US2303644A - Antenna system - Google Patents

Antenna system Download PDF

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Publication number
US2303644A
US2303644A US382848A US38284841A US2303644A US 2303644 A US2303644 A US 2303644A US 382848 A US382848 A US 382848A US 38284841 A US38284841 A US 38284841A US 2303644 A US2303644 A US 2303644A
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US
United States
Prior art keywords
antennas
signal
wave
fading
receiving
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
US382848A
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English (en)
Inventor
Katzin Martin
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 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
Priority to BE474926D priority Critical patent/BE474926A/xx
Application filed by RCA Corp filed Critical RCA Corp
Priority to US382848A priority patent/US2303644A/en
Application granted granted Critical
Publication of US2303644A publication Critical patent/US2303644A/en
Priority to FR950191D priority patent/FR950191A/fr
Priority to CH268058D priority patent/CH268058A/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
    • H04B7/0837—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using pre-detection combining

Definitions

  • 'Ihis invention relates to improvements in ultra high frequency receiving systems for receiving waves in the range above 30 megacycles.
  • the path of travel between a radio transmitter and a remote receiver is mainly by reflection from the ionosphere.
  • the ionosphere is no longer capable of reflecting waves of such high frequencies, and communication is effected mainly by means of the direct or ground wave.
  • One source of signal variation is that due to changes in the strength of the signal as received from the signal medium.
  • radio reception such variations are generally known as fading
  • the magnitude of the resultant signal wave depends on the resultant amplitudes and phase relations of both the ground wave and the sky wave produced by the atmospheric discontinuities.
  • This sky wave, which is produced by the atmospheric discontinuities should not, however, be confused with the ionosphere sky wave, because of the fact that the ionosphere is not capable of reflecting the waves of the higher frequencies with which the present in- .reiiected from the ionosphere.
  • the relations between the ground wave and the sky waves produced by the atmospheric discontinuities may be such that they substantially annul each other at the receiver, thus producing what is generally known as a fade out or a substantially complete interruption of the received signal.
  • a fade out it has been observed, may last from about one minute up to about fifteen minutes, thus rendering the circuit inoperative for this duration.
  • An object of the present invention is to overcome the signal variation caused by the sky wave in a communication system employing frequencies above 30 megacycles.
  • Another object is to provide a radio receiving system of high elciency which overcomes substantially completely the possibility of the signal fading out at the receiver by virtue of atmospheric discontinuities when communication is effected at frequencies above 30 megacycles.
  • the invention is based on the fact that if a number of signal collectors (antennas) are properly located in a vertical direction, above one another and sufficiently spaced apart to pick up a transmitted signal, the signal will not fade similarly at each of these signal pick-ups.
  • the possibility of the signal fading out equally at all of these vertically spaced signal collectors or antennas at the same time is obviously reduced with increase in the number of receiving signal collectors or antennas.
  • these receiving signal collectors be spaced from one another in a vertical direction by a i. plurality of wavelengths (at least ten wavelengths). If desired, the signal collectors may be spaced directly above one another cn the same mast, or, if desired, spaced somewhat apart from each other horizontally as well.
  • Signal collectors I and 2 are shown as electromagnetic horn antennas, generally of the type described in my copending applications Serial Nos. 354,954, filed August 31, 1940; 363,248, led October 29, 1940; 369,826, filed December 12, 1940, although it should be distinctly understood that these signal collectors may be dipoles or any other suitable type of antennas.
  • signal collector I might be a dipole or an array of dipoles, or a parabolic reflector antenna, or an electromagnetic horn, as shown, while signal collector 2 might be any one of the foregoing types.
  • the supporting mast 3 this might be a metallic mast or a wooden mast, or any other suitable supporting structure such as a building or a pole.
  • Antennas I and 2 are shown individually cou-Y pled by way of transmission lines 4 and 5 to individual receivers 6 and 1, respectively, whose outputs are combined in a well known manner for amplification in apparatus 8 prior to utilization at 9.
  • Utilization apparatus 9 may be a suitable recorder, or another transmitter for retransmitting the received signals as in a relay station.
  • a suitable automatic gain control circuit here represented by a condenser I and a resistor II forming a time-constant circuit, may be employed for controlling the gains in the receivers 6 and 'I over leads I2 and I3, respectively. This automatic gain control circuit forms no part of the present invention per se and follows well known practice.
