DE1059511B - Method and circuit arrangement for generating the carrier frequency 114 kHz and integer multiples of the frequencies 12 kHz and 4 kHz from a fundamental frequency which is an integer multiple of 114 kHz - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

PATENT 1 059 REGISTRATION DAY:

NOTICE THE REGISTRATION AND ISSUE OF EDITORIAL:

ISSUE OF PATENT LETTERING:

kl. 21 a2 39/10

INTERNAT. KL. H 04 j NOVEMBER 3, 1958

June 18, 1959

APRIL 23, 1964 DEVERS FROM

EDITORIAL

(F 26956 VHI a / 21a ¹ )

The invention relates to a method and a circuit arrangement for generating the carrier frequency 1.14 kHz and integer multiples of the frequencies 12 and 4 kHz from a basic frequency.

In two-wire carrier frequency systems with a channel bandwidth of 4 kHz, of the low-frequency news band into the high-frequency Transmission position as a channel carrier is a multiple of 4 kHz and as a pre-group carrier is a multiple of 12 kHz required; in addition, to implement the basic group 60 ... 108 kHz in the transmission layer for the opposite direction 6 ... 54 and for Intermediate implementation of the basic groups in both transmission directions in intermediate amplifiers with group swap the group carrier 114 kHz .required.

The multiples of 4 and 12 kHz have so far been obtained from a basic frequency of 4 kHz in such a way that first a frequency spectrum of the integer multiples of 4 kHz is generated by multiplying the basic frequency of 4 kHz generated in a basic generator and the required channel carriers are then generated by means of filters of 12, 16 and 20 kHz were screened out; from the frequency of 12 kHz obtained in this way, the required pre-group carriers 84, 96, 108 and 120 kHz were then obtained in the same way by multiplication and screening. The group carrier 114 kHz - since it is not a multiple of 12 kHz - could not be obtained in this way, but had to be generated in a separate basic generator for 114 kHz.

Two basic generators were therefore required to generate the required carrier frequencies. Since very high demands have to be made on the accuracy of the carrier frequencies and therefore As basic generators only quartz-controlled generators can be used, the necessity posed two basic generators represent an undesirably high effort.

It was also known to be more velvety to produce required frequencies to use a single crystal generator in the range of 100 kHz whose output voltage derives the desired frequencies through frequency converters and mixer stages will..

Another disadvantage of the previous one is the frequency multiplication or frequency division of a fundamental frequency based method is that the quartz oscillator for frequencies below about 30OkHz both in terms of their frequency stability and their strength properties extremely sensitive to vibrations and consequently are prone to failure; because of their strong temperature dependence, they must be used to achieve Method of production

the carrier frequency 114 kHz and integer multiples

the frequencies 12 kHz and 4 kHz

Patented for:

Feiten & Guilleaume Fernmeldeanlagen G.m.b.H., Nuremberg

Dipl.-Ing. Helmuth Sippel, Nuremberg,

and Helmut Schott, Fischbach near Nuremberg, have been named as inventors

the required frequency constancy can be accommodated in thermostats, which is a very significant one Requires space and represents a high cost. The thermostats are also required by the Contact thermometers are also very sensitive to vibrations and prone to failure.

In contrast, quartz crystals are suitable for frequencies in the order of magnitude of 1 MHz and above both almost insensitive to vibrations and so little temperature-dependent that the use no need for thermostats; in addition to these more advantageous properties, they show considerably less Signs of aging and have a higher quality factor. As they are therefore not available as vacuum crystals must be executed, but can be produced as air crystals, their price is around a third below that for equivalent vacuum crystals for frequencies below 300 kHz.

These advantageous properties of the quartz oscillator For frequencies in the order of 1 MHz, the invention makes use of that ·, they are used to generate the carrier frequency 114 kHz and integer multiples of the frequencies 12 and 4 kHz does not start from a subharmonic of the required frequencies, but from fundamental frequencies, the. represent integer multiples of the frequencies required.

