GB2183099A - Aerial - Google Patents

Abstract

An aerial for person-carried radio equipment, such as a walkie-talkie, comprises one or two tubular members 2, 3 made of flexible, electrically- conducting, material such as fine phosphor bronze mesh fitted end-to- end within the sleeve 1 of a garment such as a jacket and electrically insulated from one another, and a coaxial electrical connection 4 running inside the upper of the two members with the inner conductor connected to the lower member and the outer conductor to the upper member. The tubular member(s) may be fitted in a trouser leg. <IMAGE>

Description

SPECIFICATION Improvements in or relating to aerials This invention relates to aerials and in particular to aerials for person-carried radio equipment such as walkie-talkies.

Normally such equipment uses a whip aerial, but whip aerials can be inconvenient in confined spaces.

They also make the use of the equipment very conspicuous, which can be a disadvantage.

However, small aerials, or aerials close to a person's body, tend to be narrow-band and/or lossy.

According to the present invention an aerial for person-carried radio equipment comprises a tubular member made of flexible, electrically-conducting, material fitted as a lining within a portion of a garment wearable by the person so that the member encircles a part of the person, and an electrical connection to an end of said member. The part of the person may be a limb.

Preferably the aerial comprises two such members fitted end-to-end within the sleeve of a garment such as a jacket and electrically insulated from one another, electrical connections being made to the adjacent ends so that the members function as a dipole. The electrical connections are preferably the inner and outer conductors of a coaxial cable, and preferably said cable runs inside the upper of the two members past the shoulder of the garment, with the inner conductor connected to the lower member and the outer conductor to the upper member.

The material may be a fine metallic mesh, e.g.

phosphor-bronze mesh such as is used in filters for liquids.

To enable the nature of the present invention to be more readily understood, attention is directed by way of example to the accompanying drawing, which is an elevation of part of a jacket fitted with an aerial embodying the present invention.

In this drawing a sleeve 1 of a jacket contains as a lining two tubular members 2, 3 fitted end-to-end with a small gap between their adjacent ends. The members are of approximately equal length, the upper member 2 extending up to the shoulder line, although the latter is not essential. A coaxial feeder 4 runs inside member 2 past the shoulder and terminates in a suitable small plug or socket (not shown). The outer conductor of feeder 4 is connected to the upper member 2 and the inner conductor to the lower member 3 at their adjacent ends. The members 2 and 3 are made of fine phosphor-bronze mesh.

The aerial thus formed functions as a centre-fed dipole and, by virtue of its relatively large diameter, has a large bandwidth, Moreover, because the feeder runs inside the upper member, the arrangement has some electrical equivalence to a known form of aerial, viz a sleeve aerial, which is advantageous. More importantly, the wearer's conductive arm is inside the aerial in a field-free region and thus degrades its performance much less than would, say, a simple strip or wire extending up the sleeve 1. In one example the aerial was found to have an insertion loss of only 6db as compared with a loss of 20 db for a simple wire dipole located within the sleeve. In fact the loss was similar whether an arm was within the sleeve or not.

Although a dipole configuration is preferred, a monopole configuration is also within the scope of the invention, i.e. using a single continuous member instead of two as shown, with a feeder connected to one end, e.g. preferably the lower end.

The garment may include an aerial as aforesaid within one sleeve only or within both sleeves, the feeders to each being joined together in a known manner.

The associated radio equipment and batteries can be carried inconspicuously in a pocket of the jacket or elsewhere on the person.

Instead of encircling an arm or arms as described and preferred, the aerial or aerials may encircle another part or parts of the body, e.g., as a lining within a trouser leg or legs.

1. An aerial for person-carried radio equipment comprising a tubular member made of flexible, electrically-conducting, material fitted as a lining within a portion of a garment wearable by the person so that the member encircles a part of the person, and an electrical connection to an end of the member.

2. An aerial as claimed in claim 1 wherein the part of the person is a limb.

3. An aerial as claimed in claim 1 or claim 2 comprising two such members fitted end-to-end with the sleeve of a garment such as a jacet and electrically insulated from one another, electrical connections being made to the adjacent ends so that the members function as a dipole.

4. An aerial as claimed in claim 3 wherein the electrical connections are the inner and outer conductors of a coaxial cable.

