mmW local oscillator signal generator with integrathed phase shifting capabilites

Published : 1 January 2023

The most innovative communication systems for beyond 5G and future 6G applications have to face a number of challenges related to the trade-offs between link range, power consumption and data-rate. A growing interest is put on radio frequency circuits operating at mmW and sub-THz bands because at those frequencies there are large portions of available spectrum that can be used to implement high-data rate wireless links. Most of these radio systems rely on array of transmitters (Tx) and receivers (Rx) that operate jointly to implement a large overall gain in order to extend the link range. The individual elements of such Tx and Rx introduce different phase shifts in the signal in order to obtain a combined effect that maximises the signal strength in a given direction (or in a reduced number of different directions). This phase shift in the signal can be created in different ways. Most of the existing works introduce the phase shift directly on the signal path but this is done at the expenses of additional losses and require complex calibration processes. An alternative technique, yet seldomly implemented, uses the local oscillator signal (LO) of the Tx and Rx to introduce that phase shift. The goal of this Ph.D. thesis is to contribute in this domain leveraging on the extensive expertise of our research group in the development of innovative mmW and sub-THz signal generation. The main focus of the thesis is to combine energy efficient LO signal generation with phase-shifting functionality providing the phase shift accuracy required by the above mentioned arrayed signal combination.

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