US2228815A - Frequency conversion system - Google Patents

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US2228815A
US2228815A US315998A US31599840A US2228815A US 2228815 A US2228815 A US 2228815A US 315998 A US315998 A US 315998A US 31599840 A US31599840 A US 31599840A US 2228815 A US2228815 A US 2228815A
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frequency
waves
frequencies
product
oscillator
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US315998A
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Franklin M Deerhake
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General Electric Co
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General Electric Co
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Priority to FR869542D priority patent/FR869542A/en
Priority to CH232472D priority patent/CH232472A/en
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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06Receivers
    • H04B1/16Circuits
    • H04B1/26Circuits for superheterodyne receivers
    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03BGENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B21/00Generation of oscillations by combining unmodulated signals of different frequencies
    • H03B21/01Generation of oscillations by combining unmodulated signals of different frequencies by beating unmodulated signals of different frequencies
    • H03B21/02Generation of oscillations by combining unmodulated signals of different frequencies by beating unmodulated signals of different frequencies by plural beating, i.e. for frequency synthesis ; Beating in combination with multiplication or division of frequency
    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03CMODULATION
    • H03C3/00Angle modulation
    • H03C3/02Details

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  • My invention relates to a frequency conversion system of the double heterodyne conversion type, particularly adapted for converting signal-modulated waves from one high frequency to another high frequency.
  • the advantages of the double heterodyne conversion system which comprises a first heterodyne conversion to an intermediate frequency at which the signal-modulated wave is readily am- 10 plifled, followed by a second heterodyne conversion to the desired resultant frequency, are well known.
  • Such a system requires two locally generated waves 'of different frequencies for effecting the consecutive conversions.
  • Two independent oscillators may be employed or the two Waves may comprise different harmonics of a particular frequency derived from a single oscillator.
  • Another object of my invention is the provision of such a frequency conversion system adapted for stable operation at very high frequencies.
  • Another object of my invention is to provide an economical and highly stable double heterodyne conversion system in which the waves generated by one oscillator can be utilized directly in one of the conversions, thereby eliminating the need for intervening frequency multipliers or like devices which may introduce undesirable interfering frequencies.
  • Another important object of my invention is system in which fluctuations in the frequency of one of the locally generated waves may be compensated so as to have'no effect on the frequency of the resultant waves.
  • the invention is shown embodied in a radio relay station for receiving signal-modulated waves of one frequency and retransmitting or rebroadcasting similarly modulated waves of a different frequency. Since the component elements of the system are all conventional and well known to those skilled in the art, the circuit connections and elements have not been shown in detail but are represented in conventionalized form by a one line diagram.
  • High frequency waves which may be modulated in any desired manner, as by audio signals or television video signals, are received by a suitable energy reception device such as the antenna I at the left-hand side of the drawing. Waves of a different high frequency, similarly modu1ated,- are to be retransmitted or rebroadcasted by a suitable energy propagation device, such as the antenna 2 at the right-hand side of the drawing. 'It is of course obvious that the waves may be received and retransmitted by wire lines rather than by the wireless system shown.
  • a local oscillator 3 generates a substantially constant frequency wave utilized in one of the frequency conversions, to be described presently. This oscillator is of conventional design, and frequency stability may be insured in any wellknown manner, as by crystal or resonant line control. For the particular embodiment shown, representing a high frequency relay station, the frequency of the oscillator 3 will ordinarily be too low to be used directly, and hence a synchronized harmonic generator 6 is employed, operating at some fixed multiple of the frequency of oscillator 3.
  • the oscillator employed in this system for producing the second wave utilized in the frequency conversions is the master oscillator 5.
  • the frequency'of this oscillator ordinarily will not be highly constant but may fluctuate, either purposely or through inherent instability.
