US2135051A - Superheterodyne receiving system - Google Patents

Superheterodyne receiving system Download PDF

Info

Publication number
US2135051A
US2135051A US139638A US13963837A US2135051A US 2135051 A US2135051 A US 2135051A US 139638 A US139638 A US 139638A US 13963837 A US13963837 A US 13963837A US 2135051 A US2135051 A US 2135051A
Authority
US
United States
Prior art keywords
signal
frequency
circuit
quadrature
potentials
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US139638A
Other languages
English (en)
Inventor
Plebanski Jozef
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Radio Patents Corp
Original Assignee
Radio Patents Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Radio Patents Corp filed Critical Radio Patents Corp
Application granted granted Critical
Publication of US2135051A publication Critical patent/US2135051A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B9/00—Cleaning hollow articles by methods or apparatus specially adapted thereto
    • B08B9/08—Cleaning containers, e.g. tanks
    • B08B9/20—Cleaning containers, e.g. tanks by using apparatus into or on to which containers, e.g. bottles, jars, cans are brought
    • B08B9/28—Cleaning containers, e.g. tanks by using apparatus into or on to which containers, e.g. bottles, jars, cans are brought the apparatus cleaning by splash, spray, or jet application, with or without soaking
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D7/00—Transference of modulation from one carrier to another, e.g. frequency-changing
    • H03D7/06—Transference of modulation from one carrier to another, e.g. frequency-changing by means of discharge tubes having more than two electrodes
    • H03D7/10—Transference of modulation from one carrier to another, e.g. frequency-changing by means of discharge tubes having more than two electrodes the signals to be mixed being applied between different pairs of electrodes
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D7/00—Transference of modulation from one carrier to another, e.g. frequency-changing
    • H03D7/18—Modifications of frequency-changers for eliminating image frequencies

