DE1933150A1 - Antenna for miniaturized radio equipment - Google Patents

Description

EiIPL-ING. LEO FLEUCHAUS

8 MONKS 71, June 30, 1969 Melchiorstrasse 42

My reference: M51P-271 + GH

Motorola, Inc. 94-01 West Grand Avenue Franklin Park , Illinois V.St.A.

Antenna for miniaturized radio devices

The invention relates to an antenna for miniaturized radio devices, the housing of which is partly made of a conductive material and which has a chassis with conductive parts at reference potential within the housing.

Both for small transmitters suitable for dog radio operation as well as receivers that are especially designed to be carried in the hand are provided, there is the problem of creating suitable, more usable for receiving the high-frequency signals Antennas. For receivers that are suitable for operation in the normal broadcasting range and in the VHF band, e.g. ferrite antennas are used, but which are in the UIÜ? Area does not guarantee satisfactory reception. It's usage too vertical rod antennas known that come out of the housing

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protrude and are therefore often undesirable because, for example, there is a risk of unintentional contact with other objects the antenna is given. With such rod antennas there is also the risk that they are broken off or kinked. Another known type of antenna in miniaturized radio devices is designed as a loop antenna Can be constructed in the form of a cable and, due to its flexibility, hangs vertically downwards. It is also possible at Miniature broadcasting devices to accommodate the antenna in the cable, e.g. a microphone with the transmitter or a trained as a listener ear clip connects to the receiver. With the latter type of antenna, often the case occur that such a cable is either not needed or not desired, which then the device because of the missing antenna cannot be used.

The invention is therefore based on the object of creating an antenna for miniaturized radio devices that has an integral Is part of the housing and the chassis of the device. This antenna should also be suitable for VHF receivers which all parts are housed within a simple housing and which have no protruding parts. In addition, the antenna should be constructed in such a way that at least some of the antenna has additional functions in the device exercises, so that the device or the antenna can be manufactured as cost-effectively as possible.

Based on the antenna mentioned at the outset, this object is achieved according to the invention in that the antenna consists of a conductor arrangement which runs vertically in the housing in the operating position, with a first line connection being the upper end of the. Conductor arrangement connects to the conductive material of the housing and thereby forms a capacitor loading the antenna, and that a second line connection the lower end of the conductor arrangement with the

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conductive parts of the chassis and thereby the ground for the ... antenna forms.

In an advantageous embodiment of the invention, there is the conductor arrangement from a plurality of parts, wherein at least, a part in the device performs another function. The ground for the antenna is preferably based on the Chassis arranged shielding cans and formed part of the chassis.

Further features of the invention are the subject of further subclaims. -

An example embodiment of the invention is in Drawing shown. Show it:

Pig.- 1 is a perspective view of a 'receiver with - a built-in antenna according to the invention; .

Fig. 2 is a partially broken perspective view the parts from which the antenna is constructed;

Fig. 3- a section through the receiver and the antenna forming parts;

Fig. 4 is a view corresponding to FIG. 3, in which the on the antenna connected circuit is shown symbolically.

In Fig. 1, a portable receiver 10 is shown, which of People as search recipients can be carried to this Message en ... in a limited area, e.g. a city, inner half of a building or a building complex. The receiver has an insulating housing, in

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behind a perforated housing part 11 is a loudspeaker 17 (Fig. 3) is arranged for the reproduction of the hoof and / or speech signals. At the top of the case is a plate-shaped metal screen 12 is provided with a part over the top of the receiver and with a square to it The bent part extends over the front surface to the perforated housing part 11. In the top of the Receiver are also provided sockets 13 and 14 to a Connect an external antenna and headphones. The metal panel 12 is provided with corresponding openings through which the sockets protrude. One that can be operated by hand Adjustment device 15 is designed on the one hand as a Sehalter, with which the receiver can be switched on and on the other hand intended for volume control. A second, Switch 16 designed as a push-button switch can be used to carry out a further operational function. The search receiver can be constructed in such a way that a ringing tone is received first and then the push-button switch 16 must be held down in order to receive the voice information. Another species The voice information is automatically reproduced by search receivers after the Eufton, whereby with this receiver version, the push button switch 16 is used to set the receiver to respond to a different tone code.

In Fig. 2 parts of the receiver are shown with the housing removed .. In the illustration, the plate-shaped metal screen 12 can be seen on which a strip-shaped projection 20 is arranged, which rests on the edge of a conductive console.22, which the sockets 13 and 14 wears. The conductive bracket 22 is riveted to a chassis 24 with conductive rivets 25 - which is made of a printed. Circuit board can be formed. The chassis 24 is provided on the rear with conductive coatings 26 and 27, the conductive coating. · 27 _? .as- '^ ace connection for various on the chassis

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assembled parts is formed. Some of these electric Components are housed in shielding cans 28 and 29, the are mounted on the front of the chassis 24. A senior Bracket 30 is connected to the cover 26, which in turn connected to the conductive bracket 22 by the rivets 25 is. One arm of the bracket JO, which is bent at an angle, is in conductive connection with the shielding cup 28.

The vertical one. Part of the conductive bracket 22, together with the conductive coating 26 on the rear of the chassis and the vertically extending part of the bracket 30, forms a vertically oriented antenna. The rivets 25 connect the conductive bracket 22 to the conductive coating 26, to which in turn the bracket 30 is soldered. The lower end of the vertically oriented antenna is connected to the parts forming the ground, which are essentially formed by the shielding cans 28 and 29 and the conductive coating 27 which extends over the chassis 24 also below the shielding can. These conductive parts together form an effective ground for the antenna. The horizontally running upper part of the conductive bracket 22 acts together with the plate-shaped metal screen 12 and the strip-shaped projection 20 as a capacitor which loads the upper end of the vertically oriented antenna. As can be seen from FIG. 3 , a flexible insert 21 is provided behind the strip-shaped projection 20, which ensures that the projection 20 is pressed against the edge of the conductive bracket 22. When the chassis is arranged in the housing, the strip-shaped projection 20 rests against the edge of the console in a dragging manner and thus brings about a good electrical connection between the console and the plate-shaped metal panel.

