Miniaturised Microstrip Single and Multiple Passband Filters

The increasing demand on microwave spectrum for communication systems has been the driving force in the filter industry. There are increasing demands on high performance single- and multiple-band filters. In this work, different resonator structures have been investigated for narrow band filters. Using these structures, two single symmetric and asymmetric narrow passband HTS filters has been developed. A cost-function for an optimisation algorithm to achieve multiple passband filtering function has been discussed. Different HTS Filters have been designed and tested. A new analytical algorithm to realise multiple-band filters has been developed. By cascading a passband filter with one or more stopband filters, the transfer function of the system can be manipulated to allow for implementing it as a single cross-coupled resonator filter.