Advanced Radio IC Lab
Fascinated with circuits at Extreme Frequencies?
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Key Research Areas: Highlights
Millimeter-wave transceivers for 6G and automotive RADARs
High speed analog and mixed-signal circuits
Cryogenic controller IC for quantum computers
Radio frequency transceivers
Basic Analog/RF Circuits used as Building Blocks
Fascinated with circuits at Extreme Frequencies?
At Advanced Radio IC Lab (ARIL) we build CMOS radio chips for the future! Radio chips are ubiquitous, and they can be found in all wireless empowered devices including cellphones, laptops, speakers with bluetooth, printers with WiFi, self- driving cars with RADARs and so on. Even the write/read operation in today's experimental quantum computers is done using a radio chip with a transmitter/receiver! ARIL focuses on the design, implementation and testing of next generation CMOS radio chips operating in RF/millimeter-wave frequencies to meet the future demands of wide range of applications encompassing high data rate 6G wireless radios, high resolution automotive/imaging RADARs, high fidelity cryogenic controller for quantum computers, and low power WBAN/IoT radios.
The critical active blocks in a radio chip are a transmitter, a receiver and a frequency synthesizer (PLL). As their names suggest a transmitter transmits a signal, a receiver receives a signal and frequency synthesizer generates the required local oscillator signal. These blocks contain a combination of analog, RF or millimeter-wave circuits based on the type of application. ARIL develops innovative circuits and architectures to make them more energy efficient and push their performance specifications beyond the state of the art. Our designs are implemented in industry standard advanced CMOS processes and characterized through measurements.
Key Research Areas: Brief Overview
Millimeter-wave transceivers for 6G and automotive RADARs
With the ever increasing use of wireless radios the RF bands are getting crowded. Millimeter wave bands are promising because they are less crowded and can offer higher data rates. Recently, FCC has opened frequencies between 95 GHz to 3THz for 6G which has substantial opportunities for innovation especially for data intensive high bandwidth application, imaging and sensing. CMOS millimeter-wave integrated circuits and systems are ideal for these plethora of applications due to low cost, compact form factor and easier integration with digital.
Self driving cars use automotive RADAR chip as the eye to sense its surroundings. At present most of them operate at 77GHz and has limited resolution. Therefore, the operating frequency of integrated RADARs is getting extended further to sub-THz frequencies (>100 GHz) to cater to the demands for compact and high-resolution RADAR systems due to shorter wavelength and higher bandwidth. A high-resolution RADAR will enable improved autonomous driving, high precision sensing like monitoring vitals of the driver, gesture recognition, even medical imaging and much more.
Cryogenic controller IC for quantum computers
Quantum computers have unparalleled potential in exponentially speeding up intractable computing problems such as computing in quantum chemistry for drug and material discovery, meteorology, secure communication etc. Instead of storing information as 0s or 1s like a traditional digital computer, a quantum computer uses qubit which can be 0, 1 or both 0 and 1 by virtue of quantum phenomenon known as superposition. Superposition combined with quantum phenomenon of entanglement enables quantum computer to perform vast complex computation in one shot and makes it faster enough to outpace even today’s state of the art supercomputers. Two promising solid state qubits are transmons and spin qubits. Irrespective of their types, qubit states are extremely fragile and are affected by noise and therefore, are operated at extremely low temperature near absolute zero such as 10-20mK in a dilution refrigerator. Even when cooled to such low temperature, qubits are prone to errors. Fortunately, quantum error correction (QEC) algorithms may be used to perform error free computation but at the cost of large number of qubits requiring at least a million for a practical useful quantum computer.
In the last decade, significant progress has been made in development of quantum computers which basically in its simplest form consists of a quantum processor comprising of 50-100 qubits and a controller which typically uses microwave pulses to write and read a qubit. The controller consists of racks of traditional test instruments at room temperature which control the qubits in the refrigerator via long external cables. This makes it impossible to implement a practical quantum computer consisting of millions of qubits due to connection complexity and reliability. In order to scale up to the level of million qubits, an integrated circuit solution for the controller placed in the vicinity of the qubits at few kelvins inside the dilution refrigerator will be needed. However, this is not sufficient because the controller IC will generate lot of heat and the dilution refrigerator has its own limit of handling heat dissipation. Therefore, cryogenic controller ICs dissipating very low power is needed to tackle this issue thereby paving the way for a practical quantum computer. My research group is working on developing such low power cryogenic controller ICs in advanced CMOS nodes. The controller is a transceiver consisting of a transmitter which can generate microwave pulses to perform write operation and a receiver which can read the state of the qubits. Operating at cryogenic temperature of a few kelvins has its own challenges in terms of circuit design. Novel scalable architectures are being explored to increase the number of qubits that can be controlled with high precision (fidelity) which in turn sets tight specifications on the circuit blocks.
Radio frequency transceivers
Radio-frequency integrated circuits have made significant impact on our lives through the introduction of wireless communication, data, and connectivity. With the proliferation of RF communication new bands and standards are evolving with unique set of requirements which calls for novel radio architectures and circuit techniques. To be more specific, ARIL has expertise in low power radios e.g. Bluetooth Low Energy, Wireless Body Area Networks (WBAN) and Full Duplex Techniques.