Motorola Corporation

Cts Corporation

Glenn Rice

Reddy Vangala

David R Heine

Mark H Ballance

A duplexing communication signal filter has a substantially U-shaped core of dielectric material including a transmit arm, a receive arm and a base portion joining the transmit arm to the receive arm. Both the transmit arm and the receive arm each define a series of through-hole resonators. Present on the core of dielectric material is a surface-layer pattern of metallized and unmetallized areas. The pattern includes a wide area of metallization for providing off-band signal absorption, a first unmetallized area surrounding a plurality of the through-hole openings of the transmit arm, a second contiguous unmetallized area surrounding a plurality of the through-hole openings of the receiver arm, a transmitter pad metallized area on the transmit arm, a receiver pad metallized area on the receive arm, and an antenna pad metallized area.

Reduced length metallized ceramic duplexer

A bandstop filter module (200) with a shunt zero is provided. The module (200) contains a circuit substrate (202) with input and output pads and transmission lines (208). The module (200) also contains at least one dielectric monolithic block (210) mounted to the circuit substrate (202) having a plurality of metallized through holes defining resonators (224) and guard holes (226). All surfaces of the dielectric monolithic block (210) are substantially covered with a conductive material with the exception that the top surface (212) is selectively metallized providing an unshorted metallization pattern (228) relative to a ground plane in proximity to the guard holes (226). The guard holes (226) and the unshorted metallization pattern (228) provide a shunt zero in a frequency response curve of the module (200). The module also contains means for coupling each of the resonators (224) with the transmission lines (208) on the circuit substrate (202). Other module components include at least one inductor coil (230) mounted on the circuit substrate (202) and a shield (232) having tuning windows.

Growing community of inventors

Albuquerque, NM, United States of America

Glenn Rice