In the ffig. 3 and 4 show the electrical connections between the antenna and the receiver. There is one 1-way connection between the upper horizontally

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f end part of the console 22 on the coil 32 edge a changeable Capacitor 34 to the base of transistor 35 · The coil and capacitor are in Fig. 3 of their physical lorm accordingly and shown in Fig. 4 as schematic switching elements. As can be seen from Mg.-4 the transistor 35 together with one with the collector of the transistor connected coil 36 in the shielding can 28. The emitter of transistor 35 is connected to the conductive coating of the chassis which acts as a ground. the Coil 36 is part of a matched output circuit that the capacitors 37 and 38 comprises. The capacitor 38 is effective as a separating capacitor, around the coil 36 in direct current fashion to separate from ground. This allows the bias potential for the collector of transistor 35 through this Coil are applied. The bias voltage is supplied from the terminal 40, which is also applied via a capacitor 41 Ground is connected. A voltage divider network consisting of resistors 42, 43 and 44 is used for setting the correct bias values, the voltage drop across resistor 44 being the base of transistor 35 and the voltage at the voltage dropping across the resistors 43 and 44 is supplied to the collector of the transistor 35 via the coils 45 and 36. The capacitor 47, together with the resistor 48, forms a feedback path from the tuned output circuit to the base of transistor 35 · The coil 36 can connect to other be coupled to matched circuits in order to provide the desired · selectivity of the receiver for the radio frequency.

According to Fig. 4, the socket, into which an external antenna can be plugged, is connected to the shielding can 28 via a conductor 50 and to the conductive rivets 25 by means of a conductor 51 The socket for the external antenna is thus finely connected to the vertically aligned antenna connected, whereby an impedance matching between the external antenna and the j antenna formed by the receiver parts is created. ·

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The receiver circuit can be a. contain a selective Euf system based on a code built up from certain frequencies appeals to. These frequencies are selected with the aid of reed relay 55 (FIG. 2). '

The receiver shown in Fig. 1 is, for example, about 6.3 cm wide, about 13 »3 cm high and about 2.7 cm deep. The weight of the receiver including the battery, which is attached to the lower side of the housing, lies after the Kind, the battery used roughly between 310 and 3 ^ -0 grams. The plate-shaped metal screen is approximately 5.4 cm long, whereby the top surface would be about 1.9 cm and the front surface has a height of about 1.27 cm. The length of the actively active vertical antenna is approximately 0.95 cm.

The antenna previously described erxtreist in use under A diversity · ⁰ · operating conditions to be highly effective. Since they are made up of dividers. "g './ bZi.G. ^ t * is that are needed anyway in the receiver for other purposes _s -can this indoor antenna with virtually no additional JEostenaufwai .. provided v / ground.

- 7 - Claims

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Claims (1)

! Patent claims lj antenna, for miniaturized radio devices, the housing of which is partly made of a conductive material and which have a chassis with conductive parts at reference potential within the housing, characterized in that the antenna consists of a conductor arrangement which runs vertically in the housing in the operating position, that a first line connection connects the upper end of the conductor arrangement to the conductive material of the housing and thereby a die. Antenna loading capacitor forms, and that a second line connection connects the lower end of the conductor arrangement with the conductive parts of the chassis and thereby forms the ground for the antenna. 2. Antenna according to claim 1, characterized in that g e k e η η ζ e i -c h net, that the conductor arrangement is constructed from a plurality of parts, at least one part in the Device fulfills another function -, - 3. An antenna according to, claim 1, dstdurCh GEK _3>, e η η ζ η et calibration, .- that, on the Ohassiis Absch§.>Gfiungsl> e9her are arranged which at least part ₁ $ er ^ Mass-e- - form for the antenna ". 009838/1 170 OfIlQlNAt INSPECTED ^J M51P-271 + GH 4. Antenna according to one or more of claims 1 to 3 »· characterized in that the conductive material of the housing is in the form of a plate-shaped Metairblende is executed. 5. Antenna according to one or more of claims 1 to 4, characterized in that the conductor arrangement is designed in the form of a conductive bracket is, which is in conductive connection with the plate-shaped metal panel. 6. antenna, iiaprh; one or more of claims 1 to 5, by ge.kennzeich.net that on the leading Console a socket is arranged, which can be used as a connection terminal for an external antenna, and that the connection socket with a first conductor to the conductor arrangement and with a second conductor to the second line connection is connected. 7ο antenna according to one or more of claims 1 to 6, characterized ,, that is arranged on the plate-shaped metal aperture streifenformiger projection, and that the conductor arrangement and the first line connection ge from the conductive bracket part forms are provided with a part rests against the strip-shaped projection. 8. Antenna according to one or more of claims 1 to 7, characterized in that the first stage of the radio device designed as a receiver comprises a transistor, and that the transistor is connected to the first line connection via a matching network. - 9 -009835/1170 w H51P-271 + GH-- . 9. Antenna according to claim 8, characterized in that g e k e η η ze i c h— net that the base of the transistor is connected to the matching network, and that the emitter of the transistor with the second line connection and the collector of the transistor also with. the second line connection connected via a coordinated circuit. 10. Antenna according to claim 9 »characterized in that shielding cups are arranged on the chassis are who at least partially form the electrical hatred, and that the transistor as well as the matched Circuit are arranged within a shielding can. - OK - ■ 0098357.1170