Design of High-Efficiency D-Band Power Amplifier (PA) Architectures

The demand for >100Gbps data-rate in wireless communication has fueled the rapid development of integrated transceivers operating at frequency beyond 100GHz. The broad available spectrum in the D-band (110-170GHz) has gained increasing interest for such high-speed communications.

To overcome the high path loss and improve the overall system efficiency, a power amplifier (PA) with high-efficiency and sufficient output power is essential wireless D-band transceivers. High-performance transceivers have been demonstrated at RF and low millimeter-wave (mm-Wave) frequencies. For wireless communications in the D-band, no standardization has taken place yet. This situation gives the freedom to co-optimize the critical building blocks of a transceiver, together with high-level specifications like the modulation scheme and RF bandwidth.

Historically CMOS technologies are preferred due to their high-level of integration and low cost. Unfortunately, the conventional Class-A/AB CMOS-based PAs operating above 100GHz usually suffer from reduced ft/fmax and low supply voltage, resulting in subpar performance in terms of output power, power added efficiency (PAE) and linearity. Therefore, novel PA architectures are desired to overcome those challenges.  In the meantime, other technologies are considered as well for efficient power generation above 100GHz, such as BiCMOS or even compound semiconductors like indium phosphide (InP) that can generate more power per transistor than the silicon counterparts. Advanced PA architectures such as load modulated balanced power amplifier, polar power amplifier and outphasing power amplifier can be implemented with system co-design and hybrid integration, where we still enjoy the advantages of all technologies to achieve superior system performance.

In your PhD work you will focus not only on novel PA architectures for efficient power generation in the D-band, but also on the system-level optimizations, such as co-design with modulation scheme definition, control and calibrations, and antenna interface optimizations.

You will work on circuit design in various IC technologies, the implementation and the measurements. Together with the existing research teams at imec Leuven, you will contribute to the Advanced RF program of imec, while at the same time you have the freedom to propose and develop your own ideas.