5 GHz-Band CMOS Direct Digital RF Modulator Using Current-Mode DAC with Idle Current
5 GHz-Band CMOS Direct Digital RF Modulator Using Current-Mode DAC with Idle Current
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使用具有空闲电流的电流模式 DAC 的 5 GHz 频带 CMOS 直接数字 RF 调制器
DOI：
10.1109/ieee-iws.2013.6616844
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
K. Tsubouchi
中科院分区：
文献类型：
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作者：
O. Wada;T. Tan;S. Tanifuji;S. Kameda;N. Suematsu;T. Takagi;K. Tsubouchi
提出了一种基于电流模式数模转换器（DAC）的5 GHz直接数字射频（RF）调制器，并采用90 nm CMOS工艺实现。由于该调制器直接将数字基带（BB）并行输入信号转换为RF信号，因此可以实现小芯片尺寸和低直流工作。为了减少RF输出端的高阶失真分量，向来自电流模式DAC的BB电流输出提供空闲电流。通过提供满量程DAC输出电流的10%的空闲电流，减少了5 GHz载波附近的二阶和三阶失真分量，并实现了有效位数（ENOB）的提高。在5 GHz时测得的ENOB为6.36 bit（无杂散动态范围（SNDR）为40.0 dB），RF调制输出功率为−28.4 dBm。该调制器集成电路的核心尺寸为200μm × 200μm。数字BB信号转换器的核心电路（不包括反相器部分）的直流功耗为2.5 mW（2.1 mA/1.2 V）。
A 5 GHz-band direct digital radio frequency (RF) modulator using current-mode digital-to-analog converter (DAC) with idle current is proposed and fabricated in 90-nm complementary metal oxide semiconductor (CMOS) process. Since the proposed modulator directly converts digital base band (BB) parallel input signal into RF signal, small die size and low dc operation can be achieved. To reduce the higher order distortion components at the RF output, idle current is provided to BB current output from the current-mode DAC. By providing idle current of 10% of full scale DAC output current, 2nd and 3rd order distortion components near 5 GHz-band carrier are reduced and the improvement of effective number of bits (ENOB) is achieved. Measured ENOB of 6.36 bit (spurious-free dynamic range (SNDR) of 40.0 dB) with RF modulated output power of −28.4 dBm is obtained at 5 GHz. The core size of the proposed modulator integrated circuit (IC) is 200μm × 200μm. The dc power consumption of core circuit excluding inverter section for digital BB signal converter is 2.5 mW (2.1 mA/1.2 V).