US3649937A - Electronically tuned ultra high frequency television tuner - Google Patents

Electronically tuned ultra high frequency television tuner Download PDF

Info

Publication number
US3649937A
US3649937A US21563A US3649937DA US3649937A US 3649937 A US3649937 A US 3649937A US 21563 A US21563 A US 21563A US 3649937D A US3649937D A US 3649937DA US 3649937 A US3649937 A US 3649937A
Authority
US
United States
Prior art keywords
conductive
resonant circuit
section
disposed
tunable resonant
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
US21563A
Other languages
English (en)
Inventor
David John Carlson
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.)
RCA Licensing Corp
Original Assignee
RCA 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 RCA Corp filed Critical RCA Corp
Application granted granted Critical
Publication of US3649937A publication Critical patent/US3649937A/en
Assigned to RCA LICENSING CORPORATION, TWO INDEPENDENCE WAY, PRINCETON, NJ 08540, A CORP. OF DE reassignment RCA LICENSING CORPORATION, TWO INDEPENDENCE WAY, PRINCETON, NJ 08540, A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: RCA CORPORATION, A CORP. OF DE
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/0213—Electrical arrangements not otherwise provided for
    • H05K1/0237—High frequency adaptations
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION 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
    • H03B5/00—Generation of oscillations using amplifier with regenerative feedback from output to input
    • H03B5/18—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising distributed inductance and capacitance
    • H03B5/1841—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising distributed inductance and capacitance the frequency-determining element being a strip line resonator
    • H03B5/1847—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element comprising distributed inductance and capacitance the frequency-determining element being a strip line resonator the active element in the amplifier being a semiconductor device
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/18—Printed circuits structurally associated with non-printed electric components
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
    • H05K2201/10007—Types of components
    • H05K2201/10015—Non-printed capacitor
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
    • H05K2201/10007—Types of components
    • H05K2201/10196—Variable component, e.g. variable resistor
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/17—Post-manufacturing processes
    • H05K2203/171—Tuning, e.g. by trimming of printed components or high frequency circuits
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/22—Secondary treatment of printed circuits
    • H05K3/222—Completing of printed circuits by adding non-printed jumper connections

