Biography

Kasra Garakoui was born in Rasht/IRAN in 1975. He finished MSc of analog electronic circuit design at Sharif University of technology/TEHRAN/IRAN and started his work as an AIO at University of Twente/Enschede in 2007.

Project

Kasra does research on the project of CMOS Beamforming Techniques with a system to circuit design view. His work is under the supervision of Professor Bram Nauta, Professor Frank Van Fliet and Dr. Eric Klumperink.

Beamforming

Dish antenna is a traditional way for making narrow band beam patterns and they have been used for several decades for applications like: point to point communication, Radar and remote sensing and Radio astronomy . However changing the direction of the beam pattern for dish antennas, needs mechanical ways to rotate the dish structure to the desired direction which is not fast enough for some applications like Radar and remote sensing.

Beamforming not only gives us the ability to steer but also to synthesize the beam pattern , for instance: making multi beam patterns, making nulls on some specified directions and making Sidelobe reduction by amplitude tapering.

The important elements of beamforming circuits are Time delay and Phase shifter elements which there are realized in different ways according to many factors like: the frequency of operation, power consumption, power handling, degree of precision, size and cost.

Traditional ways of realizing beamforming systems are mostly based on discrete time delay/phase shifter blocks which are bulky, expensive and not so easy to be calibrated and maintained. These systems need a high volume of expensive cables and connectors for connecting discrete blocks together then integrated solutions for beamforming systems seem quite attractive.

Why CMOS technology

Current CMOS technologies offer benefits like: High frequency of operation (ft more than 100GHz), highly compatible with digital design (ability to make high speed processors by them), reliable, low cost and high volume of integration. These futures make CMOS technology attractive for military, space and communications.

Reseach Goal:

The aim of the project is to design a general purpose CMOS IC for beamforming and the research vehicle is a beamforming IC for for DVB_S home satellite receivers which works between 10.7 to 12.75 GHz. Suitable system design for beamforming is necessary to fit the abilities of the offered CMOS technology to the desired building blocks. This can be done by proper system architecture design and using both the Analog /Digital (mixed mode) abilities of the current CMOS technologies.