Traditionally, the digital implementation of modems is restricted to parts operating at baseband frequency. At higher frequencies , roughly 30 MHz and beyond, analog technologies such as SAW lters provide a better power/performance gure 1]. In this paper, we show how this barrier can be broken by trading programmability for speed. Using a digital multirate lter structure that ooers combined int...

465 news & views of amplifiers and logic devices based on graphene, actually enables a new class of nonlinear radiofrequency electronic devices. Frequency multipliers 5,6, , high-frequency mixers 7 and digital modulators 8,9 have all been recently demonstrated using this principle, with operating frequencies as high as 16 GHz and radiofrequency efficiencies in excess of 90% (ref. 10). Infrared ...

RAMACHANDRAN, RAMYA. Investigation of Surface States in Gallium Nitride Devices using a New High Frequency Measurement Technique. (Under the direction of Dr. Douglas W. Barlage). Surface states place a limitation on the high-frequency behavior of Gallium Nitride devices by causing RF dispersion. They are also a source of undesirable 1/f noise. This thesis specifically aims to explore techniques...

The electromagnetic frequency spectrum is divided into different sub-frequency bands. These bands are allocated for applications. In these days, devices operating in multiple provide significant advantages. Devices require antenna structures to operate Microstrip antennas have become prominent with their small size, portable and easy integration other systems. this study, microstrip structure w...

In view of the recent finding that different T-DNAs tend to ligate and integrate as repeats at single chromosomal positions, the frequency of transformation and cotransformation was determined during cocultivation of Arabidopsis thaliana root explants and Nicotiana tabacum protoplasts with two Agrobacterium strains. The transformation frequency of unselected A. thaliana shoots was lower than 1%...

Abstract Embedded sensors operating within a reinforced concrete structure enable the timely detection of structural degradation causes, such as chloride ions present in pore solution. The best communication protocol to use for inter‐device would ideally be wireless an ultrasonic system. Concrete is composite material which imposes constraints on transmission, especially when at frequencies abo...

The radar cross section of spherical retroreflectors operating at terahertz frequencies is investigated. Several spherical retroreflectors with diameters ranging from 2 mm to 8 mm were fabricated and their radar cross section was measured at 100 GHz, 160 GHz, and 350 GHz. A frequency selective surface was applied to the retroreflectors to demonstrate proof of concept of narrow-band terahertz re...

At high frequency, radio waves will interact with space plasmas and surfaces of local astronomical objects, producing an echo that can provide new diagnostic data. The availability of high power radars operating at high frequencies opens a window for the remote investigation of our surrounding space environment. We discuss and illustrate this technique with some specific examples.

The dynamic characteristics of GaN-based Gunn and IMPATTs are reported at same operating conditions to find out the potentiality of each device to use as high frequency signal generator. The general model is developed by the author’s group considering all the physical phenomena for both the devices. It is seen that Double Drift Region IMPATTs produce better microwave power compare to Gunn diode...

In this paper, we report on the engineering and the realization of optically transparent graphene-based microwave devices using Chemical Vapour Deposition (CVD) graphene whose sheet resistance may be tailored down to values below 30 Ω/sq. In particular, we show that the process was successfully used to realize and characterize a simple, optically transparent graphene-based wire-grid polarizer a...