This thesis presents two submodules which are part of 'an FM Chirp Waveform Generator and Detector for Radar', namely the mixer and the modulator. The goal of this project is to design and simulate these submodules from an educational perspective. The modulator is implemented as a single-ended common-base Colpitts oscillator with modulation capabilities added by means of varactor diodes. The carrier frequency of the presented modulator is tunable from 88 MHz to 108 MHz and the achieved modulation linearity for a sawtooth baseband signal is approximately 34 dB over the tuning range. The presented mixer consist of a double-balanced Gilbert-type topology with 29.5 dB (tunable) gain, 23 mW power consumption, high Input-Output isolation and single-ended output achieved by means of an active load. The project was carried out in the scope of the bachelor graduation project in the bachelor of electrical engineering at the Delft University of Technology.

Future communication scenarios will require massive Multiple-input multiple-output (MIMO) by the use of multi-beam antenna systems. Maximizing the number of beams for a given antenna size is paramount given that the space allocated to the antenna is often limited. This work aims at evaluating the maximum number of beams by analyzing the SIR in different communication scenarios for planar antenna structures. The concept of ‘observable field’ is used to quantify the power received from the desired signal as well as the power associated with the interference. Due to the planarity of the considered antenna structures, the radiating domains introduce scan loss, an effect not previously modelled when considering earlier investigations based on spherical domains. Furthermore, methods of reducing interference in order to improve the SIR were investigated, i.e., the use of a tapered current distributions on the radiating apertures and null placement techniques.