  • Waves generated by the master oscillator 5 are heterodyned with the received signal-modulated wave in the converter 8 and a selected modulation product resulting from,
  • the converter 8. often called a detector or mixer, may comprise any one of a number of conventional circuits well known in the art, and it is thought unnecessary to describe it in detail. Briefly, the converter performs the two functions of heterodyning the two waves to producers group of modulation products and of selecting one desired product as the converter output wave. Waves generated by the oscillator 5 are also heterodyned with waves supplied by the harmonic generator 4 by means of a converter I, which functions in the same manner as the converter i, and a selected modulation product is supplied to the amplifier I. Buffer amplifiers l0 and II are preferably interposed between the master oscillator I and the converters 8 and t to amplify the oscillations and prevent undesirable reactions between the various circuit elements, according to known practice.
  • the signal-modulated waves supplied to the amplifier I are next subjected to a second conversion in the converter I! in which they are heterodyned with the waves from the amplifier 9.
  • the selected modulation product of this conversion comprises the signal-modulated output wave which is supplied to the antenna 2.
  • it is first further amplified by the amplifier l3 .prior to retransmission.
  • the wave received at the antenna l is designated by f1, indicative of its frequency.
  • the output wave at antenna 2 is denoted by h, the constant frequency wave supplied by theharmonic generator l by Is, the wave supplied by the master oscillator 5 by ii, the selected modulation product supplied to amplifier 1 by Is and the selected modulation product supplied to amplifier O by fa.
  • the output frequency f is determined by the values of f1 and either fa or it, depending on the particular combination of modulation products selected in the three conversions.
  • ii and I are arbitrarily selected, and that is is to remain substantially cons
  • n Fr quency is is then selected so that I: is equal either to the sum or to the difference of 11 and fa. If it is selected equal to the sum, obviously i: must be greater than f1, whereas if it is selected equal to the difference, I: may be either greater or less than f1.
  • If and is. is may be selected as the sum frequency product of i1 and f4, fs as the sum frequency product of I: and f4, and f: as the difference frequency product of f5 and is; or It may be selected as the difference frequency product of f1 and f4, Is as the difference frequency product of f: and f4, and f: as the difference frequency product of f5 and is.
  • Table 11 illustrates various frequency relationships which will maintain is independent of variations in ft for the case where I: has been selected equal to the sum of f1 and f3.
  • the frequency of the master oscillator 5 may be varied purposely in order to frequency modulate the output wave by twice that amount.
  • the frequency multiplication efiect can be "amplified to give a frequency variation of the output wave greater than twice the frequency variation in LettersPatent of theUnited States is:
  • the method of frequency conversion which comprises the steps of receiving signal-modulated waves of a first frequency, generating waves of a second, substantially constant frequency, --generating independently. waves of a third frequency subject to frequency variations, hetero- ,dyning the waves of said first and third frequencies to produce a first modulation product the frequency of which is affected by said variations, heterodyning the waves of said second and third frequencies to produce a second modulation product the frequency of which is'also affected bysaid frequency variations and heterodyning said modulation products to produce a resultant wave the frequency of which is unaffected by said variations.
  • a frequency conversion system for converting electrical waves of a first frequency to waves of a second frequency
  • a system for theconversion of signal-modulated waves of a first high frequency to similarly modulated waves of a second high frequency comprising means for receiving the waves of said first frequency, a source of waves of a third high frequency subject to frequency variations, means for heterodyning the waves of said first and third frequencies to produce waves of a resultant frequency, means for utilizing said resultant frequency wavesto produce the waves of said second frequency, and means for preventing frequency subject to frequency fluctuations, a converter for heterodyning the waves of said first and third frequencies to produce a modulation product the frequency of which is affected by said fluctuations, , a second converter for heterodyning the waves of said second and third frequencies to produce a second modulation product the frequency of which is also affected by said 'ing one ference frequency products and for selecting one product affected by said variations in one sense, a second converter for combining the waves of said third and fourth frequencies to produce sum and difference frequency products and for selectproduct affected by said variations in the oppositesense.
  • a frequency conversion system for converting received, signal-modulated waves of a of a first frequency to waves of a second -f re-" first high frequency to similarly modulated waves quency, the combination of a source of waves of a of a second high frequency, the combination of third frequency, a source of waves of a fourth an oscillator for generating waves of a third, subfrequency, means for combining the waves of said first and fourth frequencies to produce a resultant frequency, means for combining the waves of said third and fourth frequencies to produce a second resultant frequency, and means for combining said resultant frequencies to produce said second frequency waves.
