Shulou(Shulou.com)11/24 Report--

Hello, everyone, this is Radio Frequency School.

Today we are going to learn about the famous inventions in the history of the antenna.

Franklin Antenna (invented in 1924) Today, a classmate on the knowledge planet asked about the design of Franklin's antenna. It is a shame that this is the first time I have heard of this kind of antenna. When it comes to Franklin, everyone's first impression is the great American scientist who flew kites and played lightning on a thunderstorm, but this Franklin is not Franklin, the inventor of the Franklin antenna is Charles Samuel Franklin (Charles Samuel Franklin) of England.

For a brief introduction to CS Franklin, we can also find some on the website:

Charles Samuel Franklin (Charles Samuel Franklin), published under the name CS Franklin, is a famous pioneer of British broadcasting. Born in London, Franklin was the youngest of 13 families and was educated at the Finsbury Institute of Technology in Finsbury, England, under the guidance of Silvanus P. Thompson. After graduating in 1899, he joined Marconi, where he spent his entire career. He was first sent to South Africa to equip the Boer War and then spent two years in Russia. After returning to England, he invented many important radio equipment, including variable capacitors, linkage tuning, variable coupling, coaxial cable and Franklin oscillator. Today, Franklin is famous for his shortwave antenna Franklin beam antenna. From the Poldu station of Marconi in 1923 and 1924, he sent shortwave transmissions to Guglielmo Marconi on the South Atlantic yacht Electra. Franklin was also actively involved in the early development of television. In 1935, the trustee leased part of the Alexandra Palace to BBC,BBC to use it as a production and transmission center for the new BBC television service. Franklin designed its antenna and produced the world's first public HD television broadcast from this website in 1936. "

The first antenna patent we are going to introduce today is the patent applied by CS Franklin in 1924, patent number: 242232, this patent describes in detail the technical composition of Franklin's antenna: in order to ensure that the type of antenna with electric length compared to the signal wavelength has a significant directional effect, measures must be taken to suppress the radiation from each alternating half-wavelength formed by the standing wave along the antenna. For example, figure 2 shows the normal conditions along antenna A, one and a half times the signal wavelength, curve B shows the formation of standing waves, and the polar coordinate diagram of radiation consists of six points curve C. By doubling the central stationary band of the antenna itself, the final polar curve is changed to the form shown in figure 3. Alternatively, the return part can be replaced by an equivalent electrical equivalent, such as an inductor coil with or without a shunt capacitor, which is basically tuned to the basic wavelength. The longer or higher the antenna modified in this way, the more obvious the directional effect. The present invention can be applied to antennas of the type described in specification 226246.

Zeppelin airship antenna (invented in 1909) this antenna was proposed by the German Hans Beggerow in 1909, invention patent number: German Patent Number 225204: airborne wiring diagram, marked with two suspended lines of different length, forming a Lecher system near the airship.

Hans Beggerow is a German scientist and philosopher. He is the son of Richard Beggerow, captain and company commander of the 14th Infantry Regiment, and his wife, Catherine Emsmann (Katharina nee Emsmann). After graduating from Stettin's Schillergymnasium, he studied at the universities of Berlin and Freiburg, where he earned a PhD. doctor. He then took up a variety of practical careers, including in New York. From 1901 to 1919, Hans Beggerow worked in the Radio Telegraph Science and Technology Department of the German Marine Corps and retired as a member of the Admiralty. Then he worked as a private scholar in Gottingen. He specializes in epistemology and philosophy and welcomed national socialism a long time ago. In addition, he developed a long-wire antenna called the Zeppelin airship antenna, which uses a λ / 4 ribbon cable for impedance matching. The ribbon cable is used not only as an impedance converter, but also as a counterweight, so the Zeppelin antenna can work like a symmetrical antenna without grounding. The antenna got its name from its first use on airships such as the Zeppelin in the 1920s. Hans Bigelow filed the corresponding patent as early as 1909. "

Beverage Antenna Beverage Antenna (invented in 1920) Beverage Antenna was invented by American Harold H. Beverage in 1920, patent number: US Patent Number 1381089: in implementing my invention, I used a horizontal, preferably aperiodic antenna that extends parallel to the transmission direction of the signal to be received. The antenna consists of distributed capacitance, inductance and resistance, and its value causes the current generated by the desired signal to increase gradually from the end of the antenna closest to the transmitting station and, preferably, reaches the maximum value at the farthest end from the transmitting station.

Yagi Yutian antenna (1926 invention, patent number: 69115, inventors: Hidetsugu Yagi and Shintaro Uda)

Yagi Yutian antenna is the most commonly used type of television receiving antenna in the past few decades. It is the most popular and easy-to-use type of antenna with better performance and is known for its high gain and directivity. This antenna, which is most often used for TV reception, I remember shaking it when the TV signal was bad when I was a child.

