The aim of this work is to tackle the problem of modulation wave shaping in the field of near field communication (NFC) radio frequency identification (RFID). For this purpose, a high-efficiency transmitter circuit was developed to comply with the strict requirements of the newest EMVCo and NFC Forum specifications for pulse shapes. The proposed circuit uses an outphasing modulator that is based on a digital-to-time converter (DTC). The DTC based outphasing modulator supports amplitude shift keying (ASK) modulation, operates at four times the 13.56 MHz carrier frequency and is made fully differential in order to remove the parasitic phase modulation components. The accompanying transmitter logic includes lookup tables with programmable modulation pulse wave shapes. The modulator solution uses a 64-cell tapped current controlled fully differential delay locked loop (DLL), which produces a 360° delay at 54.24 MHz, and a glitch-free multiplexor to select the individual taps. The outphased output from the modulator is mixed to create an RF pulse width modulated (PWM) output, which drives the antenna. Additionally, this implementation is fully compatible with D-class amplifiers enabling high efficiency. A test circuit of the proposed differential multi-standard reader’s transmitter was simulated in 40 nm CMOS technology. Stricter pulse shape requirements were easily satisfied, while achieving an output linearity of 0.2 bits and maximum power consumption under 7.5 mW.

中文翻译：

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调制波整形的多标准近场通信异相发射机设计

这项工作的目的是解决近场通信（NFC）射频识别（RFID）领域中的调制波整形问题。为此，开发了一种高效发射器电路，以符合最新EMVCo和NFC论坛对脉冲形状的规范的严格要求。拟议的电路使用基于数字时间转换器（DTC）的异相调制器。基于DTC的移相调制器支持幅度偏移键控（ASK）调制，以13.56 MHz载波频率的四倍运行，并使其完全差分，以消除寄生相位调制分量。随附的发送器逻辑包括具有可编程调制脉冲波形的查找表。调制器解决方案使用64单元抽头电流控制的全差分延迟锁定环路（DLL），该环路在54.24 MHz处产生360°延迟，并采用无干扰的多路复用器来选择各个抽头。来自调制器的异相输出被混合以创建RF脉冲宽度调制（PWM）输出，该输出驱动天线。此外，该实现与D类放大器完全兼容，可实现高效率。在40 nm CMOS技术中模拟了拟议的差分多标准读取器发射器的测试电路。轻松满足更严格的脉冲形状要求，同时实现0.2位的输出线性度和7.5 mW以下的最大功耗。来自调制器的异相输出被混合以创建RF脉冲宽度调制（PWM）输出，该输出驱动天线。此外，该实现与D类放大器完全兼容，可实现高效率。在40 nm CMOS技术中模拟了拟议的差分多标准读取器发射器的测试电路。轻松满足更严格的脉冲形状要求，同时实现0.2位的输出线性度和7.5 mW以下的最大功耗。来自调制器的异相输出被混合以创建RF脉冲宽度调制（PWM）输出，该输出驱动天线。此外，该实现与D类放大器完全兼容，可实现高效率。在40 nm CMOS技术中模拟了拟议的差分多标准读取器发射器的测试电路。轻松满足更严格的脉冲形状要求，同时实现0.2位的输出线性度和7.5 mW以下的最大功耗。