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Antenna design using speaker wire for a Bluetooth ear set
Zahid, Zeeshan,Lee, Hongkoo,Kim, Mingi,Kim, Hyung‐,Hoon,Kim, Hyeongdong John Wiley Sons, Inc. 2019 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS Vol.61 No.3
<P><B>Abstract</B></P><P>In this article, an antenna design using an audio wire is proposed for a compact Bluetooth ear set. The length of the audio wire is less than a quarter of a wavelength in Bluetooth ear sets. Therefore, an appropriate feed structure needs to be designed to utilize the wire as an antenna. The antenna has been tuned using an inductor and impedance matching is accomplished by a loop‐type feeding structure with lumped capacitors. The feeding structure can be used to tune various lengths of the antenna. Full wave simulations are conducted to observe the effectiveness of the proposed technique. The measured and simulated bandwidths of the antenna are in good agreement. The measured bandwidth and average efficiency of the antenna were 116 MHz and 54.74%, whereas the average total isotropic sensitivity was 80.12 dBm that comply with the desired criteria for operation of the Bluetooth ear set.</P>
Analysis of a loop type ground radiation antenna based on equivalent circuit model
Zahid, Zeeshan,Kim, Hyeongdong IET 2017 IET microwaves, antennas & propagation Vol.11 No.1
<P>A loop type ground radiation antenna has been analysed using an equivalent circuit model in this study. The proposed circuit model has been selected in such a way that the design parameters of the ground radiation antenna can be mapped onto the circuit. To demonstrate the accuracy of the model, a specific ground radiation antenna is designed in a full wave electromagnetic simulator and the equivalent circuit model of the antenna is optimised in a circuit simulator. The simulation results of the circuit simulator and full wave simulator are compared. Expressions of return loss and input impedance of the equivalent model have also been obtained. The proposed circuit model can be used to develop insight and describe the behaviour of the network parameters of the antenna.</P>
Loop-type ground radiation antenna for a discontinuous square ring-shaped ground plane
Zahid, Zeeshan,Kim, Hyeongdong IET 2017 Electronics letters Vol.53 No.12
<P>A loop-type ground radiation antenna is proposed for a discontinuous square ring-shaped ground plane. The antenna shows strong coupling with the ground mode if it is located at the maximum current density location. The location of the antenna has been evaluated using characteristic mode analysis of the currents on the ground plane. The size of the loop-type ground radiation antenna is 10 × 4.5 mm and it is fabricated on a square ring-shaped ground plane of size 50 × 50 mm having a gap of 2 mm. The design is intended for mobile device applications operating at 2.45 GHz.</P>
Tunable-Slot-Type Ground Radiation Antenna with Dual Band Operation Using LC Resonator
Zeeshan Zahid,Hyeongdong Kim 한국전자파학회JEES 2017 Journal of Electromagnetic Engineering and Science Vol.17 No.2
A dual-band tunable-slot-type ground radiation antenna is proposed. The feeding structure consists of a coplanar waveguide and a lumped capacitor to excite currents for first- and second-order resonant modes of the ground. The resonant frequencies of both bands are controlled using a series combination of a capacitor and an inductor. The proposed design may be an attractive choice for mobile devices owing to its compact geometry and tunable operating frequencies. The measurement and simulation results of the proposed antenna show good agreement, indicating good impedance matching and radiation performance.
Coupling mechanism of a loop‐type ground radiation antenna
Zeeshan Zahid,김형동 한국전자통신연구원 2019 ETRI Journal Vol.41 No.4
The coupling mechanism of a loop‐type ground radiation antenna is investigated in this paper. We use the equivalent circuit model of the antenna and a full‐wave simulation to explain the coupling mechanism of the antenna. We analyze the effects of various antenna parameters on the coupling between the antenna element and the ground plane to examine the conditions for enhancing the coupling. Based on simulations with the equivalent circuit model, full‐wave simulations, and measurements, we propose optimal design considerations for the antenna. The findings of this study will aid the design and understanding of loop‐type ground radiation antennas for mobile devices.
