DC-6GHz Ultra-wideband Low-noise Amplifier

Typically, the low noise amplifier is located in the front of the RF receiver. The performance of the LN A is directly related to the sensitivity and the noise figure of the entire receiving system, therefore, the LNA is a key part of the wireless communication system. The main task of this paper is to design a DC-6GHz UWB low-noise amplifier.Firstly, this article gave a brief introduction of the development process of the UWB LNA, then in chapter2we analyzed the basic design theories and methods of LNA in detail. After comparing several circuit structures of the broadband amplifier, ultimately we chose the negative feedback method to design the UWB LNA. In order to meet the requirement of miniaturization, this design chose FHX13X HEMT chip as amplifier. Because the frequency of this amplifier is0.2-6GHz, we selected the mixing element matching network as the matching circuit. To meet the high gain specification, the amplifier included three stages. The first stage used the transistors in parallel structure and the negative feedback circuit to extend the working bandwidth. The function of the second stage amplifier’s to meet the requirement of high-level power gain, and then compensated the input VSWR through the inter-stage matching network. The output matching circuit of the third stage used the lossy matching network to reduce the low-frequency gain and to improve the output VSWR.The simulation design’s on the basis of ADS2008. In consideration of the effects of gold-bonding in high frequency, we added the gold-bonding model during simulation. After optimized the amplifier circuit, the simulation result met the expectations. The testing result of the LNA showed the noise figure of less than1.5dB, and the gain higher than30dB, all of the indicators had met the design requirements.