JPH061845B2 - Multiple wave demultiplexer / multiplexer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multi-wave demultiplexing / multiplexing device that demultiplexes or multiplexes a plurality of waves, for example, as an antenna sharing device.

(Prior Art) A conventional multi-wave division / multiplexing device using a resonator and a coupling line has different frequencies f as shown in FIG.
Transmitter 1 for generating signal waves ₁₁₁ , f ₁₁₂ , ... F _{lmn
111, 1 112,} connect ... 1 _lmn resonator _{2 111, 2 112} of the corresponding resonant frequency, ... to 2 _lmn one-to-one,
These resonators 2 _{111 to} 2 _lmn have a length l in units of groups.
₁ each _{(2n 1 +1) λ 0/} 4 ( However, λ ₀ =
Wavelength of the center _frequency, n 1 = 0, 1, 2 ... in the first stage of the characteristic impedance Z having an electrical length of) the coupling line _{3 111, 3 112,} a plurality of first stage connected via a ... 3 _lmn junction section _{4 11, 4 12, ... 4} 1N is formed, length _{l 2} are each a plurality of junction portions ₄ 11 to 4 _1N first stage in groups _{n 2 λ 0/2} (although, _{n 2} = 1.2 ...) in the second stage of the characteristic impedance Z having an electrical length coupling line _{5 21, 5 22} ... plurality of the second stage are connected via a 5 _2M junctions _{6 21} ... 6
Forming a _2M, the junction portion _{6 21} ... 6 _2M in the second stage a length _{l 3,} respectively _{n 3 λ 0/2 (although,} n 3 = _1,
The third of the characteristic impedance Z having an electric length of 2, ...)
The junction portion 8 _3L of the final stage (third stage) formed by connecting via the coupling line 7 _31, 7 _3L stages antenna portion 9 junction portion 8 _3L of the final stage as a common terminal portion
It was a structure connected to. Such multiple wave component-multiplexing apparatus, each junction portions ₄ 11 _{~4 1N, 6 21} ~
The admittance of the channels multiplexed at 6 _2M and 8 _{3L is set} to infinity to reduce the loss (hereinafter referred to as distribution loss) due to leaking into other channels, and multiple waves (L × M ×
N) is multiplexed.

The equivalent circuit for the transmission frequency f _{lmn in} this case is the fourth
All admittance Y ₁₁ at junctions 4 ₁₁ becomes as shown in FIG is as follows. In the figure, G ₀ and G _L are normalized admittances.

Here, α is the attenuation constant of the line, Y is the admittance of the resonator, and the total admittance Y _{2 at the} junction unit 6 ₂₁ is _Similarly, the total admittance Y ₃ at the junction 8 _3L is However, Y _2M is obtained by using equations (1) and (4).

When obtained as described above, an equivalent circuit as shown in FIG. 5 is obtained, and this distribution loss can be obtained from the S matrix of the following equation.

However, β _n is the phase constant distribution loss of each line L = 20 _log | A + B + C + D | / 2 (11) When the distribution loss is calculated from the above equation, the coupling line 3 ₁₁₁ increases as the number of multiplexing increases. The frequency characteristic of the distribution loss of ˜73 _L is deteriorated.

FIG. 6 shows, as a simple model, the frequency characteristic of the distribution loss of the coupled line in which an equivalent short circuit is attached instead of the resonator.

(Problems to be Solved by the Invention) As described above, the conventional multiple wave demultiplexing / multiplexing device has a problem that the frequency characteristic of distribution loss of each coupling line deteriorates as the number of multiplexing increases.

An object of the present invention is to provide a multiple wave demultiplexing / multiplexing device that can reduce distribution loss.

(Means for Solving the Problems) The configuration of the present invention for achieving the above object will be described with reference to FIG. 1 corresponding to the embodiment. The present invention will be described with reference to a plurality of resonators 2 ₁₁₁ and 2 2. _112, ... 2 _lmn respectively a group unit _{(2n 1 +1) λ 0/} 4 ( provided that, lambda ₀ = wavelength of the center _frequency, n 1 = 0,1,2 ...) coupling the first stage having an electrical length of First plurality of junction sections 4 ₁₁ , 4 connected via lines 3 ₁₁₁ , 3 ₁₁₂ , ... 3 _lmn
12 ... 4 _1N are formed, and each of the plurality of first-stage junction portions 4 ₁₁ , 4 ₁₂ ... 4 _1N is n ₂ λ ₀ /
2 _(however, n 2 = 0, 1, 2 ...) of the coupling line ₅ 21 of the second stage having an electrical _{length, 5 22,} the second stage are connected via a ... 5 _2M junctions ₆ 21-6 _In the multiple wave demultiplexing / multiplexing device that forms _2M and _uses the junction section 8 _3L at the final stage as a common terminal section, the coupled line 5 at the second stage or higher
_{21-7 32} is characterized in that its characteristic impedance is set higher than the characteristic impedance of the first stage of the coupling line _{3 111, 3 112, ...... 3} lmn.

(Operation) As described above, the characteristic impedance of the coupling lines 5 _{21 to} 7 ₃₂ of the second stage and above is made higher than the characteristic impedance of the coupling lines 3 _{111 to} 3 _lmn of the first stage, thereby making the frequency characteristic of the distribution loss close to flat. The distribution loss can be reduced.

(Embodiment) An embodiment of the present invention will be described below with reference to FIG. The parts corresponding to those in FIG. 3 described above are designated by the same reference numerals.

In the present embodiment, the coupled lines 5 ₂₁ , 5 _{22 of} the second stage and above,
The characteristic impedance of 7 ₃₂ is set to the coupled line 3 of the first stage.
_The structure is higher than ₁₁₁ , 3 ₁₁₂ , ... 3 _lmn .