Definitions

  • the present invention relates to amplifiers, more particularly amplifiers of the 'superheterodyne type as used in radio receivers and the like, wherein anincoming signalling wave is combined with a locally produced oscillation to secure an intermediate or beat frequency signal applied to an intermediate amplifier designed for efiiciently amplifyingthe intermediate frequency signal.
  • the object of the invention is the provision of a novel circuit system of the above general character and a method of operating the same by which an interfering signal having a frequency differing from the frequency of the desired signal is canceled and its effect upon the receiver substantially eliminated.
  • a more specific object of the invention is the provision of a system for and a method of eliminating the so-called image frequency interference produced in amplifiers of the above character.
  • Another object is the provision of an automatic image frequency rejecting system in a superheterodyne radio receiver which is equally effective for all operating frequencies within the receiving range for which the receiver is designed to operate.
  • a further object is the provision of an automatic image rejector system for a superheterodyne receiver which is equally effective over the entire frequency range of the receiver, thereby enabling the use of a limited number of preselection or amplifying stages or to entirely eliminate pre-selection of the incoming signal.
  • Figure 1 is a circuit diagram showing the superheterodyne or mixing section of a radio receiver or the like constructedin accordance with the invention
  • Figure 2 is a resonance curve of the input circult of Figure 1
  • FIGS. 6 to 10 illustrate further modifications of a superheterodyne system according to the invention shown in the previous illustrations.
  • the invention in general contemplates the provision of a system for and a method of automatically balancing out or cancelling the image frequency ciu'rent obtained in the output circuit of the first detector or mixer section of a superheterodyne receiver by means of a current of opposite phase,
  • an incoming signalling wave having a frequency Js is combined with a locally produced or heterodyne signal having a frequency in by means of a modulator or mixer of any of the well known types, an intermediate or beat frequency signal is obtained having a frequency i equal to the difference of the incoming and local oscillations, viz. fh--fs. If a further sig-' nal having a frequency fs-I-Zfi is simultaneously received, it will mix with the heterodyne frequency in and produce the same intermediate frequency thereby causing interference with the desired receiving signal.
  • this interfering signal also'known as image frequency due to its location relative to the signal frequency like an object to its image on opposite sides of the local or heterodyne frequency is attenuated before it reaches the first detector or mixer stage in the receiver. Inthis way, the. interference may be reduced, but is never entirely eliminated.
  • oneor more pre-selector stages are required involving the use of at least twotuned cir-' cuits with the attendant difficulties of ganging and tracking and making it further desirable to choose an intermediate frequency "as high as possible. . This, however, has a disadvantage of greatly reducing the selectivity of the receiver.
  • the above disadvantages are substantially overcome and elimination of the image frequency interference ensured in a most efficient and simple manner without substantially impairing the efilciency'and selectivity and other characteristics of the receiver.
  • a pair of electronic modulator or mixer valves l8 and [8' of well known construction comprising, respectively, cathodes l9 and I9, first or oscillating grids 20 and 20', oscillator or anode grids 2!
  • input grids 22 and 22' are excited by potentials in phase quadrature derived from an input radio signal.
  • the grid- 2-2 of the tube i8 is connected to the junction between the condenser l3 and the non-reactive. impedance. l4
  • the grid 22 of the tube [8 is connected to the upper terminal of the condenser l3 or input inductance l2 of the input circuit.
  • the grids22 and; 22. arecontrolledin accord-- ance with reactive and non-reactive potentials derived from an input radio. signal which potentials are. in phase. quadrature asis Well under-- stood.
  • the grids 20 and 20 of the oscillator section of the valves are excited by locally produced potentials in phase quadrature through a local oscillating or tank circuit comprised of an inductance 28 shunted by a variable condenser 29- inseries with a non-reactive or ohmic impedance 30.
  • the oscillating tank circuit is connected to the oscillator grid 20- of valve l8.
  • a feed-back or tickler coil 31 connected in the supply lead from the positive or anode grid 2
  • the intermediate frequency signals obtained. at the output terminals 39" may be impressed upon an intermediate frequency amplifier which may be followed by adetector and audio amplifier in a manner'wellknown;
  • the input or control grids 22- and 2-2" may be additionally biased in a known manner by the aid of additional biasing potential sources; connected to points l1: and: I1 respectively.
  • FIG 2. there is shown a resonance curve for the input circuit of Figure 1 wherein f1 corresponds to: the frequency of: an incoming radio signal, in corresponds to: the frequency of the locally produced or heterodyne signals, and. f2 represents the image frequency or frequency of the interfering signal equal to in-(the. example illustrated wherein f2 fb fia From the foregoing it is seen that both the incoming signal having a frequency f1 and the image or interfering signal having a frequency f2 are combined or mixed with the locally.
  • the adjustment for the image frequency suppression may be effected by' varying the resistance. M in the input circuit.
  • the same result isobtained by varying the resistance 30 in the oscillating tank circuit or by adjusting the grid biasing potentials of the valves such asby varying the resistances 25 and 25 in the cathode leads or by applying variable biasing potentials tothe input grids at points I! and IT in which latter case it is desirable to use tubes of the variable mu type to obtain a uniform and smooth regulation.
  • the circuit arrangement according to the invention is especially suited for aperiodic receivers such as shown in Figures 3 and 4 illus trating aperiodic input circuits which may be substituted for the tuned input circuit shown in Figure 1.
  • the antenna I is connected through coupling condenser H to an aperiodic input circuit comprising a resistance 40 grounded at its lower end and shunted by the condenser
  • the quadrature potentials may be obtained from points a, b and a, c or from the point a and a tap d on the resistance 40 on the one hand, and between a and c on the other hand in which latter case the resistance
  • FIG. 4 An alternative method of obtaining quadrature potentials from an aperiodic input circuit is shown in Figure 4.
