JPS60141001A - Substantially resistive terminal wide band antenna - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved substantially two-resistive terminated non-resonant (non-tuned) antenna. The antenna of the invention can be used on its own or in combination with an associated directional beam generating element for the transmission and/or reception of electromagnetic waves as required.

It should be appreciated that the present invention is equally applicable to both transmission and reception, as described by way of example in connection with the transmission of electromagnetic waves.

As is the case with many types of electromagnetic wave receiving and transmitting antennas, the method of operation is theoretical for illustrative purposes, and the accuracy and otherwise of such assumptions depend on the actual performance of the antenna.

Electromagnetic spectrum users who wish to operate over large portions of the frequency spectrum must deal with the problem of determining which of the many types of antennas suit their needs.

In some cases, such as general shortwave broadcast reception, an antenna of arbitrary length may suffice.

On the other hand, since today's communications equipment must match the associated antennas and feed lines within narrow tolerance limits for effective operation, serious users of the electromagnetic spectrum have no choice but to use communications antennas of either resonant or non-resonant types. A decision must be made as to which of the two categories to use.

Resonant types may consist of a self-resonant length of wire or other electrical conductor, or any length of wire, tuned to resonate with a comprehensive inductance and capacitance device, commonly known as an antenna tuning uni-node. The first objective is to precisely match the antenna and feed lines to the relevant transmitter and receiver.

Resonant type antennas operate over a small portion of the spectrum without being retuned to resonance in some way, if a positive Uff match with the associated feed lines and transmit (S) and/or receiver equipment is to be maintained. In many cases, only a variation of about 5% from the center resonant frequency can be tolerated without the need for modification. Tuning resonances at various frequencies is difficult and time consuming. , and requires a level of Kiseki from the operator that exceeds that of many users.

For convenient multi-frequency operation, a second category of antennas, non-oscillatory or non-tunable antennas, is therefore chosen, for which there are several designs to choose from. (1) (In some designs of this antenna, there is still the disadvantage of having to tune the antenna tuning unit. However, with the advent of electromagnetic ferrite core abrasives, it is possible to tune the transmission line to this category of antennas. '1JJt h for effective wide band radio
It is now possible to design a lance. This eliminates the need for the use of complex variable antenna tuning units.

The relative power gain between resonant and non-resonant antennas is often estimated and i! This is a matter of debate, and further touching on this aspect would not accomplish the purpose.

A well-known conventional parallel conductor type resistive terminated folded bipolar antenna is illustrated in FIG.

A feature of many forms of non-tunable antennas is that they intentionally allow electromagnetic energy to be radiated into the air as the high frequency current flows from the generator to the negative end of the transmission line. It can be thought of as a transmission line. Radiation is accomplished by separating the wires from each other in terms of wavelength when radiation is desired, and by selecting the physical spacing between the conductors of the transmission line when radiation is to be limited. An example of this type of construction is shown in detail in Figure 2Q, where radiation is limited in the spacing between sections A and A1, but the increasing amount of radiation is attributable to the frequency at which the transmission line/antenna is used. will occur between the B and B1 sections in proportion to the physical spacing between them in terms of wavelength.

The resistive negative 4i1 (R) ohm value has the lowest standing wave ratio (S, W, R) throughout the length of the device.

is selected to be IM'd.

The non-tuning type antenna, an example of which is shown in Figure 2, is
One of the key features is the resonant type 5 that does not require adjustment.
% homologue range, over several octaves without the need for any coordination between the antenna and the associated feed line, subject to the use of a correctly designed wideband matching transformer and associated non-inductive termination resistors. It is possible to operate.

The design of the resistive terminated folded bipole shown in Figure 1 is attributed to Captain G. L. Countryman of the United States Navy, who published a summary of his design in the amateur radio magazine QST in 1945.
It was published in June 1951 and in CQ in November 1951.

The radiation pattern from the antenna of FIG. 1 is difficult to predict.

Referring again to FIG. 1, the antenna includes a transmission line with a 600 ohm surge impedance used to feed a terminated folded dipole antenna of substantially half a wavelength at the lowest required operating frequency. It is shown that it has. At this particular frequency, the radiation pattern resembles that of a conventional resonant half-wavelength folded antenna. Termination resistors, nominally 600 ohms, are substantially non-inductive at the radio frequencies used and are used to absorb energy not radiated into the air. The absorbed energy is dissipated as heat in the resistor. The arrows on the drawing indicate the direction of instantaneous current flow when the frequency corresponds to the case where the antenna is equal to the length of the half-wave resonant folded pole. When the electric field from a current is applied into the air at right angles to the conductor, radiation is maximum in that direction.

At a higher operating frequency using an antenna of the same length, e.g. at the second harmonic (twice the previous frequency), the 1-light current can become as shown in Figure 3.4 or 5. There is sex. Under these circumstances, adjacent sections on any one conductor may be opposite, although opposing conductors may have common mode currents. Because of this, radiation can never occur at right angles to the antenna, and any radiation that may occur is likely to be aligned with the antenna at some other intermediate angle. The aim is to eliminate or at least minimize the disadvantages of dipole antennas.

The invention therefore provides: at least one radiating element having a first and a second end; at least one conductor connected to the conductor and a substantially resistive terminal connected to either the other end of the conductor or a second αR1 of the radiating element; impedance matching means connected to the conductor as well as to the remainder of the second end of the radiating element for carrying no current between the radiating element and the feed line, so that when in use Substantially resistive terminated traveling wave wide hand antenna, characterized in that radiation from or reception by the conductor is prevented by the radiating element or by a further seal 1' interposed between the radiating element and the conductor. I will provide a.

The main difference between the antenna of the invention and known non-inductive terminated folded dipole antennas is that in the antenna of the invention at least the radiation from the conductor is intentionally prevented, so that the opposing electric field is no longer radiated into the air. be. Radiation is prevented by shielding the conductor. According to one aspect of the invention, this shielding is performed by a radiating element.

This shielding may be carried out by another shielding element interposed between the radiation element, 1. and the conductor.

The invention will now be described, by way of example, with reference to the accompanying drawings.

In the drawings, FIG. 1 illustrates a known non-tunable non-inductive end-folded antenna.

FIG. 2 illustrates a known antenna configured for transmission.

Figures 3.4 and 5 illustrate the instantaneous current flow of the antenna of Figure 1 at higher frequencies than at the lower end of the frequency spectrum.

FIG. 6 illustrates the integrated body side of an antenna fabricated according to the present invention.

FIG. 7 illustrates another embodiment of an antenna made in accordance with the present invention.

8 and 9 illustrate a method of erecting an antenna according to the present invention.

Figures 10 and 11 illustrate further embodiments of antennas according to the invention.

FIG. 12 illustrates how the antenna of the present invention can be erected to obtain a low radiation angle.

FIG. 13 illustrates another antenna according to the present invention useful for obtaining low radiation angles.

FIG. 14 illustrates the main parts of the present invention in a rhombic type antenna.

FIG. 15 illustrates another embodiment of the antenna according to the invention.

FIG. 16 illustrates a modified antenna of the present invention that can function as a resonant and traveling wave broadband antenna.

-! of the present invention! 1. An antenna following the body side is illustrated in FIG. 6, the length of which is substantially one-half wavelength of the minimum required operating frequency. Section A
and A1 is the radiating section, in which the current travels outside the tubular conductor. The ends of sections Δ and A1 are electrically connected to the ends of sections I3 and +31, which are otherwise insulated from the interior areas of sections Δ and A1. The central portions of sections Δ and A1 are electrically connected to a non-inductive termination element such as a resistor, and the central portions of sections Δ and A1 are fed through impedance matching means such as a coupling transformer. connected to the line. One winding of the transformer extends between the ends of conductor B, B1. Section Δ, Δ1
The linear frequency energy that was not radiated into the hollow from the outer surface of B1 is transmitted along the outer surface of inner conductor B, B1)
The heat flows to the collector resistor 17, where it is dissipated as heat.

1) As in the case of electrical coaxial cable type transmission lines,
Section B, the electromagnetic and electrostatic fields generated from the radio frequency current traveling along Bl towards the termination resistor n are 1) 30 degrees out of phase with the internally generated electric field due to the action of the internal transformer. so that the electric field is induced,
The conductor is section A.

Since it is used for envelope I by A1, it is prevented from being emitted into the air. Therefore, the conductors Δ and A1 are of two types 11! (on the outer surface area due to line frequency currents, an effect known as the ta + skin effect, and (bl
The outer surface of inner section B and B1 carries a current on the inner surface area resulting from induction from the current flowing towards the resistor. Radiation occurs only from the radio frequency currents on the outer surfaces of sections Δ and A1, and the radiation pattern is not influenced by the electric field from the currents traveling on the inner sections B and B1.

