Ultra-lightweight broadband WiMAX filters

The family comprises four separate filters with passbands designed to support the 2.2, 2.3, 2.5 and 3.5GHz WiMAX sub-bands-the widest range of sub-bands currently allocated for WiMAX applications across the Americas, Europe and the Asia-Pacific regions. Specifically designed for time-division domain (TDD) WiMAX applications, all member of the RFS WiMAX broadband filter family exhibit common package dimensions, regardless of the filter's passband frequency. This streamlines end-user logistics and simplifies filter mounting.

The common demand from OEMs in the WiMAX domain is for a broadband filter that can be built into active WiMAX equipment, such as Micro BTS or remote radio head. A filter family that fits into the same package dimensions, regardless of its WiMAX band, simplifies OEM logistics and equipment development. RFS achieves this, with its unique new range of WiMAX broadband filters-‘a one-size-fits-all' ultra-lightweight WiMAX broadband filter family.

RFS's unique polymer filter technology provides a filter with a body weight of less than half that of equivalent legacy aluminum filters, yet retains optimal filter performance. Mechanical stability and high-precision mechanical tolerances are ensured by incorporating glass fiber and mineral filler reinforcement in the polymer material. Optimum thermal expansion properties are achieved via a unique blend of polymer materials.

Founded on high-Q cavities and engineered to provide premium RF performance, the new WiMAX filters boast low insertion loss (typically 0.3dB in-band at room temperature) and excellent power-handling capabilities.

Each member of the WiMAX filter family provides two filters within its silver-plated combline-construction filter body. The two-channel filters feature multiple resonators-two x six resonators within the 2.2GHz and 2.3GHz variants; and two x eight resonators in the 2.5GHz and 3.5GHz models-with all resonators located in exactly the same position for easy interchangeability. All this is offered in a compact slim-line (40mm-thick/1.5-inch-thick) package of less than 0.7 liters (40 cubic inches).