Band Selection Patents (Class 455/188.1)
Uhf and vhf (Class 455/188.2)
With plural separate mixer or converter circuits (Class 455/189.1)
With frequency conversion (Class 455/190.1)
With plurality of tuned circuits (Class 455/191.1)
  • Antenna filtering arrangement for a dual mode radio communication device
    Patent number: 6185434
    Abstract: A dual mode radio apparatus has an integrated filtering part (51) which includes an antenna port (51a) for connection to an antenna (21), at least one port (51b, 51c, 51d) for connection to each of the system-specific radio-frequency parts (54, 55) of the dual mode radio apparatus and filtering means for directing the propagation of signals between ports on the basis of the signal frequency. The integrated filtering part replaces earlier separate filters and their impedance matching circuits as well as some of the required radio-frequency switches.
    Type: Grant
    Filed: September 11, 1997
    Date of Patent: February 6, 2001
    Assignee: LK-Products OY
    Inventors: Panu Hagström, Seppo Yrjölä
  • Radio receiver with adaptive bandwidth controls at intermediate frequency and audio frequency sections
    Patent number: 6178314
    Abstract: An adaptive bandwidth control system optimizes radio reception by controlling intermediate frequency bandwidth and baseband bandwidth to reduce both interference and noise while remaining compatible with AM broadcasts using the NRSC-1 standard. An adaptive IF filter detects the presence of interfering undesired sources. The IF bandwidth is narrowed if any interferers are detected. Simultaneously, the frequency content of the demodulated baseband signal is analyzed to control an optimal baseband bandwidth so that any frequencies containing substantially only noise are eliminated.
    Type: Grant
    Filed: June 27, 1997
    Date of Patent: January 23, 2001
    Assignee: Visteon Global Technologies, Inc.
    Inventors: J. William Whikehart, Nicholas Lawrence Difiore, John Elliott Whitecar