Optimization of Digital TV coverage prediction and broadcasting antennas

The work described in this thesis focuses on: 1. designing novel antenna techniques and 2. radio propagation and coverage prediction studies in UK, North Macedonia and Greece. Log-Periodic dipole antennas (LPDAs) are a class of antennas that are widely used for ultra-high frequency (UHF) television (TV) reception. Because of the evolution of mobile technologies and excellent building penetration properties in the UHF band, parts of this spectrum are being allocated to Long-Term Evolution (LTE) frequency bands. The new spectrum allocation gives rise to interference problems between these closely spaced frequency bands. Therefore, in order to provide good quality-of-service (QoS) to UHF TV users, new reception antennas are required with band rejection that could eliminate the interference of LTE-800 MHz band and GSM-900 MHz band. Thus, this thesis proposes a design methodology and prototype of a novel LPDA that can provide band rejection in the LTE-800 MHz and GSM-900 MHz bands without using any external filters. The proposed antenna provides good matching, high band rejection and ensures better QoS compared to other existing antennas in the market. It is a cost-effective antenna design as it also removes the cost of using external filters. Furthermore, the LPDA design was also implemented on printed circuit boards (PCBs) in an attempt to reduce the overall size of the antenna. Several miniaturization techniques for reducing the size of LPDAs were reviewed and two prototypes for printed log-periodic dipole antenna (PLPDA) with wide bandwidth are proposed in this thesis. The first prototype follows the conventional PLPDA, designed to operate from 0.7 GHz to 8 GHz. The second prototype is a novel PLPDA design with triangular longest dipole that has an operating frequency range from 0.4 GHz to 8 GHz. Furthermore, two prototypes for elliptical patch antennas are proposed for GPS and Iridium applications and Real-Time locating systems. This work also demonstrates an accurate simulation-assisted antenna gain determination technique in order to improve the accuracy of gain measurements. Lastly, radio propagation and coverage prediction studies were carried out using three measurement campaigns whose results were compared to several propagation models using simulations. The electric field strength, path profiles and coverage prediction were carried out for: 1. Turtel analogue TV transmitter, 2. Emley Moor digital TV transmitter and 3. Belmont digital TV transmitter.