US3543274A - Multi-band vertically stacked loop antenna array - Google Patents

Description

w. A. Haves Nov. 24, 19701 MULTIBAND VERTICALLY STACKED LOOP ANTENNA ARRAY Filed July 12, 1968 INVENTOR. WILLIAM A. HAYES United States Patent 3,543,274 MULTI-BAND VERTICALLY STACKED LOOP ANTENNA ARRAY William A. Hayes, 12 Schiller St., Hicksville, N.Y. 11801 Filed July 12, 1968, Ser. No. 744,369 Int. Cl. H01q 11/12 US. Cl. 343-742 5 Claims ABSTRACT OF THE DISCLOSURE This invention relates to high frequency antennas, for instance TV antennas.

The invention uses an open loop half wavelength antenna element for each channel and the antenna elements are mounted on a transmission line in stacked fashion so that they are each one quarter wavelength of their channel frequency from the mounting point of the transmission line, which point is an electrical short. The transmission line is preferably a rigid parallel wire transmission line which is connected to a mounting pole at the single connection point.

The antenna is suitable for use as a home TV antenna and the higher frequency channels require small enough loops so that the antenna may be an indoor antenna for the higher frequency channels.

Accordingly, a principal object of the invention is to provide new and improved high frequency antenna means.

Another object of the invention is to provide new and improved TV antenna means.

Another object of the invention is to provide new and improved high frequency antenna means comprising a plurality of open loop antennas arranged in a vertical stack.

Another object of the invention is to provide new and improved high frequency antenna means comprising a plurality of open loop antennas arranged in a vertical stack and mounted on a rigid transmission line extending at an angle to the vertical.

Another object of the invention is to provide new and improved high frequency antenna means comprising a transmission line adapted to be mouted on a support at a connection point, said transmission line extendig generally vertically, a first horizontal open loop antenna substantially half of a first wavelength long connected to said transmission line at a distance of substantially one quarter of said first wavelength from said connection point, said open loop antenna being generally circular and centrally positioned with respect to the axis of said support.

These and other objects of the invention will be apparent from the following specification and drawing:

Referring to the drawing, the antenna is mounted on a support pole 1 at a connection point 2. The antenna comprises a rigid parallel transmission line 3 which is mounted to the pole by means of a connecting stub transmission line 4. This may be a metal connection and ends in an electrical short. The antenna elements 7, 8 and 9, etc., are open circular loops, which are connected at one end to one of the wires 3a and 3b of the parallel wire line. Note that the connections alternate between the wire 3a and wire 3b, which has been found preferable. The antennas are positioned so that each antenna is a quarter wavelength along the transmission line from the connection point 2, so that each antena mounting is a quarter wave matching stub. The lower frequency antennas 2a, 4a, 5 and 6 are mounted similarly to the upper group.

The antenna feed is by means of a conventional parallel wire line 10 at the point 3. The location of the point 3' is preferably made by connecting up the antenna and adjustably moving the connection 3' for maximum reception. However, once the connection is made, it will be permanent. The connection of the stub line 4 to the transmission "line 3 is also preferably adjustable for maximum reception at any particular location. However, once the connection is made, it is permanent.

Since the support pole 1 is vertical, the planes of the loops wil be horizontal. For a typical TV band installation, the overall vertical dimension of the antenna will be about 5 ft. and the upper loop will be about 10 inches in diameter and the lowest loop will be about 2.5 ft. in diameter. The upper loops are preferably made of /8 inch solid aluminum wire and the transmission line 3 and lower loops may be made of in. aluminum tubing. The surface of the tubing is preferably anodized or plated with a high conductivity metal.

For the higher TV frequencies, the loops will only be 8-10 inches in diameter, so that the antenna may be used as an indoor antenna. Since the antenna is only supported at the one connection point 2, it is preferably reinforced in the lower area by means of an insulating spacer 11, which is connected to a horizontal spacer 12, the other end of which is connected to the pole 1 with a clamp 13 or other equivalent support means.

It has been found that the present antenna is an improvement over conventional Yagi type antennas with respect to space and it is also an improvement with respect to the problem of ghosts which is very important when using color TV.

The antenna has a reception pattern which is directional in the direction shown by the arrow.

The open loop broad band antenna of the present invention is designed to receive radio signals of two or more different groups of frequencies. The upper portion for frequencies between 179 mHz. (or me.) and 216 mHz., the lower portion for frequencies between 54 m'Hz. and 88 mHz. Other loops could include UHF and FM frequencies.

A number of open loop, half wave antennas are arranged in a stacked configuration. In the high frequency group, the lowest frequency loop is one quarter wavelength away from the short located on the supporting pole. Each succeeding loop is cut to a higher frequency and is connected to a point one quarter wavelength from the short.

At an optimum matching point of the high frequency group, the stub is bent in and becomes a mechanical support about four inches long for the upper part of the antenna. The short on this matching stub is also the short for the low frequency group in the lower portion of the sketch. The shorting stub is, therefore, common to both sections. Each half wave loop is arranged one fourth wavelength from the shorting point at the top of the supporting pole.

A second matching point for the 300 ohm ribbon transmission line is located about 14 inches from the shorted point at the top of the supporting pole. This is about ten inches from the high frequency matching point and the above mentioned 4 inch bent in part.

This loop type antenna is very compact, small in size and can be made very strong due to the configuration. This makes the antenna resistant to bending due to ice loading and perching birds.

A small compact and efficient antenna for indoor use can be designed from this configuration.

Preliminary tests show the antenna has excellent signal pickup and is very directional. The best reception is obtained when the open ends of the loops are toward the radio transmitter.

Many modifications may be made by those who desire to practice the invention Without departing from the scope thereof which is defined by the following claims.

I claim:

1. High frequency antenna means comprising:

a transmission line adapted to be mounted on a support at a connection point, said transmission line extending generally vertically,

a first horizontal open loop end fed antenna substantially half of a first wavelength long connected to said transmission line at a distance of substantially one quarter of said first wavelength from said connection point, said open loop antenna being generally circular and centrally positioned with respect to the axis of said pole.

a second open end feed loop antenna, substantially half of a second Wavelength long, said second antenna being connected to said transmission line at a distance of substantially one quarter of said second wavelength from said connection point.

2. Apparatus as in claim 1, having a plurality greater 4 than two of open loop antennas, each antenna being substantially half a wavelength long, each of said antennas being mounted on said transmission line substantially one quarter of its Wavelength from said connection point.

3. Apparatus as in claim 2, wherein a first higher frequency group of said antennas is mounted above said connection point and a second lower frequency group of said antennas are mounted below said connection point.

4. Apparatus as in claim 3 wherein said transmission line is a rigid parallel wire line and said antennas are alternately connected to one of said wires and the other of said wires.

5. Apparatus as in claim 4 wherein said support is a vertical pole extending along the axis of said loop antennas.

References Cited UNITED STATES PATENTS ELI LIEBERMAN, Primary Examiner US. Cl. X.R. 343-816, 890

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