Design of an ultra low noise amplifier for mobile communication in higher frequency band

This paper presents the design of an ultra low noise amplifier (LNA) from 6 GHz to 6.5 GHz, which is used in higher frequency band mobile communication systems. The circuit design, simulations and optimizations were performed using the Advanced Design System. The testing results indicate that the low noise amplifier has good performance: the gain is 24 dB with a 0.3 dB ripple, and the range of noise figure (connector insertion loss included) is 0.86 dB to 1.07 dB over the concerned frequency band. The developed LNA is ideal to be used in the receiver front end for the communication systems in higher frequency band.

I. Introduction

The increasing demand for higher data-rates transmission promotes the development and application of wider band communication systems. Since the spectrum at the low frequency band is becoming congested, it is a tendency to develop wireless communication systems in higher frequency band [1]. For the communication systems in the higher frequency band, the receiving sensitivity is of great importance because of the lower transmitting power and higher path loss. In the RF receiver, the low noise amplifier (LNA) usually dominates the performance such as the receiving sensitivity and dynamic range [2]. The noise figure, gain, stability, flatness, return loss and linearity, are the key specifications for a LNA [3]. In higher frequency band, it is more difficult to design an LNA with good performance.