The Design Of Circuit For RF Ultra-wideband Signal Generating Based On CMOS

With the progress of science and technology, China’s communications is also rapidly developing, from the cable communications to the modern wireless communication. However, that does not meet the requirements of people’s communication. It’s desire that wireless communication has a better quality of the communication, such as high data rate、security and so on. Modern wireless communication, using narrowband technology, needs carrier signal, which makes the circuit of wireless devices complex、 large power consumption、 low data rate. UWB technology approved by FCC transmits information using very low power, short impulses thinly spreading over a wide bandwidth. Benefiting from the extremely wide transmission bandwidth, the UWB radio exhibits large transmission channel capacity, improving data rate. Impulse radio-ultra-wideband (IR-UWB), without carrier signal, the implementation of wireless device circuit is simpler, no up/down conversion or mixer is needed leading to substantial reduction in chip area and power consumption.The research contents of this paper is the design of IR-UWB signal generating circuit. Through the theoretical research, pulse generation could be performed by direct synthesis, using step recovery diode and transmission line, however, the implement of the circuit is not easy for integration, low-cost, low-complexity purposes. Based on digital circuit architecture, this paper designs a IR-UWB signal generator, which can generate GMP UWB signal with inputting the clock signal. The circuit is simple, low power consumption, high integration, IR-UWB signal can be amplified through designing CMOS UWB LNA. Based on SMIC0.18um CMOS process, the circuit is validated by simulation.The main work of this paper is as follows:1. Through researching UWB signal generators proposed and analyzing their advantages or disadvantages, this paper designs a kind of UWB signal generator based on the digital circuit structure.2. In the process of designing the UWB signal generator, how to solve GMP pulse overlapping problem.3. How to realize the BPSK modulation, and to optimize phase shift error between BPSK signal and triangle pulse signal.4. This proposed chips include:Triangle impulse generator, GMP pulse combination circuit, BPSK modulation circuit, UWB LNA.5. The research of UWB LNA input matching, Noise figure, the relatively flat gain, how to implement the performance optimization, and to realize UWB LNA adjustable gain.6. Base on SMIC0.18um CMOS technology, simulating and verifying the features of the circuit.