Wideband, high gain, high linearity, low noise amplifier for GNSS frequencies with compensation for low frequency instability

Abstract

This paper presents the design methodology, simulation results and implementation details of a low noise amplifier (LNA) designed to operate over the whole range of Global Navigation Satellite System (GNSS) frequencies (1164MHz to 1615.5MHz). This LNA works over combined (but overlapping) frequency bands of all three GNSS constellations (GNSS consist of the American Global Positioning System (GPS), European Galileo system and the Russian GLONASS system). Designed to be unconditionally stable with gain of over 18dB and noise figure of 2dB over a considerable bandwidth of about 450MHz, the achieved results conformed quite well to the specifications. Final implementation results include a gain of 18.5dB at the centre frequency with a nominal variation of ±1.3dB over the desired bandwidth. The noise figure obtained is 2.18dB and the amplifier stability range extends from 0Hz to 9GHz. Very high degree of linearity is achieved with output ldB compression at +13dBm and output third order intercept at +23dBm. This paper describes results at every stage of design, simulation and implementation along with a solution against typical low frequency instability by a small trade-off in noise figure.