Research And Design Of Embedded Multi-mode Multi-frequency Low Noise Amplifier

The development of mobile communications technology and the Internet put forward higher requirements for the design of the RF chip. Although the single-mode communication system can meet the needs of users, but multi-mode multi-frequency system can support more protocol standards, to meet the needs of more users. The embedded multi-mode multi-frequency RF transceiver system will be an important trend of the RF chip design.Low noise amplifier (LNA) is the RF receiver front-end, which directly affects the receiver reception. GSM/DCS/PCS/WCDMA protocol located in the0.8GHz to2.1GHz band, requires low noise figure specification, which can be processed in broadband RF receiver.2.4GHz WLAN band WiFi/Bluetooth protocol standards,easily affected by environmental interference signal, which require high performance in narrow-band receiver. In this paper, a2.4GHz narrow-band and a0.8GHz-2.1GHz LNA are designed.The main achievements are listed as follows.1. An source degenerated common source and common gate (cascode) LNA is designed for the need of protocol standard of2.4GHz WiFi/Bluetooth. The tapeout test result as follows:the LNA noise figure of2.6dB, a gain of19dB, input third-order intercept point (IIP3) of-13dBm. On the basis of test results, an improved LNA is proposed,which realized by multi-transconductance stage (multi-of tan) cascode structure.2. A broadband0.8～2.1GHz LNA is designed. The chip test result demonstrated:3.3dB LNA noise figure,15dB voltage gain,-5dBm IIP3. On the basis of test results, noise cancellation technology is used to improve broadband LNA to optimize the noise performance of the LNA.3.Embedded multi-mode multi-frequency LNA test platform is proposed,and the improved LNA circuit test is prepared. The improved structure of the LNA showed:2.4GHz LNA noise figure of1.76dB, the voltage gain of19.1dB, IIP3of-3.6dBm;0.8GHz～2.1GHz broadband LNA noise figure≤1.5dB voltage gain≥19dB in-band gain flatness≤4dB low-noise performance.This dissertation work is supported by Foundation of Major national science and technology projects " Embedded multi-mode multi-frequency transceiver IP core research "(NO.2009ZX01034-002-002-001-02).