Abstract: A dual band filter network for a radio communication apparatus is provided. The network has an antenna (212) for receiving and transmitting signals from a first frequency band and a second frequency band. The network has a first duplex pair (202) including a first transmit filter (204) including a first passband and stopband. The first duplex pair (202) also includes a second receive filter (206). The first filter (204) presents a consistent phase in the second passband due to the wide frequency separation between the first filter (204) and the second filter (206). The network has a second duplex pair (202') with similar characteristics as the first duplex pair (202). The network also has a switching circuitry (210) controlled by a switch control voltage (214) for selecting the appropriate filter circuitry. The network can be provided in a small sized, low cost package that also offers improved insertion loss performance.

Abstract: An improved shield and ceramic filter. The shield includes (i) an upright portion (16) comprising a conductive material, (ii) a chamfered portion (22) disposed atop the upright portion (16), (iii) a horizontal portion (18) disposed on a distal portion of the chamfered portion (22) and (iv) one or more openings (20) disposed on the chamfered portion (22). The improved shield (12) desirably but not essentially further includes at least one slot (26) cut into a basal section of the upright portion (16). The at least one slot (26) allows a microstrip transmission line to pass under a portion of the shield (12).