DE1957760C - Filters with multiple bimodal networks - Google Patents

Description

1 S57 760

3 4

suggest that each of the bimodal, bisymmetric networks depend on the respective application and A pair of interconnected networks can range from a minimum of two over a single mode quadrupole networks each of which has two transducers coupled biinodal networks up to Has axes of symmetry, and that two connections of an indeterminable maximum number of bimodal first four-pole network which are enough with respect to the one 5 networks.

The axis of symmetry of the first quadrupole network is symmetrical. All bimodal networks 11 to 14 are arranged trically, with two connections of the two-same pair of quadrupole networks known as normal propagation modes, which are characterized in relation to, where the expression "normal mode" is the other axis of symmetry of the second four-pole network refers to a certain type of excitation, which are arranged symmetrically for the plant. In preferred io whole network remains the same. Each of the Yicrpolneizwerke is neither a network similar to that of the quadrature hybrid head. Network structure the same, but the network parameters The invention is na-wP ^r - | gend on hand are different, or around identical networks. In the implementation example. In connection with both cases, each network speaks differently on the drawings sews · - bt — liebe. It shows the two different types of excitation. This is how F i g works. 1 a B '<- K <= !. h; · -;: d of the filier, a signal coming from a signal source 18, which is coupled to the input of the filter 10 in FIG. Jber that under Yerweqd ··;. ^, Tines double conductor coaxial cable network II with a '.- r mode configuration and leads as bimodai. TietTwerk to address the network accordingly. 3 shows the impedance of the networks which the 2 ° The signal then passes through the mode converter 15, the filter according to FIG. 2 form the mode configuration in a second Anre-F i g. 4 a second embodiment of the filter changes. This results in a different response of the network 12 with a series connection of quadrature hybrid. 5 the equivalent circuit diagram of a quadrature 25 generation of a different response be * hybrid coupler with concentrated elements, neighboring networks continues until the last f Fig. 6 the frequency response of the hybrid coupler network 14 is reached. The resulting lumped element output of FIG. 5, the signal of this filter, which is delivered to the output ^{coupling network x} Fig. 7, 18 and 19, a quadrature coupler, plant 20, is a function of the response values of each network, which are switched in series T symmetrically with respect to a selected connection 3 ° and: Paar is excited, and the equivalent circuits for sym- can be controlled by the correct selection of the circuit metric excitation of the coupler with reference to the parameters and modes.
£ selected connection pair, an embodiment of such a filter is in χ Fig. 9 the symmetrical equivalent circuit diagram of each F i g. 2 shown. Each network 11, 12, 13 and 14 is a network section according to FIG. 4. 35 a section of a twin-core coaxial transmission ~ Fig. 10, 20, 11 and 21 a quadrature coupler, line with a pair of inner conductors 30 url 31, the a π »symmetrical with respect to a chosen one which is symmetrical with B ° Zug is excited on uie symmetry axis zz »connection pair, and the equivalent circuits of the transmission line are arranged and surrounded by an outer conductor 32 for antisymmetrical excitation of the coupler. The mode converter .z with respect to the selected connections, 4 ° 15, 16 and 17 contain phase-inverting over-F i g. 12 shows the antisymmetrical equivalent circuit diagram of each carrier 24, 25 and 26, which between one of the interiors of the network section according to FIG. 4, conductor 30 and the outer conductor 32 are connected in such a way, Fig. 13 aas equivalent circuit diagram of the filter according to which adjacent sections of the conductor 30 are coupled r F i g. 4 with symmetrical excitation.

