DE2909641A1 - ANTENNA FOR MULTIPLE RECEPTION AREAS WITH ELECTRONIC AMPLIFIER - Google Patents

Description

a) Title of the invention

Antenna for several input areas with electronic amplifier

b) Field of application of the invention

The invention relates to an antenna for several reception areas with an electronic amplifier that has the! shape of a dipole or Has fbnopols and in a lower and an upper frequency range emnfän-t, being the length of the dipole or fonoools very is short compared to the wavelength of the lower frequency range. The electronic antenna according to the invention is "for example as electronic car antenna, as an electronic antenna for home and home Reiseemnfänger and for other reception purposes in an upper and lower frequency range applicable.

c) Characteristics of the known technical solutions

Antennas in the form of a monopole are increasingly being used for receiving amplitude-modulated broadcasting in the long, medium and shortwave range (KTK range) and frequency-modulated broadcasting in the ultra-short wave range (VHF range *), the length of which is very short in the KIK range Often times, separate transmission paths are provided for amplifying the signals in the two frequency ranges.

In the applications DE-AS 19 19 749 and DE-AS 23 10 616 is to the Monopole a crossover connected to the outputs of which the transmission paths for the VHF and the IHK area are connected are.

In DE-AS 19 19 749 the transmission path for the LFK area connected to the monopole via an inductance and the transmission path for the VHF range via a capacitance. This circuit has

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Disadvantages for receiving the LIJK area. According to FIG. 1 the Konnel capacitor G 2 for the VHF range is parallel to the Input of the transmission path for the LMK area because the input of the transmission path for the VHF range always a Stmle L as part of a parallel resonance circuit.

2 shows, in a simplified manner, the equivalent image of the arrangement according to Pig. 1, how it is effective when the KJK area is received.

The short reception mononol acts like a signal source with the signal voltage U = E. h _ "whose source resistance is derived from the antenna

S 6 XX

capacitance G 1 and a very small, negligible for this consideration, Series resistance exists.

E = electric field strength at the location of the antenna, h "" = effective Height of the monol.

In series with G 1, when the LMK range is received, there is the coupling channel C 2 for the VHF range and, parallel to it, the input impedance of the electronic amplifier circuit, which, when using a field effect transistor, essentially consists of a capacitance G 3. G 1, together with G 2 and G 3, forms a capacitive voltage divider, so that the control voltage U ₀ for the electronic amplifier circuit is significantly less than U ₀ , so that the sum of G 2 and G 3 is greater than V 1.

C 1

^U St = ^U S

G 1 + G 2 + C 3

Particularly in the case of short ionon oils, the capacity C1 is very small, see above that the control voltage U ", for the LHK range at a relatively large G 2 and J 3 are noticeably reduced in size. This shows that with a kanazntiven Coupling of the transmission system for the VHF range, the elimination of the electronic antenna in the LMK range is unfavorable being affected.

In the case of the transmission of the UKV / range, the equivalent circuit diagram shown in FIG. 3 is effective. Most electronic antennas with separate transmission ^{paths for LMK and UK 1} Ji / have a band filter for uniform transmission of the VHF range. The primary circuit is made up of the capacitive source impedance of the antenna R 1 / G 1, L 1 and the input impedance of the amplifier for the LMK-

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Area formed. The secondary circuit consists of L 2 and C 4 as well as the input impedance of the subsequent transmission path for the VHF area. The filter is capacitively coupled by C 2. As I have just mentioned that this concurrent capacity is detrimental to catching energy of the LMK area.

