# US 4,396,920 A · Broad-band small-size radio-frequency antenna system

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- Number: US 4,396,920 A
- Document ID: US4396920A
- Status: Granted
- Kind: A
- Application number: 06/171,428
- Filed: 1980-07-23
- Granted: 1983-08-02
- Earliest claimed: 1979-12-09
- Inventors: David Grimberg; Yoram Kol
- Web page: https://patentgrep.com/patent/US4396920A

## CPC

- H01Q 9/36: with top loading
- H01Q 9/40: Element having extended radiating surface
- H01Q 9/46: with rigid elements diverging from single point
- H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72)

## Abstract

A broad-band, small-size radio-frequency antenna system includes a transmission line antenna feeding a monopole antenna, the antenna system exploiting the opposite narrow-band characteristics of the above antennas so as to complement each other and to produce an antenna system of broad-band monopole antenna characteristics.

## Claims

### Claim 1

A broad-band radio-frequency antenna system characterized in that it includes a ground plane; a first bar extending therethrough substantially at a right angle to the ground plane; a second bar connected to said first bar and extending substantially parallel to said ground plane, said second bar being located and dimensioned to form a transmission line antenna with said ground plane; and a third bar connected to the end of said second bar opposite to said first bar and extending away from said ground plane substantially at a right angle thereto to define an antenna having broad-band monopole antenna characteristics.

### Claim 2 (depends on 1)

An antenna system according to claim 1, further characterized in that it also includes a multi-turn inductance coil fixed to the end of said third bar and coaxial therewith.

### Claim 3 (depends on 1)

An antenna system according to claim 1, wherein there are four of said second bars fixed to said first bar at right angles to each other and extending parallel to the ground plane, and four of said third bars each fixed to the end of one of said second bars and extending parallel to the axis of said first bar.

### Claim 4 (depends on 3)

An antenna system according to claim 3, wherein said second bars (M.sub.1 -M.sub.4) and said first bars (T.sub.1 -T.sub.4) have the following lengths with respect to the wavelength (.lambda.) of the lowest frequency in the frequency band of the antenna system:
______________________________________ M.sub.1 = 0.1133 .lambda. T.sub.1 = 0.0316 .lambda. M.sub.2 = 0.0866 .lambda. T.sub.2 = 0.0366 .lambda. M.sub.3 = 0.12 .lambda. T.sub.3 = 0.035 .lambda. M.sub.4 = 0.133 .lambda. T.sub.4 = 0.033 .lambda.. ______________________________________

### Claim 5 (depends on 4)

An antenna system according to claim 4, wherein the ground plane is of square configuration having a length of 1/4.lambda. along each side.

### Claim 6 (depends on 5)

An antenna system according to claim 5, wherein the height of said first bar is 0.0166.lambda., and its diameter is 0.001.lambda. and is equal to that of all said second and third bars.

### Claim 7 (depends on 6)

An antenna system according to claim 6, further including a multi-turn coil fixed to the end of each of said second bars and coaxial thereto.

### Claim 8 (depends on 7)

An antenna system, according to claim 7, wherein the length and the diameter of each of said coils are both 0.007.lambda..

### Claim 9 (depends on 4)

An antenna system according to claim 4, wherein a multi-turn inductance coil is fixed to the end of each of said second bars and coaxial thereto, the lengths (M.sub.1 -M.sub.4) of the four second bars, the lengths (T.sub.1 -T.sub.4) of the four first bars, the diameter (d) of the first and second bars, the height (h) of the first bar, the diameter (.phi.) and the length (l) of each coil, and the length (a) and width (b) of the ground plane, all having the following relationships with respect to the wave length (.lambda.) of the lowest frequency antenna system frequency band:
______________________________________ M.sub.1 = 0.1133 .lambda. T.sub.1 = 0.0316 .lambda. d = 0.001 .lambda. M.sub.2 = 0.0866 .lambda. T.sub.2 = 0.0366 .lambda. h = 0.0166 .lambda. M.sub.3 = 0.12 .lambda. T.sub.3 = 0.035 .lambda. .phi. = 0.007 .lambda. M.sub.4 = 0.133 .lambda. T.sub.4 = 0.033 .lambda. l = 0.007 .lambda. a = 0.25 .lambda. b = 0.25 .lambda.. ______________________________________