Harish V. Dixit

VLSI design of fast DCTQ-IQIDCT processor for real time image compression

The Discrete Cosine Transform (DCT) is largely used for image and video compression in standards like JPEG and MPEG2. Its simplicity coupled with the fact that it can be computed faster than the Discrete Wavelet Transform (DWT) makes it an attractive option for image and video compression. Consequently a lot of research is in progress to determine novel architectures and algorithms for faster DCT computation having high throughput so that it can even be used for real time applications. For example, when transmitting and receiving videos, which have been compressed using MPEG2, one would like to receive the video, without any buffering delay. In other words, one requires such an architecture, which provides the DCTQ coeffecients at a consistent rate, with very low latency between two coeffecients. As such, a highly parallel and pipelined architecture employing 57 pipeline stages and using fast multipliers and adders is proposed in this work. The proposed DCT Processor is implemented in Spartan 3E FPGA.

A MATLAB® based tool for microwave amplifier analysis

The high frequency microwave components such as an amplifier, oscillator et cetera have a wide range of applications in todays world of Digital Communication. These are mainly used in transponders and other mobile and radar applications which are inaccessible if faults or error occur in them. So a better solution is to perform a complete analysis of the device under all possible conditions before practically implementing it. This analysis is difficult and time consuming when it is done manually. A better approach to perform analysis is with the help of computers using Computer Aided Design (CAD) tools, but they are costly. A GUI designed on MATLAB serves the purpose of mathematical computation and analysis of the device under consideration and provides the required information on device performance.

Design of a quadrature hybrid waveguide coupler at high frequency for high power applications

In recent times, research in the field of nuclear fusion systems has been on the rise. Such systems play a vital role in the study of plasma physics and for possible applications towards the generation of electricity. Designing the components for such systems is a challenge owing to the demand for operation in high-frequency region (in the range of GHz) at extremely high powers. This paper presents a structure and methodology for designing a quadrature (90°) hybrid coupler operating at 3.7 GHz and 5 GHz frequencies. Designs have been simulated in COMSOL Multi physics software and RF heating results along with scattering parameters are presented in this paper.

Design data for quick development of Folded E plane Tee

Most of the microwave communication systems have requirement of power dividers that are essential for power splitting and combining operations. This paper presents a structure and methodology for designing a rectangular waveguide Folded E plane Tee. The structure proposed has the advantage of less area consumption as compared to a conventional waveguide Tee. The paper also presents design equations using which one can design a Folded E plane Tee at any desired frequency. The designs thus obtained at some random frequencies from the equations have been simulated in COMSOL Multiphysics and the scattering parameters obtained have been presented.

A multiphysics investigation of RF dry loads

Microwave absorbers/loads find applications in many microwave systems where they are utilised in testing or protection circuits. In many waveguide based systems, often lossy dielectrics are used as absorbers. Efficient thermal management of the heat generated in the dielectric is crucial for the functioning of the load. As such the design of a load is a multiphysics problem involving RF, thermal and in some cases fluid flow analysis. In this paper, different structures of low power loads are analysed for their RF and thermal characteristics and behaviour. These loads are designed for 3.7 GHz and simulated in COMSOL Multiphysics.