  • the combination in a frequency conversion system of means for receiving waves of a first frequency, means for generating waves of a second, substantially constant frequency, means for generating independently waves of a third frequency subject to frequency variations, means for combiniig the waves of said first and third frequencies to produce a pair of sum and difference frequency products the frequencies of which are affected by said variations and for selecting one product from said pair, means for combining the waves of said second and third frequencies to produce a-second pair of sum and difference frequency products the frequencies of which are also affected by said variations and for selecting one product from said second pair, means for combining said selected products to produce a third pair of sum and difference frequency products and for selecting as a resultant wave one product of said third pair the frequency of which is unaflected by said variations.
  • a frequency conversion system for converting received, signal-modulated waves of a first high frequency to similarly modulated waves of a second high frequency, the combination of an oscillator for generating waves of a third, substantially constant high frequency, a second oscillator for generating waves of a fourth high frequency.
  • a first converter for combining the waves of said first and fourth frequencies to produce sum and difstantially constant high frequency
  • a second oscillator for generating waves of a fourth high frequency subject to frequency variations
  • a first converter for combining the waves of said first and fourth frequencies to poduce sum and difference frequency products and for selecting one product affected by said variations in one sense
  • a second converter for combining the waves of said third and fourth frequencies to produce sum and difference frequency products and for selecting one product affected by said variations in the same sense
  • a third converter for combining said selected products to produce sum and difference frequency products and for selecting theirdifference frequency product as said second high frequency waves.
  • a radio relay station for receiving signalmodulated waves of a first high frequency and for retransmitting similarly modulated waves of a second high frequency, comprising, in combination, a first oscillator for generating waves of a third substantially constant high frequency equal to the difference between said first and second frequencies, a second oscillator for generating waves of a fourth high frequency intermediate said first and third frequencies and subject to frequency fluctuations, a first converter for heterodyning together the waves of said first and fourth frequencies and for selecting their difference frequency product, a second converter for heterodyning together the waves of said third and fourth frequencies and for selecting their difierence frequency product, a third converter for heterodyning together said selected products and for selecting their sum frequency product as said second high frequency waves and means for retransmitting said second high frequency waves.

Description

1941 F. M. DEERHAKE 2,228,815
FREQUENCY couvznsxon SYSTEM Filed Jam 27, 1940 I 6 7 /2 Is 2 f I I I I 1 f2 CONVERTER AMPLIFIER coIvvERrER AMPLIFIER g f5 /o BUFFER AMPLIFIER f AMPLIFIER II s MASTER BUFFER f OSCILLATOR AMPLIFIER 8 I HARMONIC -4 GENERATOR CONSTANT FREQUENCY 3 Osc/LLATOR lnveht 01*: Franklin M. Deer" h a ke Patented Jan. 14, 1941 UNITED STATES FREQUENCY CONVERSION SYSTEM Franklin M. Deerhake', Schenectady, N. Y., assignor to. General Electric Company, a corporation of New York Application January 27, 1940, Serial No. 315,998
10 Claims. (01. 2 50-20) My invention relates to a frequency conversion system of the double heterodyne conversion type, particularly adapted for converting signal-modulated waves from one high frequency to another high frequency.
The advantages of the double heterodyne conversion system, which comprises a first heterodyne conversion to an intermediate frequency at which the signal-modulated wave is readily am- 10 plifled, followed by a second heterodyne conversion to the desired resultant frequency, are well known. Such a system requires two locally generated waves 'of different frequencies for effecting the consecutive conversions. Two independent oscillators may be employed or the two Waves may comprise different harmonics of a particular frequency derived from a single oscillator. The
former case permits greater flexibility in the choice of frequencies than the latter, but ordinarily the frequency of the resultant output wave is affected by any fluctuations in thefrequencies of the two locally generated waves in a random manner. Consequently, the advantages of greater flexibility may be ofiset either by decreased 25 frequency stability of the output wave or by the expense of providing oscillators of closely controlled frequency.