Circularly Polarized Loop-Type Ground Radiation Antenna for IoT Applications
Zeeshan Zahid,Longyue Qu,Hyung-Hoon Kim,Hyeongdong Kim 한국전자파학회JEES 2019 Journal of Electromagnetic Engineering and Science Vol.19 No.3
A circularly polarized loop-type ground radiation antenna using a ground mode tuning (GMT) structure is proposed for Internet of Things (IoT) devices. The antenna is designed to excite two orthogonal modes of equal magnitude on the ground plane. The GMT structure consists of an inductor and a metallic strip that has been installed at the edge of the ground plane to obtain a 90° phase shift between the two modes. The proposed antenna generates left-hand circularly polarized waves in the +z-direction and right-hand circularly polarized waves in the -z-direction. The antenna was fabricated to validate the simulation results. The measured -6 dB bandwidth of the antenna was 150 MHz and the axial ratio bandwidth with reference to 3 dB was 130 MHz, completely covering the 2.4–2.48 GHz band.
Circular Polarized Ground Radiation Antenna for Mobile Applications
Qu, Longyue,Zahid, Zeeshan,Kim, Hyung-Hoon,Kim, Hyeongdong Institute of Electrical and Electronics Engineers 2018 IEEE transactions on antennas and propagation Vol.66 No.5
<P>Here, we propose a ground radiation antenna (GradiAnt) with circular polarization (CP) by applying the ground-mode tuning (GMT) technique to the ground plane. We demonstrate that a GradiAnt at an arbitrary location of the ground plane can simultaneously excite two orthogonal modes of the same magnitude, and the phase difference between the two modes can be adjusted via GMT to achieve CP in mobile antennas. The proposed GradiAnt can be viewed as a combination of an electric coupler (J-type) and magnetic coupler (M-type) to the modes of the ground plane, and both modes can be excited to the same amplitude by tuning the coupling-type. GMT, applied to the ground modes using inductor-connected metal strips, can generate a 90° phase difference between the two modes of the ground plane. The proposed antenna design generates a 6 dB axial ratio bandwidth of 140 MHz from 2.38 to 2.52 GHz in the <TEX>$+\textit {z}$</TEX>-direction. Right-hand CP and left-hand CP in the <TEX>$+\textit {z}$</TEX>-direction and <TEX>$-\textit {z}$</TEX>-direction, respectively, are obtained. The tuning mechanism is presented, and measurements are taken to validate the proposed technique.</P>
TRAIL and Bortezomib: Killing Cancer with Two Stones
Qureshi, Muhammad Zahid,Romero, Mirna Azalea,Attar, Rukset,Javed, Zeeshan,Farooqi, Ammad Ahmad Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.4
Cancer genomics and proteomics have undergone considerable broadening in the past decades and increasingly it is being realized that solid/liquid phase microarrays and high-throughput resequencing have provided platforms to improve our existing knowledge of determinants of cancer development, progression and survival. Loss of apoptosis is a widely and deeply studied process and different approaches are being used to restore apoptosis in resistant cancer phenotype. Modulating the balance between pro-apoptotic and anti-apoptotic proteins is essential to induce apoptosis. It is becoming more understood that pharmacological inhibition of the proteasome might prove to be an effective option in improving TRAIL induced apoptosis in cancer cells. Keeping in view rapidly accumulating evidence of carcinogenesis, metastasis, resistance against wide ranging therapeutics and loss of apoptosis, better knowledge regarding tumor suppressors, oncogenes, pro-apoptotic and anti-apotptic proteins will be helpful in translating the findings from benchtop to bedside.
Loop-Type Ground Radiation Antenna for a C-Shaped Ground Plane
Hongkoo Lee,Zeeshan Zahid,Hyeongdong Kim 한국전자파학회JEES 2019 Journal of Electromagnetic Engineering and Science Vol.19 No.1
In this study, optimum locations for a loop-type ground radiation antenna are evaluated for C-shaped ground planes of two different sizes. To achieve good radiation performance, the antenna needs to be located such that it couples with the dominant current mode of the ground plane. Antenna locations are proposed using the characteristic mode analysis of the ground planes. The measured bandwidths of the antennas at the proposed locations have more than twice the bandwidths of the cases in which the antennas are coupled with nondominant modes. The operating frequency of the antennas is 2.45 ㎓.