That is, in the present embodiment, an example of a coupled line having 32 ends is shown. Each wave from each transmitter ₁ 111 to 1 _lmn is adapted to be inputted One Tsutawa the 50Ω line to each of the resonators ₂ 111 to 2 _lmn. Each resonator 2 ₁₁₁ to 2
_lmn is four by one electrical length _{l 1 = (2n 1 +1)} λ 0/4
Of the first stage coupled lines 3 _{111 to} 3 _lmn
Junction portions 4 ₁₁ , 4 ₁₂ ... 4 _{18 in} steps are formed. The characteristic impedance of the first-stage coupled lines 3 _{111 to} 3 _lmn is set to Z ₁ Ω. Junctions _{4 11-4 18} four increments electrical length of the first stage is _l 2 =
n ₂ lambda _0/2 of the second stage of the coupling line _{5 21, 5 22} ... 5
The second-stage junction parts 6 ₂₁ , 6 are connected by _28.
22 is formed. Coupling line of the second stage ₅ 21-5
The characteristic impedance of ₂₈ is set to Z ₂ Ω.
The electric lengths of the second-stage junctions 6 ₂₁ and 6 ₂₂ are l ₃
= Junctions _{8 31 n 3} lambda ₀ / coupling line ₇ 31 of the third stage _{2, 7 32} third stage is coupled with (final stage) are formed. The characteristic impedance of the third-stage coupled lines 7 ₃₁ and 7 ₃₂ is set to Z ₃ Ω. Junctions 8 ₃₁ of the final stage is connected to the antenna terminal 9 at 50Ω line. The junction section _{31 at the} final stage is 50
It is connected to the antenna line 9 by an Ω line.

Conventionally, in equations (3), (6), (9), and (10), the characteristic impedance of the line was normalized to Z _L / Z ₀ = 1 (where Z ₀ is the characteristic impedance 50Ω).
When each equation is converted so that the characteristic impedance of each line can be input, equation (3) yields Y _L1 = 50 / Z ₁ · coth {αl ₁ + jπ (2n ₁ +1) / 2 · (f _lmn -f ₀ ) f ₀ }
(12) Formula (6) is Y _L2 = 50 / Z ₂ · coth {αl ₂ + jπn ₂ (flm _lmn -f ₀ ) / f ₀ } (13) Formula (9) is Y _L3 = 50 / Z ₃ · coth {αl ₃ + jπn ₃ (flm _lmn -f ₀ ) / f ₀ } (14) The line constant S matrix of the line l _{1 in} the equation (10) is Is. The same applies to the lines l ₂ and l ₃ .

Admittances Y _L2 and Y in equations (6) and (9)
_{Since L3} should be as small as possible than this equation, the characteristic impedance Z of each line in equations (13) and (14)
_It can be seen that admittances Y _L2 and Y _L3 are smaller when ₂ and Z ₃ are infinite than in the conventional 50Ω line.

When these are calculated, the characteristic impedances Z ₂ and Z ₃ of each line are set to infinity, and the characteristic impedance Z _{1 of the} line is set.
Is 40 to 50Ω, the frequency characteristic of the distribution loss can be brought close to a flat value to reduce the distribution loss. However, since infinite characteristic impedance is practically impossible, Z ₂ = Z ₃ = 87Ω,
An equivalent short circuiter was attached instead of the resonator with Z ₁ = 50Ω. The frequency characteristic of the distribution loss at this time is shown by the solid line in FIG. Compared with the conventional type shown by the broken line, it can be seen that the distribution loss has a wide band and low loss characteristics.

Although the above embodiment has shown the case where the coupling line has three stages, the present invention is not limited to this, and any number of stages may be used as long as it has two or more stages.

(Effects of the Invention) As described above, the multiple wave demultiplexing / multiplexing device according to the present invention has the characteristic impedance of the coupled line of the second stage or higher as the first characteristic impedance.
Since it is higher than the characteristic impedance of the coupled line of the stage,
The distribution loss can be reduced by making the frequency characteristic of the distribution loss close to flat.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of a multiple wave demultiplexing / multiplexing device according to the present invention, FIG. 2 is a comparison diagram of frequency characteristics of distribution loss between the present invention and a conventional device, and FIG. Is a block diagram of a conventional device, FIGS. 4 and 5 are equivalent circuit diagrams of the conventional device, and FIG. 6 is a frequency characteristic diagram of distribution loss of the conventional device. 1 ₁₁₁ to 1 _lmn ... Transmitter, 2 ₁₁₁ to 2 _lmn ... Resonator,
3 _{111 to} 3 _lmn ... First-stage coupled line, 5 _{21 to} 5 ₂₈
... second stage coupling _{line, 7} 31, 7 _{32 ...} third stage coupling _{line, 4} 11-4 _{18 ...} junction portion of the first stage, 6
₂₁ , 6 ₂₂ ... Second-stage junction section, 8 ₃₁ ... Final-stage junction section.

Claims (1)

[Claims] 1. A plurality of resonators in groups _{(2n 1 +1) λ 0/} 4 ( provided that the wavelength of lambda ₀ = center _frequency, n 1 = 0, 1, 2 ...) first has an electrical length of through the one-stage coupling line to form a plurality of junctions of the first stage are connected, a plurality of junctions each n ₂ λ _0/2 of the first stage (where, n 2 ₌ 0, 1, 2 ...)
In the multi-wave demultiplexing / multiplexing device, the second-stage junction section is formed by connecting via the second-stage coupling line having the electric length of The multiple-wave demultiplexing / multiplexing device is characterized in that the characteristic impedance of the coupled line of more than one stage is set higher than the characteristic impedance of the coupled line of the first stage.