  • the latter comprises a Wheatstone bridge system with four arms consisting alternately of a resistor and a condenseras shown at 4
  • the input signal is applied to the diagonal points e, f and the quadrature potentials are derived from the other diagonal points b, c and either of the resistors in the example shown resistor 44 or point a.
  • the system shown is substantially similar to Figure 1 with the exception that the intermediate frequency circuit is con nected to the anode of valves l8 and I8 in pushpull arrangement.
  • the primary 36 of the intermediate frequency transformer has one "end connected to the anode of valve I8 and the other end to the anode of 'valve I8 and is provided with a center tap connection leading to the high tension supply source indicated by the plus symbol in a known manner.
  • a feedback inductance 40 inductively coupled with. the input inductance l2 and. inserted in the cathode lead of the valve I8. In this manner the current in the input circuit may be regenerated to'compensate for the losses produced by the resistance l4.
  • An advantage of the invention as pointed out hereinabove resides in a substantial simplification of the high frequency section of a receiving system which may be made entirely aperiodic such as by using an input circuit as shown in Figure 3.
  • the only adjustable element is the condenser or equivalent tuning element in the tank circuit of the local oscillator.
  • This mechanical connection is indicated schematically at l4 in Figure 8 of the drawings which otherwise is similar to the preceding figures.
  • Figure 9 there is shown a circuit similar to Figure 8 but differing therefrom by the provision of a resistance tuning device 4
  • the output potentials supplied from the anode rid of the valve l8 are impressed upon the junction point between the oscillating tank condenser 29 and the series impedance 30 thereby setting up a feedback current in quadrature phase relation relative tothe original oscillating current generated in the tank circuit.
  • the apparent reactive impedance or wave length of the tank circuit' may be varied within a predetermined range.
  • Resistance tuning arrangements ofthis type are described in more detail in my co-pending patent application entitled Electrical systems, Ser. No. 73,865, filed April 11, 1936 which is referred to for further details regarding the operation of Figure 9.
  • is mechanically coupled with the phase shift resistance M in the input circuit in a similar manner as described by Figure 8.
  • the two mixer valves may be combined-in the form of a composite valve such as, shown in Figure 10a
  • Thelatter is substantially identical to' Figure. 1. with the exception that a common anode 24 isprovided for both valves which are included in a single 5 envelope. Both' valve sections maybe constructed in the usual manner and mounted about a common cylindrical heater in a manner well known in the design and construction of composite discharge valves. 10
  • the new modulating, system described by the invention has other uses and applications whenever it is desired; to mutually modulate or combine separate current waves.
  • the invention may serve for producing single side 15 band modulated signals.
  • the input circuit in the examples shown serves for supplying a carrier frequency f1- from a: suitable source of oscillations or driver.
  • the oscillating or tank circuit serves for supplying amodulating 20 current having a frequency 11.
  • the theoretical equations in this case are as followsz' For valve l8:
  • the modulating circuit may be either periodic or aperiodic as shown in- Figure 4. Inthe latter case, thesystem may beused for modulating a carrier current in accordance 45 with any complex modulating. wave.
  • thenon-reactive impedance M in the input circuit involves an increased damping and loss of. input signal strength.
  • this resistance can be chosen with 50 a low value (from fi to 100 ohms).
  • the conversion conductanceofthe valve I8 should'be higher than the conversion conductance of the valve l8.
  • the phase shifting resistance 30 in the oscillating tank circuit may have-values 55 fromv 100 to 500' ohms and the damping produced thereby may easily be compensated by increasing the coupling between the tank circuit and feed:- back inductance to maintain the circuit in an oscillating condition.
  • the loss produced by the resistance M in the input circuit maybe compensated by a regeneration of feedback arrangement of any type such as illustrated by Figured
  • the desired signal' strength is also decreased slightly.
  • this decrease is more pronounced the lower the intermediate frequency 70 chosen.
  • the opposite eifect that is, an increase in signal strength, with suppression of theimage frequency.
  • the intermediate or beat frequency and the local os- 75 cillating frequency should; be chosen in such.
  • the intermediate frequency is 450-'kc; then for receiving signals of 1 or 300 kc. the local oscillating frequency should be 440 kc; or 150 kc., respectively.
  • the image frequency in the latter case will be 890'kc. or 600 kc., respectively; If the circuits are arranged and adjusted in the manner described herein so as to eliminate the: image frequency, it will be found that the 10 desired signal strength may be increased nearly twice.
  • circuit. means for receiving incoming signal oscillations, means for deriving therefrom a pairof. signal current components having a quadrature phase relation, a local. oscillator for producing'heterodyning.oscillations havinga frequency difierent from the signal frequency, means for deriving: from said oscillator current components having a quadrature phase 40 relation, a pair of modulating devices, meansfor. impressing signal current and local current components in phase quadrature relation. upon: each of said modulating devices, anda common output circuit for said modulating devices resonant to the beat frequency between the signal and localtoscillation frequencies.
  • a radio system a circuit for receiving-in coming signal oscillations, said circuitv including reactive and non-reactivev impedance elements; a pair of modulating devices, means for impressing signal potentials having a quadrature phase'relation derived from said receiving'circuit upon said modulating devices, an oscillator for producing local oscillations having a frequency different from the signal frequency, said oscillator com prising a tunedoscillatory circuit including both reactive and non-reactive impedance elements; means for impressing potentials in phase quadrature derived from said oscillatory'circuitupon said modulating devices, and a common output circuit for saidmodulating'devices resonant to the beat frequency between the signal and local oscillation frequencies;
  • a circuit for receiving in-' coming signal oscillations said: circuit including reactive and non-reactive impedance elements, a' pair of modulating devices, means for impressing signal potentials having a quadrature phase relation derived from said receiving circuitupon said modulating devices, an oscillator for producing local oscillations having a frequency different from thesignal frequency, said oscillator comprising a tuned oscillatory circuit including both reactive and non-reactive impedance: elements;
