A. R. Harish

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The problem of indoor position location tracking has been addressed in this paper, using passive UHF RFID tags. The test area is first calibrated by placing some reference tags at known positions and orientations. This data obtained by measuring the detection powers for these reference tags is later used to train an algorithm, which is in turn used to(More)
New techniques are being devised to use RFID technology to enable Indoor Position tracking of tagged objects. RFID holds immense promise in this area as tags are cheaply available and robust to various kinds of RF interference. In this paper, passive UHF (868MHz) tags placed at uniformly spaced points in a grid in different sets of orientations are used to(More)
A modified bow-tie antenna fed by a 50-Omega paired strip transmission line is proposed for dual band applications. A printed bow-tie antenna is modified by incorporating triangular shaped parasitic elements. A procedure to design an antenna that works at two arbitrary frequencies <i>f</i> <sub>01</sub> and <i>f</i> <sub>02</sub> is discussed. It is(More)
A slot and a monopole antenna fabricated on a single substrate can generate circularly polarized radiation over a broad band of frequencies. Appropriate power division network is used to feed the elements from a microstrip transmission line. Radiation pattern of antenna is circularly polarized in the broadside direction. Measured 3-dB axial-ratio (AR)(More)
Designing RFID tag antenna for metallic objects is a challenging task as antenna parameters are highly affected by metallic surface. This paper presents a miniaturized slotted RFID tag antenna with overall dimensions of 33 mm &#x00D7; 16 mm &#x00D7; 3.2 mm for metallic objects. The proposed design contains two coplanar metallic patches which are(More)
A new technique to compute the coupling, as a function of frequency, between nonidentical resonators is presented in this paper. The structure is separated by introducing electric and magnetic wall boundary conditions on the plane of separation, and coupling coefficient is computed directly from the eigenvalues of the four individual structures. The(More)
A wideband and simple torus knot monopole antenna is presented in this letter. The antenna is fabricated using additive manufacturing technology, commonly known as 3-D printing. The antenna is mechanically simple to fabricate and has stable radiation pattern as well as input reflection coefficient below -10 dB over a frequency range of 1-2 GHz. A comparison(More)
In this paper we present compact dual mode band pass filter based on trefoil torus knot resonator. The resonator is realized using additive manufacturing technology. Size of the resonator is 0.16 &#x03BB; at the center frequency of operation. Fabricated resonator prototype is about half the size of ring resonator. Simulated and measured results are(More)
We present a novel technique to improve the input bandwidth of a conventional printed dipole antenna without actually increasing its size. We show that the proposed modification results in a considerable improvement in the input bandwidth. We also propose an equivalent circuit model for this antenna and describe a procedure to determine the values of the(More)
A simple, compact, rechargeable handheld radio-frequency identification (RFID) reader was designed to detect the orientation of tagged objects. The system uses a linearly polarized reader antenna and the orientation sensor of the mobile device to identify the orientation of the tag. The system works in the ultra-high-frequency (UHF) RFID band. Detailed(More)