scispace - formally typeset
Search or ask a question
Author

Madhur Deo Upadhayay

Bio: Madhur Deo Upadhayay is an academic researcher from Shiv Nadar University. The author has contributed to research in topics: Antenna (radio) & Patch antenna. The author has an hindex of 5, co-authored 54 publications receiving 97 citations. Previous affiliations of Madhur Deo Upadhayay include Indian Institute of Technology Delhi & Indian Institutes of Technology.


Cited by
More filters
01 Dec 1992

298 citations

Book
01 Jan 2009
TL;DR: This paper describes the design and Fabrication of BAW Devices and the system-in-Package integration of these devices, and provides a comparison with SAW Devices.
Abstract: Background and History. Resonator and Filter Topologies. Baw Device Basics. Design and Fabrication of BAW Devices. FBAR Resonators and Filters. Comparison with SAW Devices. Films Deposition for BAW Devices. Characterization of BAW Devices. Monolithic Integration. System-in-Package (SiP) Integration. Index.

187 citations

Journal Article
TL;DR: In this article, the first experimental generation of high-order Mathieu beams and confirm their propagation invariance over a limited range were reported, using a computer-generated phase hologram.
Abstract: We report the first experimental generation of high-order Mathieu beams and confirm their propagation invariance over a limited range. In our experiment we use a computer-generated phase hologram. The peculiar behaviour of the vortices in Mathieu beams gives rise to questions about their orbital-angular-momentum content, which we calculate by performing a decomposition in terms of Bessel beams.

102 citations

Journal ArticleDOI
TL;DR: Numerical results demonstrate that the mode modulation (MM) based OAM system can offer a new mode dimension for vorticose communications and the AMM scheme can achieve larger SE than the EMM scheme.
Abstract: Recently, orbital angular momentum (OAM) based vorticose communication has attracted much attention because of its potential to significantly increase the spectrum efficiency (SE) of wireless communications. However, the multiple radio frequency (RF) chains used for multiple OAM modes lead to an unexpected cost for wireless vorticose communications. In this paper, we first propose the mode modulation (MM) based OAM system to allow multiple OAM modes sharing a common RF chain. The proposed MM cannot only reduce the hardware cost, but also boost the SE by introducing the mode as an additional dimension for data transmission. Moreover, without the channel state information (CSI) feedback, we develop an equal-probability mode modulation (EMM) scheme to maximize the SE of MM-based OAM systems with the limited RF chains. In addition, with the CSI feedback, we develop a Huffman coding based adaptive mode modulation (AMM) scheme, which can adaptively choose the OAM modes to further increase the SEs of OAM-based wireless communications. We also develop the joint power and probability allocation policy for the AMM scheme to achieve the maximum SEs for OAM-based vorticose communications. Numerical results demonstrate that the MM can offer a new mode dimension for vorticose communications and the AMM scheme can achieve larger SE than the EMM scheme.

33 citations

Journal ArticleDOI
TL;DR: In this paper, the authors proposed an ultrathin complementary metasurface that converts a left-handed (right-handed) circularly polarized plane wave without orbital angular momentum (OAM), which is associated with the azimuthal phase of the complex electric field.
Abstract: Electromagnetic (EM) waves with helical wavefront carry orbital angular momentum (OAM), which is associated with the azimuthal phase of the complex electric field. OAM is a new degree of freedom in EM waves and is promising for channel multiplexing in communication system. Although the OAM-carrying EM wave attracts more and more attention, the method of OAM generation at microwave frequencies still faces challenges, such as efficiency and simulation time. In this work, by using the circuit theory and equivalence principle, we build two simplified models, one for a single scatter and one for the whole metasurface to predict their EM responses. Both of the models significantly simplify the design procedure and reduce the simulation time. In this paper, we propose an ultrathin complementary metasurface that converts a left-handed (right-handed) circularly polarized plane wave without OAM to a right-handed (left-handed) circularly polarized wave with OAM of arbitrary orders and a high transmission efficiency can be achieved.

28 citations