Naga Sasikanth Mannem and David Munzer have been chosen for Analog Devices Outstanding Student Designer Awards. They are both Ph.D. students in the Georgia Tech School of Electrical and Computer Engineering (ECE). 

Mannem and Munzer received these awards for the excellence of their integrated circuits related Ph.D. research and their academic performance. They are both members of the Georgia Tech Electronics and Micro-System Lab, where they are advised by ECE Associate Professor Hua Wang.

The title of Mannem’s research is “Reliable and Secure Communication Systems.” His research is primarily targeted at improving the performance of phased array communication systems by employing circuit and architecture level techniques. Phased array systems are being employed in 5G and beyond 5G communication systems both to achieve a higher array gain and extend the distance of operation. However, conventional beamforming arrays exhibit several inherent limitations such as antenna voltage standing wave ratio (VSWR) variations at large scan angles and limited security. 

To achieve a reliable communication link even under a large antenna VSWR of 3:1, Mannem and his colleagues proposed a Reconfigurable Hybrid Series/Parallel Doherty Power Amplifier. To improve the security of a communication link between a transmitter and the desired receiver, they exploit the inherent spatial selectivity that a phased array offers and extends its security performance by using multiple input multiple output (MIMO) systems, realizing a truly directional and secure communication. This work was published at the 2020 International Solid-State Circuits Conference and in the IEEE Journal of Solid-State Circuits.

The title of Munzer’s research is “Broadband VSWR Resilient Transmitters and Built in Self-Test (BiST).” In order to compensate for the large path loss at mm-Wave frequencies, phased arrays are used. However, the antenna elements couple with one another, which causes the impedance presented to the electronics to deviate from the ideal 50Ω terminations in which they were designed for. This issue compromises both the array’s radiation pattern, as well as the electronics’ performance in both linearity and efficiency. 

To address this challenge, Munzer and his colleagues investigate different sensing circuitry to detect the antenna's impedance and real power delivered, so that they can reconfigure both the electronics and overall array under these load mismatch conditions. The broadband performance of the transceiver electronics and BiST circuitry allows these designs to cover both the commercial and military 5G frequency bands.