± Fig. 14, the Euatzschaltbild of the filter of the filter 45 is excited by a signal source 18, F i g. 4 in the case of antisymmetrical excitation which is connected to terminal 1 of the input ^{coupling network (} FIG. The connection 2 of the network 19 F i g. 4 connected signal source is terminated with a resistor, and the An-F i g. 16 and 17, the equivalent of the symmetrical connections 3 and 4 are on the conductors 31 and 30. The and antisymmetric mode with the excitation type 5 ° input coupling network 19 has a fork connector according to FIG -F i g. FIG. 1 shows a filter 10 with a plurality of sources 18 at the connection 1 according to FIG. 2 the conductors in series connected bimodal networks 11, 12, 30 and 31 are excited in phase or symmetrically. 13 and 14, which with the help of mode converters 15, 10 if on the other hand JIc Signaivjucüc iS zr. the An and 17 are coupled. A signal source 18 is connected to the circuit 2 if the conductors 30 and S1 connections 1 and 2 of the filter 10 were excited out of phase or antisymmetrically via connection 1 180 ". Applied to a four-pole input coupling network 19. The output side of the filter points The output terminal 2 of the input network 19 is connected to the coupling network 20 with a second fork transformer, a resistor. The output terminals 1 and 2 of which with loads are output, the terminals 3 and 4 of the 60 21 and 22 are connected. If the terminals 3 filter 10 are excited via a four-pole output coupling network and 4 in phase, the entire 20 is connected to a load 21, which is fed to a signal of the load 21 at terminal 1. If the terminals of the coupling network 20 are connected, terminals 2 of 3 and 4 except Phase are excited, the entire network 20 is terminated with a resistor- signal energy to the connection 2 and the load 22 sen. 65 supplied leads.

In Pi g. 1 there are only four networks and three. If the signal source 18 according to FIG. 1g. 2 to the

Mode converter shown, but in general connection 1 of the coupling network 19 is connected.

the number of used in a specific case, the conductors 30 and 31 are acted upon in phase.

5 6

Then both inner files lie on the straight line. 5 in the equivalent circuit of such a coupling

Polcntial. and the Icrs concentrated Impcdanzefcmentc forming the bimodal network 11 are used

Section of the transmission line provides with respect to the. Jn F. ta ,. 5 are the two wires through two

Signals cir * e length of a coaxial transmission. ¹ ; firmly coupled coils 50 and 51 are shown.

line with the characteristic impedance Z _t . If 5 The capacitance between the two conductors is

However, the signal on conductor 30 represents the end of the signal through the two capacitors 52 and 53.

Nctzwcrkcs. 11 reached, it learns wrong transfer 24 given. The four coupler connections are with the

denotes a relative Pftitscnverschiefonng of JSö * with reference numbers t, 2, 3 and 4, the connections 1

on the signal of the conductor 31, because of this and 4 the one pair of conjugate terminals [

Phascnvcrscbicbuttii lift the Staiale of the two io and the connections 2 and 3 form the other pair. i

hm · ι-iH-i ifi / i /*.ir ι · ι · .ι.'κ- \ mplilU'le. but one if the sdbsiiniliiktivilät of each conductor L and the

l'l. · ii. · '... iii <r> uni · order! Hii sii dall d <r antisymmc entire Kapa / Italian / wipe conductors C is so ER-

tfi! · ν · »Ι 'voriieci l> -» nn * irki OV. In addition, the characteristic impedance Z _{0 of} the coupler / u is calculated

pi-L "" j'ht.) <■ · Sij "i> -tk-n al- /v.cidrahl jbscl.ni '". one

f kt r i> - inrsli-iiiifu 'rni'') ·· γπ wave resistance / ₂ . 15 / _n VlJC (1)

w.c.h (ι /, V Inner .ils /, Kl

Im nHUi.ii ·., Many converters 16 crTa-ircn the S _{and da <} . F ^ ergicder ratio is equal to 1 for one

pn ii. ι /vr,'.c rel-iii * e i'hascnmscrreiben von Winkelfrcquenz

| kii λ, .. ah d <* '«.vrnmelrivche AnrciMiigsmodtis,

for more than 30 <, and 31 a boiling point. IcIg- ac i>" I / (2)

ln.li * i-ki d.is Nct / vsrrk 13 al * Abscfcn't a ko- \ LC a * ii! vn (ivrif, ipiinir »leiiiinf? nut dem Wellenwider-

«,,.,".) / The signal division as a function of frequency

I ni-p'i-chrnil siclli djs aniisymm? ^{We are} excited by curves 60 and 6J in FIG. 6 indicated

\ ct / * ert 14 a dependency on the guideline .->. i the a? ben. which the amplitude of the transmitted signal

kk-ini rcr Well «-n - *> dersiand /. dar components / and the reflected quadrature signal