It is an object of my invention to provide an improved double heterodyne conversion system which employs two separate oscillators and which has both flexibility and desirable characteristics.
Another object of my invention is the provision of such a frequency conversion system adapted for stable operation at very high frequencies.
Another object of my invention is to provide an economical and highly stable double heterodyne conversion system in which the waves generated by one oscillator can be utilized directly in one of the conversions, thereby eliminating the need for intervening frequency multipliers or like devices which may introduce undesirable interfering frequencies.
It is a further object of my invention to provide a double frequency conversion system in which the waves employed for effecting the consecutive conversions are interdependent though derived from independent sources.
Another important object of my invention is system in which fluctuations in the frequency of one of the locally generated waves may be compensated so as to have'no effect on the frequency of the resultant waves.
55 The features of my invention which I believe the provision of a double heterodyne conversion to be novel are set forth with particularity in the appended claims. My invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing, in which the single figure diagrammatically illustrates one embodiment of my invention.
Referring now to the drawing, the invention is shown embodied in a radio relay station for receiving signal-modulated waves of one frequency and retransmitting or rebroadcasting similarly modulated waves of a different frequency. Since the component elements of the system are all conventional and well known to those skilled in the art, the circuit connections and elements have not been shown in detail but are represented in conventionalized form by a one line diagram.
High frequency waves, which may be modulated in any desired manner, as by audio signals or television video signals, are received by a suitable energy reception device such as the antenna I at the left-hand side of the drawing. Waves of a different high frequency, similarly modu1ated,- are to be retransmitted or rebroadcasted by a suitable energy propagation device, such as the antenna 2 at the right-hand side of the drawing. 'It is of course obvious that the waves may be received and retransmitted by wire lines rather than by the wireless system shown. A local oscillator 3 generates a substantially constant frequency wave utilized in one of the frequency conversions, to be described presently. This oscillator is of conventional design, and frequency stability may be insured in any wellknown manner, as by crystal or resonant line control. For the particular embodiment shown, representing a high frequency relay station, the frequency of the oscillator 3 will ordinarily be too low to be used directly, and hence a synchronized harmonic generator 6 is employed, operating at some fixed multiple of the frequency of oscillator 3.
The oscillator employed in this system for producing the second wave utilized in the frequency conversions is the master oscillator 5. As will be explained in detail later, .the frequency'of this oscillator ordinarily will not be highly constant but may fluctuate, either purposely or through inherent instability. Waves generated by the master oscillator 5 are heterodyned with the received signal-modulated wave in the converter 8 and a selected modulation product resulting from,
thisconversionissuppliedtctheamplifier'l. The converter 8. often called a detector or mixer, may comprise any one of a number of conventional circuits well known in the art, and it is thought unnecessary to describe it in detail. Briefly, the converter performs the two functions of heterodyning the two waves to producers group of modulation products and of selecting one desired product as the converter output wave. Waves generated by the oscillator 5 are also heterodyned with waves supplied by the harmonic generator 4 by means of a converter I, which functions in the same manner as the converter i, and a selected modulation product is supplied to the amplifier I. Buffer amplifiers l0 and II are preferably interposed between the master oscillator I and the converters 8 and t to amplify the oscillations and prevent undesirable reactions between the various circuit elements, according to known practice.
The signal-modulated waves supplied to the amplifier I, as a result of the first conversion, are next subjected to a second conversion in the converter I! in which they are heterodyned with the waves from the amplifier 9. The selected modulation product of this conversion comprises the signal-modulated output wave which is supplied to the antenna 2. Optionally, it is first further amplified by the amplifier l3 .prior to retransmission.
It will be understood, of course, that one or more of the various amplifiers shown may be omitted, or that additional amplifiers may be employed where desirable as, for example, between the antenna l and the converter 6. Since frequency stability of the waves generated by master oscillator is not a primary consideration, the waves may be generated directly at the desired frequency. No frequency multiplying device, such as a harmonic generator similar to the harmonic generator [employed with constant frequency oscillator 3, will generally be required even at higher frequencies. This is a distinct advantage in that it reduces the cost and complexity of the apparatus and also minimizes the possibility that undesired parasitic frequencies will be introduced into the circuit, as will be apparent to those skilled in the art.