  • a circuit for receiving incoming signal oscillations said circuit including both reactive andnon-reactive impedance elements, 2, pair of modulating devices, means for impressing signal potentials in phase quadrature derived from said receiving circuit upon said modulating devices, an oscillator for producing local oscillations having a frequency difierent from the signal frequency, said oscillator comprising a tuned oscillatory circuit including both reactive and non-reactive impedance elements, means for impressing potentials in phase quadrature derived from said oscillatory circuit upon said modulating devices, the signal and local oscillating potentials impressed upon each of said modulating devices being in phase quadrature relative to each other, a common output circuit for said modulating devices, and means for adjusting the relative amplitudes of the signal and locally produced potentials impressed upon said modulating devices.
  • a circuit for receiving incoming signal oscillations said circuit including both reactive and non-reactive impedance elements, a pair of modulator-amplifiers, means for impressing signal potentials in phase quadrature derived from said receiving circuit upon said modulator-amplifiers, an oscillator for producing local oscillations having a frequency dif-- ferent from the signal frequency, said oscillator comprising a tuned oscillatory circuit including both reactive and non-reactive impedance elements, means for impressing local oscillation potentials in phase quadrature derived from said oscillatory circuit upon said modulating devices,
  • a circuit for receiving incoming signal oscillations said circuit including both reactive and non-reactive impedance elements, a pair of electronic mixing devices each comprising an electron discharge path, means for controlling a portion of said electron'paths in accordance with signal potentials in phase quadrature derived from said receiving circuit, alocal oscillator for producing oscillations having a frequency different from the signal frequency, said oscillator comprising a tuned oscillatory circuit including both reactive and non-reactive impedance elements, means for'independently controlling another portion of said electron paths in accordance with locally produced potentials in phase quadrature derived from said oscillatory circuit, the signal and local potentials controlling the separate portions of each of said electron paths being in phase quadrature relative to each other, and a common output circuit for said electron paths resonantto the beat frequency between the signal and heterodyning frequencies.
  • a signal input circuit including a reactive andno'n-reactive impedance element in series, a pair of modulating devices, means for impressing signal current potentials in phase quadrature derived from said reactive and non-reactive impedance elements upon said modulating devices, a local oscillator for producing oscillations having a frequency difiering from the signal frequency, means for deriving local potentials in phase quadrature from said local oscillator, means forimpressing said local quadrature potentials uponeach of said modulating devices, the signal and local potentialsapplied to each of said modulating devices being in phase quadrature relative to each other, a variable tuning element for controlling the frequencyof said localoscillations to correspond to incomingsignals of different frequencies, and
  • an input circuit for receiving signal oscillations comprising an inductive and a capacitative reactance in parallel, a
  • non-reactive impedance in series with one of said reactances a local oscillator including'an oscillatory circuit comprising an inductive and capacitative reactance in parallel, a further non-- reactive impedance in series with one of the reactance elements of said oscillatory circuit, a pair of modulating devices, means for impressing signal potentials developed across said input circuit and local potentials developed across the non-reactive impedance of said oscillatory circuit upon the first of said devices, further means for impressing signal potentials developed across the non-reactive impedance of said input circuit and heterodyning potentials developed across said oscillatory circuit upon the other modulating device, and a common output circuit for said modulating devices.
  • an aperiodic input circuit for receiving signal oscillations, comprising a reactive and a non-reactive impedance in series a local oscillator for producing oscillations of a frequency different from the signal frequency, said local oscillator including an oscillatory circuit comprising a capacitative and an inductive reactance in parallel, a non-reactive impedance in series with one of the reactances of said oscillatory circuit, a pair of modulating devices, means forimpressing signal potentials developed across said input circuit and heterodying potentials developed across the non-reactive impedance of said oscillatory circuit upon the first of said devices, further means for impressing local potentials developed across said oscillatory circuit and signal potentials developed across the non-reactive impedance of said input circuit upon the other modulating device, and a common output circuit for said modulating devices.
  • the stepsof producing quadrature signal and quadrature interfering energies generating local auxiliaryg energies having a quadrature phase relation, modulating each of the quadrature signal and interfering energies with the local energy in phase quadrature thereto, combining the modulatedoutputs and adjusting the relative magnitude of the respective quadrature energies to balance out the interfering signal in the combined output.
  • a radio system comprising means for producing quadrature signal and quadrature interfering energies, means for generating local auxiliary. energies having a quadrature phase relation, means for separately modulating each of said quadrature signal and interfering energies with the local energy in phase quadrature thereto, a combined output forsaid modulating means, and means for adjusting the relative magnitude of the respective quadrature energies to balance the interfering signal in the combined output.
  • a system for translating carrier signals comprising means for producing quadrature signal energies and quadrature interfering energies, further means for producing local quadrature energies, means for producing beat energies from each of the quadrature signal and interfering energies with the local energy 'in quadrature phase relation thereto, and a common output for the beat energies produced.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Superheterodyne Receivers (AREA)
  • Branching, Merging, And Special Transfer Between Conveyors (AREA)
  • Wrapping Of Specific Fragile Articles (AREA)
US139638A 1936-12-01 1937-04-29 Superheterodyne receiving system Expired - Lifetime US2135051A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PL496154X 1936-12-01

