PhD Defense of SHARMA Ekta

«Design of Millimetre wave VCO based on slow-wave transmission lines»
Friday, October 14,  2016 at 14:00

This work focuses on the design of mm-wave VCO for Backhaul applications in BiCMOS 55 nm technology. All the proposed VCO designs are compared to the conventional LC-tank oscillator. The first proposed oscillator design operates between 81-86 GHz. The innovation is linked to the use of a slow-wave coplanar strip (S-CPS) as a differential inductor.  Thanks to high quality factor (≈ 33) of S-CPS, the phase noise was improved by 20 dBc/Hz at 10 MHz offset and the power consumption was reduced by 14 % as well. The achieved frequency tuning range (FTR) was 5.3 GHz only. The second VCO design is based on loaded line phase shifter as a resonator. The phase shifter has been designed using an unsymmetric topology of S-CPS in order to achieve better FTR. But the achieved VCO performance was not improved a lot due to the loading parasitic capacitance. So, with the same unsymmetric phase shifter based resonator a distributed standing wave oscillator was designed, which reduced the loading effect and lead to a FTR of 8 GHz. Finally, a buffer less mm-wave standing wave oscillator was designed. In this proposed buffer less oscillator it is shown that any output characteristic impedance can be envisaged thanks to a careful choice of the output position. Hence, no output buffer is needed in the proposed design, due to the flexibility in choosing the output position along the SWO. This innovation leads to two merits. Firstly a 50Ω output can be synthesized without any additional power consumption and secondly the size is reduced if a matching network is needed to connect the VCO to a mixer or another building block of the transceiver system.
Members of the  jury :
-M. Sylvain BOURDEL
: Supervisor
-M. Emmanuel PISTONO
: Co-supervisor
-M. Philippe FERRARI: Co-supervisor
: Reviewer
-M. Didier VINCENT:


Thesis prepared in the  laboratory: UMR 5130 - IMEP-LAHC  (Institut de Microélectronique,Electromagnétisme, Photonique – Laboratoire Hyperfréquences et Caractérisation) managed  by Mr BOURDEL Sylvain  and co-supervised by Mr FERRARI Philippe
Date infos
Defense of a doctoral thesis of SHARMA Ekta, for the University Grenoble Alpes , speciality "NANO ELECTRONIC & NANO TECHNOLOGIES ", entitled:

Location infos
Room Z-108  Building Z/Phelma2/Minatec
3 rue parvis Louis Néel
38016 Grenoble cedex1