An important feature of my invention is the mannerin which the frequencies of the waves are related. Referring to the drawing, the wave received at the antenna l is designated by f1, indicative of its frequency. Similarly the output wave at antenna 2 is denoted by h, the constant frequency wave supplied by theharmonic generator l by Is, the wave supplied by the master oscillator 5 by ii, the selected modulation product supplied to amplifier 1 by Is and the selected modulation product supplied to amplifier O by fa.
The output frequency f: is determined by the values of f1 and either fa or it, depending on the particular combination of modulation products selected in the three conversions. First assume, as is usually the case, that ii and I: are arbitrarily selected, and that is is to remain substantially cons n Fr quency is is then selected so that I: is equal either to the sum or to the difference of 11 and fa. If it is selected equal to the sum, obviously i: must be greater than f1, whereas if it is selected equal to the difference, I: may be either greater or less than f1.
'Now under the above-assumed conditions, for any chosen value of 14 a particular combination of the sum or difference frequency modulation smears products will produce the desired value of is. There are a number of combinations which will give 1:, determined by the relative magnitudes of [1, I: and f4 and on the choice of modulation products.
Under these conditions it is desired to investigate the effect of variations in master oscillator frequency 14 upon the output frequency is. This effect will depend upon the relative magnitudes of 11, f: and f4 and upon the particular modulation'products is and fa selected. However, for any possible combination a variation in is will produce one of two results: either the frequency variation in {4 will not vary j: at all, or it will produce twice this frequency variation in {2. Thus the frequency variation in h will either be compensated completely or multiplied as far as its effect upon I: is concerned.
In some situations it may be desirable to utilize the frequency multiplication effect just described, but in the particular embodiment illustrated it is desired to utilize the frequency compensation effect. As stated, there are a number of different combinations of the sum or' difference frequency modulation products is and fa which will produce this compensation effect. In general, there are two possible combinations of these principal modulation products for any selected values of f1, f3 and f4. It can also be stated as a general rule that if the selected modulation products is and fa" vary in the same sense as variations in it, then I: must be their diflerence frequency product; whereas, if the selected modulation products It and fa vary in the opposite sense with variation in {4, then I: must be their sum frequency product. If it is desired to utilize the frequency multiplication effect, obviously the converse .is true.
To illustrate these rules more clearly tables are presented below of some possible combinations of frequencies which will eliminate the effect of variations in master oscillator frequency 14 upon the output frequency In. Table I im mediately below illustrates various frequency relationships which will maintain I: independent of variations in ft for the case where f: has been selected equal to the difference between 11 and f3.
Thus in the first case above, when it is either greater than or less than both If and is. is may be selected as the sum frequency product of i1 and f4, fs as the sum frequency product of I: and f4, and f: as the difference frequency product of f5 and is; or It may be selected as the difference frequency product of f1 and f4, Is as the difference frequency product of f: and f4, and f: as the difference frequency product of f5 and is.
Table 11 below illustrates various frequency relationships which will maintain is independent of variations in ft for the case where I: has been selected equal to the sum of f1 and f3.
aaaasis Summarizing the above if f1, f5 and' one' oscillatorfrequency are selected, then for any bination of modulation products can beselected to give the desired result. For example, in an actual installation Of the system shown in the drawing it was desired to convert a band of signal-modulated waves having a carrier frequency of 157.25 me. to an identicalband having a carrier frequency of 67.25 mc. The combination of frequencies indicated by asterisks in Table I above was selected. The actual values of the various frequencies were as follows:
f1=157.25 mc. f2=67.25 mo. f =90 mc. f4=123375 mc. j =28.5 mo.
fer-38.75 me.
It will be seen that I have provided a simple frequency conversion system having the flexibility of the double heterodyne system employing independent oscillators while retaining the fre= quency stability of the single oscillator system.