Publications (1)

Publication Number Publication Date
US2135051A true US2135051A (en) 1938-11-01

Family

ID=19936403

Family Applications (1)

Application Number Title Priority Date Filing Date
US139638A Expired - Lifetime US2135051A (en) 1936-12-01 1937-04-29 Superheterodyne receiving system

Country Status (3)

Country Link
US (1) US2135051A (fr)
FR (1) FR830232A (fr)
GB (2) GB496254A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2476946A (en) * 1944-02-24 1949-07-19 Bell Telephone Labor Inc Phase shifter circuit
US2666851A (en) * 1946-11-11 1954-01-19 Tesla Slaboproude A Radiotechn Frequency generator with phase shifter

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE970592C (de) * 1954-05-14 1958-10-09 Enzinger Union Werke Ag Vorrichtung zum Zentrieren von auf den Klapptischen von Reinigungsmaschinen befindlichen Flaschen

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2476946A (en) * 1944-02-24 1949-07-19 Bell Telephone Labor Inc Phase shifter circuit
US2666851A (en) * 1946-11-11 1954-01-19 Tesla Slaboproude A Radiotechn Frequency generator with phase shifter

Also Published As

Publication number Publication date
FR830232A (fr) 1938-07-25
GB496154A (en) 1938-11-25
GB496254A (en) 1938-11-28

Similar Documents

Publication Publication Date Title
US1794932A (en) Frequency modulation
US2240428A (en) Electrical circuits
US2410983A (en) Discriminator-rectifier circuit
US2044745A (en) Receiving circuits
US2038879A (en) Reduction of interference in thermionic valve circuits
US2363288A (en) Electrical apparatus
US2135051A (en) Superheterodyne receiving system
US2115676A (en) Selectivity control
US2164032A (en) Carrier wave signaling
US2491809A (en) Radio receiver
US2528182A (en) Frequency discriminator network
US2357932A (en) Phase modulation and amplitude modulation receiving system
US2750496A (en) V. h. f.-u. h. f. receiver having local oscillator convertible to an i. f. stage
US2279177A (en) Superheterodyne receiving system
US2228084A (en) Radio receiving system
US2808505A (en) Constant-gain amplifier system
US2229640A (en) Signal receiver
US2379764A (en) Frequency modulation detection
US2404669A (en) Converter
US1819299A (en) Tuning system
US2534606A (en) Double superheterodyne radio receiver
US2273134A (en) Dual intermediate frequency amplifier circuit
US2360764A (en) Phase modulated carrier receiver
US2162883A (en) Automatic frequency control system
US2156376A (en) Series crystal phase modulation receiver