Filters from L-band to X-band using GaAs technology

Microwave filters are essential components in communication systems and their successful integration will yield benefits in the form of reduced size, weight and cost. Although GaAs has some disadvantages compared with silicon, such as higher FET output conductance, frequency dispersion and higher cost, there have been attempts to exploit the high bandwidth of GaAs MESFETs to realise high frequency filters, including switched capacitor filters in the VHF to UHF bands and active filters up to S-band. The purpose of this paper is to report recent work at UCL on the development of active and switched capacitor filters realised in GaAs technology aimed at further increase of the maximum frequency of operation