KR100351973B1 - N-Way High Isolation Power Splitter / Combiner - Google Patents

Abstract

The present invention relates to an N-way high isolation power splitter / synthesizer for distributing one high frequency signal into multiple paths or combining high frequency signals inputted from multiple paths into one high frequency signal as a communication component used in mobile communication equipment. This is to improve the isolation between adjacent ports.

The present invention provides an N-way high isolation power divider / synthesizer,

The first transmission line having a predetermined length connected to the input port, the N second transmission lines having one side connected to the other side of the first transmission line, and the N even numbers connected to the other side of the N second transmission lines. Three transmission lines, N isolators coupled in series to increase isolation on one side of the third transmission line,

Consuming reflected power to isolate the two lines between output ports for outputting signals distributed to one side of the N isolators, one end of the other side of the second transmission line, and both ends of the other side of the third transmission line. An N-way high isolation power divider / synthesizer is characterized in that balanced differential resistors are connected respectively.

Description

N-Way High Isolation Power Splitter / Combiner}

FIELD OF THE INVENTION The present invention relates to high frequency systems (Micro wave systems), and more particularly to N-way high isolation power dividers / synthesizers.

In general, a microwave system includes a power splitter for distributing a high frequency signal into a plurality of paths and a synthesis for synthesizing a plurality of signals into a single path.

Power Combiner is used.

For example, a power divider is used to distribute a microwave signal (Micro Wave) output from one signal source to a plurality of output ports at a constant rate, and a synthesizer can divide a microwave signal input from multiple signal sources into a single Used to synthesize to the output port.

One example of a power divider / synthesizer in this regard is the N-Way divider proposed by Wilkinson, where N is an integer greater than one. The basic configuration of the N-way Wilkinson power divider has an input port for inputting at least one high frequency signal, and one or more output ports for distributing and outputting the high frequency signal inputted to the input port. Such a configuration can be manufactured in various forms, but a typical example is composed of a micro strip line or a strip substrate.

Figure 1 shows the structure of a conventional N-way power divider / synthesizer, which is proposed by Wilkinson and named N-way equivalent Wilkinson power divider.

The configuration and operation of the N-way equal Wilkinson power divider configured as shown in FIG. 1 will be briefly described as follows.

Now, when the high frequency signal RF is input to port 1, the high frequency signal RF is input to one node N1 of transmission lines 20, 22, 24 and 26. At this time, the length of each of the transmission line 20, 22, 24 and 26 /4( Denotes the wavelength of the input high frequency signal.) Each of the other nodes N2 is connected to the other side of the isolation resistors 50, 52, 54, and 56 having one side commonly connected to the common node CN. In addition, ports 4, 6, 8, and 10 for outputting a divided signal are provided at the other side of the plurality of isolation resistors 50, 52, 54, and 56 and the other nodes N2 of the transmission lines 20, 22, 24, and 26. do.

Port 1 is used as a common input / output port, and ports 4, 6, 8, and 10 are used as ports for inputting and outputting signals individually. Each of these multiple ports 4, 6, 8 and 10 is connected to a transmitter, a receiver for outputting a high frequency signal, or a high frequency power amplifier circuit for amplifying the high frequency signal.

Therefore, when the high frequency signal RF is input to the port 1 as described above, the power of the input high frequency signal RF is divided into signals having the same phase and amplitude, and thus N ports (four ports 4, 6, 8 and 4 in the configuration of FIG. 10) separated output. At this time, if the load of each of the ports 4, 6, 8, and 10 is matched, power is supplied to the isolation resistors 50, 52, 54, and 56 connected to the other node N2 of each of the transmission lines 20, 22, 24, and 26. ) Is not lost.

Therefore, the high frequency signal is distributed and transmitted only to ports 4, 6, 8, and 10 used as output terminals.

At this time, in the configuration of FIG. Transmission lines 20, 22, 24 and 26 connected between port 1 and a plurality of isolation resistors 50, 52, 54 and 56 with a length of / 4 are used to phase the reflected signal from ports 4, 6, 8 and 10. To make it the same.

The characteristic impedance of these transmission lines 20, 22, 24 and 26 is Z It is expressed as Equation 1 below.

= √ nx R

In Equation 1, N is a non-zero natural number, and R Is the line resistance of transmission lines 20, 22, 24 and 26. At this time, the input impedance Zin of the N-way Wilkinson power divider equal to 1 is Z Becomes

When designing a power divider / synthesizer as shown in Fig. 1, it is very important to match the resistance values of the isolation resistors 50, 52, 54 and 56 with the output resistances of the ports 4, 6, 8 and 10.

