To combine transmit and receive wireless signals in both building and transportation systems, a range of system- combiner boxes now offers an expanded range of frequency bands and facilities. The boxes promise to minimize loss and passive intermodulation (PIM) through the careful application of filters, hybrids, low-PIM loads, and other passive components. These combiner boxes are most commonly used to merge up to four wireless carriers in the operating band to single or multiple antenna feeds or distribution cables. In situations where four similar feeds can be utilizedas required in many in-building applicationsall four outputs may be used. This capability eliminates the need for terminating unused ports and the 6-dB hybrid loss. Port return loss and isolation have been optimized while passive intermodulation (PIM) has been minimized. In addition, the input and output connectors have been separately grouped for convenient connection. Each connector is spaced to allow controlled wrench-tightening.

Microlab/FXR, a subsidiary of Wireless Telecom Group, Inc., 25 Eastmans Rd., Parsippany, NJ 07054; (973) 386-9696, FAX: (973) 386-9191, Internet: