US2440081A - Tuning arrangement - Google Patents

Tuning arrangement Download PDF

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Publication number
US2440081A
US2440081A US455827A US45582742A US2440081A US 2440081 A US2440081 A US 2440081A US 455827 A US455827 A US 455827A US 45582742 A US45582742 A US 45582742A US 2440081 A US2440081 A US 2440081A
Authority
US
United States
Prior art keywords
antenna
inductance
reactance
frequency
tuning
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
US455827A
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English (en)
Inventor
Clifford G Fick
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.)
General Electric Co
Original Assignee
General Electric Co
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
Priority to BE476813D priority Critical patent/BE476813A/xx
Priority to FR961813D priority patent/FR961813A/fr
Application filed by General Electric Co filed Critical General Electric Co
Priority to US455827A priority patent/US2440081A/en
Application granted granted Critical
Publication of US2440081A publication Critical patent/US2440081A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H2/00—Networks using elements or techniques not provided for in groups H03H3/00 - H03H21/00
    • H03H2/005—Coupling circuits between transmission lines or antennas and transmitters, receivers or amplifiers
    • H03H2/006—Transmitter or amplifier output circuits
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J3/00—Continuous tuning

Definitions

  • Such a series resonance combination is capable of developing the high voltage necessary to excite an antenna at a frequency at which it exhibits high reactance and high resistance.
  • an antenna exhibits anv inductive reactance which is so great that the extremely low value of capacity required for series resonance cannot be physically realized.
  • Stray capacity from the antenna connection near the transmitter and from the capacity with which the antenna is to be made series resonant are sufiicient in such cases to make the required condenser capacity less than zero. It is accordingly an object of my invention to provide new and improved means whereby an antenna system may be excited efiiciently at a frequency where it exhibits such high inductive reactance.
  • Fig. 1 illustrates an antenna tuning circuit embodying my invention
  • Fig. 2 shows certain impedance characteristics of antennae of the type shown in Fig. 1
  • Fig. 3 illustrates certain vectorial. relations existing between the voltages and currents in the circuit depicted in Fig. 1.
  • an antenna l0 which is shown schematically, is supplied with high frequency power from a radio transmitter ll through a tuning arrangement l2.
  • the output of the transmitter H is impressed across an inductance l3, of which one terminal is grounded, and which is arranged Where a particuin adjustable inductive relation with a second inductance M, of which one terminal is also grounded.
  • the ungrounded terminal of inductance I4 is connected through an adjustable inductance I5 to a movable switch member l6 which cooperates with three stationary contacts l1, I8 and 19.
  • Condensers 20, 2! and 22, of different sizes are connected respectively between fixed contacts I1, I 8 and t9 and a terminal 23 to which the antenna system I! is connected.
  • An inductance 24 of very low resistance is connected between the terminal 23 and ground.
  • the antenna alternatel be comes eapacitively reactive and inductively reactive, passing through a point of zero reactance; or resonance, each time the sign of its reactance changes.
  • Curve 33 of Fig. 2 illustrates the variation of resistance of an antenna with changes in frequency.
  • the major part of such resistance is radiation resistance, which is maximum at frequencies where the reactance of the antenna changes sign most abruptly.
  • the radio transmitter ll operates at frequencies at which the antenna I0 exhibits large inductive reactance
  • the inductance 24 has a reactance at the frequency of operation of the transmitter I l which is small relative to the inductive react ance of the antenna H).
  • Switch member I 6 is operated to connect that one of the condensers 20, 2
  • the tuning means I5 through 22 may be any suitable reactance element or combination of reactance elements suitable for tuning the parallel combination of antenna Ill and inductance 2.4,. Itmay, for example, be a single variable condenser, or if greater range of frequency adjustment isv de- "sired, it may be a plurality of such condensers with suitable switching'means.
  • the reactance of that one of the condensers 20.2 22 w i h is se c ed a the ar u a ope atin frequency o the ransm tter It mu be larger than the reactance of the inductance 15, so that the net reactance of inductance i5 and that one of the condensers Z0, 21, 22 which is connected in circuit is capacitive. This capacitive reaotance is adjustable by adjustment. of the inductance l5 and serves to tune the entire system.
  • the vector E represents the voltage which appears between the antenna It) and ground. that is, the voltage across, the inductance 24.
  • This voltage as explained previo iSly, must be extremely high in order to excite the antenna n at a fr q y at. whi h it exhi its extremely high impedance.
  • This high volta e is attained y t t i me ns 5 t rou h 2.
  • the cu re vector I24 represents the current flow through the inductance 24 when the voltage represented by the vector Em exists across it.
  • the vector I o ile lustrates the current flowing into the antenna II] when the voltage represented by the vector E10 xists betwe n the ntenna nd round.
  • the vecor Ila-.22 represents the vectorial resultant of the current vectors Ill) and 1 2 and represents the total current flowing through the tuning means l5 through Since the total current flowing through the tuning means I5 through 22, as represented by the vector Ira-g2, is much larger than the current flowing through the antenna it ⁇ , represented by the vector In), the impedance of the parallel combination of inductance 24 and the antenna I0 is much smaller than the impedance of the antenna alone at the particular operating frequency represented by the v ctors of Fi 3. It should be noted that. the vector In makes a much smaller angle with the vector E than does the vector I24, because radiation resistance and the like of the antenna l0 produce a substantial apparent resistance in the antenna It].
  • the inductance 24 placed in parallel to the exciting connections for the antenna [0, acts as a transformer, the inductive reactance of the combination appearing at the connection 23 as a much smaller reactance than if the inductance 24 were omitted from the circuit.
  • a source of high frequency energy a load circuit exhibiting high inductive reactance at the frequency of energy from said source. means fo onne t n said l ad and source and for tuning said load. to the frequency of energy from said source, the inductive reactance of said load being so high, as to require the capacity of said tuning means to be vanishingly small for resonance, and means comprising an inductance connected across said load for reducing the efiective inductive reactance of said load as it appeal-S in combination with said inductance to an inductive reactance sufficiently low that said tunine means s a phr eall real z e c p y.
  • a source or high frequency ground having an inductive reactance at the fre- 5 quency of energy from said source small relative to the reactance of said antenna, a capacitive reactance connected between said source and the point of connection of said antenna and said inductance, said capacitive reactance being of such value as to resonate the inductive reactance presented to said point by said antenna and said inductance at the frequency of said high frequency energy.