While I have shown one form of my invention embodied in a radio relay station, it will of course be understood that I do not wish to be limited thereto. As previously mentioned, there may be occasions when it is desirable to utilizethe frequency multiplication effect which can be obtained by suitable combinations of selected modulation products. Thus, the frequency of the master oscillator 5 may be varied purposely in order to frequency modulate the output wave by twice that amount. Furthermore, by selecting modulation products in the three; conversions which are higher harmonics of'the combining frequencies, rather than the principal sum or difference frequency products, the frequency multiplication efiect can be "amplified to give a frequency variation of the output wave greater than twice the frequency variation in LettersPatent of theUnited States is:
1 The method of converting-electrical waves frequencies to oscillator I. The tables above illustrate only combinations of principal modulation products giving the frequency compensation effect. It is not thought necessaryto enumerate combinatime producing the converse effect since these are thought to be obvious from the above de- -scription.- Since this and many othermodiflcati'onsfmay be-m'ade, bdh in the circuit arrange- I .ment and instrumentalities employed, I contemplate by the-appended claims to coveranysuch modifications as fall, within the true spirit. and
- scope'ofniy inventionl" I What I'claim asnew and desire to secure by of a first frequency to waves of a second frequency which comprisesthe steps offp'roducing waves. of a, thirdfrequency, producing waves of a fourth frequency, combining the waves of said first'and-third frequencies to produce a resultant f. frequency, combiningflthe waves of said 1 third value of the other oscillator frequency a com-Q and fourth frequenciesito produce a second resultant frequency, and combining said resultant produce said second frequencywaves. r
2. The method of frequency conversion which comprises the steps of receiving signal-modulated waves of a first frequency, generating waves of a second, substantially constant frequency, --generating independently. waves of a third frequency subject to frequency variations, hetero- ,dyning the waves of said first and third frequencies to produce a first modulation product the frequency of which is affected by said variations, heterodyning the waves of said second and third frequencies to produce a second modulation product the frequency of which is'also affected bysaid frequency variations and heterodyning said modulation products to produce a resultant wave the frequency of which is unaffected by said variations.
3. In a frequency conversion system for converting electrical waves of a first frequency to waves of a second frequency, the combination of an oscillator for generating waves of a third frequency, a second oscillator for generating independently waves oi a fourth frequency, a converter for combining the waves of said first and fourth frequencies and for selecting adesired modulation product, a converter for combining the waves of said third and fourth frequencies and for selecting a second desired modulation product, and a converter for combining said selected modulation products and for selecting as a resultant modulation product waves of said second frequency.
4. A system for theconversion of signal-modulated waves of a first high frequency to similarly modulated waves of a second high frequency comprising means for receiving the waves of said first frequency, a source of waves of a third high frequency subject to frequency variations, means for heterodyning the waves of said first and third frequencies to produce waves of a resultant frequency, means for utilizing said resultant frequency wavesto produce the waves of said second frequency, and means for preventing frequency subject to frequency fluctuations, a converter for heterodyning the waves of said first and third frequencies to produce a modulation product the frequency of which is affected by said fluctuations, ,a second converter for heterodyning the waves of said second and third frequencies to produce a second modulation product the frequency of which is also affected by said 'ing one ference frequency products and for selecting one product affected by said variations in one sense, a second converter for combining the waves of said third and fourth frequencies to produce sum and difference frequency products and for selectproduct affected by said variations in the oppositesense. and a third converter for combining said selected products to produce sum and fluctuations, and a third converter for heterodyn-/ ;diiferene frequency products and for selecting ing said modulation products to produceare- 'sultant wave the frequency of which is unaffected by said fluctuations.
6. In a system for converting electrical waves their sum frequency product as said second high frequencywaves.
9. In a frequency conversion system for converting received, signal-modulated waves of a of a first frequency to waves of a second -f re-" first high frequency to similarly modulated waves quency, the combination of a source of waves of a of a second high frequency, the combination of third frequency, a source of waves of a fourth an oscillator for generating waves of a third, subfrequency, means for combining the waves of said first and fourth frequencies to produce a resultant frequency, means for combining the waves of said third and fourth frequencies to produce a second resultant frequency, and means for combining said resultant frequencies to produce said second frequency waves.
