HTS AMPS-A and AMPS-B filters for cellular receive base stations

The multiple, interleaved pass band nature of the AMPS cellular system prov ides an excellent opportunity for high performance HTS filter technology fo r base station reverse link applications. The 25 MHz spectrum is divided in to 4 unequal bands, 2 each for the A and B operators. For AMPS-A, the two b and pass filters are connected in parallel, while for AMPS-B a band pass fi lter is cascaded with a band reject filter. All band pass filters have fini te transmission zeros and the band reject filter is designed to have an equ al ripple stop band. The design and performance of high selectivity filters for this application is described.