Including Lc Resonant Circuits Tuned Above And Below Input Signal Carrier Frequency Patents (Class 329/339)
  • Patent number: 7884680
    Abstract: One embodiment relates to a circuit for active loss compensation. The circuit includes a parallel inductor-capacitive (LC) tank circuit having a first single-ended output. A first adjustable capacitor, which includes a first terminal and a second terminal, is coupled to the first single-ended output. The circuit also includes a first pair of transistors having sources coupled to a first common node. One transistor of the first pair of transistors has a drain coupled to the first single-ended output and the other transistor of the first pair of transistors has a gate coupled to the second terminal of the first adjustable capacitor. Other embodiments are also disclosed.
    Type: Grant
    Filed: June 30, 2008
    Date of Patent: February 8, 2011
    Assignee: Infineon Technologies AG
    Inventors: Alfred Raidl, Christoph Schmits, Wolfgang Thomann
  • Patent number: 7860478
    Abstract: Provided is a poly-phase filter capable of removing an image frequency of a terrestrial digital multimedia broadcasting (T-DMB) receiver in a low intermediate frequency (IF) structure applied to a mobile communication terminal and a receiver having the poly-phase filter. The poly-phase filter includes: a calibration control block for generating first and second filter characteristic control signals which determine electrical characteristics of the filter in response to a control signal including instructions for changing the characteristics of the poly-phase filter and holding the changed values; and a poly-phase filter block for performing filtering on a plurality of input signals having different phases from each other in response to the first and second filter characteristic control signals. Accordingly, the poly-phase filter has advantages of having constant electrical characteristics regardless of changes in a manufacturing process and temperature and a high-performance image rejection function.
    Type: Grant
    Filed: October 17, 2007
    Date of Patent: December 28, 2010
    Assignee: FCI, Inc.
    Inventors: Kyoo Hyun Lim, Sun Ki Min
  • Patent number: 7405613
    Abstract: A circuit and method for differential slope demodulator circuit are shown that utilize amplitude stabilizing of a frequency modulated signal to obtain an amplitude stabilized signal. Also shown is bandpass filtering of the amplitude stabilized signal for a first frequency that is offset by a shift frequency below an intermediate frequency, to obtain a first filtered signal and bandpass filtering the amplitude stabilized signal for a second frequency that is offset by the shift frequency above the intermediate frequency, to obtain a second filtered signal. The circuit and method further operate by detecting an envelope of the first filtered signal to obtain a first envelope signal, detecting an envelope of the second filtered signal to obtain a second envelope signal, and differencing the first and second envelope signals to obtain a demodulated output signal.
    Type: Grant
    Filed: April 6, 2006
    Date of Patent: July 29, 2008
    Assignee: Integration Associates Inc.
    Inventor: Hendricus C. De Ruijter