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  • Transmitters (AREA)
US455827A 1942-08-24 1942-08-24 Tuning arrangement Expired - Lifetime US2440081A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
BE476813D BE476813A (enrdf_load_stackoverflow) 1942-08-24
FR961813D FR961813A (enrdf_load_stackoverflow) 1942-08-24
US455827A US2440081A (en) 1942-08-24 1942-08-24 Tuning arrangement

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US455827A US2440081A (en) 1942-08-24 1942-08-24 Tuning arrangement

Publications (1)

Publication Number Publication Date
US2440081A true US2440081A (en) 1948-04-20

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ID=23810428

Family Applications (1)

Application Number Title Priority Date Filing Date
US455827A Expired - Lifetime US2440081A (en) 1942-08-24 1942-08-24 Tuning arrangement

Country Status (3)

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US (1) US2440081A (enrdf_load_stackoverflow)
BE (1) BE476813A (enrdf_load_stackoverflow)
FR (1) FR961813A (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2583128A (en) * 1947-01-21 1952-01-22 Singer Mfg Co Dual electrode tuning units for electric bonding machines
US2679581A (en) * 1950-05-20 1954-05-25 Westinghouse Electric Corp Antenna tuning system
US2989624A (en) * 1949-08-06 1961-06-20 Westinghouse Electric Corp Radio transmitter with tunable antenna
US3277377A (en) * 1963-10-25 1966-10-04 Gen Motors Corp Coupling circuit for all-transistor high frequency transmitter
US3504304A (en) * 1967-03-02 1970-03-31 Merrimac Research & Dev Inc Wideband hybrid ring network
US3750181A (en) * 1971-09-07 1973-07-31 Radionics Inc Ground independent antenna
US4145693A (en) * 1977-03-17 1979-03-20 Electrospace Systems, Inc. Three band monopole antenna

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1123098A (en) * 1912-12-14 1914-12-29 Louis Cohen System of distribution for oscillatory electrical currents.
US1551624A (en) * 1924-06-30 1925-09-01 Western Electric Co Circuits for wave transmission
US1809630A (en) * 1927-12-29 1931-06-09 Telefunken Gmbh Valve transmitter arrangement
US1830880A (en) * 1928-07-19 1931-11-10 American Telephone & Telegraph Antenna circuit
US1876971A (en) * 1930-03-19 1932-09-13 Rca Corp Transmission system
US1893136A (en) * 1926-10-02 1933-01-03 Rca Corp Circuit arrangement
US1998322A (en) * 1933-04-29 1935-04-16 Gen Electric High frequency circuit

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1123098A (en) * 1912-12-14 1914-12-29 Louis Cohen System of distribution for oscillatory electrical currents.
US1551624A (en) * 1924-06-30 1925-09-01 Western Electric Co Circuits for wave transmission
US1893136A (en) * 1926-10-02 1933-01-03 Rca Corp Circuit arrangement
US1809630A (en) * 1927-12-29 1931-06-09 Telefunken Gmbh Valve transmitter arrangement
US1830880A (en) * 1928-07-19 1931-11-10 American Telephone & Telegraph Antenna circuit
US1876971A (en) * 1930-03-19 1932-09-13 Rca Corp Transmission system
US1998322A (en) * 1933-04-29 1935-04-16 Gen Electric High frequency circuit

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2583128A (en) * 1947-01-21 1952-01-22 Singer Mfg Co Dual electrode tuning units for electric bonding machines
US2989624A (en) * 1949-08-06 1961-06-20 Westinghouse Electric Corp Radio transmitter with tunable antenna
US2679581A (en) * 1950-05-20 1954-05-25 Westinghouse Electric Corp Antenna tuning system
US3277377A (en) * 1963-10-25 1966-10-04 Gen Motors Corp Coupling circuit for all-transistor high frequency transmitter
US3504304A (en) * 1967-03-02 1970-03-31 Merrimac Research & Dev Inc Wideband hybrid ring network
US3750181A (en) * 1971-09-07 1973-07-31 Radionics Inc Ground independent antenna
US4145693A (en) * 1977-03-17 1979-03-20 Electrospace Systems, Inc. Three band monopole antenna

Also Published As

Publication number Publication date
BE476813A (enrdf_load_stackoverflow)
FR961813A (enrdf_load_stackoverflow) 1950-05-23

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