Патент USA US2407861код для вставки
Sept; 17, 1946. > L. J. ‘WOLF ' 2,407,860 COMMUNICATION SYSTEM FOR ULTRA HIGH FREQUENCY Filed April 22,. 1942 @1 3" Amt/M 18.5 ?MPuF/Ez ozrz'cme ' 0A0 19- KC. 191/010 ??PUf/E/B ', a , /7. M c. .55 ' ‘ Imventor zwzerJimgr ‘ 8g ‘w'M ' attorney Patented Sept. 17, 1946 2,407,860 UNITED STATES PATENT OFFICE 2,407,860 I ‘ COMMUNICATION SYSTEM FOR ULTRA HIGH FREQUENCIES Lester J. Wolf, Audubon, N. J ., assignor to Radio Corporation of America, a corporation of Dela ware 1 Application April 22, 1942, Serial No. 439,964 4 Claims. (Cl. 179-1715) This invention relates generally to radio transmitters and particularly to ultra-high fre quency pulse transmitters modulated by voice or other signal frequencies. It has long been recognized that considerable difficulty is experienced in generating ultra-high frequencies with transmitting tubes of high power rating. At present, high power telephone com munication at frequencies of the order of 100 megacycles or higher is limited in the transmitter because of the dif?culty in constructing vacuum tubes to handle large amounts of radio frequency power at these frequencies. This difficulty is seemingly inherent because of the interelectrode 2 . cuits, consisting of tuned transmission lines, is shown in combination with a modulator having a conventional input circuit. The oscillator tubes ' l and 2 have 'a balanced anode circuit compris ing the resonant lines 3 and 4 tuned by the shorting bar 6. The shorting bar 5 is connected to a source of anode potential which may be of the order of at least ten times the normal volt age rating for the tubes. The shorting bar 5 is also connected to the anode of the modulator tube l3. The grids of the oscillator tubes l and 2 are connected respectively to the tuned .resonant 7 lines 6 and ‘l which are tunedby the shorting bar 8. The cathodes of the oscillator tubes l capacity and transit-time losses in conventional 15 and 2 are connected respectively to the resonant high power transmitting tubes. In a similar lines 9 and [0 which are tuned by the shorting manner communication at these frequencies is bar It. A capacitor 12 is connected between the limited in the receiver because of noise level due shorting bars 8 and H. The shorting ‘bar 8 is to static, ignition noises, etc., and to transit-time also connected to the cathode of the modulator losses and reduced ampli?cation. One solution 20 tube l3. . to this problem is the use of a pulse transmitter ,The grid circuit of the modulator I3 includes in which extremely short pulses having high peak power are radiated from the transmitter. It is perfectly practical under these conditions to the secondary of a modulation transformer M and an adjustable source of grid potential 15. The primary of the modulation transformer M radiate a peak output of as much as 100 times 25 is supplied with modulating potential applied to the continuous power rating of a transmitting. tube designed for operation at the frequencies previously mentioned. Among the objects of the invention are to pro vide improved methods and means for generat ing and modulating ultra-high frequency pulses of radio frequency energy having peak power many times greater than the continuous power the input terminals IS. The negative terminal of the high potential anode power supply is con nected to the shorting bar I l. ' In operation the modulator tube acts as a grid 30 leak of very high resistance for the grid capacitor l 2 in the oscillator circuit. When the high anode voltage is applied to the oscillator tubes l and 2, they commence to oscillate very abruptly, and a high peak power radio frequency current is gen is to provide an improved method and means for The resultant‘ high grid current in the modulating ultra-high frequency pulses of radio 35 erated. oscillator circuit rapidly charges the small con-' frequency energy by controlling the blocking and denser l2, and the bias on the oscillator tubes unblocking of an oscillator circuit in response to rises to a blocking value within a few microsec modulation potentials. Another object is to pro onds. The oscillator tubes l and. 2 will remain vide improved means for blocking an oscillator 40 blocked until the condenser I2 can discharge _ circuit and unblocking the circuit through a leak through the leakage path provided by the anode age path through a modulator tube circuit. circuit of the modulator tube l3. The invention will be described by reference to The bias potential onthe grid of the modulator \ the drawing of which Figure 1 is 'a schematic tube [3 is adjusted to the value which will provide circuit diagram of one modi?cation of the in 45 an anode resistance of a predetermined