AT386305B

AT386305B - Carrier frequency station

Info

Publication number: AT386305B
Application number: AT184686A
Authority: AT
Inventors: Othmar Dr Lasser
Original assignee: Siemens Ag Oesterreich
Priority date: 1986-07-08
Filing date: 1986-07-08
Publication date: 1988-08-10
Also published as: ATA184686A

Abstract

Carrier frequency station having a plurality of oscillators 2, 2' which are phase-regulated by means of assigned control voltages and are arranged together with assigned phase discriminators and assigned low-pass filters 3, 4; 3', 4' in individual phase-locked loops and whose oscillator frequency amounts to integer multiples of the frequency of a fundamental generated by a central fundamental generator. The oscillations of the oscillators 2, 2' are synchronized, by means of assigned phase discriminators, by the synchronizing pulses derived from the fundamental. The invention consists in the fact that the phase discrimination of all the phase-locked loops is of identical construction and that each phase discriminator has a differential stage 5, 6; 5', 6' which converts the oscillation of the assigned oscillator 2, 2' into in-phase pulses and whose output signal is fed into the input circuit of the low-pass filter 3, 4; 3', 4'. The synchronizing pulse duration is less than or equal to the half-period of the oscillator oscillation - to be synchronized - with the highest frequency and the low- pass filter of each phase-locked loop, which low-pass filter is constructed from a respective resistor 3, 3' and a capacitor 4, 4' having the resistances R and capacitances C, respectively, is dimensioned in accordance with the specification R . C = 2 1/2 . (k0 . KD)-1 where the constants KO and KD are the gain factors of the associated oscillator 2, 2' and of the associated phase discriminator, respectively. <IMAGE>

Description

  

   <Desc/Clms Page number 1> 
 
 EMI1.1 
 

 <Desc/Clms Page number 2> 

 Synchronisiert werden alle trägerfrequenten Schwingungen durch Synchronisierimpulse, die von der Steuerfrequenz abgeleitet sind. 



   Im einzelnen erfolgt die Regelung der   Oszillatoren-2, 2'-   in der Weise, dass mit Hilfe von Phasendiskriminatoren, die selbst keine eigene Bezeichnung tragen, in jedem Phasenregelkreis je eine vom Phasenunterschied zwischen dem jeweiligen Synchronisierimpuls und der zugeordneten Oszillatorschwingung abhängige Steuerspannung gewonnen wird. Da die durch den Phasenvergleich erhaltenen Signale in Form von Impulsen anfallen, die Steuerspannungen hingegen eine Gleichspannung sein muss, ist in jedem Phasenregelkreis je ein aus einem   Widerstand-3, 3'-   und einem   Kondensator-4, 4'-   aufgebautes Tiefpassfilter vorgesehen, das die Phasenvergleichs- 
 EMI2.1 
   SignaleOszillatorfrequenz.   



   Zur Erkennung der Abweichung der Frequenz eines der   Oszillatoren --2, 2'-- von   der vorgesehenen Trägerfrequenz wird der erwähnte Phasenvergleich in jedem Phasenregelkreis mit Hilfe einer zugeordneten Differenzstufe durchgeführt, die im einzelnen aus zwei Transistoren   - -5, 6   bzw. 5', 6'- besteht, die mit ihren Emittern an eine Konstantstromquelle --7 bzw. 7'-angeschlossen sind, die den Stromdurchfluss durch jeweils einen der beiden Transistoren-5 oder 6 bzw.   5'oder 6'-auf   einen konstanten Wert hält. Während die Basis des Transistors 
 EMI2.2 
 tritt, die phasengleich sind den Schwingungen des zugeordneten Oszillators --2 bzw.   2'--,   charakterisiert durch sein Zeitverhalten die Phasenlage der Oszillatorschwingung. 



   Der Transistor --9 bzw. 9'-- liegt im Eingangskreis des zugeordneten   Tiefpassfilters-3, 4   bzw. 3', 4'-- und steuert zufolge seiner Anordnung in Basischaltung dessen Eingangsstrom, der über den Transistor --5 bzw.   5'-- zugeführt   wird. Die weiters in den Stromkreis des Transistors --5 bzw.   5'-- einschaltbaren Transistoren --10, 11   bzw.   10',   11' -- liegen zueinander parallel und werden über die für alle Phasenregelkreise gemeinsamen Leitungen --12 und 13-von zwei gegenphasigen, zeitlich um die Dauer T der Synchronisierimpulse gegeneinander versetzten Rechtecksignale angesteuert, derart, dass mindestens einer während der ganzen Phasendauer 
 EMI2.3 
 te von der Dauer T, die die Synchronisierimpulse implizit darstellen, sind beide Transistoren   - 10   und 11 bzw.

   10'und 11'-gesperrt, so dass der vom Transistor-5 bzw. 5'--gelieferte Strom über den Transistor --9 bzw.   9'-- zum Tiefpassfilter --3, 4   bzw.   3',   4'- in einem von der Phasenlage abhängigen Ausmass abfliessen kann. 



   Die Erzeugung der die   Transistoren-10, 10' bzw. 11, 11'-   ansteuernden Rechteckimpulse erfolgt in der Weise, dass die die Steuerfrequenz aufweisende Grundschwingung des Grundgenerators --1-- einem ersten   Schmitt-Trigger --14-- zugeführt   wird, dessen Ausgangs-Rechtecksignal über die Leitung --12-- den Transistoren --10 bzw. 10'-- zugeführt werden. An den Ausgang des ersten Schmitt-Triggers --14-- ist ein Verzögerungsglied-15-- mit der Verzögerungszeit 
 EMI2.4 
 

 <Desc/Clms Page number 3> 

 
 EMI3.1 
 
 EMI3.2 
 
 EMI3.3 




   <Desc / Clms Page number 1>
 
 EMI1.1
 

 <Desc / Clms Page number 2>

 All carrier-frequency vibrations are synchronized by synchronization pulses that are derived from the control frequency.



