GB2334823A - A portable aerial for television recievers - Google Patents

Abstract

A UHF aerial including a pair of phased dipole loops 12,14, each loop being hingedly connected to a supporting base so as to be movable between a collapsed stowed position and an erected position, the loops in their stowed positions overlying the base 30 and being located one above the other and in their erected positions projecting from the base and being located parallel to one another. The aerial may also include UHF monopole antenna 50.

Description

A PORTABLE AERIAL FOR TELEVISION RECEIVERS The present invention relates to an aerial, in particular but not exclusively, a portable aerial for television receivers.

It is recognised that reception of UHF signals can best be received with aerials having phased dipole aerial loops. Portable aerials of this type are known having two dipole loops standing substantially vertically from a horizontal base.

However, these known portable aerials are usually unsightly when erected and are not normally constructed so as to be easily collapsed for storage when not in use.

It is a general aim of the present invention to provide an aerial, particularly a portable aerial which is easily collapsed for storage and which may provide optimum performance.

According to one aspect of the present invention there is provided an aerial including a pair of phased dipole loops, each loop being hingedly connected to a supporting base so as to be movable between a collapsed stowed position and an erected position, the loops in their stowed positions overlying the base and being located one above the other and in their erected positions projecting from the base and being located parallel to one another.

Preferably the distance between the parallel loops when in their erectedpositions is approximately 1/4 of the wavelength of the signal to be received.

Preferably each loop is a continuous length of a suitable flexible conductor which is constrained within a rigid loop support which is hingedly connected to the base.

Preferably one or both of the rigid supports is in the form of a lid.

Preferably the base defines a housing for supporting a signal amplifier to which each loop is electrically connected.

Preferably the conductor of each loop is fed from the loop to the amplifier through its associated hinge connection such that the conductor is twisted in a torsional manner when the loop is moved between its stowed and erected positions.

Various aspects of the present invention are hereinafter described with reference to the accompanying drawings, in which : Figure 1 is a perspective view of an aerial according to one embodiment of the present invention shown in its erected position; Figure 2 is a view similar to Figure 1 showing the aerial without one of the dipole loops and partly broken away; Figure 3 is a plan view of the aerial of Figure 1 shown in its stowed position; Figure 4 is a sectional view taken along line IV-IV in Figure 3; Figure 5 is a sectional view taken along line V-V in Figure 3; Figure 6 is a sectional view taken along line VI-VI in Figure 3; Figure 7 is a schematic side view representation of the interrelationship of the dipole loops used in the present invention Figure 8 is a schematic perspective view of the aerial shown in Figure 7.

The aerial 10 of the present invention includes a pair of phased dipole loops 12,14 which are electrically interconnected by intermediate conductors 16.

When erected as seen in Figure 7, the loops 12,14 are spaced apart by a distance d which is preferably 1/4 of the wavelength of the signal which the aerial is designed to receive. In the case of UHF signals, the wavelength is about 500 mm and so the distance 9 between the loops 12,14 is about 125 mm.

In addition the length of each loop is chosen to be close to the wavelength of the signal as modified in dependence upon the frequency of the signal the aerial is intended to receive.

In the presently preferred embodiment, the aerial is preferably arranged to receive UHF signals ranging in frequency from about 470 to 860 MHz.

Accordingly the length of loop 12 is chosen to be about 455 mm and the length of loop 14 is chosen to be about 495 mm.

The aerial of the present invention is arranged to be collapsible to a stowed condition (as seen in Figures 3 to 6). This is achieved by hingedly arranging the loops 12,14 so as to be movable to the stowed position whereat they lie one above the other in an erected position (as seen in Figures 1, 2, 6 and 7) whereat they are arranged to be substantially parallel to one another.

As seen schematically in Figure 7, loop 12 is hingedly movable about a hinge connection 20 and loop 14 is hingedly movable about a hinge connection 21.