(ι μ '/ eipi svmbohs ».h da. J illcr after ί ι g. 2 ' » mponente /: specify, where

mn. ₂ .. ₂

leu · mi »read V ·» hurry * understanding /,. followed by Ab- 1 \ k \. (3)

s · tiniiitn <icr I bcriraeiinpsleilung with the smaller 30

«Αι ·:» n «.it'crsun <1 Z ₁ Mar. erlcnnl. that durvh from Basically, the transferred component has a

ΓΜΐ / ιιΐ ι-de · · niersi hiedli * the mode response maximum at the frequency zero and takes with it

emc ..ppclleiier Koatiaücinmg significantly different · - increasing frequencies. The reflected compo-

DiTK clekiristhe I pensthaf'en without changing the nente, on the other hand, has a minimum at frequency zero

ph. ί set up the line. 35 and increases with increasing frequencies. In the

ΛI ¹ λ of my ec-atf. ha. the introduction of periodic transition frequency o> _a are the two components

V! «« I - n-i events along a bimt / dalen arrangement.

«■ me -Jen I ffeki. because the effective properties of the equivalent circuit according to Fig. 5 shows is a

bumps VJoden see add up. Quadrature hybrid coupler bisymmetric or double

I ι ρ -J / de.·£! a according to the invention. Execution ^ - 40 axially symmetrical with respect to two right-

Nr-Sp _{1 of} a coupling device40 with a series of angled axes zz and γ-γ, each of which denotes the

stri.titirrni · mn y'i.idralur-HyrndkoppIern 41 to 46. Coupler divided into two identical bipoles. This

f> at> s-i »ird« i-T expression »Ouadratui hybrid coupler« are used in the following as »two-part prototypes«

in its usual sense Senut / 1. denoted by a Fnergie- and can be conveniently used for examination

divide / »erfc mn to describe four connections, use 45 of the coupler as each of them all

the d "f connections are in pairs, with the properties of the original quadrupole,

fedes Pj ^ r forming connection "-conjugated to each other. The coupler can also be known as" bimodal "

sin »J and draw with the connections of the other pair, which means that in each group of

couple · * also lie the split signal connections / is the reciprocal of V and that each

components by 90 out of phase, whereupon the 50 group of connections is the reciprocal of the others

drawing "Quadratu ^ KoppIer is based. Group is. This is to be done in the following by separate

The following is the structure of a variety of motion of the coupler in the symmetrical and the

K'-ppelfiiJer arrangements are shown with quadrature hybrid coupling antisymmetric mode,

lcr'j described. For the purpose of explanation, in accordance with FIG. 4 are those that form the filter 40

couplers entering into concentrated element couplers in pairs 41-42, 43-44 and 45-46

as these are the easiest to describe arranged, with each pair being one of the bimodal

leave. . ^ ___ _c , networks 11, 12 and 13 in Fig. 1.

!:?; Coupler Has k ^ mx ^ _m , t ^ izsn elements, Regarding each I * aares, the second coupler is around 90 "

/ »Ei oneunaiH'i-T insulated conductors. whose electrical twisted against the first coupler so that a pair

I än ^ e a! Clesner fraction of the wavelength at the 60 of ports 3 and 4, which are symmetrical to one

Operational frequency is required. Typically, lengths of the axes of symmetry will be, with a pair of angles

m the order of an eighth! of shafts 1 and 3 coupled symmetrically with

length and who used aer. The ladder can be in relation to the other axis of symmetry,

Neither mutually twisted to a constant Neighboring pairs are via phase shifter 47

«Retain correct orientation or can be 65 or 48 with a relative phase shift of

on etitgsrsengesetyten sides of a dielectric Ma- 180 coupled, which in one of the connection paths

'«« "Anssroidnci sern. These phase shifters correspond to the mode

Wctsrt »<3cr small electrical length can according to transducers 15 and 16 in Fig. 1.