In particular, the divider is typically implemented as a single circuit. Another conventional embodiment related to the known N-way power divider / synthesizer is disclosed in patent publication 1998-014459. The disclosed invention has a common load, a first transmission line having a predetermined length connected to one input / output port, an isolation resistor connected to one side of the first transmission line, and a length longer than the predetermined length. N signal transmission paths including a second transmission line having one side connected to the other side; The configuration including N switches connected in pairs between the common input / output port and the second transmission lines in the N signal transmission paths is revealed.

In the conventional N-way power divider / synthesizer, the isolation between output ports is separated from the N-way power divider / synthesizer which is currently intended to be used in a base station in the process of distributing one high frequency signal through a plurality of paths. Due to the lower than the noise due to the interference between the adjacent ports, there is a problem that the call quality is reduced.

SUMMARY OF THE INVENTION The present invention provides an N-way high isolation power divider / synthesizer that can improve the quality of a call by eliminating interference between frequencies by increasing the isolation between adjacent ports to solve the problems of the prior art. There is this.

The technical idea to achieve the object of the present invention is in the N-way high isolation power divider / synthesizer,

A first transmission line having a predetermined length connected to an input port, N second transmission lines having one side connected to the other side of the first transmission line, and an even number of N connected to one side of the other side of the N second transmission lines Three transmission lines, N isolators coupled in series to increase isolation on one side of the third transmission line,

N output ports for outputting signals distributed to one side of the N isolator other side,

N-way high isolation power, characterized in that balanced differential resistors consuming reflected power are connected between both ends of one side of the second transmission line and both ends of the other side of the third transmission line. A dispenser / synthesizer is shown.

1 is a diagram illustrating an N-way power divider structure according to the prior art.

2 is a diagram illustrating an N-way power divider structure according to another conventional technique.

3 is a diagram illustrating the structure of an N-way isolation power divider / synthesizer according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawing

1, 2, 3: Input ports 4, 6, 8, 10, 12, 14, 16, 18: Output ports

20, 22, 24, 26, 28: first transmission line 30, 32, 34, 36, 38, 40: second transmission line

42, 44, 46, 48: third transmission line 50, 52, 54, 56: isolation resistance

60, 62, 64: Differential resistance 70, 72, 74, 76: Isolator

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a diagram illustrating a structure of a 4-way high isolation power divider / synthesizer according to an embodiment of the present invention.

Each of the transmission lines 28, 38, 40 and 42, 44, 46, and 48 of FIG. 3 has a length of λ / 4 (λ denotes a wavelength of an input high frequency signal).

When a high frequency RF signal is input to the port 3 through which the signal is commonly input or output, the input signal is connected to the first transmission line so that the signal is divided into two parts with the same magnitude and phase of the signal through the first transmission line 28. The second transmission lines 38 and 40 are distributed, and when the mismatch occurs between the second transmission lines 38 and 40, the reflected power is applied between the other sides of the second transmission lines 38 and 40 to isolate the second transmission lines 38 and 40. Connect the balanced differential resistor 60 to consume.

The second transmission line is connected to the third transmission line 42, 44, 46, and 48 connected to the second transmission line so that the two transmission lines of the second transmission line 38 and 40 are again divided into two parts with the same magnitude and phase of power. Like the furnace, balanced differential resistors 62 and 64, which consume reflected power when mismatch occurs, are connected to the other side between the transmission lines 42 and 44 and between 46 and 48, respectively. In addition, the third transmission lines 42, 44, 46, and 48 transmit radio waves with little attenuation in the forward direction, but absorb in the reverse direction so that the radio waves do not pass through the isolators 70, 72, and 74. And 76 can be connected in series to increase isolation between adjacent ports.

One side of the other side of the connected isolators 70, 72, 74, and 76 is configured with output ports 12, 14, 16, and 18 having the same voltage and distributing in-phase power, respectively.

The power distribution (or synthesis) operation of the 4-way power divider synthesizer shown in FIG. 3 is briefly described as follows.

When the high frequency signal is input to the input port 3 of FIG. 3, the high frequency signal is distributed to two parts of the second transmission line 38 and 40 in the same size and phase through the first transmission line 28.