In a further solution specified in the application DE-AS 23 1-0 616, the load capacity at the input of the transmission path for the LMK area through a transformative decoupling the signals of the VHF range are reduced. Fig. 4 shows the equivalent circuit as it is for the transmission of the UKV / - and LMK range is effective. The tirimeric and secondary resonance allowed a loose coupling of the coils L 1 and L 2, d. H. the distance can be chosen so that there is a lower capacitive load on the amplifier input for the LMK range. The primary circle is formed from the capacitive source impedance of the antenna R 1 / C 1, from L 1 and the input impedance of the amplifier V 1 for the LMK range, which essentially consists of a capacitance C 3. The secondary circuit is formed from L 2, C 4 and the input simn edanz of the subsequent transmission path V 2 for the VHF area. Through the electrical fields of the atmosphere Frictional electricity or from touching the antenna rod with electrically charged bodies can be caused by arcing AC voltage caused the input transistor of the transmission path destroy for the LMK area. A protective diode D 1 is often provided to limit these voltages. From the secondary side of the transmitter for the VHF range, an additional impedance is transformed to the primary side, which leads to a deterioration the sensitivity in the MK area. In this and in the unavoidable capacitive load on the input of the amplifier for the LMK range due to the capacity between the two tubes of the transmitter for the VHF range, there are disadvantages this solution.

In the application DE-OS 21 15 657 a circuit arrangement is specified, in which the different frequency ranges are amplified together in a field effect transistor, and the separation takes place on different transmission paths in such a way that the lower frequency range at the source and the upper frequency range at the drain

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be disconnected. By separating the signals of the upper and lower frequency range on separate transmission paths at the output of a field effect transistor, the above. additional capacitive Avoid stress on the gate of the field effect transistor and the sensitivity in the lower frequency range is improved. Circuit arrangements in which the signals of the different frequency ranges are amplified jointly in active elements, however, compared to the described circuit arrangements with separate transmission paths, inter alia. Significantly poorer large-signal properties because of the non-linearity of the transfer characteristic the signals of the upper and lower frequency range interfere with each other, so that the awake parts predominate overall.

Those specified in Funkschau 1976, issue 14, pages 578 ... 580 Circuit principles represent the current technical Stand of electronic car antennas. It's the special problems the separation of the signals of the different frequency ranges separate transmission paths clearly shown. In this publication, well-known authorities in the professional world are of the opinion that a further improvement in the sensitivity of electronic Car antennas in the UJK area with a given length of the antenna rod is no longer possible.

d) Object of the invention

The aim of the vorlior ^en <3e ⁿ invention is the Emnfindlichkeit electronic antennas in a lower and an upper frequency range, for example, in the LMS and the VHF range ernofangen, to electronic antennas with a crossover between the receiving antenna element and the amplifiers for different To improve frequency ranges in the lower frequency range and at the same time to maintain the favorable large-signal properties of these known solutions with separate transmission paths.

e) Statement of the essence of the invention

The object of the invention is, in electronic antennas, at which the signals of the upper and lower frequency range have in common are fed to a first electronic amplifier element, a common amplification of the signals of both frequency ranges to avoid in this electronic amplifier element.

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The task is with the antenna for several peripheral areas with electronic amplifier that takes the form of a dipole or monopole and receives in a lower and an upper frequency range and at which the length of the dipole or MonoDol is very short compared to is the wavelength of the lower frequency range and the separation the signal «of the lower and upper frequency range on separate transmission paths at the output of the first electronic amplifier element takes place in such a way that the signals of the lower frequency range by means of an inductance, which the signals of the upper frequency range largely snerrt, are disconnected at the source, for example of a field effect transistor, in that the Signals of the upper frequency range also at the source by means of a capacitance that largely absorbs the signals of the lower frequency range snerrt, corrugated and between the source and drain of the field effect transistor a significantly lower resistance in the upper frequency range Imnedance than all others acting in the drain and source Impedances is switched.