A modification of the antenna of the invention is illustrated in FIG.
The only difference is that the central conductors B and B1 are connected to the transmission line, or the matching transformer is connected to the transmission line, and the central sections of the radiating sections Δ and A1 are connected to the terminating resistor. The light waves generated from the radio frequency current traveling along sections Δ and 81 can be expected to be at an angle of about 45 degrees with respect to the direction of travel of the Group 5 wire frequency current. Therefore, the directivity of the radiation pattern from an antenna constructed according to the invention depends on whether the radio frequency energy from the transmitter is supplied to the antenna via sections A and A1 or via sections B and B1. will. In the former case, a wide radiation pattern can be expected, and in the latter case, a sharp pattern can be expected.

Irrespective of the direction of travel of the current along the radiating section of the invention, an antenna arranged to receive radio waves from the invention has secondary characteristics that are found to be expensive in the invention in which it is generated. will survive regular sinusoidal fluctuations in the electric field strength without changing from the opposing electric field strength.

Pointing of antennas uses it in conventional arrays of parasitic or driven element designs, with the advantage that its impedance for matching purposes differs little from that when used as a conventional antenna. This allows for intentional changes in one-way mode.

An antenna according to the invention can be fabricated by placing a conductor in the interior of an electrically conductive hollow tube. Alternatively, the antenna can be constructed entirely from conventional coaxial type transmission lines.

The antenna of the present invention has a shape in which most resonant type antennas can be erected, such as the horizontal type antenna shown in Fig. 8, the inverted ■-shape shown in Fig. It can be erected like the vertically polarized antenna shown in Figures 10 and 11.

The vertical antenna shown in FIG. 10 resembles a conventional grounded vertical resonant type antenna, which must have a frequency substantially equal to one-fourth of the wavelength at the lowest required operating frequency. However, with the antenna of the present invention, it has been found that an antenna of a given length can often operate at lower frequencies with acceptable performance.

Figure 11 shows all amateur radio frequency band 3.
5.7.10.14.18.24 and 28 Mllz
Throughout the entire range of scents, 1. '5: Measurement t1. of 1 or less. Figure 2 illustrates a construction method that has been found to work satisfactorily over a frequency ratio of 10:1 (3 to 30 Mllz) with s, $Q, and Ima. Tests have shown that intermediate frequency operation is satisfactory in most cases.

The vertical section is made of aluminum tubing, in which is housed the wire that serves as the non-radiating section. The other half of the antenna, shown horizontally in the drawing, is made of energized coaxial cable. Then a hollow tube can be used. This section of the antenna, which can be thought of as a countervoice, is
It has been found that it can be grounded or coiled as desired, with little apparent variation in performance. However, a more constant steady-state liquid ratio will be maintained as the counterbodies are placed above ground.

FIG. 12 illustrates how to erect the antenna of the present invention as a long slope wire for low angle radiation.

Figure 13 shows another low angle number using the present invention! Directional paralysis (i) The directionality depends on the length of the radiators and the angle between them with respect to the operating frequency.

FIG. 14 illustrates how to construct a rhombic antenna using the principles of the present invention, where adjustments to the value of the final I/iMI Ill:resistor can be made at the feed point if desired;
Also, since the directivity of the antenna can be changed by 180 degrees at the feed point, it has the advantage over conventional terminated rhombic antennas that no additional feed line is required at the opposite point of the antenna.

Another embodiment of the invention is shown in FIG.

The coaxial cable and its inner core may be coiled to physically fit inside a hollow nonconductor such as fiberglass, or it may be coiled onto the outer surface of an insulating material (=j
i: I will be. With this specific example, it is possible to fabricate an antenna suitable for mobile station operation, and a prototype model with a length of only 21TI has an acceptable performance as a mobile station Poynop antenna.
It is clear that E is 4' (j).

A 10 m long block of the Jl-type is working very well, it stands up freely and a simple mechanical device for removing it (=JC: + It has the advantage of requiring less than &J. Its operating frequency is from 3.5 MIIZ to 30 MII2.

