Channel-reconfigurable filter with integrated switch in multilayer LCP package

This paper investigates a new scheme of channel-switchable filter, which consists of 2 stages of optimum stub filters. By integrating a double pole double throw (DPDT) switch, 4 different states/channels with the same absolute bandwidth have been achieved by switching each stage between open-stub and short-stub filters. Compared to original implementation which deploys loads of PIN diodes, this scheme minimizes the loss as well as the cost of the filter. To minimize dispersion and maintain a high periodicity, stripline configuration is chosen to implement the filters. Multilayer liquid crystal polymer (LCP) technology and laser machining are used for high accuracy circuit fabrication and integration of the DPDT switch.