Licentia Patent-verwaltungs Gmbh

Deutsche Thomson-brandt Gmbh

Dieter Rottmann

Otto Klank

Stephan Wuttke

Helmut Wossner

Apparatus in a receiver for adaptively adjusting the receiver response to changing signal conditions includes a shift register for serially loading signal and having parallel output taps for providing a plurality of signal samples in parallel. Matrix circuitry, coupled to the output taps, is arranged to provide the signal samples in a predetermined order to facilitate forming sums of products of such signal samples.

Adaptive digital filter for multi path distortion cancellation

In a digital tuning system for a radio receiver, which system includes a station memory having a plurality of memory locations for storing digit representations identifying respective broadcast frequencies to be received, a plurality of station selector elements each connected to be actuatable for addressing a respective memory location to cause the tuning system to tune the receiver to the station identified by the representations stored in the addressed memory location, a plurality of band selector elements each connected to be actuatable for causing the receiver to be tuned within a respective signal band, and components operable for continuously varying the receiving frequency to which the receiver is tuned, the station memory is provided with a plurality of additional memory locations and each band selector element is connected to address, upon being actuated, a respective additional memory location to cause the tuning system to tune the receiver to the station identified by representations stored in the addressed additional memory location, the additional memory locations not being addressable by the station selector elements.

Digital tuning system for a radio receiver

A tuning circuit for a high frequency receiver in which the received frequency is determined by a voltage-controlled oscillator, the present tuning frequency is indicated by a counter connected to the oscillator and producing a representation of each digit of the decimal number identifying the current received frequency, representations of the digits of the number identifying the desired received frequency are fed in via a keyboard, and the decimal number representations are compared in a comparator to produce a control voltage that brings the oscillator frequency to the desired value, and in which the comparator is capable of comparing only one digit of the number representations at a time and is associated with multiplex circuitry which supplies the digits of corresponding significance thereto in sequence, starting with the most significant digit.

Tuning circuit for high frequency receivers

A tuning circuit for high frequency receivers including a superheterodyne oscillator whose frequency can be varied by a tuning voltage to tune in desired stations and a comparison circuit which produces the tuning voltage by comparing a first number representing the broadcast frequency to which the oscillator is tuned, produced by a counting device which periodically counts the oscillations of the superheterodyne oscillator under consideration of the intermediate frequency with a second number representing the desired received frequency fed in via an input keyboard with series-connected coder and the comparison circuit includes a single comparator suitable only for the comparison of but a single digit of the two numbers at one time and receives the digits of the two numbers to be compared in multiplex operation in succession beginning with the digit assigned the highest value. The counting result from the counting device is displayed on an optical display device controlled in the same multiplex operation as the comparator with the multiplex phase signals required for the multiplex operation of the comparison circuit being obtained from a regenerating circuit which is controlled by at least one synchronizing signal from the counting device and by at least one clock pulse signal appearing per multiplex signal of the display device, so that the resulting multiplex signals for the comparator occur synchronously or in synchronous rhythm with the multiplex signals for the display device. The clock pulse signal is obtained from a control circuit which is connected to the counting device and which circuit together with the regenerating circuit controls the sequence of the entire comparison circuit. Preferably the entire comparison circuit, including the control and regenerating circuit and the comparator is designed to be a single integrated circuit unit.

A tuning circuit for a high frequency receiver in which the received frequency is determined by a voltage-controlled oscillator, the present tuning frequency is indicated by a counter connected to the oscillator and producing a representation of each digit of the decimal number identifying the current received frequency, representations of the digits of the number identifying the desired received frequency are fed in via a keyboard and stored in a dynamic memory having a feedback connection from its last memory cell to its first memory cell, the decimal number representations are compared in a comparator to produce a control voltage that brings the oscillator frequency to the desired value, the comparator being capable of comparing only one digit of the number representations at a time and being associated with multiplex circuitry which supplies the digits of corresponding significance thereto in sequence, starting with the most significant digit, and a station tuning memory is provided to store representations of the frequency and band of selected broadcast stations and is connected by a linkage circuit to the dynamic memory to permit transfer in either direction between the memories of station frequency and band representations.

Broadcast receiver tuning circuit with station memory

In a circuit arrangement for digitally indicating the tuned frequency of a radio receiver operating in the AM and FM ranges in which the oscillations of the AM tuning oscillator and of the FM tuning oscillator are amplified, converted to rectangular oscillations, counted by means of electronic counters and then digitally displayed, the oscillations of the AM tuning oscillator and the oscillations of the FM tuning oscillator are amplified by a common broadband amplifier which is sufficiently broadbanded so that the oscillator frequencies for the AM range as well as those for the FM range are both passed and amplified and the coupling of the input of the broadband amplifier to the outputs of the tuning oscillators is so loose that the tuning oscillators are not noticeably detuned by changes in capacity in the broadband amplifier.

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Hanover, Germany

Dieter Rottmann