5. An aerial as claimed in claim 4 wherein the cable runs inside the upper of the two members with the inner conductor connected to the lower member and the outer conductor to the upper member.

6. An aerial as claimed in any preceding claim wherein the member or members are made of fine metallic mesh.

7. An aerial for person-carried radio equipment substantially as hereinbefore described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in or relating to aerials This invention relates to aerials and in particular to aerials for person-carried radio equipment such as walkie-talkies. Normally such equipment uses a whip aerial, but whip aerials can be inconvenient in confined spaces. They also make the use of the equipment very conspicuous, which can be a disadvantage. However, small aerials, or aerials close to a person's body, tend to be narrow-band and/or lossy. According to the present invention an aerial for person-carried radio equipment comprises a tubular member made of flexible, electrically-conducting, material fitted as a lining within a portion of a garment wearable by the person so that the member encircles a part of the person, and an electrical connection to an end of said member. The part of the person may be a limb. Preferably the aerial comprises two such members fitted end-to-end within the sleeve of a garment such as a jacket and electrically insulated from one another, electrical connections being made to the adjacent ends so that the members function as a dipole. The electrical connections are preferably the inner and outer conductors of a coaxial cable, and preferably said cable runs inside the upper of the two members past the shoulder of the garment, with the inner conductor connected to the lower member and the outer conductor to the upper member. The material may be a fine metallic mesh, e.g. phosphor-bronze mesh such as is used in filters for liquids. To enable the nature of the present invention to be more readily understood, attention is directed by way of example to the accompanying drawing, which is an elevation of part of a jacket fitted with an aerial embodying the present invention. In this drawing a sleeve 1 of a jacket contains as a lining two tubular members 2, 3 fitted end-to-end with a small gap between their adjacent ends. The members are of approximately equal length, the upper member 2 extending up to the shoulder line, although the latter is not essential. A coaxial feeder 4 runs inside member 2 past the shoulder and terminates in a suitable small plug or socket (not shown). The outer conductor of feeder 4 is connected to the upper member 2 and the inner conductor to the lower member 3 at their adjacent ends. The members 2 and 3 are made of fine phosphor-bronze mesh. The aerial thus formed functions as a centre-fed dipole and, by virtue of its relatively large diameter, has a large bandwidth, Moreover, because the feeder runs inside the upper member, the arrangement has some electrical equivalence to a known form of aerial, viz a sleeve aerial, which is advantageous. More importantly, the wearer's conductive arm is inside the aerial in a field-free region and thus degrades its performance much less than would, say, a simple strip or wire extending up the sleeve 1. In one example the aerial was found to have an insertion loss of only 6db as compared with a loss of 20 db for a simple wire dipole located within the sleeve. In fact the loss was similar whether an arm was within the sleeve or not. Although a dipole configuration is preferred, a monopole configuration is also within the scope of the invention, i.e. using a single continuous member instead of two as shown, with a feeder connected to one end, e.g. preferably the lower end. The garment may include an aerial as aforesaid within one sleeve only or within both sleeves, the feeders to each being joined together in a known manner. The associated radio equipment and batteries can be carried inconspicuously in a pocket of the jacket or elsewhere on the person. Instead of encircling an arm or arms as described and preferred, the aerial or aerials may encircle another part or parts of the body, e.g., as a lining within a trouser leg or legs. CLAIMS

1. An aerial for person-carried radio equipment comprising a tubular member made of flexible, electrically-conducting, material fitted as a lining within a portion of a garment wearable by the person so that the member encircles a part of the person, and an electrical connection to an end of the member.

2. An aerial as claimed in claim 1 wherein the part of the person is a limb.

3. An aerial as claimed in claim 1 or claim 2 comprising two such members fitted end-to-end with the sleeve of a garment such as a jacet and electrically insulated from one another, electrical connections being made to the adjacent ends so that the members function as a dipole.

4. An aerial as claimed in claim 3 wherein the electrical connections are the inner and outer conductors of a coaxial cable.

5. An aerial as claimed in claim 4 wherein the cable runs inside the upper of the two members with the inner conductor connected to the lower member and the outer conductor to the upper member.

6. An aerial as claimed in any preceding claim wherein the member or members are made of fine metallic mesh.

7. An aerial for person-carried radio equipment substantially as hereinbefore described with reference to the accompanying drawing.