High Performance and Compact Balanced-Filter Design for WiMAX Front-End Modules (FEM) Using LCP-Based Organic Substrates

In this paper, high performance RF integrated balanced-filters were proposed and designed for single band WiMAX front end application. This FEM includes an on-chip RF power amplifier and one switch, with two receive and one transmit paths. In addition to module size requirement, the WiMAX standard presents several passive design challenges: (1) The power amplifier (PA) provides an increase in rated power, hence a higher transmit gain which forces a more stringent output spurious/harmonic levels specification. (2) Received unwanted signals and blockers levels deplete the linearity performance of the receiver lineup. The module was designed on a multilayer organic (MLO) substrate. The highly integrated, fully shielded RF module incorporates embedded passive components including filters and baluns. Simulated results show excellent electrical performance with low insertion loss, high rejection and good return loss. Additionally, the module exhibits excellent thermal stability over the range of operating parameters.