The height h of loop 12 from its hinge connection 20 is chosen to be less than distance 9 in order that the loop 12 may be hingedly moved (in direction of arrow A in Figure 7) to its stowed position whereat it lies substantially horizontally above conductors 16.

In order to achieve height k, the loop 12 is preferably shaped in the form of a flattened circular loop as seen more clearly in Figures 1 and 8.

Preferably loop 14 is similarly shaped, primarily for aesthetic reasons.

In the preferred embodiment illustrated in Figures 1 to 6, the aerial 10 includes a base 30 to which a pair of aerial loop supports 31, 32 are hingedly attached.

Loop support 31 houses the aerial loop 12 and loop support 32 houses aerial loop 14.

Loop support 31 is hingedly connected to the base 30 to define hinge connection 20 and loop support 32 is hingedly connected to the base 30 to define hinge connection 21.

Preferably, the loops 12, 14 and the conductors 16 are in the form of a flexible electrical conductor 40 which extends about each respective aerial support and into the base 30. The flexible conductor 40 is preferably continuous as shown eg. in Figure 2.

The conductors 16 are connected to a signal amplifier 34 which is preferably housed within the base 30.

The flexible electrical conductor 40 is fixedly constrained within the respective supports 31, 32 to extend in the desired loop shape.

At the base of each support 31, 32 the conductor 40 has a portion 40a which extends along a path which is substantially in line with the respective hinge axes. Accordingly when supports 31, 32 are moved about their respective hinge axis, conductor portions 40a are twisted in a torsional manner. This enables the conductor to be hinged repeatedly without detriment and without affecting the shape of the loop 12 or 14.

Preferably the hinge axis of hinge 21 is located slightly above the hinge axis 20 to enable the supports 31 and 32 to assume a stowed position wherein the base 30 and supports 31 and 32 are located one above the other.

Preferably each support 31, 32 is in the form of a dished lid, preferably formed from plastics material. Each lid includes a peripheral inwardly facing wall 45 which defines a reaction face for receiving a support ring 46. The support ring 46 has an outer periphery which resiliently abuts against the wall 45 to hold the ring 46 in place. The conductor 40 is trapped between the ring 46 and wall 45.

Although each lid is shown as being imperforate, it will be appreciated that one or both lids may have a large central aperture such that the support 31 or 32 visually appears to be ring shaped.

In order to enable the aerial 10 to receive VHF signals, one or more telescopic aerials 50 are preferably mounted on the base 30.

When telescopically retracted, the aerials 50 are arranged to lie against the top face of the base 30 within recess 38 and be totally enclosed by the supports 31, 32 when in their stowed position.

Conveniently, the base 30 is hollow and houses batteries (not shown) for supplying electrical power to the amplifier.

Claims (7)

1. CLAIMS 1. An aerial including a pair of phased dipole loops, each loop being hingedly connected to a supporting base so as to be movable between a collapsed stowed position and an erected position, the loops in their stowed positions overlying the base and being located one above the other and in their erected positions projecting from the base and being located parallel to one another.
2. 2. An aerial according to Claim 1 wherein the distance between the parallel loops when in their erected positions is approximately 1/4 of the wavelength of the signal to be received.
3. 3. An aerial according to Claim 1 or 2 wherein each loop is a continuous length of a suitable flexible conductor which is constrained within a rigid loop support which is hingedly connected to the base.
4. 4. An aerial according to Claim 3 wherein one or both of the rigid supports is in the form of a lid.
5. 5. An aerial according to any preceding claim wherein the base defines a housing for supporting a signal amplifier to which each loop is electrically connected.
6. 6. An aerial according to Claim 5 wherein the conductor of each loop is fed from the loop to the amplifier through its associated hinge connection such that the conductor is twisted in a torsional manner when the loop is moved between its stowed and erected positions.
7. 7. An aerial substantially as herein described with reference to and as illustrated in the accompanying drawings.