Multilayer LTCC bandpass filter design

This paper describes the design and performance of a band-pass filter for wireless communication systems implemented in a low temperature co-fired ceramic (LTCC) substrate. The designed filter provides enhanced stopband characteristics and occupies a small volume in the substrate. The proposed filter shows low insertion loss in the 1710-1910 MHz band and offers high rejection at 824-915 MHz, at the harmonic frequencies and for the Bluetooth/WLAN (IEEE 802.11 b/g) band (2400... 2500 MHz). For the passband the measured insertion loss was better than -1 dB. The rejection for 824...915 MHz was more than 15 dB and for the harmonics more than 30 dB. For the Bluetooth/WLAN band the rejection was more than -20 dB.