With the increasing demand for smart products in daily life, the upgrading of 5G Internet of Things (IoT) devices has become a focus. To address this, the Massachusetts Institute of Technology (MIT) in the United States has developed a receiver compatible with 5G IoT devices. Not only does it have lower power consumption and cost, but its anti-interference ability is 30 times stronger than traditional wireless receivers.
Traditional IoT receivers use a single narrowband filter to suppress interference, with a simple structure and low cost. However, incorporating 5G technology into network receivers using existing equipment can limit their performance and make it difficult to achieve cost-efficient and energy-saving operation.
The MIT research team has designed a new chip and receiver for 5G IoT devices, making them smaller in size, lower in price, and more energy efficient, while also having a wider signal bandwidth range. The research results were presented at the mid-June IEEE Radio Frequency Integrated Circuits Symposium.
The newly developed receiver has an effective area smaller than 0.05 square millimeters, and the new chip only requires a low voltage of 0.6 volts to operate normally. The key lies in the new chip’s use of passive filtering mechanisms, resulting in a static power consumption of only 1 milliwatt. This method not only makes the new devices more energy-efficient but also protects the amplifiers inside them from interference by other devices or wireless signals.
In order to reduce the size, cost, and power consumption of 5G IoT devices, researchers chose to abandon bulky off-chip filters in traditional IoT devices in favor of MIT’s previously developed “switched capacitor network” to solve these issues.
They employed the newly developed “switched capacitor network” as a feedback path for negative gain amplifiers, allowing small capacitors to function similar to large capacitors while filtering out unnecessary signals. This approach not only reduces interference but also minimizes power consumption when devices are affected by interference.
Researchers also utilized a special circuit technology called “bootstrap clocking” instead of traditional clocking techniques, enabling the receiver to precisely control voltage fluctuations and ensure stable operation of switches.
The key core technology of the new chip involves using innovative “precharged stacked capacitors” connected through micro switches and networks. When the chip receives a signal, capacitors charge up and retain the charge for subsequent data processing upon closing. This mechanism significantly reduces power consumption during switching on and off, resulting in a much smaller chip size compared to traditional receivers.
Researchers point out that these advantages allow the new 5G IoT devices to operate in a more cost-effective and energy-efficient manner without requiring a large number of electronic components and devices. This brings improved data speed and network capabilities to a range of IoT applications and holds promise for various IoT devices in the future.
They explain that this low-cost receiver is particularly suitable for battery-powered IoT devices, such as environmental sensors, smart thermostats, wearable health devices, smart cameras, industrial monitoring sensors, or other equipment requiring long continuous operation.
Currently, they have developed a prototype and plan to power the entire chip and device by collecting Wi-Fi or Bluetooth signals from the environment, enabling devices to operate without dedicated power sources like batteries or energy.
Soroush Araei, an MIT electrical engineering and computer science (EECS) graduate student and the lead author of the receiver paper, mentioned, “This receiver makes smart devices like health monitors and industrial sensors more compact with longer battery life.”
Araei added, “They can also become more reliable in complex wireless environments such as factory floors and smart city networks. Moreover, the newly developed chip operates quietly and does not pollute radio waves during operation. The reason behind this is the tiny switches set up, minimizing antenna signal leakage and interference with wireless radio signals.”
Araei further noted that designing an excellent 5G IoT receiver is highly challenging, stating, “We not only need to consider the receiver’s power and cost but also whether it can flexibly adapt to environmental interference.”
This research received partial support from the National Science Foundation (NSF) of the United States.