Novel compact LTCC UWB bandpass filter with simple semi-lumped circuit model

Abstract

Novel circuit model and design method for miniature LTCC UWB bandpass filter were presented. The filter prototype is simply composed with several semi-lumped elements (transmission lines and capacitors) for easy fabrication in LTCC process as size of3.2x2.5x1.0mm 3 and half-circuit synthesis was also proposed for transmission zero and reflecting poles discussions. Two parallel capacitors added on general chebysheve bandpass filter contributed two additional zeros to extend stop band in higher band The filter measurement agreed with the EM siumlation as expected and behaves an ultra wider 3dB bandwidth range from 3.1~10.6GHz with the insertion loss less than1.0 dB cross centre band and 20dB minimum of rejection on zeros.The wider stop band in higher band also achieved due to additional two zeros contribution in novel design.