7 8

Connection 1 of the hybrid head 41 is shown in FIG. 9. It can be seen that the result is a simple one

Fiftcr input response with which a signal source is 49 LC series resonance circuit, its resonance frequency

ferbundcn, output signals are given by the An o> _{0 is}

# ehluB2 dt * first. Hybridkopplcrs41 and the connection 1

# ehluü2 of the last hybrid coupler 46 taken. 5 (O ₀ = -prrr '(4)

|) he connection 4 of the coupler 46 is through a resistor \ iL _s C _s
MiMd completed,

Ks Although only three hemodal networks are shown, substituting IL for L ₈ and C / 2 for C, gives

fcer further sections can be added _{as required}

be approved, io 1 f

The mode of operation and the properties of the filter "Ό, * 5)

4i «« ilen jet /: can be examined by first using the \ LL
■ iixjj'cn l.ipcnsthaflcn of a quadrature hybrid coupling

lcrs mn with respect to its two axes of symmetry gc- namely the transition frequency for each of the couplers,

be checked, i.e. the coupler should first be symmetrical 15 consequently correspond in the area of the symmetrical

And then begin to -.> never be stimulated. Operating two identical, combined in the manner shown

In the modal characteristics of the coupler, group-switched couplers are given to a /.C series resonance. by the coupler with its normal circle, whose resonance frequency is equal to the transition mo-len stimulated and which is then the frequency of the coupler from the coupler. typically they are The given claims will be bcobathtci. These two couplers are not identical. In this general claim values, which all internal interactions ren case, the inductive component comes from one (It will be noted that -n only with regard to the coupler and the capacitive component from the other • Shown with noticeable effects. So let coupler. Then the crossover frequencies and For example, all use the representations of the modal response and the resonance frequency of the equivalent circuit mutual inductive influences must be indistinguishable.

ligl. since this internal interaction is important for everyone. The equivalent circuit for the antisymmetric

(Mimmlen mode clearly defined and in that of Irish mode with reference to ports 1 and 2

iuiten observable claim is contained. can be derived by making these connections in accordance with

The first modal pickup value to be tested is F i g. 10 to opposite connections of a common

i) -mmclri% chc Modu% with reference to the connections I 30 sation signal source 80 can be switched on. The arrival

• nd 2 (and because of the symmetry of the coupler with terminations 3 and 4 are separated by a resistor

fet / ug on dse Anv_hlü% sc3 and 4) l.r is determined, closed. In such operation, the conductors are 50

By d * f ports 1 and 2 according to FIG. 7 and 51 180 energized out of phase. Hence the flow

4 through two in-phase radial sources 70 and 71 currents in the two conductors in opposite directions

Mil pie. Rather amplitude be angcregi. The direction, so that no component of an inductive

Hallows 3 and 4 are completed under adaptation. tive current results. Ice flows only a capacitive one

ton die I eiJef SO '«ru? 53 always at the same potential current, namely at Cirund the through the condensate

licgcn. when the connections 1 and 2 symmetrically an- an- an- 52 and 53 shown capacitance between the

gcrcgi »earth, flow! no Va; aziliver stream, and ladders. Accordingly, that shown in FIG

each of the signals see a symmetrical impedance Ζ. *, 40 antisymmetrical equivalent circuit with regard to the connection

4k is inductive and. dd the C icgeninductivity between key and 2 (as well as 3 and 4) a cross capacitance

4c is approximately 1 in both learning. approximately equal to Can , which is equal to the conductor capacitance C of the coupler

Il is. Accordingly, the Frs, it, -, circuit contains the ist and between terminals 1 and 2 (as well as 3

Coupler for symmetrical operation m 1 reference to the and 4) lies.

Connections I and 2 (as well as connections 3 and 4) 45 The anisymmelrische equivalent circuit with regard to

Larger Fig. IX zv.ci series coils with the value of the connections 1 and 3 (as well as 2 and 4) is through

Lt 2L. F s it should be pointed out again that when a signal source 81 / is switched on, the