FIG. 16 shows another specific example of the anchor according to the present invention. Details of the terminating elements and matching means have been omitted for ease of understanding. This antenna has radiating element A
, A1, with conductors B, 13x disposed therein, and one end of which is connected to element A, AI. The extensions C and C1 have a length equal to giving a total length X to Xl equal to 1/2 of the wavelength of a frequency lower than the frequency at which the wide antenna is intended to operate when functioning as a traveling wave antenna. There is. This antenna allows use as a conventional resonant antenna at low frequencies and as a wide-hand antenna at high frequencies.

The antenna of the present invention allows for more uniform and predictable transmit and receive field patterns than parallel conductor type resistively terminated dipole antennas for IJ'j.

The antenna according to the invention is suitable for high frequency (3 to 30 Ml
lz) and VIIF (50 to 500 Mllz)
can operate satisfactorily over a frequency ratio of 1 (11). The operating range is determined by the physical length of the antenna, the matching device, and the selection of conductors.

An additional advantage of the antenna of the present invention is that there is no longer a transformer action between the two conductors and the current in the radiating section is increased by a factor of about 1.4 with improved field strength over a conventional three-conductor folded bipole. This is something that can be expected to happen.

By extending its length to achieve resonance, the antenna of the present invention can be used at frequencies lower than those for which it is intended to be used as a traveling wave type antenna.
It can also operate as a conventional resonant type antenna. This design change does not significantly affect the wide-hand 11-, LR characteristics of the antenna at the higher frequencies of use.

[Brief explanation of the drawing]

1 is a schematic diagram of a known non-tuned non-inductive end-Al folded antenna; FIG. 2 is a schematic diagram of a known antenna configured for transmission; FIGS. FIG. 6 is a schematic diagram of one embodiment of the antenna of the present invention; FIG. 7 is a schematic diagram of an antenna according to eleven embodiments; FIGS. Figures 10 and 11 are schematic diagrams of antennas according to other specific examples, and Figures 12 and 13 are schematic diagrams for setting up low radiation angles ('', i). Figure 14 is a drawing showing how to set up the antenna.
Figures 15 and 16 are diagrams of an antenna according to yet another specific example. 8 and 81 are radiation safety lines, B and +3z are conductor sections, and R is a resistor. FIG, 1 FIG, 3 FIG, 4 FIG, 6 FIG, 7 FIG, 8 FIG, 10 FIG, 12 FIG, 13 FIG, 14 FIG, 15

Claims (1)

Claims: +11 at least one radiating element having first and second ends;
at least one conductor extending and having two ends connected to a first end of the radiating element I; and a substantially substantially a resistive termination element; and an impedance match connected to the other end of the conductor or to the remainder of the second end of the radiating element for passing current between the conductor or the radiating element 1 and the feed line. a substantially resistive means, characterized in that in use radiation from or reception by the conductor is prevented by the radiating element or by another shield interposed between the radiating element and the conductor; Terminated traveling wave wideband antenna. (2) The antenna of clause 1 including two said radiating elements each having said conductor extending therein. (3) The terminal element is the second of the radiating elements.
The antenna of the second term extends between θj1.1 of . (4) The antenna of clause 2, wherein the terminal element 11.1 extends between the other ends of the conductor. (51i%iJ) The impedance matching means is an antenna according to item 4, which is a transformer in which one winding extends between the second ends of the radiating element. (6) The impedance matching means has one winding extending between the other ends of the conductor. (7) The terminating element is connected between the other end of the conductor and a reference potential, and the matching means is such that one winding is connected to the second end of the radiating element. (8) The antenna of any one of clauses 2 to 5, wherein one of the radiating elements acts as a countervoice element. (9 ) the radiating element has the same electrical length as the second radiating element;
The antenna according to any one of items 6 to 8. 00) one of said radiating elements has a length substantially equal to at least one quarter of the wavelength at the lowest operating frequency, and the other of said radiating elements has a length equal to several times the wavelength at the lowest operating frequency; An antenna according to any one of the second to sixth terms and the eighth term. 01) An antenna according to any one of clauses 1 to 10, wherein the shielding of the conductor to prevent radiation or reception is achieved by another shield interposed between the radiating element and the conductor. (+2) Each of said radiating elements has a radiating extension of equal length giving a total length equal to half the wavelength of the operating frequency, so that the antenna can be used at frequencies lower than the frequency at which it is intended to be used as a traveling wave antenna. The antenna according to any one of items 2 to 11, which can also operate as a resonant type.