Definitions

  • the conductive [56] References cued sections of the lines are disposed on opposite surfaces of the UNITED STATES PATENTS dielectric plate with like ends of the lines adjacent opposite edges of the plate. 2,545,623 3/1951 Mackenzie ..333/82 A X Dachert ..307/320 X 32 (Ilaims, 22 Drawing Figures l A i 9/- I i I l I PATENTEBHARMIQYE SHEET 1 OF 6 N. JM 8 s:
  • the present invention relates to ultra high frequency (UHF) tuners, and more particularly to UHF tuners which are tuned by voltage responsive variable capacitance devices.
  • UHF tuners used in television receivers are generally of the type including a conductive housing having a number of components enclosing capacity end-loaded unbalanced transmission line structures,
  • each transmission line includes a conductor suspended within the compartment and endloaded by a parallel plate air dielectric capacitor.
  • the capacitor includes stator plates which are attached to one end of the transmission line conductor and rotor plates.
  • the rotor plates of the capacitors for each transmission line are mounted on a tuning shaft which passes through the several tuner housing compartments.
  • the UHF television band encompasses 70 channels making it difficult to provide a reliable inexpensive preset tuning mechanism which provides a tuning operation similar to the detented step-by-step very high frequency (VHF) tuning (Channels 2-13) on most television receivers.
  • VHF very high frequency
  • the manufacture of the present types of UHF tuners requires considerable hand labor and close tolerances must be maintained because of the frequency ranges involved.
  • a UHF tuner embodying the invention is tuned by voltage responsive capacitance means such as variable capacitance diodes. Since the tuning operation does not require the precision mechanical presetting ofa variable capacitor shaft, preset tuning operations may be provided more conveniently.
  • a UHF tuner embodying the invention can be made by mass production techniques, and does not require as much precision hand labor as is required in the manufacture of tuners of the type now available.
  • the tuner includes transmission lines formed on a dielectric plate. Each transmission line includes a first and a second conductive section disposed on one side of the plate opposite a ground plane disposed on the other side of the dielectric plate.
  • a tuning capacitance device such as a variable capacitance diode, couples the first and second conductive sections of each of the transmission lines.
  • isolation may be provided between two of the transmission lines by locating the conductive sections for the transmission lines on opposite sides of the plate.
  • corresponding ends of the two lines to be isolated are directed toward opposite edges ofthe plate.
  • a double tuned circuit may be formed on the dielectric plate.
  • the double tuned circuit includes a pair of transmission lines each having a first and a second conductive section coupled by a variable capacitance device and disposed on one face of the dielectric plate opposite a conductive ground plane disposed on the other dielectric plate face.
  • Uniform coupling between the two circuits which are both tunable across a wide band of frequencies may be obtained by two coupling means.
  • a first coupling means interconnects the first conductive sections of each of the two circuits to provide dominant coupling toward the lower end of the desired band while the second coupling means interconnects the second sections of each circuit to provide dominant coupling toward the upper end ofthe band.
  • FIG. 1 is a schematic circuit diagram of a UHF television tuner embodying the present invention
  • FIG. 2 is a perspective view, partially broken away, of the tuner schematically shown in FIG. 1;
  • FIG. 3 is a bottom view of the tuner shown in FIG. 2;
  • FIG. 4 is a left side view with the tuner cover and chassis frame broken away to expose the tuner components
  • FIG. 5 is a right side view of the tuner shown in FIG. 2 with the tuner cover and chassis frame broken away to show the tuner components;
  • FIG. 6 is a plan view of the tuner substrate and pattern shown in FIG. 4, drawn to scale, with all the tuner components and the substrate coating material removed;
  • FIG 7 is a plan view of the tuner substrate and patterns shown in FIG. 5, drawn to scale, with all the tuner components and the substrate coating material removed;
  • FIG. 8 is a series of curves showing plots of tuning capacity as a function of resonant frequency for the tunable resonant circuits of the tuner;
  • FIG. 9 is an enlarged partial section view of the substrate showing details of the tuner
  • FIGS. 10a-c are enlarged partial section views of the substrate showing one of the adjustable tracking inductors set for minimum, nominal and maximum inductance;
  • FIGS. lla-e are a series of curves showing standing voltage waves helpful in understanding the operation of the tuner
  • FIGS. IZa-e are a series of curves showing standing waves ofcurrent corresponding to the curves shown in FIG. 11.
  • a UHF television tuner 50 is enclosed in a metal housing 52 which is maintained at a reference potential, shown as ground.
  • the UHF tuner includes an RF amplifier stage 54, an oscillator stage 56, a mixer stage 58, and an IF amplifier stage 60.
  • UHF television signals are intercepted by an antenna, not shown, and applied to a UHF input terminal 62.
  • the input signals are amplified in the amplifier stage 54 and heterodyned in the mixer stage 58 with locally generated signals from the oscillator stage 56 to produce an intermediate frequency signal which is thereafter amplified in the IF amplifier stage 60 to produce an amplified intermediate frequency signal output at an IF output terminal 64.
  • the tuner includes four tunable resonant circuits 66, 68, 70 and 72.
  • the tunable resonant circuit 66 is associated with the RF amplifier input circuitry, while the tunable resonant circuits 68 and 70 are part of a double tuned interstage network between the RF amplifier stage 54 and the mixer stage 58.
  • the tunable resonant circuit 72 is used to establish the frequency of oscillation of the oscillator stage 56.
  • the tunable resonant circuits 66, 68, 70 and 72 include transmission line structures which are tuned by variable capacitance diodes. All of the transmission line structures include conductive elements formed on both faces of a dielectric plate.
  • Tunable resonant circuit 66 includes aligned transmission line sections 67a and 67b; tunable resonant circuit 68 includes the transmission line sections 69a and 69b,- tunable resonant circuit 70 includes the transmission line sections 710 and 71b; and finally, tunable resonant circuit 72 includes the transmission line sections 73a and 73b.
  • One end of the second line sections 67b, 69b, 71b and 73b is connected to the point of reference potential, Each pair of line sections cooperate with the ground plane on the opposite side of the dielectric plate to operate as transmission lines.
  • each composite transmission line is coupled by variable capacitance tuning diodes 75, 79, 83 and 87 and adjustable tracking inductors 77, 81, 85 and 89, respectively.
  • Each of the series connected variable capacitance diodes 75, 79, 83 and 87 exhibit a capacitance whose magnitude varies inversely with the magnitude of reverse bias applied across the variable capacitance diode.
  • the tunable resonant circuits 66, 68 and 70 are apportioned to tune across a frequency band ranging from 470 MHz. through 890 MHz., while the tunable resonant circuit 72 associated with the oscillator stage 56 is apportioned to tune across a band of frequencies ranging from 517 MHz. through 931 MHz.
  • Each composite transmission line is apportioned so that the second sections 67b, 69b and 71b of the line are one quarter wavelength resonant at a frequency above 890 MHz., the highest desired frequency to which the tunable resonant circuit must tune.
  • the first transmission line sections 67a, 69a and 71a are apportioned to be half wavelength resonant above the highest frequency to which the tunable resonant circuit must tune, i.e., 890 MHz.
  • the second section of transmission line 73b associated with the oscillator tunable resonant circuit 72 is apportioned to be one quarter wavelength resonant at a frequency above 93] MHz.
  • the first transmission line section 73a is apportioned to be half wavelength resonant above 931 MHz.
  • the resonant frequency of each section may be measured by electrically disconnecting the variable capacitance tuning diode and adjustable tracking inductor and thereafter coupling a unit impulse of energy into the section under investigation.
  • the unit impulse will cause the section to ring simultaneously at several related frequencies, which can be measured, for example, by a sampling oscilloscope.
  • the fundamental resonant frequency is the lowest frequency present in the ringing section.
  • the mode of resonance can be determined by measuring the standing wave ratios along the section to determine the voltage maxima and null points.
