This thesis is about better wireless network connectivity. The main goal is to provide wireless service to several use cases and scenarios that may not be adequately covered today. Some of the considered scenarios are: Home connectivity through fixed, street-based infrastructure, emergency situations; disaster areas; special events’ areas; and remote areas that suffer from problematic / inadequate network and possibly power infrastructure. A target system that we consider for such scenarios is that of an energy-efficient self-backhauled base station (also called “portable access point – PAP”) that is mounted on a drone to aid / expand the land-based network. The base station could also be mounted on a lamp post in a street for fixed wireless communications. 
 
For the wireless backhaul link of the PAP, as well as for the fronthaul of the street-mounted base station, we consider newly built multi-active / multi-passive parasitic antenna arrays (MAMPs). These antenna systems lead to increased range / signal strength with low hardware complexity and power needs. This is due to their reduced number of radio frequency chains, which result in decreasing the cost and weight of the base station system. MAMPs can show a performance close to traditional multiple input / multiple output (MIMO) systems that use as many antenna elements as RF chains and to phased arrays. They can produce a directional beam in any desired direction with higher gain and narrow beamwidth by just tuning the load values of the parasitic elements. The MAMP is designed based on radiation conditions which were produced during the research in order to ensure good radiation properties of the array. 
 
A complement to these studies is the understanding of the wireless propagation environment of these systems. For this, channel measurements were performed for high data rate next-generation wireless networks operating at mmWaves. A number of measurement campaigns were performed in Athens in order to characterize the path loss and other channel characteristics for fixed wireless communications.