RADIO RECEIVER FOR SINGLE SIDEBAND RECEPTION

• US 3,739,282 A
• Filed: 12/10/1970
• Issued: 06/12/1973
• Est. Priority Date: 12/11/1969
• Status: Expired due to Term

• Current Assignee: Telefunken Fernseh Und Rundfunk GmbH
• Original Assignee: Walter Bruch, Werner Scholz
• Inventors: Bruch, Walter, Scholz, Werner
• Primary Examiner(s): Mayer, Albert J.
• Application Number:
  US05/096,901
• Time in Patent Office: 915 Days
• Field of Search: 331/172-174 325/50,330,419,420 329/50,122 179/15FS 332/45
• US Class Current: 455/199.1
• CPC Class Codes: H04B 1/302 for single sideband receivers demodulator circuits H03D1/24

Abstract

In a single sideband radio receiver for the selective reception of signals transmitted by a plurality of transmitters at equal frequency spacing ( Delta fs) the local oscillator in the receiver, which may produce voltages for either heterodyning or demodulating the received signal, is controlled by means of an arrangement including an ultrasonic delay line which serves as the frequency standard for the spacing of the local oscillator frequencies ( Delta fo) so that it locks in and oscillates only at defined oscillator frequencies corresponding to the frequencies of the transmitters. Various alternative embodiments of controlling the local oscillator in this manner are disclosed.

Claims

1. In a radio receiver for the selective reception of single sideband signals (fs) transmitted by a plurality of transmitters at equal frequency spacing ( Delta fs) including a frequency selective amplifier for receiving the transmitted signals, a local oscillator, which is tunable in synchronism with said amplifier, for producing output signals having defined frequencies at a frequency spacing ( Delta fo) equal to n or 1/n times the frequency spacing ( Delta fs) of the transmitter frequencies, where n is a whole number (1, 2, 3 . . .) and means for combining the received signal and the output signal from said local oscillator to detect the received signal, the improvement comprising:

means, including an ultrasonic delay line whose delay time ( Tau ) is equal to the reciprocal value of the spacing of the oscillator frequencies ( Delta fo) and which serves as the frequency standard for the spacing of the local oscillator frequencies ( Delta fo), for controlling the frequency of said local oscillator so that it locks in and oscillates at only said defined frequencies.

2. The radio receiver as defined in claim 1 wherein said means for controlling the frequency of said local oscillator comprises:

a generator means for producing an output pulse train having a frequency which is equal to the spacing of the oscillator frequencies ( Delta fo), said ultrasonic delay line being the frequency determining member of said pulse generator; and

means for coupling said output pulse train to a frequency controlling input of said local oscillator.

3. The radio receiver as defined in claim 2 wherein said coupling means comprises means for directly feeding said pulse train to said local oscillator to synchronize said local oscillator to the selected oscillator frequency by a direct locking action.

4. The radio receiver as defined in claim 2 wherein said coupling means further includes a phase comparison means for comparing said pulse train and the output signal of said local oscillator and for producing an output voltage which is coupled to said local oscillator and acts as a control voltage on the frequency of said oscillator.

5. The radio receiver as defined in claim 2 wherein said coupling means includes means responsive to said pulse train for producing oscillations of the order of magnitude of a local oscillator frequency, which oscillations are interrupted at frequency intervals corresponding to said frequency spacing ( Delta fo).

6. The radio receiver as defined in claim 5 wherein said means responsive to said pulse train comprises a start-stop oscillator which is actuated by each of the pulses of said pulse train to generate a number of oscillations at a local oscillator frequency.

7. The radio receiver as defined in claim 5 wherein said coupling means further includes a phase comparison means for comparing the phase of said interrupted oscillations and the output signal of said local oscillator and for providing an output voltage which is coupled to said local oscillator and serves as the control voltage (UR) for controlling the frequency of said local oscillator.

8. The radio receiver as defined in claim 1 wherein said means for controlling the frequency of said local oscillator comprises said ultrasonic delay line which is disposed in the feedback path of said local oscillator.

9. The radio receiver as defined in claim 1 wherein said means for controlling the frequency of said local oscillaTor comprises said ultrasonic delay line which is connected between the output and a synchronizing input of said local oscillator to provide direct locking synchronization thereof.

10. The radio receiver as defined in claim 1 wherein said ultrasonic delay line has its input connected to the output of said local oscillator and wherein said means for controlling the frequency of said local oscillator further includes means for comparing the phase of the input and output signals of said ultrasonic delay line to provide an output voltage which is coupled to said local oscillator and serves to control the frequency thereof.

11. The radio receiver as defined in claim 1 wherein said ultrasonic delay line is a PAL delay line with a delay time ( Tau ) which is adapted to the frequency spacing ( Delta fo) of the oscillator frequencies (fo).