  • a dielectric plate or substrate 91 which supports the composite transmission lines, is mounted in a conductive enclosure (FIG. 2).
  • the enclosure includes detachable covers 99 and 101 and a chassis or frame member 97.
  • Two ground plane sections 93 and 95 are disposed on opposite sides of the substrate 91.
  • the composite transmission lines 69, 71 and 73 include and are disposed opposite the ground plane section 95, while the RF input composite transmission line 67 includes and is disposed opposite the ground plane section 93.
  • the substrate 91 and its conductive areas are shown in FIGS. 6 and 7, which are drawn approximately to scale.
  • the substrate height is 3,375 inches and the substrate width is 3.500 inches.
  • While the several RF composite transmission lines 67, 69, and 71 are designed to resonate at approximately the same frequency for a given diode capacitance, they differ slightly in size to compensate for the effects introduced by the different tuner components connected as shown in FIGS. 4 and 5.
  • the substrate 91 which is about 50-milli-inches thick, is fabricated from an aluminum oxide consisting of approximately 85% AL O and 15 percent mixture of calcium oxide, magnesium oxide and silicon dioxide.
  • a conductive pattern about 0.0005-inches thick, is disposed on both the substrate faces and consists of silver and glass which has been fused at 900 C. The entire pattern is covered by a copper plating 0.0002 to 0.0005 inches thick.
  • a moisture and solder resistant silicon, modified to harden, is applied to the entire substrate and copper plated pattern, with the exception of bonding pads used to electrically connect the tuner components to the substrate pattern.
  • One suitable modified silicon is manufactured by Electroscience Corporation and designated 240-SB.
  • the exposed bonding pads on the substrate facilitates rapid and accurate assembly of the tuner. in FIGS. 2, 4 and 5, the conductive sections on the substrate (the transmission line sections, the ground plane sections, and the capacitor plates associated with the oscillator circuit) are shown crosshatched to indicate the, insulative coating which normally covers these components has been removed
  • Shaping of each composite transmission line section 67b, 69b and 71b provides a relative tracking between the tunable resonant circuits 66, 68 and 70 and oscillator tunable resonant circuit 72.
  • the shaping is in the form of an exponential taper between the grounded and diode ends of each section. Because of the exponential tapers, the impedance versus frequency characteristic of each of the composite transmission lines 67, 69 and 71 is modified.
  • curve (a) represents the plot of tuning capacity as a function of resonant frequency for the oscillator tunable resonant circuit 72 and curves (b,) (0,) and (d) represent the plot of tuning capacity as a function of resonant frequency for the RF tunable resonant circuit 66 for different inductance settings of the adjustable tracking inductor 77, minimum, nominal and maximum.
  • the adjustable tracking inductors will be discussed in greater detail hereinafter. Since the curvatures of the plots for the two tunable resonant circuits are similar, tracking of the resonant circuits is provided across the entire desired frequency band of each circuit.
  • the resonant frequency of each of the transmission lines is determined by its total reactance which includes the reactive impedances of the upper and lower aligned sections, the variable capacitance diode and the adjustable tracking inductor.
  • the reactive contribution of the upper section varies in a nonlinear manner with frequency, while the reactive contribution of the variable capacitance diode and adjustable tracking inductor provides capacitive reactance whose magnitude is determined by the tuning voltage (identical variable capacitive diodes having the same tuning voltage impressed across them may be used in all the tunable resonant circuits).
  • the capacitive reactance is varied and tunes the transmission line across the band of frequencies.
  • the oscillator tunable resonant circuit must resonate above the RF tunable resonant circuits by a given constant amount for any given tuning voltage adjustment.
  • the dissimilarly shaped lower sections of the RF signal selection and oscillator tunable resonant circuits cause the rate of change of the total reactance with frequency to be modified.
  • the lower section of each RF transmission line includes an exponential taper and the lower section of the oscillation transmission line includes a substantially linear taper. Consequently, these sections differ in rate of reactance change with frequency from each other and from their respective upper sections.
  • each transmission line This causes the total reactance of each transmission line to vary with frequency in a manner which provides tracking between the RF and oscillator tunable resonant circuits. It should be noted that the several tapered edges on the upper section of each of the transmission lines compensate for the effects of fringing of the electromagnetic and electrostatic fields at the section ends.
  • variable capacitance diode 75 lead lengths of less than 0.1 inch results in a several picofarad reduction in capacitance required by the tunable resonant circuit 66 for it to resonate at 470 MHz.
  • This series inductive effect provides a potential source of detuning between the several tunable resonant circuits 66, 68, and 72 as well as variation from one tuner to the next. The inductive effect, however, may be controiled and utilized to provide a means for centering or aligning the tunable resonant circuits.
  • variable capacitance diode is positioned in an aperture 750 in the substrate 91.
  • the hole 750 provides a location means for the body of the variable capacitance diode 75 and permits accurate positioning of the components.
  • the diode 75 is secured to two bondings pads 75b and 75c on opposite sides of the aperture 75a.
  • the bonding pad 75c is an area on the second section of transmission line while the bonding pad 75! is a separate conductive pad.
  • the bondings pads 75b and 750 are spaced a predetermined distance apart and help minimize the series inductance variations by providing a control for the lead lengths of the variable capacitance diode 75.
  • the aperture 75a in the substrate material 91 reduces the dielectric adjacent the body of the diode 75 to thereby minimize the distributed shunt capacitance between the ends of the diode and also eliminates the need to bend the diode leads (increasing its inductance) during mounting of the components.
  • the adjustable tracking inductor 77 is connected in series between the bonding pad 751; and one end of the first section of the composite transmission line 67a.
  • the inductor 77 consists of a thin wide strip of copper which may be adjusted to change its inductance. To change inductance, the configuration of the loop may be changed from a tall thin structure for minimum inductance to a more circular structure for maximum inductance. This is most clearly shown in FIGS. l0a-c where the adjustable tracking inductor 77 is shown set for minimum, nominal and maximum inductance, respectively.
  • the series adjustable inductor for each of the composite transmission lines 67, 69, 71 and 73 swamps minor inductance variations due to the diode lead length and provides a controllable series inductive effect.
  • Centering of the tracking for each of the tunable resonant circuits 66, 68, 70 and 72 is obtained by adjusting the shape of the inductive loop associated with each composite transmission line.
  • the effect of adjusting the inductor 77 is shown in FIG. 8 where the three plots of tuning capacity as a function of resonant frequency (b, c, and d) represent the effects of setting the adjustable tracking inductor 77 between its minimum, nominal and maximum inductance positions, respectively.
  • the inductive loops are adjusted such that a proper constant frequency separation is obtained between the resonant frequencies of the RF tunable resonant circuits and the oscillator tunable resonant circuit across their frequency bands.
  • Received UHF television signals applied at the input terminal 62 are coupled through a high pass filter comprising the inductors 74 and 76 and the capacitor 78, to the RF amplifier input circuit 66.
  • the high pass filter functions to pass frequencies within the UHF frequency band; that is, frequencies ranging from 470 MHz. to 890 MHz.
  • the tunable resonant circuit 66 is coupled via a capacitor 80 to the emitter electrode of a grounded base transistor amplifier 82.
  • the transistor 82 is shown encapsulated in a conductive housing which is connected to ground by lead 102 to reduce the likelihood of parasitic oscillations.
  • Operating potential for the transistor 82 is obtained from a source of B+ applied to a terminal 84 which is bypassed to ground for radio frequencies by a feedthrough capacitor 103.
  • the potential is applied to the collector electrode of the transistor 82 through a radio frequency decoupling inductor 86, a resistor 88, and an RF choke 90.
