JPH06318829A - High frequency power distributer-combiner - Google Patents

Abstract

PURPOSE:To reduce a power loss when power amplifiers whose number of ports is a few are operated in parallel by matching best the line with a load in the distribution/combining through prescribed connection of a line. CONSTITUTION:One end of a line 11 is connected to a distribution/combining point (p) and the other end is connected to a distribution/combining number switching diode D., to best match the line with a load in the case of [(n/2)41] distribution/-combining. Then an n-port high frequency power distributer/ combiner is formed by using a line whose characteristic impedance is [(n/2)+1<1/2>.Z0 and whose length is[(2m1).lambda/4]. Thus, the impedance when viewing an output/-input from the point (p) is best matched with a load when the distribution/-combining number is [(n/2)+1], and the passing loss when the distribution/combining number is larger than [(n/2)+1] and that when the distribution/combining number is smaller than [(n/2)+1] are almost made equal to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency power distributor / combiner used in a power amplifier. In the power amplification unit of the multiplex wireless device, for example, a plurality of power amplifiers are operated in parallel, and the number of parallel operations (the number of power amplifiers) is increased or decreased according to the grade of the system.

Therefore, when using a high-frequency power distributor / combiner with the number of ports commensurate with the number of power amplifiers operating in parallel, if the number of parallel operations increases or decreases, the ones used up to now are removed and the corresponding ports are used. It has to be replaced with one that has a number, which is costly. In addition, if the power amplifier in use fails, the power must be turned off while the failed power amplifier is replaced, and system down is inevitable and reliability is poor.

On the other hand, if a high frequency power distributor / combiner having a maximum number of ports of power amplifiers that are operated in parallel is prepared in advance, if the number of power amplifiers to be used is less than the maximum number, the ports to which power amplifiers are not connected are Must be terminated,
The power loss in the circuit is very high.

For example, when connecting three power amplifiers to a 4-port high-frequency power distributor / combiner, the remaining ports must be terminated, so the passage loss is 1/4 (6 dB) each. However, if a 3-port high-frequency power divider / combiner is used, the passage loss will be 1/3 (4.8 dB) each, so
If the former is used, it will be degraded by 1.2 dB.

Therefore, there is a need for a high frequency power distributor / combiner capable of reducing the power loss as a power amplifier even when the power amplifiers having a number smaller than the number of ports are operated in parallel.

[0006]

2. Description of the Related Art FIG. 6 is an explanatory diagram of a conventional example, (a) is an explanatory diagram of parallel operation of a high frequency amplifier, and (b) is a principle configuration diagram.
Japanese Examined Patent Publication No. 55-15881 (High-frequency amplifier parallel operation system)
2 is the same as FIG.

First, in the prior art, when it is necessary to increase the number of power amplifiers operating in parallel to upgrade the system, or when it is necessary to replace the power amplifiers operating in parallel due to a failure, FIG. As shown in b), the configuration of the n-port high-frequency power distributor / combiner is distributed from the composition / composition point 7 so that there is no system disconnection when replacing the high-frequency power distributor / combiner. Characteristic impedance [(n) ^1/2 ] -Z ₀ , length
L = (2m −1) · (λ / 4) lines are short-circuited across the line. Note that m and n are positive integers, and Z ₀ is the characteristic impedance of the circuit.

Here, the passage loss when the above configuration is taken is simulated by taking a 4-port high frequency power distributor / combiner as an example.

[0009]

[Table 1]

As shown in Table 1, the distribution / combination number is 4, 3,
In the case of "ideal case" where the corresponding distributor / combiner is used in case of 2, the values are 6.0, 4.8 and 3.0 dB. However, when using a high frequency power distributor / combiner with four ports when the number of distributors / combiners is 4, 3 and 2, all of the 6.2 dB (line itself Since it was simulated including the loss of, the deterioration was 0.2 dB compared to the “ideal case”), and the passage loss increases in response to the increase in the number of unused ports compared to the “ideal case”.

In the "conventional example", matching can be achieved when there is no unused port number (4 distribution / combining state). However, when the unused port is 2, the impedance seen from the distribution point 7 to the unused port side becomes infinite and cannot be seen, but the matching is broken in the port in use, so it is 0.8 dB compared to the ideal case. Although deteriorated, the passage loss is improved as compared with the case of "no switching".

That is, in the case of a 4-port high frequency power distributor / combiner, the passage loss is minimum when the number of distributors / combiners is 4, 2.
At the maximum, the passing loss at the time of switching between 4 and 2 becomes non-uniform, but this non-uniformity increases as the number of ports increases.
Remarkably appears.

