The LNA (Low Noise Amplifier) is also known as the backbone of RF communication receivers. As the usage of wireless technology is growing together with the advancing technologies, it is important to have a strong grip in the LNA knowledge as RF receivers uses LNA to amplify received signals. A good LNA should be able to provide extra amplification to very small input signal with as little noise possible to the subsequent stages in the circuit. For the LNA to perform well, the biasing circuit plays a major role. The main purpose of the biasing circuit is to bias the LNA’s transistor into the wanted operating mode, which normally is the saturation mode. This report attempts to explain the pro and cons of various design of biasing circuit normally used, and the steps of how the final design is obtained. All the biasing circuits and the LNA is built based on Silterra 0.18 μm technology through Cadence software and to simulate it’s operation. The main purpose is to find a biasing circuit that is stable against various conditions like temperature variation, supply voltage variation, etc. Based on the results obtained from simulation, the biasing circuit that is most stable in various conditions is selected and matching redone to optimize the performance of the LNA. The finalized circuit layout will be drawn, Design Rules Check (DRC) and Layout Versus Schematic (LVS ) is performed using Cadence layout tool was used. To a large extent, the objectives were met, thereby satisfying the requirements of the project. However, further study is proposed to explore the utilization of this technology in other applications.
Stable biasing techniques for LNA in WCDMA application_ERIC CHEW CHOON YEAN_E3_2007_NI