On the other hand, this impedance must be connected in parallel with all others effective impedances im lower frequency range compared to the input impedance of the transmission path sufficiently high impedance for the lower frequency range to avoid negative effects on the frequency response of the amplification to be avoided in this frequency range. The above impedance is required between drain and source in order to pass through the field effect transistor amplified currents of the upper frequency range in the sourcezv / eig approximate short circuit of the drain-source path to a large extent prevent, so that their influence on the transmission behavior of the transmission path for the upper frequency range is negligible is. This impedance can, for example, be a capacitance or a series resonant circuit be. Furthermore, an inductive impedance that is sufficient in the upper frequency range must be switched into the drain feed line high resistance, sufficiently low resistance in the lower frequency range. It ensures that the series connection of the inroedance between Drain and source of the field effect transistor with the impedance switched on in the drain lead in the upper frequency range is high resistance and thus does not affect the transmission behavior for the upper frequency range. In the lower frequency range is the impedance of this inductance is negligible, so that the field

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Effect transistor in drain circuit works. The inductive impedance in the drain lead of aes field effect transistor, together with the channels acting between the drain and the reference potential, forms a parallel resonant circuit. The resonance voltage of this circuit is fed back to the source electrode via the impedance between drain and source, so that the oscillation condition can be fulfilled. The oscillation of this stage can be avoided with certainty?; Ground if the quality above . Resonant circuit is sufficiently reduced. The j is possible by connecting a resistor in parallel to the inductance.

In the case of the transmission of the upper frequency range it proves to be advantageous with regard to sensitivity and selection to design the circuit following the output coupling so that it, together with the capacitive source impedance of the antenna, has an isolating capacitance and an inductance between the The gate of the field effect transistor and the massive antenna element, the input capacitance of the field effect transistor and the output capacitance result in an oscillating circuit or a band filter and the connection to the transistor of the transmission path for the upper frequency range takes place in such a way that a favorable signal-to-noise ratio is achieved. Depending on the required bandwidth and the uniformity of the amplification in the transmission range, there are various courtesies for designing the switching of the transmission path for the upper frequency range following the output channel capacity. If the transmission behavior of an individual circuit is sufficient, in the simplest case the input of the amplifier transistor of the upper frequency range can be connected to the Auskormelkapazitat. Its input impedance is therefore part of the resonant circuit for the upper frequency range. Further possibilities for designing the transmission behavior and the signal-to-noise ratio in the upper frequency range are obtained if instead of the coupling capacitance a capacitance is switched directly or the output capacitance is switched to the reference potential via an inductance and the amplifier input is switched to the upper frequency range oarallel is turned to this capacitance, or & \ x this inductance. The use of a single circuit for selection and transformation has the advantage of lower insertion loss than one at the resonance frequency

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Band filter. If a larger bandwidth is required in the upper frequency range, for example in the UKIV area, it proves to be advantageous between the passive antenna element and the amplifier for the upper frequency range a band filter with critical or light supercritical & r coupling to be inserted. For the realization there is various possibilities. All known types of coupling can be used.

Compared to the application DE-AS 23 10 616 is to design the transmission path a much higher degree of freedom is given for the upper frequency range.

Between the above Selection means and the input of the amplifier for the upper frequency range can improve the transmission behavior and impedances improving the signal-to-noise ratio are switched will. The diode for protecting the field effect transistor from high voltages can advantageously also be used for the gate of the Field effect transistor and the input of the transmission path for the upper frequency range switch when this is through a coil low inductance is connected to the reference potential.

The inventive circuit arrangement proposed here results in further improvements over known circuit arrangements, so that the previous prejudice of experts can be considered to have been dispelled with the solution. The essential feature of overcoming lies in the fact that 4 && dimensional imri! MagBgmim & the Sig- f>"'of the upper and lower frequency range pass through a common transmission path, while avoiding additional load capacitances to the gate of a field effect transistor or a similar-acting enhancer element according to the invention in the upper frequency range due to a sufficiently low-resistance shunt to the drain-source path, zv / ischen gate and source acts like a capacitance that is part of a selective, linear transmission network of the upper frequency range in which no amplification occurs 21 15 S5 7 only the lower frequency range is amplified in the first electronic element, non-linear effects are significantly reduced, which means that the circuit arrangement ensures significantly more favorable (pulse signal properties).

