Design of an ASK RF Transceiver for ETCs with Hybrid ASK Modulator and Ultra Low Power Wake-Up Receiver

Abstract

This article proposes a transceptor structure of RF with modulation by shifting amplitude (ASK) for ETC (electric charging system). To meet the Korean and Chinese standards, the modulator of TX supply to propose a method of hybrid approach. The Korean model is 1024 kbps, the Chinese OBU is 512 kbps and the road unit (RSU) has a data transfer speed of TX of 256 kbps. The hybrid structure has advantages over the analog type in terms of area, energy consumption, process, voltage, variation of temperature (PVT). The China ETC way is working with battery and should reduce the consumption of energy. The transceptor of main RF is switched off until the Wake-up receiver (WuRx) receives the Wake-up signal of the RSU, for what most of the time that the Wake-up receiver is working is busy, so it is essential to minimize power consumption of the WuRx. In WuRx, the detector involving detects the envelope of the Wakeup signal using the current feature of the MOSFET which operates in the region of the subumbral, which allows the operation with ultrabaja power. The digital filters used to improve the reliability of the alarm signal. The Wakeup bloc's total power consumption is 3.6uA. ETC is communicating when OBU's RSU at high speed. Therefore, the automatic control of profit from RX is not possible. In the common recipients, there is an automatic controller of profit to avoid saturation of Rx power. But ETC cannot adjust the gain, for what it takes a performance of the receiver with an extended Rx dynamic range when used as with a steady profit. To comply with the highest P1dB specification and the wide range of Rx dynamic, the receiver is proposing a structure for demodular the ASK signal with LNA, mezclador and signal intensity indicator received (RSSI). The Rx dynamic range is 70dB. The transceptor be implemented in a 1P8M CMOS process of 130 nm, with an active area of 3.5mm × 3.5 mm, including the ESD screening platform.