  • the choke 90 is a single component including a kilo-ohm resistor providing the wire winding form for an inductor, both of which are electrically connected in parallel.
  • the resistor reduces the figure of merit or Q of the choke to reduce the possibility of spurious parasitic resonances.
  • the emitter electrode of the transistor 82 is connected to ground by a resistor 92 to complete the collector-emitter DC current path.
  • Bias to the base electrode of the transistor 82 is provided from the source of operating potential applied at the terminal 84 through the collector-emitter current path of an automatic gain control transistor 94.
  • An automatic gain controlling potential is applied to the base electrode of the transistor 94 via a terminal 96. Terminal 96 is bypassed to ground for radio frequency signals by a feedthrough capacitor 105.
  • the automatic gain control transistor 94 controls the base bias to the RF amplifier transistor 82, and thus, the RF amplifier stage gain.
  • Transistor 94 is connected as an emitter-follower so that substantial isolation is provided between the automatic gain control circuits and the RF amplifier 82. Further RF isolation for the 13+ supply and the AGC circuitry is provided by two feedthrough capacitors 98 and 100, respectively.
  • the feedthrough capacitor 100 additionally provides a low impedance RF path to ground for the base electrode of transistor 82 establishing the grounded base mode of operation.
  • a capacitor 104 couples the collector electrode of the RF amplifier transistor 82 and the tunable resonant circuit 68.
  • Signals developed in the tunable resonant circuit 68 are inductively coupled to the tunable resonant circuit 70 by the inductors 106 and 108.
  • the inductor 106 provides the dominant coupling toward the lower end of the UHF frequency band, while the inductor 108 provides the dominant coupling toward the higher end of the UHF frequency band.
  • the tunable resonant circuits 68 and 70 with the coupling inductors 106 and 108 combine to form a double tuned interstage network interconnecting the RF amplifier stage 54 and the mixer stage 58.
  • the mixer stage 58 includes a mixer diode 110 having its cathode connected to a tap point 112 in the tunable resonant circuit 70.
  • the anode of the mixer diode 110 is connected by a pickup loop 114, an inductor 116 and a capacitor 118 to the input of the IF amplifier stage 60, terminal 119-119.
  • inductor 116 and capacitor 118 are apportioned to transform the diode output impedance to match the IF amplifier stage input impedance.
  • a DC bias is applied to the mixer diode 110 from the B+ supply to maintain a DC current flow of approximately 1.5 milliamperes through the mixer diode.
  • the bias to the diode is applied from the terminal 84 through the inductor 86 and to series connected resistors 120-122, and the pickup loop 114 to the anode of the mixer diode 110.
  • the cathode of the diode is returned to ground through a portion of the tunable resonant circuit 70.
  • Amplified UHF signals are applied to the mixer diode 110 from the tunable resonant circuit 70 at the tap connection 112.
  • An oscillator wave is applied to the mixer diode from the oscillator stage 56 so that the mixer diode heterodynes the amplified UHF signals and the locally generated signal to provide a desired IF output signal.
  • the oscillator signal is coupled from the tunable resonant circuit 72 to the pickup loop 114 connected to the anode of the mixer diode 110.
  • a feedthrough capacitor 124 coupled between the inductive pickup loop 114 and the point of reference potential is selected to provide a low impedance path to ground for both the amplified UHF signals and the oscillator signal and a higher impedance path for IF signals, As a result, intermediate frequency signals generated in the mixer diode 110 are passed and applied to the IF amplifier stage 60 for amplification.
  • the oscillator stage 56 includes a transistor 126 connected as a modified colpitts oscillator whose frequency is determined by the tunable resonant circuit 72.
  • Operating potential for the oscillator transistor 126 is provided by the B+ supply via the terminal 84, the inductor 86 and the resistor 120 to a junction 128 which is bypassed to ground for UHF waves by a feedthrough capacitor 130.
  • the potential at the junction 128 is applied to the collector electrode of the oscillator transistor 126 through a resistor 132 and an RF choke 134.
  • a DC emitter ground return for the transistor is provided by a resistor 136.
  • Base bias is obtained through the voltage divider resistors 138 and 140, connected between the junction 128 and ground.
  • a capacitor 142 connects the base electrode of the transistor 126 and ground to provide a frequency dependent signal path between the base electrode and ground.
  • a capacitor 144 couples the collector electrode of transistor 126 to the tunable resonant circuit 72.
  • a portion of the voltage developed at the collector electrode of the transistor is coupled to the emitter electrode of the transistor through a capacitive voltage divider including the three capacitors 146, 148 and 150.
  • capacitor 148 is selected to roll off the high frequency response of the transistor. Consequently, the capacitor 148 is selected to be lossy; that is, have a frequency dependent resistive component causing resistive loading of the oscillator transistor at the higher frequencies.
  • One suitable capacitor is an 0.82 pf, type GA, capacitor manufactured by the Stackpole Corporation.
  • tunable resonant circuit 72 includes a low impedance, alumina dielectric, transmission line, a relatively large value coupling capacitor 144 (as compared to the typical UHF television tuner high impedance air dielectric, half wave transmission line) is required for impedance matching purposes. This necessitates large capacitors in the capacitive voltage divider to provide the proper signal feedback voltages.
  • the capacitors 144, 146 and 150 are conductive areas formed on the substrate 91 (FIGS. 4 and 5).
  • the capacitor 144 consists of a conductive area 501 formed over a conductive area 503 on the opposite side of the substrate within a window 505 in the ground plane 95.
  • Capacitor 146 consists of a conductive area 503 cooperating with a conductive area 507 disposed within the window 505 adjacent area 503, and capacitor 150 consists of a conductive area 507 cooperating with the adjacent portion of the ground plane 95 to the right of the conductive area as viewed in FIG. 5.
  • the capacitors 144, 146 and 150 may be fabricated, as other conductive areas, by printed circuit techniques.
  • the oscillator tunable resonant circuit 72 exhibits an undesired resonance at about 1,400 MHz.
  • the parasitic resonant frequency is not substantially affected by the capacitance of the variable capacitance diode 87. With the component values shown, it has been found that the undesired resonant frequency changes by approximately 60 MHz. with a capacitive varia tion of approximately 13 pf.
  • the parasitic resonant frequency of the oscillators composite transmission line is a second harmonic frequency centered on approximately 700 MHz. which is within the desired UHF oscillator frequency band.
  • a reduction of fundamental frequency oscillator signal voltage is observed as the oscillator tunable resonant circuit 72 is adjusted to resonate within this vicinity. This reduces the available oscillator signal which may be coupled to the tuner mixer diode 110. It is believed that the reduction of the fundamental frequency oscillator signal voltage is due to a suck out effect caused by the parasitic circuit.
  • the first section 730 of the oscillators composite transmission line is coupled to the oscillator transistor 126 at the parasitic frequency voltage null point. This results in minimum spurious signal energy transfer from the tunable resonant circuit 72 through the coupling capacitor 144 to the oscillator transistor 126.
  • the ground plane section 95 associated with the oscillator composite transmission line is not infinite in size and conductivity, current flows in the ground plane establishing voltages.
  • a potential coupling path is provided for coupling these voltages from the ground plane section 95 through, capacitor 142 to the base electrode of the oscillator transistor.
  • the coupling path tends to encourage the parasitic mode of resonance. This occurs because the spurious signal which is applied to the transistor base electrode establishes a base-collector electrode differential voltage which is introduced into the oscillator feedback network.
  • the capacitor 142 is positioned on the ground plane section 95 directly over the parasitic null point on the first section of the oscillator composite transmission line.
  • the capacitor 142 consists of a bare disc 509 (FIG. 5).
  • the disc 509 is of dielectric material having conductive areas disposed on opposite faces.
  • the base electrode of transistor 126 is electrically connected to one of the conductive faces while the opposite conductive face is positioned on the ground plane section over the null point.
