High Performance Microstrip Components for Mobile-Radio Antenna Systems

This paper presents the development of high performance multiport hybrid networks based on the Butler matrix and a new type of phase-shifters with thick film microstrip technology for mobile-radio antenna applications. A Butler matrix can be used in DCS 1800 Base Stations as a transmit combining network and as a key element of Multiport Power Amplifiers (MPA's). As far as the phase-shifters are concerned, an innovating way of providing a phase-shift together with a very accurate slope equalization of the phase over a specified frequency band of operation is shown. This constitutes a very powerful tool in view of the design of beam forming networks for multibeam or reconfigurable antennas operating over a large bandwidth. All designs were carried out using Libra software (by Eesof) to operate over the 1.7-1.9 GHz band and prototypes were manufactured on Rogers RT6006 Duroid substrate.