A mutual coupling between key and 3 according to FIG. 11 is not derived from the illustration. Because

tchim the coils L, is present. the fixed coupling between the coils 50 and '«I

In the equivalent circuit diagram for symmetrical mode 50 (Λ / = & 1), the two coils are essentially at the same potential with respect to connections 1 and 3 and because of the same potential, and there is no capacitive symmetry of the coupler between connections 2 current. The equivalent circuit of the coupler for the and 4 is determined by the connections 1 and 3 being antisymmetrical mode with reference to the connection: according to FIG. 8 by two signal connections 1 and 3 (as well as 2 and 4) in phase accordingly, sources 72 and 73 of the same amplitude are excited, referring to FIG. 21 a shunt inductance L _as equal to the. Since opposite ends of the coils 50 and 51, the self inductance L of a single coil.
are always at the same potential when the connection Fig. 12, which is a series connection of the Ersatzsshbs ί ssd 3 spsseinsefe ssgeregi viZTdcn, SkSt schaltunger, according to F i g. 20 and 21 shows no inductive current. The only current flow is antisymmetrical equivalent circuit of each of the bimodal capacitors 52 and 53. Accordingly, 60 network sections 11, 12 and 13 of the filter 40. The equivalent circuit diagram of the coupler f ^; > r the sym- C _a s C and Las ~ L , the circuit is a metric operation with reference to the connections 1 simple LC parallel resonance circuit, its resonance and 3 (as well as the connections 2 and 4) frequency according to FIG. 19 w "equal to the transition frequency of the two series capacitors with the value OC / 2. Section forming two couplers is !.

The equivalent circuit for symmetrical operation for 65 Since the equivalent circuit for the symmetrical

each of the bimodal networks II, 12 and 13 of the mode (Figs. 18 and 19) the dual networks of the

Fihers 40 are obtained by connecting the equivalent circuits for the antisymmetric mode in series

18 and 19 according to (F i g. 20 and 21), it can be seen that the quadrature

I 957 760

9 10

coupler with lumped elements bisymmetriwh of the filter aeif each of the two mod d separately analy-

iit. This is a general property of all quadrature slots and then adds up the two pickup values.

Hybrid coupler. The practical circuits for this will now be explained with reference to FIGS. 6 and 17

Distributed Element Couplers, d. H. Transmission carried out, which the entire signal distribution to the

line couplers, however, are more complicated. 5 four connections of the filter due to the symmetrical

It turns out that the mere series connection of shy and antisymmetrical excitation modes

Network sections not to the desired filter point «.

aLibau feel, since such a series circuit generates a linisprechend Fig. 16, a symmetrical series of ZC-series resonant circuits at signal amplitude E / 2, which is applied to the terminals 1 excitation in symmeirischen mode and a row io and t of the first Hybridkoppfers 41 , a circuit of IC parallel resonance circuits with excitation let-through signal component / Γ / 2 /, would form at each of the movement in the antisymmetric mode. Connections 2 and 4 of the coupler 46 and a reflector therefore require a device for the converted signal component E / 2 k, at each of the connections between the modes, so that regardless of this, connections 1 and 2 of the coupler 41. where /, the over-soft excitation mode is applied to the first section of the application coefficient for the symmetrical mode of the, this in the second and subsequent straight-filter and k _{t of} the reflection coefficient. for the sym-number networks are converted into the other mode the metric mode of the filter,
delt and in the original excitation mode in FIG. 16 shows the response to the antisymmetric all subsequent odd-numbered networks to Irish signal with f E / 2 at the terminal! and the reconverted -E / 2 Wiru This mode conversion loading AÖ port 2 of the coupler 41. The Signa produces ¹ E / 2 affect the Phasenschieoer 47 and 48 relative to a a transmitted "signal E / 2 to * at terminal 2 phase shift of 180 °. which are arranged between adjacent coupler 46 and a reflected signal composite network 11-12 and 12-13, respectively. nenfe EfI k _a , at connection 1 of the coupler 41. Au. ' For example, the phase shifter 47 converts the similar manner, the signal -E / 2 generates by symmetric to the input terminals 1 and 2 * 5 transmitted signal component E / 2 t _a "at port 4 of the hybrid coupler 42 applied excitation mode in the coupler 46, and a reflected signal compods antisymmetric excitation mode at the antenna E / 2 k _a * at the connection of the coupler 41, with conclusions I and 2 of the hybrid coupler 43 around. The / «# the antisymmetric mode coefficient for the first birr adale network 11 appears due to the filter's passage and k _a , the symmetrical modes of the symmetrical excitation coefficient applied to it are for the reflection of the filter,
modes as / C series resonance circuit. While the equivalent circuits for the symmetrical second bimodal network 12 due to the applied and antisymmetrical mode are duai to each other, • asymmetrical excitation mode as LC parallel - they have the same transmission coefficient, while resonance circuit appears. Correspondingly, the third will have their reflection coefficients negative to one another. Network symmetrically excited and forms an LC- 35 That is,