'1. The combination in a frequency conversion system, of means for receiving waves of a first frequency, means for generating waves of a second, substantially constant frequency, means for generating independently waves of a third frequency subject to frequency variations, means for combiniig the waves of said first and third frequencies to produce a pair of sum and difference frequency products the frequencies of which are affected by said variations and for selecting one product from said pair, means for combining the waves of said second and third frequencies to produce a-second pair of sum and difference frequency products the frequencies of which are also affected by said variations and for selecting one product from said second pair, means for combining said selected products to produce a third pair of sum and difference frequency products and for selecting as a resultant wave one product of said third pair the frequency of which is unaflected by said variations.
8. In a frequency conversion system for converting received, signal-modulated waves of a first high frequency to similarly modulated waves of a second high frequency, the combination of an oscillator for generating waves of a third, substantially constant high frequency, a second oscillator for generating waves of a fourth high frequency. subject to frequency variations, a first converter for combining the waves of said first and fourth frequencies to produce sum and difstantially constant high frequency, a second oscillator for generating waves of a fourth high frequency subject to frequency variations, a first converter for combining the waves of said first and fourth frequencies to poduce sum and difference frequency products and for selecting one product affected by said variations in one sense, a second converter for combining the waves of said third and fourth frequencies to produce sum and difference frequency products and for selecting one product affected by said variations in the same sense, and a third converter for combining said selected products to produce sum and difference frequency products and for selecting theirdifference frequency product as said second high frequency waves.
10. A radio relay station for receiving signalmodulated waves of a first high frequency and for retransmitting similarly modulated waves of a second high frequency, comprising, in combination, a first oscillator for generating waves of a third substantially constant high frequency equal to the difference between said first and second frequencies, a second oscillator for generating waves of a fourth high frequency intermediate said first and third frequencies and subject to frequency fluctuations, a first converter for heterodyning together the waves of said first and fourth frequencies and for selecting their difference frequency product, a second converter for heterodyning together the waves of said third and fourth frequencies and for selecting their difierence frequency product, a third converter for heterodyning together said selected products and for selecting their sum frequency product as said second high frequency waves and means for retransmitting said second high frequency waves.
FRANKLIN M. DEERHAKE.
US315998A 1940-01-27 1940-01-27 Frequency conversion system Expired - Lifetime US2228815A (en)

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CA411423A CA411423A (en) 1940-01-27 Frequency conversion system
US315998A US2228815A (en) 1940-01-27 1940-01-27 Frequency conversion system
FR869542D FR869542A (en) 1940-01-27 1941-01-28 Further training in frequency changing devices
CH232472D CH232472A (en) 1940-01-27 1941-08-13 Relay station for the transmission of high frequency oscillations.

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Cited By (20)

* Cited by examiner, † Cited by third party
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US2451430A (en) * 1946-04-23 1948-10-12 Jefferson Standard Broadcastin Carrier frequency shift signaling
US2460781A (en) * 1943-10-07 1949-02-01 Rca Corp Circuit for stabilizing frequencies of transmitter-receiver systems
US2501591A (en) * 1945-08-27 1950-03-21 Premier Crystal Lab Inc Multiband superheterodyne radio receiver having a push-button station selector