At this time, the second transmission lines 38 and 40 divided into two parts have the same voltage, and in phase, no current flows between the second transmission lines 38 and 40. Therefore, the equilibrium condition is not established when the second transmission line 38 and the transmission line 40 are insulated, and when the transmission lines 38 and 40 are mismatched, the reflected power is consumed by the balancing differential resistor 60 to isolate the two ports. do.

In addition, the differential resistor 62 connected between one side of the other side of the third transmission line 42 and 44 and the differential resistor 64 connected between one side of the other side of the third transmission line 46 and 48 are also the third transmission line 42, 44. When the third transmission line is mismatched due to a failure of any of the circuits connected to the output ports 46, 48, and 48, the equilibrium condition is not established, thus consuming reflected power to isolate the two lines.

That is, when mismatch occurs due to a short or other cause by a circuit connected to one of the N output ports in steps of the second transmission line and the third transmission line, it is reflected by each of the differential resistors 60, 62, and 64. By dissipating power, it is possible to prevent the supply of power concentrated on one side.

In addition, the isolators 70, 72, 74 and 76 connected in series to the output ports 12, 14, 16 and 18 and the third transmission lines 42, 44, 46 and 48, respectively, are ferrite (MO.Fe₂O₃, M is bivalent). Magnetic material having excellent linearity can be used.

Therefore, when the electromagnetic wave passes through the ferrite, the magnetic field is rotated by an angle (Faraday effect) when the magnetic field is applied in the direction of propagation. Since it does not pass through, it does not affect the frequency interference on adjacent ports.

Therefore, by using ferrite material with good straightness in isolator 70, 72, 74, and 76, for example, high frequency signal input to input port 3 passes through the signal without attenuation in the output direction. Does not affect the port.

By changing the input and output of the N-way high isolation power divider, the N-way power combiner can combine the power of a high frequency signal. For example, if ports 12, 14, 16 and 18 are used as input ports for inputting high frequency signals, and port 3 is used as output ports for outputting synthesized high frequency signals, it can be applied as an N-way power synthesizer. Looking at the operation as follows.

When the output ports 12, 14, 16, and 18 are input ports, and the input port 3 is an output port, each of the high frequency signals RF2, RF3, RF4, and RF5 amplified and output from the high frequency signal output devices or a plurality of amplifiers, respectively. When power is input to the output ports 12, 13, 16, and 18, the input signal passes through the third transmission lines 42, 44, 46, and 48 through the isolators 70, 72, 74, and 76, and the second transmission line 38 Synthesized as 40.

The high frequency signal synthesized by the second transmission line 38 and 40 is finally synthesized by the first transmission line 28 and output through the input port 3 with the same voltage and phase.

In particular, the input high frequency signals RF2, RF3, RF4 and RF5 pass the high frequency signal inputted by the isolators 70, 72, 74 and 76 without frequency interference between adjacent ports without attenuation in the output direction. Since most of the signals are absorbed, signals that are not affected by adjacent ports can be synthesized and output.

The present invention is a communication component used for all equipment used for mobile communication, N-way high isolation that distributes one high frequency signal into multiple paths or combines high frequency signals input from multiple paths into one high frequency signal. Isolators configured in series on N transmission lines based on the power divider / synthesizer configuration can improve the isolation from adjacent ports. Also, the differential resistors configured in each transmission line can reduce the short circuit or other causes of circuits connected to the output ports. By concentrating the power to one port can be prevented, and based on the configuration of the present invention there is an effect that can provide a communication service with excellent quality without interference with the adjacent port to the communication user.

It is also possible to apply to a synthesizer based on the configuration of the present invention.

Claims (3)

N-way high isolation power divider / synthesizer, A first transmission line connected to one input port, N second transmission lines connected to the first transmission line, N third transmission lines connected to the N second transmission lines, N isolators coupled in series to increase isolation from the third transmission line, N output ports for outputting a signal distributed from the isolator, N-way characterized in that the balanced differential resistor that consumes reflected power is connected between both ends of the second transmission line and the third transmission line, and between the third transmission line and the isolator, to isolate the two lines. High Isolation Power Splitter / Synthesizer The N-way high isolation power splitter / combiner of claim 1, wherein the isolator uses ferrite. The method according to claim 1, in order to use the configuration of the N-way high isolation power divider as a synthesizer, using the output port as a plurality of signal input ports, And an input port of the power divider as an output port for synthesizing and outputting the plurality of signals.