Experimental results and EM simulation of substrate noise in wideband low noise amplifier for UWB systems

Abstract

Impact of substrate noise on a 6−10 GHz low noise amplifier (LNA) is investigated in this work. The measurement results show significant substrate noise in the bandwidth of LNA due to an oscillator. An electromagnetic (EM) approach is proposed to predict the behaviour of substrate noise at LNA's input. The behaviour of substrate coupling is also evaluated by a lumped model developed from EM simulations. The lumped model predicts the magnitude of substrate noise obtained by EM simulation.

Design and implementation of UWB CMOS LC filters LNA for carrier less impulse radio receivers

“…In the case of small fractional bandwidths the input matching cell relations are given by (1)(2)(3)(4)(5)(6)(7)(8)(9). Equation (7) can be approximated by (25) because J 3 must be chosen in order to be low in comparison to unity in the input matching cell design as mentioned above.…”

“…This way, practical inductor values leading to high SFR value and high Q factor can be chosen according to the LNA operating bandwidth. Once the values of inductors L 1 and L 2 are fixed, relations (1)(2)(3)(4)(5)(6)(7)(8)(9) give the input matching cell element values for a given power consumption and a given value of the degeneration inductance L S .…”

“…In addition a constant group delay is required in the signal bandwidth to maintain the signal integrity of the pulsed wideband signal. Wide band CMOS LNA have been designed by using several topologies: distributed amplifiers [1,2], feedback amplifiers [3][4][5], common gate [6][7][8], or LC ladder filters LNA [9]. Beside the others topologies, LC ladder filter LNA allow constant gain and group delay in a well controlled bandwidth.…”