  • the RF tunable resonant circuit 66, the interstage tunable resonant circuits 68 and 70, and the oscillator tunable resonant circuit 72 are not compartmentalized in conductive enclosures to prevent interaction between the several resonant circuits, and more importantly, to prevent a radiation of oscillator energy through the RF tunable resonant circuit 66 and out the UHF antenna.
  • the tuner 50 is provided with a partial inner oscillator conductive cover 550 (FIG. 2) which overlies the oscillator transmission line sections 73a-73b.
  • the inner partial cover 550 because it is permanently secured as part of the tuner chassis frame 97, minimizes possible detuning effects of distance variations between the oscillator stage 56 and detachable tuner covers 99 and 101 after removal and reattachment.
  • the fringing effect of the fields can cause the oscillator energy to be coupled to the RF tunable resonant circuit 66 to be radiated via the UHF antenna. Moreover, the coupling can adversely affect the automatic gain control characteristics of the tuner.
  • the undesired effects of oscillator radiation are eliminated by disposing the composite transmission line of the RF tunable resonant circuit 66 on the opposite side of the alumina substrate 91 from the double tuned interstage and oscillator composite transmission lines 69, 71 and 73.
  • the ground plane sections 93 and 95 are, likewise, disposed on opposite sides of the alumina substrate. In this manner, the effectiveness of the electromagnetic and electrostatic coupling between the tunable resonant circuit 66 and the remaining tunable resonant circuits ofthe tuner 50 is minimized.
  • the second shaped section 67b of the RF composite transmission line is disposed toward the top of the substrate while the first section 67a of the RF composite transmission line is disposed toward the bottom of the substrate.
  • the oscillator and interstage composite transmission lines each have their second section disposed toward the bottom of the alumina substrate with their first section disposed toward the top.
  • the emitter electrode of the RF transistor 82 is coupled to the low impedance shaped section 67b of the RF input composite transmission line 67 and the collector electrode of transistor 82 is coupled to the high impedance section 690 of the interstage composite trans mission line 69.
  • the composite transmission lines 67 and 69 disposed in inverted relationship, as previously described, it is possible to utilize very short lengths for the RF transistor 82 emitter and collector electrode coupling leads.
  • the IF amplifier stage 60 includes a transistor 152 mounted external to the conductive housing 52 and connected as a grounded base amplifier. External mounting of the transistor tends to prevent an undesired interaction between the IF amplifier stage and the RF amplifier and mixer stages.
  • the IF input signals are applied to the transistor emitter electrode, and the collector electrode is connected to the IF output terminal 64 by a double tuned IF bandpass filter.
  • a feedthrough capacitor 154 provides a radio frequency bypass to ground for the transistors base electrode.
  • a ferrite bead 155 is applied to the collector electrode of the transistor 82.
  • the first section of the double tuned IF bandpass filter includes a feedthrough capacitor 156, an inductor 158 and a feedthrough capacitor 160.
  • the second section of the double tuned bandpass filter includes the feedthrough capacitor 160, an inductor 162 and the capacitors 164 and 166; capacitor 160, common to both filters, provides the requisite signal coupling between the sections of the filter.
  • a standoff terminal 163 provides a small capacitance mechanical support for the junction of the inductor 162 and capacitor 164. Resistive loading of the filters (resistors 172, 174 and an IF signal cable, not shown, coupled to terminal 64) is selected so that the signal response of the IF amplifier stage 60 is flat across the entire desired IF band.
  • equal amplification of signal voltages is provided between both ends of the intermediate frequency band (approximately 41 MHz. to 46 MHz.).
  • the shaped IF response commonly associated with television intermediate frequency amplifiers is achieved in later IF stages associated with the television receiver chassis and the VHF tuner. In the latter case, the VHF tuner may be used to provide additional amplification of the UHF tuner IF output signal.
  • the IF bandpass filter transforms the output impedance of the grounded base IF amplifier transistor 152 to a resistive output of 75 ohms at the center frequency of the IF band, 43 MHZ. This is achieved by adjusting the tuning slugs in inductors 158 and 162 while applying an IF input signal at test point terminal 169.
  • the impedance transformation provided by the bandpass filter is frequency dependent, the deviation from 43 MHz. to the upper and lower ends of the IF band is not sufficient to materially change the nature of the output impedance at the terminal 64. Specifically, the impedance at both the high end and the low end of the IF frequency band remains predominantly a resistive impedance of 75 ohms.
  • the tuner IF output terminal 64 When the tuner IF output terminal 64 is coupled to succeeding lF amplifying stage associated with the television receiver chassis by a 75-ohm coupling cable, the impedance looking into the terminal 64 closely matches the characteristic impedance of the cable and no reflections occur back along the cable. As a result, any length ofcoupling cable can be used to couple signals between the television tuner and chassis. Naturally, termination of the cable on the television chassis must, likewise, be a 75-ohm resistive load. Moreover, because resistive coupling is provided between the tuner 50 and the television chassis, any capacitive variations which occur due to coupling cable dress do not detune the coupling link as there is no inductance with which the capacitance can resonate. Consequently, the dress of the IF coupling cable is not critical to proper performance of the tuner. It should be recognized that since an amplified IF output signal is provided by the tuner 50, any minor losses in the resistive coupling are not significant.
  • Operating potential for the IF amplifier transistor 152 is obtained from the B+ supply at the terminal 84, through the inductor 86, an RF isolation inductor I68 and the inductor 158 to the collector electrode of the transistor 152.
  • a resistor 170 is connected between the emitter electrode of the transistor and ground to complete the DC current path.
  • Base bias for the transistor 152 is provided by a voltage divider including the resistors I72 and 174 connected between the inductor 158 and ground.
  • a source of variable DC tuning voltage 175 for biasing the variable capacitance diodes associated with the four tunable resonant circuits has an internal resistance of 1,000 ohms and is connected between terminal 176 and ground. The terminal 176 is bypassed for radio frequency signals by a feedthrough capacitor 177.
  • the tuning voltage is applied via the resistors I78 and 180 to ajunction 190 which provides a common point of tuning potential for the four tunable resonant circuits.
  • the junction 190 is coupled to the tunable resonant circuit 66 via the resistors 180 and 179 and to the tunable resonant circuit 70 via the resistor 182.
  • junction I90 voltage applied to the tunable resonant circuit 70 is applied to the tunable resonant circuit 68 via the inductor 106.
  • the junction 190 is also coupled to the tunable resonant circuit 72 by resistor 185, a resistor 187 and the RF choke 188.
  • Three feedthrough capaciiii) tors 184, I86 and 183 cooperate with the resistors 180 and 185 to prevent RF and oscillator signal energy from being coupled via the DC tuning line between the several tunable resonant circuits and into the source of tuning voltage 175.
  • variable capacitance diode having a capacitance range of approximately 13 picofarads will permit the RF tunable resonant circuits 66, 68, and and the oscillator tunable resonant circuit to be tuned across their respective frequency bands.
  • One suitable variable capacitance diode is the BA I41 diode manufactured by the International Telephone & Brass Corporation.
  • the BA 141 diode provides a capacitance ranging from 15 picofarads to 2.3 picofarads as the tuning voltage is adjusted between approximately 1 and 25 volts DC.
  • the tuning of the tunable resonant circuits may be understood by reference to FIGS. 11 and 12 showing the standing waves of voltage and current, respectively, along the RF input composite transmission line 67 which is shown at the top of the FIGURES.
  • a voltage is applied across the variable capacitance diode such that it exhibits a predetermined capacitance. This capacitance causes the composite transmission line to resonate with a voltage null on the transmission line section 6711 located at a point between the center and the diode end of the section.
  • An increase in the voltage across the diode 75 reduces the diode capacitance and causes the composite transmission line 67 to resonate at a higher frequency.
