Research And Design Of Multi-mode Lownoise Amplifier

The recent rapid development of science led to the need of multi-mode RF front-end circuits with long battery life. Generally, a multi-mode RF receiver is a receiver that can transmit data over a wide spectrum of frequency bands.The receiver with very low power and the power with very high system conversion efficiency can help the receiver to have a long battery life. The LNA(low noise amplifier) is one of the most important active blocks of the RF front-end. Firstly, we introduce some basic LNA topologies and the concept of noise figure, linearity and so on. We discuss noise figure optimization techniques for LNA. Secondly, a 2.45-GHz zigbee radio receiver according to IEEE 802.15.4 standard is presented. We use some propose methods to generating an optimal system-level specification for each block of the receiver. Some detailed analysis is presented for the effect on the performance of the receiver caused by the voltage ripple and the channel conditions. The results show that we can use a switched capacitor DC-DC converter with very low voltage ripple to power a RF receiver. The dynamic configuration of the blocks can reduce the power dissipation. Thirdly, we present a multi-mode LNA applied for GNSS(global navigation satellite system). The LNA has a gain of about 40 dB and a noise figure about 0.5d B. Then we use the suspend substrate stripline to design a dual-band prefilter. The stimulation results indicate that the insert loss is 1dB in passband and 30 dB in stopband. We also design a CMOS LNA applied for GNSS. The RLC parameters matrix of the IC package can be outputted by the Ansoft Q3 D. Finally, we presented a CMOS LNA used for zigbee technology. Some detailed analysis is presented for the relationship between the supply voltage, the working current and the performance of the LNA. It turned out that the performance of the LNA can be controlled by varying the supply voltage and the working current. We can use this method to realize the dynamic adjustment of a multi-mode LNA. We use ADS(advanced design system) to generate the system level of the receiver and design the GNSS LNA. We implement the chip-level LNA in a 0.18μm CMOS technology provided through the CSMC.