Showing papers by "Shiban K. Koul published in 2012"

Design and development of a surface micro-machined push-pull-type true-time-delay phase shifter on an alumina substrate for Ka-band T/R module application

Abstract: A radio frequency micro-electro-mechanical system (RF-MEMS) phase shifter based on the distributed MEMS transmission line (DMTL) concept towards maximum achievable phase shift with low actuation voltage with good figure of merit (FOM) is presented in this paper. This surface micro-machined analog DMTL phase shifter demonstrates low power consumption for implementation in a Ka-band transmit/receive (T/R) module. The push–pull-type switch has been designed and optimized with an analytical method and validated with simulation, which is the fundamental building block of the design of a true-time-delay phase shifter. Change in phase has been designed and optimized in push and pull states with reference to the up-state performance of the phase shifter. The working principle of this push–pull-type DMTL phase shifter has been comprehensively worked out. A thorough detail of the design and performance analysis of the phase shifter has been carried out with various structural parameters using commercially available simulation tools with reference to a change in phase shift and has been verified using a system level simulation. The phase shifter is fabricated on the alumina substrate, using a suspended gold bridge membrane with a surface micromachining process. Asymmetric behaviour of push–pull bridge configuration has been noted and a corresponding effect on mechanical, electrical and RF performances has been extensively investigated. It is demonstrated 114° dB−1 FOM over 0–40 GHz band, which is the highest achievable FOM from a unit cell on an alumina substrate reported so far. A complete phase shifter contributes to a continuous differential phase shift of 0°–360° over 0–40 GHz band with a minimum actuation voltage of 8.1 V which is the highest achievable phase shift with the lowest actuation voltage as per till date on the alumina substrate with good repeatability and return loss better than 11.5 dB over 0–40 GHz band.

A Planar End-fire Array in S-band for Airborne Applications

Abstract: Planar end-fire arrays can be used in airborne radar applications for forward and rear vision. The purpose of this work is to demonstrate the viability of constructing end-fire arrays with good ban...

Analysis and design of a fully integrated, linear dual band LNA for WLAN and Wi-MAX application

Abstract: This work reports development of a fully integrated dual band low noise amplifier(LNA) in 0.18 μm CMOS at 2.8/3.4GHz for WLAN and Wi-MAX applications. Dual-band operation is achieved by switching one capacitor each in input and output matching networks. Measured results show a gain of 5 dB/7 dB at 2.8GHz/3.4GHz. Key features of the LNA are: high IIP3 > +1.5dBm (in both bands) while consuming 5.7mA from a 1.8V supply, a single control input and active area of 0.16mm2. An analytical expression for voltage gain has also been derived and verified in both bands.