A 2.4 GHz Power Receiver Embedded With a Low-Power Transmitter and PCE of 53.8%, for Wireless Charging of IoT Wearable Devices
Abstract : This article presents a 2.4 GHz and high-efficiency wireless power receiver (Rx) integrated with a low-power transmitter (Tx) for wireless charging of the Internet-of-Things (IoT) or wearable devices. A single pole double throw (SPDT) circuit isolates the operation of the Rx from Tx, thereby offering the capability of sharing antenna between them. The Rx employs a high-efficiency radio frequency (RF)-dc converter, which is facilitated with threshold voltage cancellation technique for enhancing the efficiency, and adjustable internal impedance matching network to compensate the nonlinear behavior of the input impedance with respect to input power level. In addition, it includes a boost dc-dc converter to charge the storage element with a fixed voltage and current. The Tx utilizes a low-power phase-locked loop (PLL) and a class-D power amplifier (PA). Several techniques are adopted to achieve low power consumption. The chip is implemented in a 180 nm CMOS process with a die size of 2.3 mm x 5 mm. The Rx shows the measured RF to dc maximum power conversion efficiency (PCE) of 53.8% at the input power level of 0 dBm. The Tx achieves a variable output power range of -10 to 10 dBm, while consumes 4 and 23 mA at 0 and 10 dBm output power, respectively.
? A variety of devices that utilize the same frequency as specified low power systems exist.
? However, due to reflection and other phenomena, areas with predominately weaker signals may not be always be constant, since in actual space both weak and strong signals exist.
? To distinguish between data intended for the target device or other equipment, a special system-level data string is placed at the beginning of the data packet.
? Conventional specified low-power products typically only include a wireless block and function for outputting demodulated data, so an external MCU is needed to perform data discrimination.
? In order to address the limits of the OFDM decode-and-forward relay system performance, the authors detailed a Power Allocation (PA) optimization problem to expand its feasible data rate.
? The problem is non-curved and does not have direct solutions, the authors designed an RA approach by treating it as two separate sub-problems.
? The authors have shown that the problem is NP-hard, and presented two approximation algorithms based on the greedy and relax rounding schemes to achieve better and guaranteed performance in the context of charger placements.
? In particular, they examined the impact of information transmissions and energy transfer in the same frequency band.
• Various LPWAN protocols have been proposed, but each has its advantages and disadvantages, and even the suitability of the LPWAN method itself may be called into question. In response, we are offering a proposal.
• This ensures compatibility with a range of applications and markets, from IoT, industrial equipment, and automotive to electronic toys and consumer devices.
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• ROHM Sub-GHz specified low power wireless communication modules are capable of transmitting and receiving over longer distances with very low power, making them ideal for smart meters and smart communities along with the M2M and IoT markets.
? To be specific, the authors have assembled a proof-of-idea model of the framework and probed the model to assess its plausibility and performance on a small-scale system.
? Their major goal was to get the sensor networks powered efficiently with/without batteries to keep the network lifetime at the greatest level and avoid any degradation in the network’s performance.
? The UGV position is chosen to be in the centroid of the cluster in order to ensure that wireless charging takes place in the context of the cluster nodes efficiently.
? The harvested and accessible energy of the sensor network’s was managed with an improved energy efficient ant-based routing protocol, which basically helped much in optimizing the available power.
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