In the actual use state, as shown in FIG. 6 (a), the distributed high frequency signals are amplified by the corresponding amplifiers and then re-synthesized and output.
The port high frequency power divider / combiner is less than ideal.
An extra pass loss of 8 dB × 2 = 1.6 dB occurs, and the power loss of the power amplifier becomes large.

[0014]

SUMMARY OF THE INVENTION As described above, for example,
If two power amplifiers are connected to a 4-port high-frequency power distributor / combiner to operate as a power amplifier, the pass loss at the time of two-distribution / combining will be larger than the ideal case. There is a problem that power loss becomes large.

It is an object of the present invention to provide a high-frequency power distributor / combiner that requires less power loss as a power amplifier even when power amplifiers having a number smaller than the number of ports are operated in parallel.

[0016]

FIG. 1 is a block diagram showing the principle of the first aspect of the present invention. In the figure, 11 has a characteristic impedance of [(n /
2) +1] ^1/2 · Z ₀ , length [(2m−1) · λ / 4] 1st line, 21 has a specified characteristic impedance and length [(2m−1)
-[Lambda] / 4] second line, 41 is a connection line in which one end of the second line is connected to the other end of the first line.

In the first aspect of the present invention, one end of the first line is a distribution / combining point p, and the other end is a distribution / combining number switching diode D.
Each of them is connected to _{11 so} that the best matching with the load is made at the time of [(n / 2) +1] distribution / combination.

In the second aspect of the present invention, one end of the second line is connected to the other end of the first line. In the third aspect of the present invention, the diode is deleted when the connection line is always used.

[0019]

2 is a comparison diagram of the passage loss of the first invention and the conventional example. The present invention has a characteristic impedance of [(n / 2) +1] ^1/2
・ The output from the distribution / combining point p (distributor) by configuring an n-port high-frequency power distributor / combiner using a line with a length of [(2m−1) · λ / 4] at Z ₀ / When looking at the input (combiner) side, the impedance is the distribution / combining number [(n / 2) +1]
At the time of, it matches the load best, and the distribution / combining number is [(n / 2) +
The passing loss when it is larger than 1] is made almost equal.

On the other hand, in the conventional example, the distribution parts can be matched when all n ports are used, so if the number of unused ports becomes large, the matching cannot be achieved and the passage loss increases (see FIG. 2). .

That is, when n = 4, the distribution / combination number is 4,
Although the present invention can be used with 3 and 2, the present invention has a central distribution / composite number n.
Since it is designed to get the best matching when = 3,
The mismatch values that occur when switching to n = 4 or n = 2 are approximately equal.

Further, although the diode D ₁₁ is connected, the diode connected to the line 11 in use is off, so that all the high frequency power transmitted through the line is supplied to the power amplifier (not shown). However, since the diode connected to the unused line is turned on, the impedance seen from the distribution / combining point p to the on diode side is infinite, and the unused line is cut off from p point. Is equivalent to

[0023]

FIG. 3 is a block diagram of the first embodiment of the present invention.
(a) is a main part pattern diagram, (b) is a pattern diagram in a bias circuit in (a), and an equivalent circuit diagram. FIG. 4 is a block diagram of the second embodiment of the present invention, and FIG. 5 is a block diagram of the third embodiment of the present invention.

The same reference numerals denote the same objects throughout the drawings. 3 to 5 will be described below with n = 4 and m = 1, but since the configurations of the respective branch parts are the same, the branch parts to which reference numerals are added will be described.

In FIG. 3 (a), the high frequency power input from the terminal IN passes through the 50 Ω line 213 and is divided into 4 at the p point to obtain the characteristic impedance [(4/2) +1] ^1/2 · 50 = 86.6 Ω. , The line 11 of length λ / 4, the lines 211 and 212 of Z ₀ = 50 Ω, and the terminal OU
It is applied to a load (not shown) connected to T-1.

The bias voltage for the diode is shown in FIG.
It is applied via a circuit as shown in (b), but when the load is connected, the diode is in the off state, when the load is not connected, it is in the on state. , 10Ω.

Here, by connecting the p point, which is a distribution / combining point, and the diode D ₁₁ with a line having a characteristic impedance of 86.6Ω and a length of λ / 4, the output terminal OUT-1 can be seen from the p point. Impedance Z ₁ = [(86.6) ² ] / 50 = 150 Ω. The impedance when looking at the other output terminals is the same value,
(150/4) = 37.5Ω = 0.75Z ₀ when distributed / combined.