Yagi antenna is a dipole array coupled by electric field and magnetic field. It was effectively used as a radar antenna by allies in World War II and then widely used as a television receiving antenna all over the world. This extraordinary structure allows components to be combined into a high-gain unidirectional array without the need for interconnected feeders. Each element is a continuous piece of metal with no insulator in the middle and has a high strength and simple structure. Compared with the gain, the weight and wind load of the antenna are also very low.

Bruce Antenna (1927 invention, Patent number: 1813143, inventor: Edmond Bruce)

Due to the physical size of the antenna, the energy provided by the local radiation source or the energy from the waveguide incident on the antenna generates a current in phase with each other in the active element.

Steppa Antenna (invented by Ernest J. Sterba in 1929, Patent number: 1885151)

One object of the present invention is to transmit or receive radio frequency waves with greater directivity on the earth plane than has been practiced so far. Another object of the present invention is to transmit or receive radio frequency waves at a very low projection angle. Through the invention, the above two purposes can be jointly realized, thus making it possible to be very close to the theoretical ideal of point-to-point communication, wherein all transmission energy is utilized at the relevant receiver. A further object of the present invention is to transfer energy between the antenna elements and their associated translation devices, with relatively less energy loss and in a simpler and cheaper manner than before.

Diamond antenna (Edmond Bruce invented in 1931, patent number: 2285565)

Excerpt: one object of the present invention is to enable the directional antenna to operate effectively over a considerable wavelength range. Another purpose is to ensure a relatively high receiving or transmitting angle. Another object of the invention is to make the antenna sensitive and selective. Another purpose is to save the cost of the supporting structure compared with the previous antennas with similar directional characteristics. Another object of the present invention is to distinguish unwanted horizontal projected energy.

Gate antenna (George H. Brown invented in 1935, patent number: 2086976) excerpt: I know that vertical antenna systems with a height of no more than half a wavelength can be used for horizontal radiation. This system is satisfactory for long waves, but defective for short waves. It has been proposed to reverse the phase between alternating half-wavelength portions, thereby allowing the use of multiple half-wavelength portions. Several half-band antenna systems have practical difficulties in isolating these segments separately. It has also been proposed to use horizontal antenna elements with insulation rods and phase adjustment circuits, but this system has serious structural and electrical difficulties. The novel arrangement I proposed can be used to overcome these difficulties and improve radiation efficiency at the same time.

Folded dipole antenna (Philip S. Carter invented in 1937, patent number: US2283914) excerpt: although the dipole has tuning characteristics wide enough to provide satisfactory transmission and reception in frequency bands such as those used in television, it has been found that when this type of half-wave antenna matches any transmission line, it has been found in known common ways (such as by using parallel impedance elements, or sectors and taps of transmission lines. Or by using the 1/4 band of the line), the tuning characteristics of the dipole become very narrow and insufficient for the frequency bands that are now commonly used for television purposes. As a result of a test of a half-wave dipole

Coaxial antenna (Arnold B. Bailey) was invented in 1937. (patent number: US2184729) excerpt: one object of the present invention is to generate an undistorted wireless electric field of maximum intensity. Another object of the present invention is to eliminate radiation from transmission lines and other auxiliary devices associated with the antenna system. Another object of the invention is to ensure the antenna directional characteristics which are the same as the corresponding theoretical characteristics in practice. Another object of the present invention is to prevent the establishment of an electric current on the outer surface of the sheath in a coaxial system.

Butterfly dipole antenna US Patent No.: 2175253 year: 1938 inventor: Philip S. Carter

The invention relates to a shortwave antenna system, one of the purposes of which is to provide a simple form of shortwave antenna whose impedance pair frequency characteristic is much wider than that of a simple dipole type antenna.

Slot Antenna UK Patent No.: 515684 year: 1938 inventor: Alan Dower Blumlein

Abstract: the high-frequency transmission line is also used as a radiator and consists of a copper metal conductive tube 1, as shown in figure 1, with a longitudinal slot 2. The tube forms a "magnetic flux transmission channel", which is equivalent to a line with inductors in series and parallel inductors and capacitors. The high frequency signal current may be fed to the line through the coil 4 or through the lead wire 4a connected to the slot and drawn out by the coil 5. The flux leakage on the slot can be adjusted by board 6. Figure 2 may adjust the size of the slot and adjust the circuit to the operating frequency, as shown in the figure. 3 and 5. The tube can be used as a transmitting antenna to produce maximum radiation at right angles to its length, while axial radiation is relatively small. It is equivalent to a single loop or frame with a length of one wavelength. The feed can be in the center or at one end. As shown in FIG. 6, the tube 7 is supported at the voltage node 9 by the hollow mast 8 and is fed with signal energy at points 10 and 11 at a distance of half wavelength, and the lead wire drawn upward from the mast is as shown in FIG. 7. Tubes with diameters of 6 to 12 inches are suitable for transmitting wavelengths of 5 meters, although larger diameters with multiple slots can be used to cover a wide frequency range.

Angular reflection Antenna US Patent number: 2270314

Year: 1940

Inventor: John D. Kraus

This article is from the official account of Wechat: radio Frequency School (ID:RF_Center), author: RF Carpenter

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