Series resonance circuit. t, = t _as (6)
The equivalent circuit of the symmetrically excited -k = k in
Filter 40 is shown in Fig. 13 It contains the * "" ^{l /} '
Series resonance circuit of network 11, the parallel By superimposing! 2, the total resonance circuit signal of the Nct / »erks! 2 and the series 4 ° at each of the connections can be obtained by using the resonance circuit of network 13. Normal mode response values On the other hand, if the connections 1 and 2 of the hybrid circuit are summed up at each of the connections, if the filter at connection 1 couplers41 are excited antisymmetriscb, then the coupler41 in the manner shown in FIG. 15 speaking the first and third networks 11 and 13 are excited .

• ntisymmetrischen mode as ZC-Parallelersatzschal- as at port 1 of the coupler 41, the reflected

• rag an, and the network 12 in the symmetrical signal

LC series switching mode. The filter _ EE

Replacement circuit for the antisymmetrical excitation ⁿ ~ V 2 ~ ^
Mode is in FIG. 14 It turns out that this

Circuit the dual network of the circuit according to 50 The filter does not reflect.
F ί g. 13 is. The reflected signal E _n at connection 2 of the coupling in the practice will, however, more typically be 41
wise not exclusively either in the symmetrical "

or excited in the antisymmetric mode, but E _n = —k _s - - k _as = Ek (9)

in both modes at the same time This can be seen from 55 2 2
of Fig. 15, in which a signal source 49

'. Signa! Et ₂ at connection 2 of the

signal + E applied to terminal 1, while the

signal applied to terminal 2 is NuIi. This 60 EE

The type of excitation can be seen in such a way that two compo- Et ₂ = - t, - \ / „, - Et ,. (10)

nents are present. The first component is a 2 2

symmetrical mode with + E / 2 at both connections and the second component an antisymmetrical The let through signal E _ti at connection 4 of the Irish mode with + E / 2 at connection 1 and ' -E / 2 65 coupler 46 is
at port 2. The sum of these two components at port 1 is + E and the sum at £ ·. = Ä _t , -JL _in - η fin Port 2 is zero. One can therefore address the 2 ₂

Il

The signal applied to the connection 1 of the coupler 41 is thus divided proportionally to k " and /" between the connection 2 of the coupler 41 and the connection 2 of the coupler 46. Since both t and k> change with frequency, a broadband signal applied to the filter is split up in such a way that one output signal is bandwidth dependent on the frequency dependence of t, and the other output signal bandwidth is determined by the frequency dependence of k, is limited, where

ι.

(12)

A bimodal network can thus be characterized by two mutually independent mode response values; but both can be made available at the same time despite their independence, moreover

shows that the mode response values for interpretation a variety of filter arrangements can be used. At higher frequencies, a Filter similar to that shown in FIG. 2 shown below

Use of a limited transmission line built in place of a double-ended coaxial cable because in a known way the different transmission M.odan different field distributions so that a very different fashion

ίο Response value due to discontinuity at a certain Steep is generated within the waveguide. Similarly, it can be different Response of gyromagnetic materials to circularly polarized waves with opposite directions Direction of rotation through a special arrangement of semi-circular panels that are spaced apart in the longitudinal direction be exploited.

