Yogesh Ranga

Bio: Yogesh Ranga is an academic researcher from Commonwealth Scientific and Industrial Research Organisation. The author has contributed to research in topics: Antenna (radio) & Monopole antenna. The author has an hindex of 15, co-authored 69 publications receiving 1173 citations. Previous affiliations of Yogesh Ranga include Macquarie University & Indian Institute of Technology Bombay.

A Single-Layer Frequency-Selective Surface for Ultrawideband Electromagnetic Shielding

Abstract: An efficient approach to achieve the shielding effectiveness (SE) by using a frequency-selective surface (FSS) is presented. This FSS, which consists of cross dipoles and rings printed on the opposite sides of a single-layer FR-4 substrate, exhibits a wide, 7.5-GHz stopband to provide simultaneous shielding in both X- and Ka-bands. Experimental results confirm SE of the prototype over an ultra-wide band with more than 20-dB measured attenuation. The design is compact and suitable to provide shielding against the radiation interference caused by license-free and other radio systems.

Ultrawideband Printed Elliptical Monopole Antennas

Abstract: Parametric study of ultrawideband printed elliptical monopole antennas have been presented. Design curve for the length of the feed transmission line for various lower band edge frequencies has been generated. Variation of bandwidth with ellipticity ratio of these configurations has also been studied. Experiments have been performed to measure bandwidth and radiation patterns of these configurations, which tally well with simulated results. The elliptical configuration with ellipticity ratio of 1.1 gives ultrawide impedance bandwidth ratio of 12.4:1 as compared to 10.2:1 of the circular monopole antenna. This antenna introduces minimum ringing and distortion/dispersion of the pulse in time domain

Multioctave Frequency Selective Surface Reflector for Ultrawideband Antennas

Abstract: In this letter, we demonstrate the gain enhancement of an ultrawideband (UWB) antenna, achieved using an appropriately designed multioctave dual-layer frequency selective surface (FSS) reflector. The proposed novel FSS reflects effectively in phase over a bandwidth of about 120%. Hence, significant enhancement in antenna gain has been achieved with a low-profile configuration without compromising the impedance bandwidth of the UWB antenna. The proposed FSS reflector has a low transmission coefficient and linearly decreasing phase over an ultra-wide frequency band, which is the key requirement for providing an effectively in-phase reflection at the antenna plane. The composite structure is compact, with a total height of λ/4, where λ is the free-space wavelength at the lowest operating frequency of 3 GHz. Experimental results show an impedance bandwidth of 122%. The antenna gain is maintained around 7.5 dBi from 3 to 7 GHz. Between 7-14 GHz, the antenna is more directive with a gain of about 9 dBi with ±0.5 dB variation. Experimental measurements con firm the predicted wideband antenna performance and gain enhancement due to the FSS reflector.

An Ultra-Wideband Quasi-Planar Antenna with Enhanced Gain

Abstract: A new ultra-wideband antenna with enhanced and nearly constant gain is presented. This quasi-planar antenna is composed of a CPW-fed printed monopole and a short horn, both made out of a single substrate. The measurements demonstrate an almost ∞at peak gain of 5:5dBi § 0:7dB from 2.5GHz to 15GHz with the average gain difierence in XZ plane is roughly 2dB up to 8GHz, which further rise to 6dB at 10GHz. The antenna also has a nearly linear phase response in this band. Well tested performance both in frequency and time domains, along with broad azimuth pattern, results in minimal ringing of a radiated pulse. The new antenna is suitable for establishing good line of sight link for UWB transmission and other broadband applications.

A Simple Ultra Wideband Printed Monopole Antenna With High Band Rejection and Wide Radiation Patterns

Abstract: A compact ultra wideband antenna with strong notch-band rejections up to VSWR = 26, that is tunable over a wide frequency range from 3.55 GHz to 6.8 GHz, is presented. It has wide radiation patterns and yields a measured 10 dB return-loss bandwidth from 3 GHz to 10.5 GHz.

Response to FCC 98-208 notice of inquiry in the matter of revision of part 15 of the commission's rules regarding ultra-wideband transmission systems

Abstract: In general, Micropower Impulse Radar (MIR) depends on Ultra-Wideband (UWB) transmission systems. UWB technology can supply innovative new systems and products that have an obvious value for radar and communications uses. Important applications include bridge-deck inspection systems, ground penetrating radar, mine detection, and precise distance resolution for such things as liquid level measurement. Most of these UWB inspection and measurement methods have some unique qualities, which need to be pursued. Therefore, in considering changes to Part 15 the FCC needs to take into account the unique features of UWB technology. MIR is applicable to two general types of UWB systems: radar systems and communications systems. Currently LLNL and its licensees are focusing on radar or radar type systems. LLNL is evaluating MIR for specialized communication systems. MIR is a relatively low power technology. Therefore, MIR systems seem to have a low potential for causing harmful interference to other users of the spectrum since the transmitted signal is spread over a wide bandwidth, which results in a relatively low spectral power density.

Method and apparatus for coupling an antenna to a device

Abstract: Aspects of the subject disclosure may include, for example, receiving, by a feed point of a dielectric antenna, electromagnetic waves from a dielectric core coupled to the feed point without an electrical return path, where at least a portion of the dielectric antenna comprises a conductive surface, directing, by the feed point, the electromagnetic waves to a proximal portion of the dielectric antenna, and radiating, via an aperture of the dielectric antenna, a wireless signal responsive to the electromagnetic waves being received at the aperture. Other embodiments are disclosed.

Remote distributed antenna system

Abstract: A distributed antenna system is provided that frequency shifts the output of one or more microcells to a 60 GHz or higher frequency range for transmission to a set of distributed antennas. The cellular band outputs of these microcell base station devices are used to modulate a 60 GHz (or higher) carrier wave, yielding a group of subcarriers on the 60 GHz carrier wave. This group will then be transmitted in the air via analog microwave RF unit, after which it can be repeated or radiated to the surrounding area. The repeaters amplify the signal and resend it on the air again toward the next repeater. In places where a microcell is required, the 60 GHz signal is shifted in frequency back to its original frequency (e.g., the 1.9 GHz cellular band) and radiated locally to nearby mobile devices.

Method and apparatus for sensing a condition in a transmission medium of electromagnetic waves

Abstract: Aspects of the subject disclosure may include, for example, a device that facilitates transmitting electromagnetic waves along a surface of a wire that facilitates delivery of electric energy to devices, and sensing a condition that is adverse to the electromagnetic waves propagating along the surface of the wire. Other embodiments are disclosed.

Method and apparatus that provides fault tolerance in a communication network

Abstract: Aspects of the subject disclosure may include, for example, a system for detecting a fault in a first wire of a power grid that affects a transmission or reception of electromagnetic waves that transport data and that propagate along a surface of the first wire, selecting a backup communication medium from one or more backup communication mediums according to one or more selection criteria, and redirecting the data to the backup communication medium to circumvent the fault. Other embodiments are disclosed.