireless communication link. This research article presents an implantable compact folded dipole antenna of size 10 mm 3 15 mm 3 2 mm, designed to operate in the industrial-scientificmedical band (2.4-2.48GHz). A three-layered phantom representing the human arm is used to evaluate the subcutaneous antenna performance. The tag antenna embedded in the middle of the fat layer offers a maximum gain of 216.3 dBi. The tag antenna performance as a function of implant position and phantom dimensions is analyzed. Link budget calculations show that with the achieved antenna gain the link power exceeds the required power by 38.37 dBm, and hence wireless communication is viable.
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| 4. |
- Aslam, Bilal, et al.
(author)
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A high capacity tunable retransmission type frequency coded chipless radio frequency identification system
- 2019
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In: International Journal of RF and Microwave Computer-Aided Engineering. - : WILEY. - 1096-4290 .- 1099-047X. ; 29:9
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Journal article (peer-reviewed)abstract
- This article presents a 12-bit frequency coded chipless RFID system in the frequency range of 3 to 6 GHz. The system consists of a fully printable chipless tag and a pair of high-gain reader antennas. The tag also incorporates its own antennas to improve the read range. Information is encoded into frequency spectrum using a multi-resonant circuit. The circuit consists of multiple microstrip U and L-shaped open stub resonators patterned in a unique configuration. The proposed configuration aids in capturing more data in a reduced space as well as tunable frequency operation. Tag and reader antennas utilize techniques such as stepped impedance feeding line, defective partial ground plane, and stair-step patch structure to achieve wide-band impedance bandwidth in miniature size. The results of the wireless measurements in the non-anechoic environment show that the proposed system has a reading range of more than 20 cm. The presented system possesses great potential for low-cost short-range inventory tracking.
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| 5. |
- Aslam, B., et al.
(author)
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Miniaturized decoupled slotted patch RFID tag antennas for wearable health care
- 2017
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In: International Journal of RF and Microwave Computer-Aided Engineering. - : John Wiley & Sons. - 1096-4290 .- 1099-047X. ; 27:1
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Journal article (peer-reviewed)abstract
- In this article, a couple of two-layered RFID tag antenna designs exhibiting improved performance descriptors for on-body applications are presented. The antennas are designed to operate in the microwave band (2.4–2.48 GHz) ensuring high data transmission rates ideal for real-time subject monitoring applications. The radiating element of both the antennas is a slotted patch structure provisioned with a pair of T-shaped slots realized on a commercial FR4 substrate. The augmentation of a systematic sequence of narrow comb-like etchings into the design enhances the impedance bandwidth considerably. A high permittivity silicon layer embedded with the radiating patch provides resilience from the human body dielectric losses. A modified antenna design utilizing patch miniaturization technique, resulting in an overall footprint reduction by 32%, is also proposed. The designed tag antennas offer a gain of more than 1.8 dBi and an attractive read range greater than 6.8 m in the operating band.
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| 6. |
- Aziz, Imran, et al.
(author)
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28 GHz Circular Polarized Fan-out Antenna Array with Wide-angle Beam-steering
- 2022
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In: International Journal of RF and Microwave Computer-Aided Engineering. - : Hindawi Publishing Corporation. - 1096-4290 .- 1099-047X. ; 32:3
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Journal article (peer-reviewed)abstract
- The article presents 28 GHz circular polarized antenna arrays designed in an embedded wafer level ball grid array (eWLB) package for 5G applications. The antenna arrays are realized on a re-distribution layer (RDL) in the fan-out region of the chip package. Two separate but identical arrays perform RX and TX operations where a crossed dipole is used as a building block of the array. These 4-element arrays have <−10 dB impedance bandwidth covering 25.3–29.8 GHz (4.5 GHz bandwidth) while presenting 10 dBi maximum realized gain. The measurement results show <3 dB axial ratio in the band 26–29.5 GHz, and the main beam can be steered in ±50° in the azimuth plane when array elements are fed by appropriate phases from the chip. The radio frequency module provides 31 dBm maximum equivalent isotropic radiated power (EIRP).
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| 7. |
- Chagtmi, Nadia, et al.
(author)
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Augmented Hammerstein model for the calibration of six-port based dual band wireless receivers
- 2019
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In: International Journal of RF and Microwave Computer-Aided Engineering. - : Hindawi Limited. - 1096-4290 .- 1099-047X. ; 29:2
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Journal article (peer-reviewed)abstract
- Two architectures of concurrent dual-band six-port-based receiver (SPR), which are modeled and calibrated using the augmented Hammerstein model (AHM) are proposed for the first time in this article. The receivers are based on six-port junctions with one or two local oscillators (LO). The proposed single step calibration algorithms achieve the recovery of the two in-phase (I1 and I2) and quadrature (Q1 and Q2) components of an RF signal with two frequency components (RF1 and RF2). Experimental validations have been performed to verify the performance of the proposed concurrent dual-band receivers and to test the efficiency of the AHM based calibration algorithms. As a performance metric, the Error Vector Magnitude (EVM) has been measured to compare the transmitted and recovered baseband signals and to evaluate the performance and efficiency of the proposed calibration algorithms for the two receiver topologies. The IQ data has been recovered with EVMs no higher than 2% for the two LOs based receiver excited with a QAM modulated dual-band RF signal. The single LO based receiver has been tested with a dual-band LTE signal and the recovered IQ data exhibited EVMs no higher than 4%.
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| 8. |
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| 9. |
- Fan, Jin, et al.
(author)
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Investigation of ultra-wideband Bowtie antennas for phased array feed application
- 2020
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In: International Journal of RF and Microwave Computer-Aided Engineering. - : Hindawi Limited. - 1096-4290 .- 1099-047X. ; 30:11
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Journal article (peer-reviewed)abstract
- In this article, two new ultra-wideband (UWB) dual-polarized Bowtie antennas are investigated as the elements for a phased array feed for reflectors. In addition to its UWB impedance matching characteristic, the Bowtie antennas have stable large beam-width and a low cross-polar level over a wide frequency band with a compact size, which is an essence for phased array applications. The simulated and measured results state a low ohmic loss, good impedance matching (S11 below −15 dB) and good radiation performance, with a simple structure for easy manufacturing. The proposed antennas can be good candidates for phased array feed (PAF) in FAST and the SKA (square kilometer array) pathfinder PHAROS2 projects, and massive MIMO antennas in wireless communication systems.
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| 10. |
- Fanyaev, I., et al.
(author)
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Synthesis of novel 8 x 8 beam-forming network for broadband multibeam antenna array
- 2022
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In: International Journal of Rf and Microwave Computer-Aided Engineering. - : Hindawi Limited. - 1096-4290 .- 1099-047X. ; 32:2
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Journal article (peer-reviewed)abstract
- Synthesis of a novel 8 x 8 beam-forming network (BFN) for broadband multi-beam antenna arrays in the X-band has been proposed. The synthesized BFN has 6 less path crossings than a classic Butler matrix. The BFN design is realized using basic elements such as slot-line transition and magic-Ts. A numerical simulation for the analysis of the frequency characteristics of the proposed BFN is carried out. In addition, we offer a design of an eight-channel multibeam antenna array consisting of the synthesized BFN and Vivaldi antennas. Eight spatial beams cover approximately 120 degrees in the azimuth plane with a peak gain of 12 dB in the range of 8.3-11.7 GHz. The proposed broadband multibeam antenna array has good performance, compactness, and ease of fabrication that would be an attractive candidate for radar, satellite communication, and wireless computer networks.
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