The invention is explained in more detail below using exemplary embodiments.

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j'ig. 5 'shows .e 3 ^A circuit arrangement, the erfindungsgcmäßen solution with minimal effort. For the case of the transmission of the upper frequency range nind click canacitive source impedance of the passive anterm element C 1 / R 1, the separation capacitance C 5, the line inductance L 1, the input capacitance of the field effect transistor G 3, the output capacitance C 6 and the input impedance of the subsequent transmission path of the upper frequency range components of an oscillating circuit. In the simplest case, the amplifier transistor for an upper frequency range is connected directly to the output channel C 6. Its input impedance is thus part of the above-mentioned oscillating circuit. In the upper frequency range, G 7 forms a selrr low-impedance shunt to the drain-source path of the field effect transistor V 1 and thus largely prevents currents of the upper frequency range from flowing through the field effect transistor V 1 between the source and reference potential. With a suitable dimensioning of the resistor R 3, the oscillation of this stage is prevented. Furthermore, the series connection of C 7 and L G / li 3 is still sufficiently high-resistance in the upper frequency range so that there is no significant influence on the transmission path in the upper frequency range. In the case of the transmission of the lower frequency range, the impedances of the inductances L 1, L 3, L 6 and those of the capacitances G 6 and C 7 are negligible, so that the field effect transistor Y 1 operates in a drain circuit. At the source resistor R 2, the signal of the lower frequency range is disconnected via G 8.

'. Further courtesies for structuring the transference behavior and the signal-to-noise ratio in the upper frequency range is obtained if, as in FIG. 6, instead of the AuskotiOelkatiazität a capacitance G 9 is switched to reference potential and Tj parallel to this Ka * v-ity of the amplifier for the upper frequency range connected v.'i ^ d, which in this circuit variant must be high-resistance in the lower frequency range.

Entr, nr, chend Fig. 7 is in series to Ausko ^ Oelkanacity C 6 a Inductance L 4 switched to reference potential. Parallel to L 4 v / the amplifier for the upper frequency range is connected.

Tn Fig. 3 is the transmission path of the upper frequency range as

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Band filter with inductive l'Yiss point connection. The P ^ imärkreis is taken from the already described in the description of the Pig. 5 mentioned Components and the primary and secondary circuit common inductance L 4 formed. The secondary circuit also consists of L 5, C 4 and the E inrangsiin ^ edance of the amplifier for the upper i''requcnzbereich.

The D-Ode D 1 can be in this circuit arrangement with regard to the Transmission behavior in the upper frequency range is advantageous between the junction of C 6 and L 4 and the gate of the field effect transistor V 1 switched to ground.

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Claims (2)

