Rajesh Kunnath

In this paper, design and development of a 2x2 MIMO RF front end is demonstrated. It has an RF board with commercial transceiver chips and operates at 2.4GHz. In the RF front end the transmitting and receiving paths are separated by using switches. These switches are controlled by transmitter and receiver switches. The signals are then recombined after amplification on both sides. Many advances in radio design and architecture are now allowing for rapid changes in the field of radio design. These changes allow reduction of size, cost, complexity and improve manufacturing by using digital components to replace unreliable and in-accurate analog components. For this to happen, many advances in semiconductor design and fabrication were required and have come to fruition over the last few years. Some of these advances include better integrated mixers, LNA, improved SAW filters, lower cost high performance ADCs and programmable digital tuners and filters.

With the increasing use of power electronics in all types of appliances, and with the increasing penetration of solar PV, distribution of power in the DC form is becoming attractive. This paper brings together various concerns that have been expressed in DC distribution at low voltages for consumption in domestic and other building needs. The paper presents various arguments and attempts to arrive at a solution from various points of view. A suitable voltage level of 48 V, and a suitable distribution scheme are presented along with some field experiences of installation of such systems.

This paper presents the design of RF Power amplifier for WLAN(Wireless Local Area Network) application is a challenging job as it is required to meet stringent specifications like stable Performance of the system, operate at temperature extremes and other mechanical aspects. For narrowband operation (2.3- 2.9GHz), it is necessary to design RF Power Amplifier with optimal gain around 13dB. The RF Power Amplifier using CREE GaN technology designed specifically for high gain, high efficiency and wide bandwidth capabilities for wi-fi and wiMAX applications. It plays a major role in amplifying the required high frequency RF signal without distortions and other impairments which would decrease the usefulness of the signal. To address this, efforts has been made to design an RF power amplifier operating at 2.4GHz of frequency by using GaN technology by using ADS software. Index terms-power amplifier, Gallium Nitride HEMT, WLAN, ADS(Advanced Design System)software.

ABSTRACT Many developing countries suffer from intense electricity deficits. For instance, the Indian electricity sector, despite having the world's fifth largest installed capacity, suffers from severe energy and peak power shortages. In February 2013, these shortages were 8.4% (7.5 GWh) and 7.9% (12.3 GW) respectively. To manage these deficits, many Indian electricity suppliers induce several hours of power cuts per day that impact a large number of their customers. Many customers use lead-acid battery backups with inverters and/or diesel generators to power their essential loads during those power cuts. The battery backups exacerbate the deficits by wasting energy in losses (conversion and storage) and by increasing the load (by immediately charging the batteries) when the grid is available. The customers also end up incurring additional costs due to aforementioned losses and due to limited lifetimes of batteries and inverters. In this paper, we discuss the issues with power cuts and backups in detail and illustrate their impact through measurements and simulation results.