Here · 2 sheets of drawings

Claims (5)

1 2 When designing a filter using patent claims: two-pole components, the components must be arranged in such a way that they meet the requirements for achieving the desired 1. Filters with several bimodal networks Filter characteristic required combinations of and at least one 5 series and parallel circuits connecting the networks. Four-pole converter, whereas all networks have the same two components, however, are bimodal and accordingly through orthogonal modes and the wall kr as two different normal modes and two different mode converters is designed, which characterizes the mode response values. Consequently Configuration of the entire incoming shaft can be used to achieve the same component essentially energy from one to the other orthogonal io of different functions in a filter circuit converts, thereby recognizing. draws that the equivalent modal. One of the more well-known quadrupole components is the Circuits bisymmetrical (double symmetry quadrature hybrid coupler. Such a coupler has Irish) networks (30, 31, 32 oaer Fig. 5) an impedance matching over a relatively are. 15 wide frequency range. It is therefore special 2. Filter according to claim 1. characterized marked usable in systems in which an Impediinzleichnet, that each of the bimodal asymmetric matching at low losses in a large Networks a four-pole network (11, 12, 13, 14) frequency range is required. This is true in typical there is way for systems using tunnel diodes 3 filter according to claim 2, wherein the modes 20 this in a known manner a negative resistance Wa & Jler are designed as 180 'phase shifters, show over a frequency range that extends downwards characterized in that each bimodal extends bi- to direct current. Because of this possibly symmetrical Network a section of a borrowed instability must therefore be associated with Double-conductor coaxial table with two of such active elements filter circuits used-outer conductor (32) enclosed inner liner (30, 31) 25 det, both outside and inside having. de? frequency band of interest impedance 4. Filter according to claim 1, characterized thereby shows that each of the bimodal, bisymmetric From the journals »The Microwave Journale, Networks has a pair of vol. 11, No. 1, (January 1968, pp. 100 to 107) and quadrupole networks (41, 42) coupled to one another, - "of which 30" The Bell System Technical Journal ", Vol. 47 (May / June each has two axes of symmetry (yy, z- ), and 1968), No. 5, pp. 651 to 722, circuit arrangements are known that two connections G, 4) of the first four-pole networks are made up of a plurality of Gabe! - works (41) which, with regard to one symmetry arrangement with ISO 'phase shifters between the axis (zz) of the first four-pole network, consist of symmetrically conjugated connections,
are arranged trically, with two connections 35. These circuit arrangements are (1, 3) of the second four-pole network (42) connected, however, not to filiers, to which the invention is based, which draws with regard to the other symmetry, but to All-pass networks.
axis (γ-γ) of the second. Four-pole network sym- The invention, on the other hand, has the task to- are trically arranged. reasons to set up a filter circuit under 5. Filter according to claim 4, characterized in that a cascade of bimodal networks is used draws that each of the quadrupole networks simplify one. Quadrature Hybrid Coupler (Fig. 5). Based on a filter specified at the beginning NEN Art. The invention proposes to solve this problem that d ^; e equivalent modal switchgear 45 Asymmetrical (double-axis symmetrical) networks are. Because of this filter structure, they become more symmetrical and antisymmetric modes under The invention relates to a filter with a plurality of uses of mode converters between adjacent modals Networks and at least one of the networks sequentially in such a way in the circuit works interconnecting transducers, all networks 50 being related to that similar asymmetrical bimodal have the same two orthogonal modes and use networks for each section the converter is designed as a mode converter. who can. the mode configuration of the entire incoming As far as in known circuits bimodal network Wave energy used by one in the other orthotics were converted to ümiuic imymimii't gonal mode. 55 see Q ^: "-Networks of this kind are not Usually one sees circuit elements as being used, and also the two-pole components required to build up a filter assembly, for example coils, condensers - the characteristics required could be combined with the capacitors and resistors. These basic construction are known circuits representing all-pass-Neizwerke not only the usual components, but cannot be obtained. In addition, they can be manufactured very cheaply and sufficiently small, 60. In a preferred embodiment, each of the bimodal networks, which enables use in large numbers of bisymmetric networks, is a four-pole network. When it is light. Recently, however, the quadrature training of the mode converter as a 180 ° phase hybrid coupler (90 ° hybrid coupler) has been developed so far that it is also very cheap and small in a further embodiment of the invention provided that every bimodal asymmetrical • can be divided. Thus, for the design of 65 network, a section of a two-wire coaxial circuit stands for a further basic component with a multitude of cables with two number of interesting and useful properties, surrounded by an outer conductor.
lur disposal. As a further development of the invention is also provided