A 4 GHz quadrature output fractional-N frequency synthesizer for an IR-UWB transceiver

• Published in: Journal of semiconductors Vol. 31; no. 3; pp. 74 - 79
• Main Author: 郭诗塔 黄鲁 袁海泉 冯立松 刘志明
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.03.2010
• Subjects: GHz; UWB; 小数; 收发器; 正交; 红外; 输出; 频率合成器
• ISSN: 1674-4926
• DOI: 10.1088/1674-4926/31/3/035002

This paper describes a 4 GHz fractional-N frequency synthesizer for a 3.1 to 5 GHz IR-UWB transceiver. Designed in a 0.18μm mixed-signal ＆ RF 1P6M CMOS process, the operating range of the synthesizer is 3.74 to 4.44 GHz. By using an 18-bit third-order ∑-△ modulator, the synthesizer achieves a frequency resolution of 15 Hz when the reference frequency is 20 MHz. The measured amplitude mismatch and phase error between I and Q signals are less than 0.1 dB and 0.8° respectively. The measured phase noise is -116 dBc/Hz at 3 MHz offset for a 4 GHz output. Measured spurious tones are lower than -60 dBc. The settling time is within 80°s. The core circuit conupSigmaes only 38.2 mW from a 1.8 V power supply.