The Development Of Miniature Balanced Low Noise Amplifier

The development of mobile communication has stimulated the research of relative products. With the continuous progress of semiconductor technologies, the products of mobile communication network are using mostly the microwave integrated circuits to achieve the miniaturization of products and to reduce costs. In these products, the low noise amplifier is an indispensable part, whose circuit structure has an impact on the miniaturization of products. In addition, because of the request to the sensitivity of communication system receiver is higher and higher, the low noise amplifier with a higher performance is in need, which is the key part of the system. First of all, this paper presents a balanced low noise amplifier based on the superfine hybrid microwave integrated circuits technology, and then, a Frequency Selecting Amplifier Module based on this balanced low noise amplifier is described. The main contents are as following:Chapter 1 briefly introduces the history and development of mobile communication, the applications of the low noise amplifier in the mobile communications and the circuit technology.The basic theory and the principles of designing of the low noise amplifier is described in Chapter 2. First, it presents the various parameters due to the performances of the low noise amplifier, for example, Gain, Noise Figure, Stability, and so on. And then, the principles of designing are analyzed in detail.Chapter 3 describes the design process of the balanced low noise amplifier in detail. First, the indicators of the low noise amplifier are determined, and with these indicators, the project is designed. After comparative analysis, the balanced circuit structure is chosen. And then the bias circuit and matching network are designed with ADS, finally, the whole design is optimized.Chapter 4 presents a Frequency Selecting Amplifier Module based on the balanced low noise amplifier. According to the theory of quasi-elliptic function filter, a filter is designed with a center frequency of 1.95GHz, which is integrated with the balanced low noise amplifier to create a Frequency Selecting Amplifier Module, and then optimize it with ADS.Chapter 5 presents the realization of the technology of the balanced low noise amplifier and Frequency Selecting Amplifier Module. The practical circuit is debugged, tested and analyzed.Chapter 6 summarizes the above work.The balanced low noise amplifier mentioned in this subject presents a good work performance in the working frequency, having achieved the request to the indicators, and small, could be used in the WCDMA repeater system, so can reduce the size of the system and realize the miniaturization of the repeater.