US2502294A (en) * 1943-08-19 1950-03-28 Wallace Marcel Double sweep panoramic radio receiver
US2509963A (en) * 1947-01-30 1950-05-30 Collins Radio Co Radio receiving and frequency conversion system
US2555391A (en) * 1946-03-04 1951-06-05 Arthur A Glass Radio oscillator control
US2633492A (en) * 1948-12-30 1953-03-31 Bell Telephone Labor Inc Guided wave frequency range, frequency selective and equalizing structure
US2643329A (en) * 1945-05-14 1953-06-23 Standard Telephones Cables Ltd Tracking system between receiver and transmitter
US2647992A (en) * 1948-12-03 1953-08-04 Gen Electric Frequency stabilized radio receiving system
US2656459A (en) * 1945-10-30 1953-10-20 John H Tinlot Wide frequency coverage beacon receiver
US2666141A (en) * 1946-05-08 1954-01-12 James K Clapp Single side band mixer for moving target indicating radar systems
US2710343A (en) * 1950-08-09 1955-06-07 Dale Belford Secrecy system for transmitting television signals
US2800580A (en) * 1952-04-21 1957-07-23 Philco Corp Delay system
US3310740A (en) * 1962-09-19 1967-03-21 Siemens Ag Directional radio system with angle modulation
DE2208610A1 (en) * 1971-03-01 1972-09-21 Western Electric Co Frequency division multiplex messaging system
US3921123A (en) * 1967-02-02 1975-11-18 Us Navy Torpedo target simulator
US4083004A (en) * 1976-06-08 1978-04-04 Westinghouse Electric Corporation Expendable repeater employing harmonic mixing
USRE31295E (en) * 1971-03-01 1983-06-28 Bell Telephone Laboratories, Incorporated Carrier supply for frequency division multiplexed systems
US4580290A (en) * 1982-05-19 1986-04-01 Alps Electric Co., Ltd. Amplifier for use with local oscillators
US4991144A (en) * 1963-03-29 1991-02-05 The United States Of America As Represented By The Secretary Of The Navy Dopplerized echo repeater

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2691065A (en) * 1951-01-12 1954-10-05 Rca Corp Multiplex relay system

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2502294A (en) * 1943-08-19 1950-03-28 Wallace Marcel Double sweep panoramic radio receiver
US2460781A (en) * 1943-10-07 1949-02-01 Rca Corp Circuit for stabilizing frequencies of transmitter-receiver systems
US2643329A (en) * 1945-05-14 1953-06-23 Standard Telephones Cables Ltd Tracking system between receiver and transmitter
US2501591A (en) * 1945-08-27 1950-03-21 Premier Crystal Lab Inc Multiband superheterodyne radio receiver having a push-button station selector
US2656459A (en) * 1945-10-30 1953-10-20 John H Tinlot Wide frequency coverage beacon receiver
US2555391A (en) * 1946-03-04 1951-06-05 Arthur A Glass Radio oscillator control
US2451430A (en) * 1946-04-23 1948-10-12 Jefferson Standard Broadcastin Carrier frequency shift signaling
US2666141A (en) * 1946-05-08 1954-01-12 James K Clapp Single side band mixer for moving target indicating radar systems
US2509963A (en) * 1947-01-30 1950-05-30 Collins Radio Co Radio receiving and frequency conversion system
US2647992A (en) * 1948-12-03 1953-08-04 Gen Electric Frequency stabilized radio receiving system
US2633492A (en) * 1948-12-30 1953-03-31 Bell Telephone Labor Inc Guided wave frequency range, frequency selective and equalizing structure
US2710343A (en) * 1950-08-09 1955-06-07 Dale Belford Secrecy system for transmitting television signals
US2800580A (en) * 1952-04-21 1957-07-23 Philco Corp Delay system
US3310740A (en) * 1962-09-19 1967-03-21 Siemens Ag Directional radio system with angle modulation
US4991144A (en) * 1963-03-29 1991-02-05 The United States Of America As Represented By The Secretary Of The Navy Dopplerized echo repeater
US3921123A (en) * 1967-02-02 1975-11-18 Us Navy Torpedo target simulator
DE2208610A1 (en) * 1971-03-01 1972-09-21 Western Electric Co Frequency division multiplex messaging system
USRE31295E (en) * 1971-03-01 1983-06-28 Bell Telephone Laboratories, Incorporated Carrier supply for frequency division multiplexed systems
US4083004A (en) * 1976-06-08 1978-04-04 Westinghouse Electric Corporation Expendable repeater employing harmonic mixing
US4580290A (en) * 1982-05-19 1986-04-01 Alps Electric Co., Ltd. Amplifier for use with local oscillators

Also Published As

Publication number Publication date
CH232472A (en) 1944-05-31
CA411423A (en) 1943-03-30
FR869542A (en) 1942-02-04

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