Patents by Inventor Frank de Jager

Frank de Jager 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: 4420723
    Abstract: A modulated carrier signal, the amplitude variations of which are smaller than the amplitude of the unmodulated carrier, is not very suitable for transmission over radio links because the required use of non-linear components, such as class-C amplifiers, result in an unwanted widening of the transmitted spectrum. According to the invention an arrangement for amplifying such a signal comprises two oscillators (16, 17) the desired relative phase of which is adjusted in a loop including a control circuit 22. On combining the oscillator signals v'.sub.k and v'.sub.g, there is produced a resulting signal r which is a replica of the input signal v having the amplitude variations. As the oscillators 16 and 17 produce signals having a constant amplitude, these signals can be easily amplified, for example by class-C amplifiers.
    Type: Grant
    Filed: March 27, 1981
    Date of Patent: December 13, 1983
    Assignee: U.S. Philips Corporation
    Inventor: Frank de Jager
  • Patent number: 4320499
    Abstract: A system for transmitting n-level data signals by means of an angle-modulated carrier having a constant amplitude and a continuous phase. The constant amplitude enables amplification in non-linear transmitter output stages. Associated with the n-levels are k(k>n) phase variations in accordance with such a rule, depending on preceding phase variations, that the spectrum of the angle-modulated signal becomes narrower. In a symbol interval the phase of the carrier changes by an amount from the sequence extending from -(k-1).pi./n to (k+1).pi./n in increments of 2.pi./n. The receiver is formed by a differential n-phase receiver. The system is used inter alia for radio transmission of digital information.
    Type: Grant
    Filed: March 12, 1980
    Date of Patent: March 16, 1982
    Assignee: U.S. Philips Corporation
    Inventors: Dirk Muilwijk, Cornelis B. Dekker, Frank de Jager
  • Patent number: 4292593
    Abstract: The invention relates to a method of demodulating a quadphase coded data signal and a receiver for carrying out the method. The quadphase code comprises four elementary wave forms, each wave form representing two bits of the original non-coded binary signal. An elementary wave form consists of four half bit intervals, the signal corresponding to the first and the second bit, respectively, being transmitted in the first and the second half bit interval and the signal corresponding to the inverted value of the first and the second bit, respectively, being transmitted in the third and the fourth half bit interval. In a receiver according to the invention such a signal is sampled in each of the four half bit intervals. In principle all information is already available after the sampling operations in the first and the second half bit interval, but by utilizing all four samples a proper protection from noise, interference and zero level shifts is obtained.
    Type: Grant
    Filed: June 29, 1979
    Date of Patent: September 29, 1981
    Assignee: U.S. Philips Corporation
    Inventors: Frank de Jager, Rudolf A. Van Doorn, Johannes J. Verboom, Marino G. Carasso
  • Patent number: 4276650
    Abstract: The invention relates to a method for the clock synchronization of a receiver for demodulating a quadphase coded data signal and to a clock synchronization device for carrying out the method.In the method according to the invention the first bit is compared (correlated) with the third bit and the second bit with the fourth bit: a high degree of correlation indicates that synchronization has been obtained and a low degree indicates absence of synchronization.
    Type: Grant
    Filed: July 11, 1979
    Date of Patent: June 30, 1981
    Assignee: U.S. Philips Corporation
    Inventors: Frank de Jager, Rudolf A. van Doorn, Johannes V. Verboom, Marino G. Carasso
  • Patent number: 4229821
    Abstract: A system having a transmitter and a receiver for transmitting binary data signals of a given symbol rate, an angle-modulated carrier signal of a substantially constant amplitude and a continuous phase being generated in the modulation stage of the transmitter, and the transmitted modulated signal being orthogonally, coherently demodulated in the receiver. The modulation stage of the transmitter is arranged so that the phase of the modulated signal changes in each symbol interval by an amount from the sequence -.pi./2, -.pi./4, 0, .pi./4, .pi./2 (rad.), which amount is determined for the relevant symbol interval by at least two successive data symbols, and the value of the phase within the relevant symbol interval is determined by a filtered version of at least these two succesive data symbols.
    Type: Grant
    Filed: August 23, 1978
    Date of Patent: October 21, 1980
    Assignee: U.S. Philips Corporation
    Inventors: Frank de Jager, Cornelis B. Dekker, Dirk Muilwijk
  • Patent number: 4204163
    Abstract: A transmission system which on the transmission side comprises a pulse-code modulation device, which is adapted for the pulse code conversion of consecutive minimum groups of two signal, elements of the information signal, the pulse code modulation device comprises a shape encoder, which in each group interval, encodes by a pulse code a normalized-amplitude shape of the signal variation of the two signal elements, and furthermore comprises an amplitude encoder, which in each group interval, encodes an associated amplitude value by a pulse code. The receiver comprises a multiplier stage for multiplication of the normalized-amplitude shape, which is transmitted in pulse code, in each group interval, by the associated amplitude value.
    Type: Grant
    Filed: June 21, 1978
    Date of Patent: May 20, 1980
    Assignee: U.S. Philips Corporation
    Inventor: Frank de Jager
  • Patent number: 4074199
    Abstract: A vestigial-sideband transmission system for synchronous data signals. The transmitter is provided with a filtering and modulating circuit for generating a vestigial-sideband channel signal which at the location of its carrier frequency and at the location of a frequency which is spaced from this carrier frequency by a distance equal to one half of the clock frequency of the data signals is a double-sideband modulated signal. In the receiver the reference carrier for coherent domodulation and the reference clock signal for regeneration can be simply recovered from the transmitted vestigial-sideband channel signal itself.
    Type: Grant
    Filed: November 16, 1976
    Date of Patent: February 14, 1978
    Assignee: U.S. Philips Corporation
    Inventors: Frank de Jager, Juan J. Martomy