Liquid Crystal Polymer-Based Planar Lumped Component Dual-Band Filters For Dual-Band WLAN Systems

This paper presents the design and implementation of dual-band filters using lumped components that are completely embedded in a multi-layer organic process technology, which incorporates multiple liquid crystalline polymer (LCP) substrates. The paper presents the design methodology and measurement results of the small form factor fully-integrated filters that are directly applicable to WLAN systems. The fully-functional embodiments of single-input single-output filters were designed to have passbands with independently controllable bandwidths around the center frequencies of 2.4 GHz and 5.2 GHz. The filters present low insertion loss (-1.1 dB) and return loss better than 15 dB at both the frequencies. The fully-packaged filters were designed in an area of 5.1 times 5.3 mm², providing a 5X reduction in area as compared to any previously reported works on dual-band filters