(1 .J An beano f'.lr several receivers; wherein the County ^ e of the Dir> ols c ier "ono-iolc very short ^ erenliber the wavelength of the lower Frequenzbero Vcl'iric; rat and with the A ^ anr the electronic Verstürkerr = ';h:.'^l." An in which the '- ¹ Om is connected, that the signals of both frequency ranges from the connections of the Dir> ol3 or Ilonoriols via a separator:. ^ a:; itt t (J 5) and a lane are active (L 1) uu the control path; ines 5r ^ i;:.;: i flel-.trr-African Yerstüricereletrients (Y 1) with hGchohr.:i£: kar _,; .ritiYe ^ 3inc-inr ·:; jertra £ * e: i be, being the Karc.sität des Dinol or J'ononcli: (C! 1), -Mc LJln ^ are ^ .lcti.vifcio (L 1), the AßS-n _; ™ skaria2it-Xt ( ^! r: 3), for example, a field effect transistor, and more ■ 7 / ;: ir; ch-'R: i. n se - ™ source and P.e2u £ s "oteiitial arranged Ijanc. ! dansen freaue: i "bectir ^^ end Best3.r .. parts of a SChv / inf.kreises- öes upper Prequenz'oereiehen are and the separation on the signals from the lower and upper Prequens ^v 'accuracy of signal range on separate übertra; un £ sv. ^R ege at the output "sn first electronic amplifier elimination (V 1) takes place in such a way that" l · ^5. " largely blocks, u: z source beisrielnv: eise of a field effect transistor (V 1) ausrrekormelt v.'oruen, characterized in that the signals of the upper frequency range at the source by means of a capacitance (Λ ¹ 6). _s die di- ": Hirnale den in the lower frequency range largely blocks, out-C ^ kon ^ elt ν earth and κν / ischen source and drain of the field effect transistor (V 1) a significantly lower impedance in the upper frequency range (3 7) than all others acting in the drain and source branches ! medallion is switched, which in parallel with the output (CG) of the upper frequency range in the lower frequency range still has a sufficiently high impedance: e impedance above the input impedance dt π JOertixirun ^ swcxes of the lower frequency range, and that fe? ΐί di · -. in the drain feed line: les field effect transistor i ;; ■ ...;!: ti ve Ir.:-.edanz (L 6) is designed in such a way that it has a sufficiently high resistance in the upper! '' requunr.borf-ich, im lower B'requenz-rer & I ■ nusreioheirl nic-dsroliriic: is, and- that the quality of the rfc therethrough and the drain of the ■ sr 7elde:; ttranni; itorc (7 1) v / irksnpen Kanazitäten rebilk te ;. "-U-Ii ¹ IoIs ::!:" ¹ 3 n ~ '; reicen on the · Kc ^ o nanzfri.qaenz is so low <3, tiai? <■ ·. ·.! O "..: illit.-rv; j the · - · stage is definitely avoided. 909842/0647 , BAD ORIGINAL 2. Antenna according to point 1, characterized in that that the Auskoowel capacitance (C 6, Fig. 5) directly with the input of the Amplifier for the upper frequency range is connected. 3. Antenna according to item 1, characterized in that instead of the Auskotmelkanacity a capacitance (C 9, Fig. 6) Reference potential is connected and the input of the amplifier of the upper frequency range via an isolating capacitance at the source of the field effect transistor is coupled, the input impedance of the amplifier of the upper frequency range in the lower frequency range hochohmir: must be. 4. Antenna according to point 1, characterized in that that between the Auskonpelkanacity (C 6, i'ig. 7) and the reference> otential an inductance (L 4) is connected and the amplifier of the upper frequency range is connected in parallel with it. 5. Antenna according to item 1, characterized in that the subsequent to the Auskormelka-capacity (C 6, Fig. 8) Circuit arrangement is designed so that between the terminals the wet antenna and the connections of the amplifier for the upper frequency range a band filter with inductive footprint regulation is realized. 6. Antenna according to point Ί, characterized in that that the subsequent to the Auskopnelkanacity (C 6, Fig. 5) Circuit arrangement is designed so that between the terminals the passive antenna and the connections of the amplifier for the upper frequency range a band filter with any kind of Kotmlungsart is realized. Y. antenna according to item 1 to 6, characterized in that that between the selection means and the input of the amplifier for the upper frequency range further the transmission behavior and the signal-to-noise ratio improving impedances are switched are. 909842/0647 BAD ORSGiNAL ■ 290.9541 G. Antenna according to point 1, characterized in that that the innedans between the drain and source of the field effect transistor is a ca-nczitiAt (G 7, Pie · 8). 9. Antenna according to point!, Characterized in that there.? the impedance between the drain and source of the field effect transistor a row circle 1st. 10. Antenna according to point!, Characterized in that the quality of the inductance in the drain feed line of the field effect transistor "bef in c ¹ lic he η by connecting a resistor (2 3, / ir · 2) in parallel reduces v; ird. 11. Antenna according to point!, Characterized in that da.?· a protective diode between the gate of the field effect transistor (V 1, Fi ;;. S) un-.ί the connection of the (C 6) is switched on. 2./064? BATH ORIGINAL