Radio Corp. of America v. Mackay Radio & Telegraph Co.

16 F. Supp. 610, 1936 U.S. Dist. LEXIS 1833
CourtDistrict Court, E.D. New York
DecidedOctober 14, 1936
DocketNo. 7234
StatusPublished
Cited by1 cases

This text of 16 F. Supp. 610 (Radio Corp. of America v. Mackay Radio & Telegraph Co.) is published on Counsel Stack Legal Research, covering District Court, E.D. New York primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Radio Corp. of America v. Mackay Radio & Telegraph Co., 16 F. Supp. 610, 1936 U.S. Dist. LEXIS 1833 (E.D.N.Y. 1936).

Opinion

CAMPBELL, District Judge.

This is a suit for the alleged infringement of certain claims of five patents as follows :

1. Patent No. 1,623,996 issued to Philip S. Carter, assignor to Radio Corporation of America for radio transmission system, granted April 12, 1927, on an application filed June 25, 1923, of which claims 1, 2, 5, and 7 are in suit. This patent will be hereinafter referred to as the first Carter patent.

2. Patent No. 1,909,610 issued to Philip Staats Carter, assignor to Radio Corporation of America for electric circuit, granted May 16, 1933, on an application filed March 12, 1930, of which claims 1 to 5 inclusive are in suit. This patent will be hereinafter referred to as the second Carter patent.

3. Patent No. 1,884,006 issued to Nils E. Lindenblad, assignor to Radio Corporation of America for antenna, granted October 25, 1932, on an application filed September 7, 1928, of which claims 23 to 27 'inclusive are in suit. This patent will be hereinafter referred to as the first Lindenblad patent.

4. Patent No. 1,927,522 issued to Nils E. Lindenblad, assignor to Radio Corporation of America for antenna for radio communication, granted September 19, 1933, on an application filed December 24, 1928, of which claims 9, 10, 19, and 23 are in suit. This patent will be hereinafter referred to as the second Lindenblad patent.

5. Patent No. 1,974,387 issued to Philip Staats Carter, assignor to Radio Corporation of America for antenna, granted September 18, 1934, on an application filed June 11, 1930, of which claims 1, 2, 3, 4, 10, 12, 15, 16, 28, 34, 35, 36, 38, and 40 are in suit. This patent will be hereinafter referred to as' the third Carter patent.

The first two Carter patents are directed to the subject of impedance matching. The two Lindenblad patents and the third Carter patent are directed to the subject of antennas. I will consider them in the two respective groups.

The defendant by answer has pleaded the defenses of invalidity and non infringement.

The title to the patents in suit is in the plaintiff and notice of infringement was properly given.

There is no dispute as to the construction or arrangement of the defendant’s antenna systems, and they are fully described in the agreed descriptions, diagrams, and tabulations of dimensional data comprising plaintiff’s Exhibits 7 to 13 inclusive. The antennas which are asserted to infringe are known as V-antennas Nos. 1 to 11 inclusive (two of which have been rebuilt) and certain other antennas known as “dipole arrays.” The antennas referred to as having been rebuilt are obviously defendant’s, antennas Nos. 2 and 3, the rebuilding of which was occasioned by commercial requirements oí establishing additional communication channels in a different direction from that in which tljey had previously been used. Various alterations occurred in the rebuilding process, and as these rebuilt antennas were not rebuilt until after the main and supplemental bills of complaint were filed in this suit, they cannot properly be considered by this court under the charge of infringement on the pleadings in this suit.

The desirability for, and the utilization of an impedance matching arrangement-was known many years prior to the earliest date which could be claimed by Carter. In the transmission of electrical [612]*612energy over a line, whenever, as is usually the case, the impedance of the load differs from the impedance of the transmission line, energy will not flow smoothly into the load, but part of it will be reflected back into the line towards the source of power, and cause “reflection,” “standing waves,” “reflection loss,” etc. Also, when there is a sharp bend in a transmission line a difference of impedance results which causes reflection. If, however, the impedance of the load is matched to the impedance of the line there, are no reflected waves, and there is obtained what is termed a “reflectionless line,” “a traveling wave,” a “line of electrically infinite length,” etc. • These terms (as well as others mentioned on the trial and in the briefs herein) are synonymous and the desirability for impedance matching, as well as the means employed for effecting it, is not concerned with the purpose for which the current being transmitted is used. I can see no difference whether impedance matching be effected in a radio receiving system, a radio transmission system, a telephone line, a power line or in any circuit. The second Carter patent in suit is entitled “Electrical Circuit,” and is applicable to any circuit arrangement where efficient transfer of energy without reflection is desired. Unequal impedance is always the cause of reflected waves, and the cure is always equal or matched impedance.

Impedance matching devices for the purpose of preventing reflection on transmission lines have been used for many years in radio transmitting systems, at least, since 1920, and as the first Carter patent in suit was not applied for until 1923, there was nothing novel at that date in the necessity for matching impedances, or in the principle that by matched impedances reflected waves on the transmission line were avoided.

The first Carter patent No. 1,623,996:

This patent is directed to the subject of a reflectionless transmission line obtained by matching the surge impedance of the line' with the load impedance of the antenna which it feeds. A transformer is the only means shown or suggested for accomplishing that purpose, and two forms of transformers are illustrated namely the usual two coil transformer illustrated in Figs. 1, 3, and 5, and the auto (one coil) transformer of Fig. 2.

It is pointed out in the patent that in the past it has been the custom to erect the antenna of a transmitting system as close as possible to the point when the radio frequency power is generated in order to have “a minimum power loss between the generator and the antenna.” The patentee in his specification states the objects of his invention to be as follows: “The provision of a transmission line which will supply radio frequency energy from a power-house to an antenna located at a considerable distance away, thus making possible the utilization of existing apparatus at a high efficiency where hitherto only a low efficiency was possible. Another object of the invention is to provide a new and improved system giving directional transmission utilizing separate antennae fed from a single source through a plurality of transmission-lines.”

Claims 1, 2, and 5 have to do only with the first stated object. Claim 7 has to do only with the second stated object.

It is pointed out in the specification that in order to attain the first object of the invention it is necessary that the apparatus work “at unity power factor; that is to say that the current and voltage in the transmission line should be in phase,” and the patent further says : “Such a result may be obtained if the transmission line is made reflectionless or of electrically infinite length. Under these conditions no waves can be reflected back from the ends to interfere with the natural flow of energy into and out of the transmission line.”

The invention of the patent consists in making reflectionless the transmission line extending between the source of the current and the load. The patentee says in his specification: “This result may be obtained by closing the transmission line 10 at 11 in such a manner that the effective impedance at the load end of the line is equal to the surge impedance of the transmission line.”

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16 F. Supp. 610, 1936 U.S. Dist. LEXIS 1833, Counsel Stack Legal Research, https://law.counselstack.com/opinion/radio-corp-of-america-v-mackay-radio-telegraph-co-nyed-1936.