   In particular, the control of the oscillators-2, 2'- is carried out in such a way that with the aid of phase discriminators, which do not have their own designation, a control voltage dependent on the phase difference between the respective synchronization pulse and the associated oscillator oscillation is obtained in each phase-locked loop. Since the signals obtained by the phase comparison occur in the form of pulses, but the control voltages must be a direct voltage, a low-pass filter made up of a resistor 3, 3 'and a capacitor 4, 4' is provided in each phase-locked loop the phase comparison
 EMI2.1
   Signals oscillator frequency.



   To detect the deviation of the frequency of one of the oscillators --2, 2 '- from the intended carrier frequency, the phase comparison mentioned is carried out in each phase-locked loop with the aid of an assigned differential stage, which in particular consists of two transistors - -5, 6 and 5' , 6'-, which are connected with their emitters to a constant current source --7 or 7'-, which keeps the current flow through one of the two transistors-5 or 6 or 5'or 6'- to a constant value . While the base of the transistor
 EMI2.2
 occurs, which are in phase with the vibrations of the assigned oscillator --2 or 2 '-, characterized by its time behavior, the phase position of the oscillator vibration.



   The transistor --9 or 9 '- is in the input circuit of the associated low-pass filter-3, 4 or 3', 4 '- and controls its input current according to its arrangement in the basic circuit, which via the transistor --5 or 5 '- is fed. The further transistors --10, 11 or 10 ', 11' - which can be switched into the circuit of the transistor --5 or 5 '- are parallel to one another and are connected via the lines --12 and 13- common to all phase-locked loops. controlled by two antiphase rectangular signals offset in time by the duration T of the synchronization pulses, such that at least one during the entire phase duration
 EMI2.3
 te of duration T, which the synchronization pulses implicitly represent, are both transistors - 10 and 11 or

   10 'and 11'-blocked, so that the current supplied by transistor 5 or 5' - via transistor --9 or 9 '- to low-pass filter --3, 4 or 3', 4'- can flow to an extent dependent on the phase position.



   The rectangular pulses driving the transistors 10, 10 'and 11, 11' are generated in such a way that the fundamental oscillation of the basic generator --1-- having the control frequency is fed to a first Schmitt trigger --14--, whose output square wave signal are fed via line --12-- to transistors --10 or 10 '-. At the output of the first Schmitt trigger --14-- is a delay element -15-- with the delay time
 EMI2.4
 

 <Desc / Clms Page number 3>

 
 EMI3.1
 
 EMI3.2
 
 EMI3.3

Claims

B. PATENT CLAIMS: 1. Carrier frequency station with several, by means of assigned control voltages phase-controlled oscillators, which are arranged together with assigned phase discriminators and assigned low-pass filters in individual phase-locked loops and whose oscillator frequencies are integral multiples of the frequency (control frequency) of a fundamental oscillation generated by a central basic generator and whose vibrations are synchronized by means of assigned phase discriminators by means of synchronization pulses derived from the fundamental vibration,

the output signal of each phase discriminator, which is dependent on the phase difference between the respective synchronization pulse and the associated oscillator oscillation, being supplied to the associated oscillator as a frequency-determining control voltage via an associated low-pass filter, the phase discriminators of all phase-locked loops being constructed identically, characterized in that each phase discriminator has one of the oscillations of the assigned oscillator (2, 2 ') in differential phase converting in-phase pulses (5, 6; 5', 6 '), which is fed by a constant current source (7, 7') and whose output signal in the input circuit of the low-pass filter (3, 4; 3rd ', 4') is fed in, which contains a transistor (9, 9 ') arranged in the base circuit and that the input circuit has two transistors (10, 11;

10 ', 11') are connected in parallel, which, apart from the duration of the synchronization pulses, short-circuit the input circuit and which are controlled by two phase signals, which are derived from the control frequency and are offset in time by the synchronization pulse duration, the synchronization pulse duration being less than or equal to the half period of the Oscillator oscillation to be synchronized with the highest frequency and that the low-pass filter of each phase locked loop constructed according to R. C = V2 from a resistor (3, 3 ') and a capacitor (4, 4') with the resistance or capacitance values R, C . (K0. Ko fl is dimensioned, the constants Ko and K being the amplification factors of the associated oscillator (2, 2 ') or the associated phase discriminator. EMI4.1 ten (K and K) is selected.

3. Station according to claim 1 or 2, characterized in that the first square wave signal derived directly from the fundamental wave is generated by means of a first Schmitt trigger (14) and that the second square wave signal is generated by means of a second Schmitt trigger connected to a delay element (15) (16) is molded.

4. Station according to one of the preceding claims, characterized in that the output signal of the differential stage (5, 6; 5 ', 6') are protected by a separating stage (8, 8 ') in the sense of a cascode circuit against being influenced by synchronization pulses.

5. Station according to one of the preceding claims, characterized in that via a series resistor (19, 19 ') at a fixed DC voltage (20, 20') base of the in the input circuit of the low-pass filter (3, 4; 3 ', 4' ) connected transistors (9, 9 ') is connected via a capacitor (18, 18') to a resistor (17, 17 ') connected upstream of the collectors of the transistors (10, 11; 10'11') connected in parallel with the input circuit.

6. Station according to one of the preceding claims, characterized in that between EMI4.2