US2166538A

US2166538A - Frequency doubler

Info

Publication number: US2166538A
Application number: US149647A
Authority: US
Inventors: Shore Henry
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1937-06-22
Filing date: 1937-06-22
Publication date: 1939-07-18
Anticipated expiration: 1956-07-18

Description

July 18, 1939. H. SHORE I FREQUENCY DOUBLER Filed June 22, 1957 m m 5 M 0 w PMTEIVMTAGE' m w w 0 F. m w m P E Vm T 0 +0 w w P P ,N .l

INVENTOR HENRY 0196 BY 7%? ATTORNEY Patented July 18, 1939 UNITED STATES PATENT OFFICE FREQUENCY DOUBLER ware Application June 22, 1937, Serial No. 149,647

1 Claim.

This application concerns a new and improved means for multiplying or doubling the frequency of Wave energy of any form of frequency derived from any source. A feature of my means is the use of aperiodic circuits in a frequency doubling system. Of the many advantages of this use of aperiodic circuits or means for doubling the frequency of wave energy a large numher are apparent and others will appear from the detailed description of my invention which follows.

In describing my invention reference will be made to the attached drawing wherein,

Figures 1 and 4 illustrate two circuit arrangements each including the essential elements of my frequency doubler. Additional amplifying or doubling means or both may be added;

Figure 2 is a curve illustrating the grid current plate voltage characteristic of an electron discharge tube operated in accordance with my invention; and

Figure 3 illustrates the plate input current of original frequency and the grid output current of double frequency.

Referring to Figure 1 wave energy of any frequency from any source 2 may be impressed on the anode 8 and cathode l2 of an electron discharge tube 4. This input anode circuit includes no source of potential and may be coupled inductively t the source 2 as indicated, or may be coupled in any approved manner to the source 2. The control grid II! is coupled to an output circuit 6. This circuit includes a direct current branch comprising an impedance 9 and source a of potential 14 which impresses a positive potential on the control grid Ill relative to the cathode l2 and an alternating current branch comprising a coupling condenser II and a reactance l3. This latter branch may be coupled in any manner to the load circuit, such as for example, capacitively, or inductively as illustrated. The load It may include amplifiers or additional doublers and amplifiers. The wave energy of frequency f impressed by 2 on the input circuit of 4 is doubled, due to the characteristics under which tube 4 operates and the double frequency 2;! appears in 6 and Hi. The doubler, including its input and output circuits, maybe aperiodic, or untivity one or more of the circuits following 6 or 5 including 6 may be tuned to the double frequency. In case efficiency is a requirement the input circuit may be tuned in any manner such as by condenser E 8 as shown in Figure 4.

The operation of my frequency doubler as de- 10 scribed above, depends on the grid current plate voltage characteristic of the tube 4 which is as indicated in Figure 2. The plate voltage is varied in accordance with the wave energy supplied from 2 only and with a constant positive potential e on the grid of the tube supplied by I4, the tube has a conical characteristic as indicated. The output alternating current in the circuit I0, I 4, I 2 is of double frequency and is superposed on a steady direct current plate component, unless means such as 9 and H is provided to separate the direct current and alternating current components. Thus, where capacitive coupling is used, as in Figure 1, the coupling capacity will block and remove the direct current component from the output.

In a preferred modification as illustrated in Figure 4 the direct current component is bucked out by connecting a second source 20 and variable resistance 22 in shunt to 9 to produce a current in which opposes and bucks out current i I claim: In a system for doubling the frequency of wave energy, an electron discharge device having an anode and a cathode, means for coupling said anode and cathode to a source of said wave energy only, said electron discharge device having a grid, an output circuit coupled only to said grid and cathode, means for applying a positive potential to said grid relative to said cathode whereby wave energy of double the frequency of the wave energy of said source is produced in said output circuit and means including a variable resistance and a source of potential connected in said output circuit to buck out the direct current component produced therein.

HENRY SHORE.