value for vention; Figure 2 is a graph showing the operat pulsing the oscillator. circuit at any desired fre ing characteristics of the circuit; and Figure 3 quency. Modulation potential applied to the is a block diagram of a receiver for signals from terminals I 6 of the modulation transformer I4 the system to be described. It should be under will vary the grid potential of the modulator l3, stood that the invention will be adaptable to 50 which in turn will vary the anode resistance of any standard transmitter circuits and that the the modulator. Any change in the anode re circuit described and illustrated is merely one sistance of the modulator l3 will vary the dis embodiment of the invention. charge time of the capacitor I2 in the grid cir Referring to Fig. 1, a push-pull oscillator cir cuit of the oscillators l and 2. Variations of the cuit utilizing tuned anode, grid, and cathode cir 55 discharge time of the capacitor I2 will vary the rating of the transmitting tubes. Another object 2,407,866 3 interval between successive pulses of radio fre quency power in the oscillator circuit, and may possibly vary the shape of the individual pulses. 4i lator anode and control electrode circuits for varying the time‘ intervals between pulses gener ated by said oscillator in accordance with said modulator anode circuit variations. The use of the extremely high anode voltage on 2. A pulse transmitter including a pair of oscil the oscillators and modulator will also tend to $1 lator tubes having push-pull tuned anode and reduce the transit-time losses in these circuits. control electrode circuits coupled to provide oscil Fig. 2 shows the variation in time interval be lations, a capacitor in said control electrode cir tween successive radio time frequency pulses cuit connected to effectively block said oscilla resulting from a variation in the resistance of the leakage path through the tube i3 for the 10 tions, a modulator having control electrode and capacitor l2. Fig. 3 is a block diagram of a receiver which will provide satisfactory reception of the signals anode circuits, means for applying modulating potentials to said modulator control electrode circuit to vary the resistance of said modulator anode circuit, and means connecting said modu radiated from the transmitter of Fig. '1. The receiver may be of any conventional design such 15 lator anode circuit between said oscillator anode and control electrode circuits for varying the time as a radio frequency ampli?er 3| followed by a intervals between pulses generated by said oscil detector-A, V. C. circuit 32, and an audio ampli lator in "accordance with said modulator'anode ?er 33 connected to a reproducer 34. The .auto circuit variations. ‘ matic volume control circuit is shown connected 3. A pulse transmitter including a pair of to the radio frequency ampli?er by the line 35, 20 oscillator tubes having push-pull tuned anode, so as to bias off all but the peak portion of the control electrode and cathode circuits coupled to received’ pulses as shown by the pulse peaks 22 provide oscillations, a capacitor connected be above the dash line 2% in Fig. 2. The average tween said control electrode and said cathode noise level‘indicated by the curve 2| in Fig. 2 ordinarily will be considerably lower than the 25 circuits to effectively block said oscillator tubes, a modulator tube having a variable resistance A. V. C. limiting value 20 and will, therefore, anode circuit, means for varying said anode re provide substantially noiseless reception. It sistance of said modulator as a function of modu should be understood that this limiting feature lating potentials applied to said modulator,- and may be applied to any conventional radio receiver by this or other well known methods. I claim as my invention: 1. A pulse transmitter including an oscillator having tuned anode and control electrode circuits coupled to provide oscillations, a capacitor in said control electrode circuit connected to effectively block said oscillations, a modulator having control electrode and anode circuits, means for applying modulating potentials to said modulator control electrode circuit to vary the resistance of said modulator anode circuit, and means connecting 40 said modulator‘ anode circuit between said oscil means connecting said modulator anode circuit between said oscillator anode and control elec trode circuits for varying the time intervals be tween pulses generated by said oscillator in ac cordance with said modulator anode circuit varia tions. . 4. Apparatus of the type described in claim 2 including variable means in said modulator circuit for adjusting said modulator anode circuit re sistance. _ ~ LESTER J. WOLF. '