  • the voltage null on the transmission line section 67a displaces toward the center of the section (FIG. 11a).
  • a reduction in the voltage across the diode 75 increases the capacitance and causes the composite transmission line 67 to resonate at a lower frequency.
  • the voltage null on the transmission line section 67a displaces toward the diode end of the section.
  • the amount of frequency change for a given capacitance increase is dependent upon the characteristic impedance of the transmission line which is a function of the width of the line, the spacing from the ground plane and the dielectric of the intervening medium.
  • a still further reduction of the voltage across the diode 75 continues to lower the resonant frequency of the composite transmission line 67 (FIGS. 11b and e).
  • the voltage at the diode end of the transmission line section 67a increases and the composite transmission line 67 resonates in a modified one-quarter wavelength mode.
  • variable capacitance diode 75 helps maintain a high figure of merit. This is because the variable capacitance diode 75 is located at a lower current point as compared to the grounded end of the composite transmission line (FIG. 12). As a result, 1 R diode losses are minimized.
  • the oscillator diode 87 has a reverse bias of approximately 1.0 volt.
  • the oscillator voltage developed across the diode is of sufficient amplitude during a portion of each cycle to exceed the diode reverse bias causing rectification of the oscillator voltage.
  • the rectified voltage increases the reverse bias decreasing the diode 87 capacitance. This in turn causes the tunable resonant circuit 72 to become tuned to a different frequency. No rectification occurs in the RF tunable resonant circuits 66, 68 and 70 because the RF UHF signal in these circuits is in the order of millivolts as opposed to the order of approximately 1.0 volt in the tunable resonant circuit of the oscillator.
  • the total resistance to ground from the diode 87 through the DC tuning line and the source of tuning voltage 175 is selected to be small compared to the oscillator stage driving resistance. in this manner, the tuning voltage at the terminal 176 predominates in controlling the voltage across the diode because the diode current flowing through the total resistance sets up a relatively small voltage which is insufficient to appreciably change the average DC voltage across the diode.
  • a tunable resonant circuit comprising:
  • a voltage responsive capacitance device coupled between said first and second sections and adapted to tune said tunable resonant circuit over a desired band of frequencies
  • said second section selected to be one-half wavelength reso nant above the highest frequency in said desired band of frequencies, and said first section selected to be onequarter wavelength resonant at a frequency above the highest frequency in said desired band of frequencies;
  • means including said transmission line sections for applying a voltage to said voltage responsive capacitance device to control the resonant frequency of said tunable resonant circuit.
  • a tuner comprising:
  • a dielectric plate having a first and a second face
  • first variable capacitance device coupled between said first and said second sections such that said first and said second sections and said first ground plane cooperate to form a first tunable resonant circuit
  • a second variable capacitance device coupled between said third and fourth sections such that said third and said fourth sections and said second ground plane cooperate to form a second tunable resonant circuit.
  • a tunable resonant circuit as defined in claim 6 wherein one conductive section of each tunable resonant circuit resonates with a voltage null on said section above a predetermined frequency and the other conductive section is electrically connected to the oppositely disposed conductive ground plane.
  • a tunable resonant circuit comprising:
  • a conductive ground plane disposed on the other of said major surfaces opposite said first and said second sections;
  • variable capacitance device coupled between said first and said second section and adapted to tune said tunable resonant circuit over a desired band of frequencies
  • said second section selected to be one-half wavelength resonant above the highest frequency in said desired band of frequencies, and said first section selected to be onequarter wavelength resonant at a frequency above the highest frequency in said desired band of frequencies.
  • a tunable resonant circuit as defined in claim 12 wherein said circuit resonates with a voltage null on said second conductive section above a predetermined frequency and said first conductive section is electrically connected to said conductive ground plane.
  • a conductive ground plane disposed on the other of said major surfaces opposite said conductive sections;
  • variable capacitance device coupled between said first and said second section, and a second variable capacitance device coupled between said third and said fourth section;
  • first coupling means interconnecting said first and said third conductive sections
  • second coupling means interconnecting said second and said fourth conductive sections
  • a dielectric plate having two major surfaces with a conductive ground plane disposed on one of the surfaces;
  • a first tunable resonant circuit including a first and a second conductive section disposed on the other surface coupled by a first variable capacitance device, and a second tunable resonant circuit including a third and a fourth conductive section disposed on the other surface coupled by a second variable capacitance device;
  • first coupling means interconnecting the first and third conductive sections to provide dominant coupling toward the upper end of said desired band of frequencies
  • a second coupling means interconnecting the second and fourth conductive sections to provide dominant coupling toward the lower end of said desired band of frequencies, said first and said second coupling means cooperating to provide substantially uniform coupling between said first and said second tunable resonant circuits across said desired band of frequencies.
  • a structure comprising:
  • a dielectric plate having a first and a second surface
  • a first tuned circuit including at least one conductive section disposed on said first face of said dielectric plate and a first conductive ground plane disposed on said second face of said dielectric plate opposite said one conductive section on said first face of said dielectric plate;
  • a second tuned circuit including at least one conductive section disposed on said second face of said dielectric plate and a second conductive ground plane disposed on the first face of said dielectric plate opposite said one conductive section on said second face of said dielectric plate.
  • said first tuned circuit includes another conductive section disposed on said first face of said dielectric plate and coupled to said one section section by a variable capacitance device; and said second tuned circuit includes another conductive section disposed on said second face of said dielectric plate and coupled to said one section by a variable capacitance device.
  • a circuit comprising:
  • a dielectric plate having a first and a second face
  • an active device having a first and a second electrode
  • an input resonant circuit including a conductive section disposed on said first face of said dielectric plate and a first ground plane disposed on said second face of said dielectric plate opposite said conductive section;
  • an output resonant circuit including a conductive section disposed on said secondface of said dielectric plate and a second ground plane disposed on the first face of said dielectric plate opposite said conductive section; and second means coupling said active device second electrode to said output resonant circuit.
  • a circuit comprising:
  • a dielectric plate having a first and a second face
  • an active device having a first and a second electrode
  • an input tunable resonant circuit including a first and a second conductive section disposed on said first face of said dielectric plate and coupled by a first variable capacitance device and a first conductive ground plane disposed on said second face of said dielectric plate opposite said first and second conductive sections;
  • an output tunable resonant circuit including a first and a second conductive section disposed on said second face of said dielectric plate and coupled by a second variable capacitance device and a second conductive ground plane disposed on said first face of said dielectric plate opposite said conductive sections;
  • a circuit as defined in claim 30 wherein one end of said input tunable resonant circuit first conductive section is electrically connected around said one edge to said oppositely disposed ground plane, and one end of said output tunable resonant circuit first conductive section is electrically connected around said another edge to said oppositely disposed ground plane.

