Patents by Inventor Johannes S. Vromans

Johannes S. Vromans has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6795695
    Abstract: A receiver having a phase-locked loop (PLL) for synchronizing its oscillator with a carrier (CA). A calibration circuit (CAL) calibrates the phase-locked loop's oscillator (OSC) in the following manner. It measures (FMC) the frequency difference (dF) between a nominal frequency (Fnom) of the carrier (CA) and a frequency (Fosc) of the phase-locked loop's oscillator (OSC). Furthermore, it adjusts the frequency (Fosc) of the PLL oscillator in accordance with the measured frequency difference (dF). As a result, the phase-locked loop's oscillator will be substantially tuned to the nominal frequency of the carrier. The actual frequency of the carrier may differ from the nominal frequency. In general, such a difference will be sufficiently small for the phase-locked loop (PLL) to capture the carrier (CA).
    Type: Grant
    Filed: May 20, 1998
    Date of Patent: September 21, 2004
    Assignee: U.S. Philips Corporation
    Inventors: Johannes H. A. Brekelmans, Hans J. Kunz, Johannes S. Vromans
  • Patent number: 5272534
    Abstract: TV receiver including an RF section, a mixer stage to which a tuning frequency is applied from a tuning oscillator, an IF section, a synchronous detection device and a frequency and phase-locked loop circuit having a PLL and a FLL, the IF section being coupled to a phase detector of the PLL and to a frequency detection device of the FLL, the phase detector and frequency detection device being commonly coupled to a loop branch having the two loops in common and incorporating a loop filter and a controllable oscillator, the controllable oscillator applying a local in-phase carrier to the synchronous detection device and a local phase quadrature carrier to the phase detector.
    Type: Grant
    Filed: May 5, 1992
    Date of Patent: December 21, 1993
    Assignee: U.S. Philips Corporation
    Inventors: Johannes S. Vromans, Hubertus J. F. Maas, Johannes Dollee
  • Patent number: 4918402
    Abstract: A third-order all-pass network for a delay circuit is formed by four coupled transconductors (G.sub.10 to G.sub.13) which are each represented by two transistors whose bases constitute the inputs and whose collectors constitute the outputs of the transconductor. A first input of these transconductors (G.sub.10 to G.sub.13) is connected to ground (3). Between the second inputs (25,26) of the first transconductor (G.sub.10) and the second transconductor (G.sub.11) a first capacitor (C.sub.1) is arranged, between the second inputs (26,27) of the second transconductor (G.sub.11) and the third transconductor (G.sub.12) a second capacitor (C2) is arranged, and between the second inputs (27,28) of the third transconductor (G.sub.12) and the fourth transconductor (G.sub.13) and a third capacitor (C3) is arranged. Further, a fourth capacitor (C4) is arranged between the second inputs (25,27) of the first transconductor (G.sub.10) and the third transconductor (G.sub.
    Type: Grant
    Filed: February 22, 1989
    Date of Patent: April 17, 1990
    Assignee: U.S. Philips Corp.
    Inventors: Johannes O. Voorman, Pieter J. Snijder, Johannes S. Vromans
  • Patent number: 4853651
    Abstract: A third-order all-pass network for a delay circuit is formed by four coupled transconductors (G.sub.10 to G.sub.13) which are each represented by two transistors whose bases constitute the inputs and whose collectors constitute the outputs of the transconductor. A first input of these transconductors (G.sub.10 to G.sub.13) is connected to ground (3). Between the second inputs (25,26) of the first transconductor (G.sub.10) and the second transconductor (G.sub.11) a first capacitor (C.sub.1) is arranged, while between the second imputs (26,27) of the second transconductor (G.sub.11) and the third transconductor (G.sub.12) a second capacitor (C2) is arranged, and between the second inputs (27,28) of the third transconductor (G.sub.12) and the fourth transconductor (G.sub.13) a third capacitor (C3) is arranged. Further, a fourth capacitor (C4) is arranged between the second inputs (25,27) of the first transconductor (G.sub.10) and the third transconductor (G.sub.
    Type: Grant
    Filed: September 8, 1987
    Date of Patent: August 1, 1989
    Assignee: U.S. Philips Corp.
    Inventors: Johannes O. Voorman, Pieter J. Snijder, Johannes S. Vromans