  • the present invention is believed to find particular application in systems employing frequencies of the order of 100 megacycles and higher. the relaying of signals by radio, for which reason the present invention is useful in a repeater or terminal station of a radio relaying system,
  • the signal collector I might be spaced a distance of about 400 feet above ground, while the signal collector 2 may be spaced a distance of 200 to 300 feet above ground, these collectors being emmegacycles.
  • Such ultra high frequencies are useful in ⁇ signal collectors and 2 are spaced apart from one another vertically at least ten wavelengths apart.
  • the method of reducing fading due to atmospheric discontinuities in a radio communication system operating at frequencies above thirty megacycles which comprises receiving the same signal wave at a plurality of points each spaced vertically apart from the next adjacent one by a distance at least equal to several wavelengths at the operating frequency, and combining the waves received at said points.
  • the method of reducing fading due to atmospheric discontinuities in a radio communication system at frequencies above thirty megacycles which comprises receiving the same signal wave at a plurality of points each spaced apart from the next adjacent one in a vertical direction by a distance equivalent to at least several wavelengths at the operating frequency, and selectively utilizing only the strongest signal re" ceived at said points.
  • a receiving system for reducing or eliminating fading at ultra short wavelengths due to atmospheric discontinuities between transmitter ⁇ and receiver comprising a plurality of antennas.,V
  • a receiving system for reducing or eliminating fading at ultra short wavelengths due to atmospheric discontinuities between transmitter and receiver comprising a plurality of antennas each spaced apart from the next adjacent one in a vertical direction by a distance equal at least. to several wavelengths at the operating frequen-v cy, individual receivers connected to said antennas, and means for selectively utilizing only the strongest signal in the outputs of said receivers.
  • a radio relaying system for relaying ultra high frequency Waves of the order of 100 megacycles and higher, a relaying station having a' plurality of receiving antennas, each antenna being spaced vertically apart from the next adjacent one by a distance at least of the order of ten wavelengths at the operating frequency, and ⁇ a utilization circuit coupled in common to said receiving antennas.
  • a relay station having a. plurality of receiving antennas of the electromagnetic horn type mounted on a single mast, each of said antennas being spaced apart vertically from the next adjacent antenna by a distance at least of the order of ten wavelengths at the operating frequency, there being a utilization circuit coupled in common to said antennas.
  • an antenna arrangement for reducing or eliminating fading due to atmospheric discontinuities between the transmitter station and the remote receiver station comprising a plurality of antennas at one of said stations, each of said antennas being spaced apart from the next adjacent antenna in a Vertical direction by a distance at least equal to several wavelengths at the operating frequency, and translation apparatus coupled in common to said antennas.
  • an antenna arrangement for reducing or eliminating fading due to atmospheric discontinuities between the transmitter station and the remote receiver station comprising a plurality of antennas at one of said stations, each of said antennas being spaced apart from the next adjacent antenna in a vertical direction by a distance at least equal to ten wavelengths at the operating frequency, and translation apparatus coupled in common to said antennas.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Radio Relay Systems (AREA)
  • Radio Transmission System (AREA)
US382848A 1941-03-12 1941-03-12 Antenna system Expired - Lifetime US2303644A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
BE474926D BE474926A (fr) 1941-03-12
US382848A US2303644A (en) 1941-03-12 1941-03-12 Antenna system
FR950191D FR950191A (fr) 1941-03-12 1947-06-26 Système d'antenne
CH268058D CH268058A (de) 1941-03-12 1947-07-11 Radiostation mit einer Antennenanlage für Ultrakurzwellen.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US382848A US2303644A (en) 1941-03-12 1941-03-12 Antenna system

Publications (1)

Publication Number Publication Date
US2303644A true US2303644A (en) 1942-12-01

Family

ID=23510644

Family Applications (1)

Application Number Title Priority Date Filing Date
US382848A Expired - Lifetime US2303644A (en) 1941-03-12 1941-03-12 Antenna system

Country Status (4)

Country Link
US (1) US2303644A (fr)
BE (1) BE474926A (fr)
CH (1) CH268058A (fr)
FR (1) FR950191A (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2505266A (en) * 1944-05-12 1950-04-25 Radio Electr Soc Fr Radioelectric communication device
US2610292A (en) * 1946-03-12 1952-09-09 Rca Corp Fading compensation radio signaling system
US2860238A (en) * 1953-03-05 1958-11-11 Motorola Inc Diversity receiving system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2505266A (en) * 1944-05-12 1950-04-25 Radio Electr Soc Fr Radioelectric communication device
US2610292A (en) * 1946-03-12 1952-09-09 Rca Corp Fading compensation radio signaling system
US2860238A (en) * 1953-03-05 1958-11-11 Motorola Inc Diversity receiving system

Also Published As

Publication number Publication date
CH268058A (de) 1950-04-30
FR950191A (fr) 1949-09-20
BE474926A (fr)

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