Landscapes

  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
US21563A 1970-03-23 1970-03-23 Electronically tuned ultra high frequency television tuner Expired - Lifetime US3649937A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US2156370A 1970-03-23 1970-03-23

Publications (1)

Publication Number Publication Date
US3649937A true US3649937A (en) 1972-03-14

Family

ID=21804920

Family Applications (1)

Application Number Title Priority Date Filing Date
US21563A Expired - Lifetime US3649937A (en) 1970-03-23 1970-03-23 Electronically tuned ultra high frequency television tuner

Country Status (12)

Country Link
US (1) US3649937A (de)
JP (1) JPS5136081B1 (de)
AT (1) AT322645B (de)
BE (1) BE764661A (de)
CA (1) CA946947A (de)
DE (1) DE2114056C3 (de)
DK (1) DK139830B (de)
ES (1) ES389481A1 (de)
FR (1) FR2084985A5 (de)
GB (1) GB1309212A (de)
NL (1) NL7103823A (de)
SE (1) SE367104B (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3832602A (en) * 1969-12-31 1974-08-27 Siemens Ag Print for control modules of contact-free control and regulating systems
US3889214A (en) * 1973-05-18 1975-06-10 Int Standard Electric Corp Pass-band filter having electronically adjustable midfrequency
US4075580A (en) * 1975-12-18 1978-02-21 Siemens Aktiengesellschaft Microwave transistor oscillator for wide band frequency tuning
US4145659A (en) * 1977-05-25 1979-03-20 General Electric Company UHF electronic tuner
US4384367A (en) * 1980-02-12 1983-05-17 Theta-Com Of California MDS Receiver
US20120258678A1 (en) * 2009-12-15 2012-10-11 Jan Johannes Maria Van Den Elzen Enhanced power cable arrangement apparatus and method of reducing a common-mode interference signal

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58161504A (ja) * 1982-03-19 1983-09-26 Nec Corp 電圧制御発振器
DE4029665A1 (de) * 1990-09-19 1992-03-26 Licentia Gmbh Interdigitalfilter
US9333519B2 (en) 2010-12-02 2016-05-10 Sata Gmbh & Co. Kg Spray gun and accessories
RU2601337C2 (ru) 2011-06-30 2016-11-10 САТА ГмбХ унд Ко. КГ Пистолет-краскораспылитель с возможностью легкой очистки, принадлежности для пистолета-краскораспылителя и способ их монтажа и демонтажа
CN105289870B (zh) 2014-07-31 2019-09-24 萨塔有限两合公司 喷枪的制造方法、喷枪、喷枪本体以及盖
CA159961S (en) 2014-07-31 2015-07-17 Sata Gmbh & Co Kg Spray gun
DE102015006484A1 (de) 2015-05-22 2016-11-24 Sata Gmbh & Co. Kg Düsenanordnung für eine Spritzpistole, insbesondere Farbspritzpistole und Spritzpistole, insbesondere Farbspritzpistole
DE102015016474A1 (de) 2015-12-21 2017-06-22 Sata Gmbh & Co. Kg Luftkappe und Düsenanordnung für eine Spritzpistole und Spritzpistole
CN205995666U (zh) 2016-08-19 2017-03-08 萨塔有限两合公司 喷枪及其扳机
CN205966208U (zh) 2016-08-19 2017-02-22 萨塔有限两合公司 风帽组件以及喷枪
DE102018118738A1 (de) 2018-08-01 2020-02-06 Sata Gmbh & Co. Kg Grundkörper für eine Spritzpistole, Spritzpistolen, Spritzpistolen-Set, Verfahren zur Herstellung eines Grundkörpers für eine Spritzpistole und Verfahren zum Umrüsten einer Spritzpistole
DE102018118737A1 (de) 2018-08-01 2020-02-06 Sata Gmbh & Co. Kg Düse für eine Spritzpistole, Düsensatz für eine Spritzpistole, Spritzpistolen und Verfahren zur Herstellung einer Düse für eine Spritzpistole
US11826771B2 (en) 2018-08-01 2023-11-28 Sata Gmbh & Co. Kg Set of nozzles for a spray gun, spray gun system, method for embodying a nozzle module, method for selecting a nozzle module from a set of nozzles for a paint job, selection system and computer program product
CN113922019A (zh) * 2020-07-09 2022-01-11 大富科技(安徽)股份有限公司 合路器及通信设备