Further, in the case of 3 divisions, there are three lines to which loads are connected, and the impedance when the output terminal is viewed from the point p is 150 Ω as described above, but the lines to which no load is connected are [(86.6) ² ] / 10 = 750Ω. So 150 /
A parallel connection of 3 Ω and 750 Ω results in 46.9 Ω = 0.94Z ₀ .

Further, in the case of the two-way distribution, the load is connected to two lines (150/2) = 75Ω, and the load is not connected to two lines (750/2) = 375Ω, which is a parallel connection of 62.5. Ω = 1.2
It becomes 5Z ₀ .

That is, the impedance viewed from the point p to the output side is 0.75Z ₀ when 4 divisions / combining, 0.94 when 3 divisions / combining.
Z _0, 2 1.25Z ₀ next time the distributing and combining, consistent with best load during 3 distributing and combining, pass loss at 4 distributing and combining time and 2 distributing and combining is approximately equal uniform.

It should be noted that, when comparing the conventional example and the passing loss designed according to the present invention with Table 1 above, it is 0.4 dB, which is about 1/2 of 0.8 dB in the case of two-partitioning / combining. Therefore, if the input power per passage is 10 W, the output power is improved to 8.3 W in the conventional example and 9.1 W in the present invention.

Next, referring to FIG. 4, diodes D ₁₁ and D ₁₄
To output terminals OUT-1 to OUT-4 length L ₂ = (2m −1) ・
By connecting with the line of (λ / 4), even if the short circuit by the diode is incomplete, the output terminal of the line not used
When OUT is opened, the voltage distribution at the diode connection point becomes 0, and it looks more infinite when looking at the corresponding diode side from p point.

Further, in FIG. 5, a diode is provided for each line, but in the case of a 4-port high frequency power distributor / combiner, for example, among the lines for switching between 4, 3 and 2 passages,
If the 4th and 3rd pass lines are designated as always used (only the 1st and 2nd pass lines are used / not used), the designated line's die auto is off as shown in Fig. You can At this time, set the length of the passing lines of 4 and 3 to m
・ (Λ / 2) = 2L ₁ needs to be set.

That is, according to the present invention, the n-port high-frequency power distributor / combiner distributes or combines n, n−1, ... By making the losses as uniform as possible and reducing the distribution / combining loss, it contributes to the efficient operation of the system, and the improvement of circuit reliability by reducing the number of parts, low power consumption, low loss and low price. large.

[0035]

As described above in detail, according to the present invention, the high frequency power distributor / combiner which can reduce the power loss as the power amplifier even when the power amplifiers of which the number is smaller than the number of ports are operated in parallel. Is effective.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of a first present invention.

FIG. 2 is a comparison diagram of passing loss between the first present invention and a conventional example.

3A and 3B are configuration diagrams of the first embodiment of the present invention, in which FIG. 3A is a principal part pattern diagram, and FIG. 3B is a pattern diagram in a bias circuit in FIG.

FIG. 4 is a configuration diagram of a second embodiment of the present invention.

FIG. 5 is a configuration diagram of a third embodiment of the present invention.

FIG. 6 is an explanatory view of a conventional example, (a) is an explanatory view of parallel operation of a high frequency amplifier, and (b) is a principle configuration diagram.

[Explanation of symbols] 11 First line 21 Second line 41 Connection line D ₁₁ Diode for switching distribution / composition number

Claims (3)

[Claims] 1. A high-frequency power distributor / combiner for distributing high-frequency power by n or combining n-distributed high-frequency power with a characteristic impedance of [(n / 2) +1] ^1/2 · Z ₀ and a length. Is [(2m−1) ・ λ / 4] (n and m are both positive integers), one end of the first line (11) is the distribution / combining point (p) and the other end is the distribution / combining number. Connect to each switching diode (D ₁₁ ), and select [(n / 2)
+1] A high-frequency power distributor / combiner characterized by having the best matching with the load when distributing / combining. 2. A second line having a predetermined characteristic impedance and a length of [(2m−1) · λ / 4] at the other end of the first line.
The high frequency power distributor / combiner according to claim 1, wherein one end of (21) is connected. 3. The diode connected to the other end of the first line is deleted when the connection line (41) in which one end of the second line is connected to the other end of the first line is always used. The high frequency power distributor / combiner according to claim 2.