FR2559623A1 - Omnidirectional miniature transmission and reception antenna with gain. - Google Patents

Abstract

The invention relates to an aerial for transmission or reception of radio waves in the field of telecommunications or telemeasurement or radio communications or the like. It consists of a feed area 1, for two lines 2, forming a lambda /8 dipole, feeding two other lambda /4 shaped lines 3, in opposition, which form the base. A lambda /8 vertical whip 4 is connected at one end to the feed point and includes, at the other end, a loop 5 tuned to lambda /4. A slider device 6 provides for adjustment of the loop 5, on the whip 4, to obtain a minimum standing-wave ratio. The antenna according to the invention is particularly intended for the transmission or reception of radio waves.

Description

2..59623

  The present invention relates to an aerial for transmission or

  the reception of hertzian waves, in the field of telecommunications-

  tions or telemetry or radio communication or other.

  Omnidirectional antennas are generally bulky and gainless. The antenna according to the invention has a powered ground plane and

  granted, that is to say a doubling of an eighth wave which feeds at its ends

  mitée two quarter-wave line in opposition, a whip tuned to an eighth wave and including at its end a feedback loop I0 tuned to a quarter wave, Its gain is ten decibels minimum per

  compared to a dipole, with a minimum standing wave ratio.

  Figure 1, ropr6aente the antenna in a perspective.

  Figure 2 shows an example of a standing wave ratio.

  res creates a working frequency of 145 megahertz.

  here, the antenna shown in FIG. 1, is composed of a feeding zone

  half (1), for the ooaxial cable, and a spacing of 5 to 10 mil-

  limeterq approximately. This power point can be mounted in an isi.znt box at the frequency concerned. Two lines (2), forming a dipole 2 feed two other lines (3), square or

  oirilaire or other of __ in opposition, which form the base.

  A vertical whip (4), tuned to is fixed at one end to the feeding point, and comprises at the other end a loop (5), of ear or circular shape or other tuned to A un oinsing device (6), for setting the minisum standing wave ratio by changing the position of the loop

(5), on whip e4).

  The antenna is made with copper wire or tube, brasses alui. ni'um, stainless steel or other, whose section and nature may vary

according to use.

  430 This antenna comprising several points of radiation has a vertical alignment, and is omnidirectional, with a minimum gain of 10 dpcibel a compared to a dipole. Its overall size is do4nc much smaller than current antennas (8 times more; pitecs than a donkey working in full wave, and 4 times more

?, 5 pe-i; t e ee Ri.tenn half-wave).

  2 2r59623 For example, a frequency centered on I45 # 6gahertz according to figure 1, and considering that the wavelength X is equal to:

  Light speed - 300,000 Km / s - 2 m = 2,000 mm.

  Frequency I45,000 Khz / as The lines (3), of i -500 mm which in their square shape give a wedge of length 250 mm.

  The vertical whip (4), from A - 250 mm.

  The loop (5), of> = 500 ma, which in its square form gives

the summer with a length of I25 amm.

  The standing wave ratio according to the example shown in I0 Figure 2, is minimum, which indicates that the antenna works

  correctly in transmission as in reception.

  The antenna according to the invention is intended to be used in transmission-

  transmission or reception of all telecommunication or telemetry, or radiocommunication or other fixed or mobile systems, in a very broad spectrum of I5 frequency which has no limit except the possibility of manufacturing

  in a minimum or maximum size.

Claims (2)

  1) Miniature omnidirectional gain antenna, characterized in that it comprises a feed zone (1). Two lines (2), forming a dipole> feed two other form lines   square, or circular (3) A in opposition which form the base.   A vertical I (4) of \ connected at one end to point d. 'alimntatlion and comprising at the other end a loop (5) of! 5re square cu circular, granted a To adjustable on the whip by the oulisseam (u) poeur a standing wave ratio XO 2) 2nd antenna] on the revndiciion i characterized by the plane of aol alimentét, forr, 4 des ii A (2), and> \ (3) 3) Dipositif 'le, ia -evedioaio. 2nd characterized by the úfouet. (4), aliimon granted A 4) Dilpositii ie1lon claim 3, characterized by the i5 loop (5) acode /) Device solon claim 4, characterized in that the cculisseau <) asure the aocord of the loop (5), relative at t4).   8) i nme according to any one of the preceding claims   evenly increased as it is made of copper wire or tube, laii.or ,,! uminiur. stainless steel = -   t7) Ant; nns 2cirn 17any of the preceding claims   oarct4r:; s, if we see that the section of the elements can vary according to J 7.1 c