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2545623A (en) * 1948-08-17 1951-03-20 Kenneth R Mackenzie Frequency modulation system
US3109152A (en) * 1960-05-03 1963-10-29 Csf Microwave phase-shift devices
GB1100751A (en) * 1964-02-01 1968-01-24 Telefunken Patent Improvements in or relating to tuning arrangements

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1850852U (de) * 1962-03-07 1962-05-03 Graetz Kommandit Ges Uhf-stichleitung.
DE1197518B (de) * 1964-09-02 1965-07-29 Telefunken Patent Leitungskreis fuer hochfrequente elektrische Schwingungen
US3377568A (en) * 1966-03-25 1968-04-09 Kruse Storke Electronics Voltage tuned oscillator
DE1297719B (de) * 1967-01-12 1969-06-19 Stassfurt Fernsehgeraete Abstimmbare Leitungskreise fuer hochfrequente elektrische Schwingungen in Streifenleitertechnik
DE1591789A1 (de) * 1967-04-17 1971-03-04 Stassfurt Fernsehgeraete Abstimmeinheit fuer hochfrequente elektrische Schwingungen,insbesondere fuer Fernsehrundfunksignale
DE1296225B (de) * 1967-07-14 1969-05-29 Telefunken Patent Abstimmvorrichtung fuer hochfrequente elektrische Schwingungen
US3651409A (en) * 1970-03-23 1972-03-21 Rca Corp Electronically tuned ultra high frequency television tuner with frequency tracking tunable resonant circuits

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2545623A (en) * 1948-08-17 1951-03-20 Kenneth R Mackenzie Frequency modulation system
US3109152A (en) * 1960-05-03 1963-10-29 Csf Microwave phase-shift devices
GB1100751A (en) * 1964-02-01 1968-01-24 Telefunken Patent Improvements in or relating to tuning arrangements

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3832602A (en) * 1969-12-31 1974-08-27 Siemens Ag Print for control modules of contact-free control and regulating systems
US3889214A (en) * 1973-05-18 1975-06-10 Int Standard Electric Corp Pass-band filter having electronically adjustable midfrequency
US4075580A (en) * 1975-12-18 1978-02-21 Siemens Aktiengesellschaft Microwave transistor oscillator for wide band frequency tuning
US4145659A (en) * 1977-05-25 1979-03-20 General Electric Company UHF electronic tuner
US4384367A (en) * 1980-02-12 1983-05-17 Theta-Com Of California MDS Receiver
US20120258678A1 (en) * 2009-12-15 2012-10-11 Jan Johannes Maria Van Den Elzen Enhanced power cable arrangement apparatus and method of reducing a common-mode interference signal
US9225067B2 (en) * 2009-12-15 2015-12-29 Tomtom International B.V. Enhanced power cable arrangement apparatus and method of reducing a common-mode interference signal

Also Published As

Publication number Publication date
DE2114056A1 (de) 1971-10-07
GB1309212A (en) 1973-03-07
ES389481A1 (es) 1973-06-01
BE764661A (fr) 1971-08-16
AT322645B (de) 1975-05-26
CA946947A (en) 1974-05-07
JPS5136081B1 (de) 1976-10-06
DK139830C (de) 1979-10-01
SE367104B (de) 1974-05-13
DK139830B (da) 1979-04-23
DE2114056C3 (de) 1981-07-16
DE2114056B2 (de) 1973-03-01
NL7103823A (de) 1971-09-27
FR2084985A5 (de) 1971-12-17

Similar Documents

Publication Publication Date Title
US3649937A (en) Electronically tuned ultra high frequency television tuner
US4835499A (en) Voltage tunable bandpass filter
EP0133799B1 (de) Abstimmsystem auf dielektrischen Substraten
US3643168A (en) Solid-state tuned uhf television tuner
US6538532B2 (en) Magnetically coupled series-tuned air coil resonators having very low C/L ratios to achieve higher QL, lower insertion loss and improved out-of-band rejection
US4214212A (en) Tuner device for a television receiver
US5187451A (en) Oscillator using microstrip line having minimized line width and length
US3909726A (en) UHF Hybrid tuner
US3651409A (en) Electronically tuned ultra high frequency television tuner with frequency tracking tunable resonant circuits
US5107233A (en) Amplitude correction of field coupled varactor tuned filters
US4121182A (en) Electrical tuning circuit
US3852670A (en) Tuner with integral input filter
US4623856A (en) Incrementally tuned RF filter having pin diode switched lines
US4897624A (en) Unitary capacitance trimmer
US3624554A (en) Ultrahigh frequency oscillator utilizing transmission line tunable resonant circuits
US3471812A (en) High impedance printed conductor circuit suitable for high frequencies
US3624515A (en) Ultrahigh frequency tuner with helical resonators coupled through apertures in shields
US3806844A (en) Uhf varactor tuner having a chassis of unitary construction
US3553600A (en) Electrical circuit
US3818349A (en) Thick film vhf tuner wherein uhf subchassis is used as external ground element for vhf tuner
US2714192A (en) U. h. f. band pass filter structures
US4267604A (en) UHF electronic tuner
US4646360A (en) Constant bandwidth RF filter with improved low frequency attenuation
US3757258A (en) High frequency filter apparatus
US4254390A (en) Compact electronic tuning device

Legal Events

Date Code Title Description
AS Assignment

Owner name: RCA LICENSING CORPORATION, TWO INDEPENDENCE WAY, P

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:RCA CORPORATION, A CORP. OF DE;REEL/FRAME:004993/0131

Effective date: 19871208