The inventive method for generating the carrier frequency 114 kHz and integer multiples the frequencies 12 kHz and 4 kHz is identified

409 573/309

characterized by the use of a first fundamental frequency stabilized by a high-frequency oscillating crystal, which is an integer multiple of 114 kHz and. is on the order of 1 MHz, as well through the joint application of the following procedural steps:

a) Halving the first basic frequency n times, 2 "· 114 kHz by means of η successive binary frequency dividers and branching off the frequency 228 kHz before the last binary frequency divider; where ή is an integer;

b) Generation of the second basic frequency 12 kHz by means of a backmix divider from the frequency 228 kHz;

c) Multiplication of the second fundamental frequency 12 kHz and. Screening out the required pre-group carriers requenzeh; . .

d) Generation of the third fundamental frequency 4 kHz by means of a backmix divider from the fundamental frequency 12 kHz;

e) Multiplication of the third fundamental frequency 4 kHz and removal of the required channel carrier frequencies.

In the application example of the inventive concept shown in the block diagram, a basic generator for a frequency of 912 kHz (= 2 ³ · 114 kHz) is assumed; the group carrier 114 kHz is obtained from this basic frequency by means of three binary frequency division; As a result of the binary frequency division, the frequency 228 kHz is available after the second or before the last binary divider stage, without the need for special filter elements. The base frequency Ϊ2 kHz is generated from the frequency 228 kHz by means of a backmix divider and then - in a known manner - the pre-group carriers 84, 96, 108 and 120 kHz by frequency multiplication and filtering out the required multiples of 12 kHz and by doubling the frequency 108 kHz, the frequency of 216 kHz required for backmixing was obtained. Since the frequency 108 kHz has already been sufficiently screened by the high-quality pre-group carrier filter, no further screening is required for the frequency 216 kHz obtained by doubling this frequency.

Similarly, the frequency generated in the aforementioned backmix divider becomes 12 kHz The fundamental frequency of 4 kHz is generated in a second backmixing divider and multiplied from this and screening out the channel carriers 12, 16 and 20 kHz won.

With the method according to the invention, this can result in a substantial reduction in the effort can be achieved that for generating the fundamental frequencies 12 or 4 kHz in the backmixing dividers and one and the same frequency multiplier is used to multiply these frequencies.

According to a further feature of the invention ^: - without deviating from the basic inventive concept - the group carrier 114 kHz ^! also by means of a backmix divider from the basic; frequency wll4 kHz won and the frequency kHz the frequency multiplier of this reverse; mixing divider can be taken .. where m is a; whole number:

With the invention. Proceedings will be not only the disadvantages of the Q u ar ζ oscillators for frequencies below 30OkHz, as described at the beginning avoided, but also a considerable reduction in space requirements and a significant reduction in costs achieved, which at the same time also has the advantage of greater operational reliability is.

Claims (3)

Patent claims: 1. Method for generating the carrier frequency I. 114 kHz and integer multiples of the frequencies 12 kHz and 4 kHz, identified by the Use of a first fundamental frequency stabilized by a high-frequency quartz oscillator, which is an integer multiple of 114 kHz and is on the order of 1 MHz, as well as through the joint application of the following procedural steps: ■ a) w-times halving of the first base frequency 2 "-IHkHz by means of η successive binary frequency dividers and branching of the frequency 228 kHz before the last binary frequency divider; b) Generation of the second base frequency 12 kHz. by means of a backmix divider from the frequency 228 kHz; c) Multiplication of the second basic frequency of 12 kHz and removal of the required "pre-group carrier frequencies" ; d) Generation of the third fundamental frequency 4 kHz by means of a backmixing divider from the second Fundamental frequency 12 kHz; e) Multiplication of the third fundamental frequency 4 kHz and removal of the required channel carrier frequencies. ■ 2. Modification of the method according to claim 1 with regard to the partial feature a), characterized in that the carrier frequency 114 kHz is obtained by means of a backmix divider from a first base frequency m ■ 114 kHz and the frequency 228 kHz is taken from the frequency multiplier of this backmix divider. 3. The method according to claim 1, characterized in that for performing the method steps b) and c) or .. d) and e) for generating the fundamental frequencies 12 kHz and 4 kHz in the backmixing dividers and to multiply these frequencies one and the same frequency multipliers serve. . 1 sheet of drawings © 909 557/292 6.