A Compact Integrated ISM Bandpass Filter Based on Combline Structures on Organic Substrate

In Bluetooth systems, the requirements for the front-end modules are that they have to be compact and cost-effective. Yet the band pass filter often occupies a relatively large size compared to the other components within the RF module. In this paper, a compact realization of an ISM bandpass filter suitable for system-in-a-package (SiP) applications, which utilizes a novel meander configuration, is introduced. To reduce the fabrication cost, the miniaturized filter is implemented on a standard organic material (FR-4) instead of on ceramic substrates (Awai, 2000)