KR101297577B1 - Switching apparatus for rf perforence test - Google Patents

Abstract

PURPOSE: A switching device for radio frequency (RF) performance tests is provided to directly measure a path loss for an actually used frequency and perform calibration. CONSTITUTION: Multiple RF switches (S1-S10) include a first group of RF switches, a second group of RF switches, and a third group of RF switches. The third group of RF switches is placed on a path from a sub-input port to one of output ports. The third group of RF switches connects the sub-input port to the output port. A control part controls the on/off of the RF switches according to external measuring equipment connected to a part of or all of the ports. The control part takes charge of communications between the RF switches and the external measuring equipment.

Description

Switching apparatus for RF perforence test

The present invention relates to a switching device for RF performance testing, and in particular, in performing an RF test for a communication terminal, the communication terminal and the measurement equipment are automatically controlled through a switch control in a state in which a communication terminal and a plurality of measurement equipment are connected to each port. The present invention relates to a switching device for RF performance test that enables not only to perform a predetermined test sequentially by connecting a circuit, but also to automatically perform calibration for each path and frequency in a short time.

In general, a test device or a measurement device of a communication system must satisfy various items according to the purpose for which the user intends to test. As communication systems become more complex and sophisticated, test devices that test their performance are also required to have accurate and reliable performance tests and measurements of various test items for the communication system.

In addition, the same characteristics should be maintained in various frequency bands in order for the measurement results of various test items to be more reliable.

1 is a block diagram of a test apparatus for a performance test of a conventional DVB-H terminal. As shown in FIG. 1, the conventional test apparatus 10 includes a baseband signal generator 11 for generating an I mode baseband signal and a Q mode baseband signal, and a modulator for modulating I and Q mode baseband signals. A carrier output unit 12 for outputting a carrier and a test signal generator 13 for combining the I and Q mode baseband signals with the carrier to generate a test signal.

Here, the reliability of the performance test result can be ensured if the test signal of the test apparatus 10 transmitted to the DVB-H terminal is modulated under ideal conditions to test the performance of the DVB-H terminal. However, when the test apparatus 10 is manufactured, the characteristics of elements used for each test apparatus 10 are different, and the baseband signal generator 11, the carrier output unit 12, the test signal generator 13, and the like are different. There is a problem in that the reliability of the test signal output from the test apparatus 10 is not sufficiently ensured because the ideal matching is not performed at the time of combining, and there is a problem in that different test apparatuses provide different test results.

To this end, the conventional test apparatus 10 secures uniformity of characteristics according to frequency through calibration of frequency calibration, output power level calibration, IQ modulation calibration, and modulation carrier calibration, and the like. Spectrum analyzers or network analyzers for characterization, and power meters for measuring whether the test signal is transmitted at the correct power level.

However, in testing several items for DVB-H terminals, conventionally, after performing a frequency analysis and disconnecting the spectrum analyzer while directly connecting a test apparatus, a DVB-H terminal, and a spectrum analyzer using an RF cable, In connection with the power meter to measure the power level, such as to test the appropriate measuring equipment for each test item, the test is not only a cumbersome cable replacement process, but also a long time-consuming problem. First of all, this cable replacement connection problem made it impossible to perform the test automatically according to a predetermined schedule while replacing the appropriate measuring equipment for each test item.

In addition, since the calibration was performed for each path and frequency band while all the measurement equipment used in the test was connected via RF cable for sophisticated calibration, it took a lot of time and effort.

In order to solve this problem, the applicant has applied for a "RF performance test switching device" in 2010 Patent Application No. 88577 (application date: September 9, 2010).

Applicant's prior application described above includes a plurality of input ports; A plurality of output ports; An intermediate port having at least one intermediate output port and at least one intermediate input port; A plurality of RF switches and ON of the RF switch that selectively connect the input port to any one of the intermediate input port and the output port and alternatively connect the intermediate output port to any one of the output ports It includes a control unit that controls the on / off and communication between the external measuring equipment, and automatically connects the broadcasting terminal and the measuring equipment through the switch control while the broadcasting terminal and the plurality of measuring equipment connected to each port The present invention discloses a switching device for RF performance testing, which not only enables a predetermined test to be performed sequentially but also automatically performs calibration for each path and frequency band within a short time.

However, according to the foregoing applicant's prior application, the switching device is mainly developed for the broadcast terminal, so that the RF performance of the third generation mobile communication terminal or the fourth generation mobile communication terminal such as 3GPP (3rd Generation Partnership Project) or the like is tested. There was a lack.

In addition, since the calibration for each frequency to compensate for each path loss is performed by a predetermined frequency step (interval), and the calibration for the remaining frequencies is indirectly performed by interpolation, accurate calibration cannot be performed. There was a problem that only a path can be selected and a user cannot directly generate an arbitrary path by manipulating an RF switch.

The present invention has been made to solve the above-described problems, one of the predetermined paths through the switch control in the state in which the communication terminal and the plurality of measurement equipment connected to each port in performing the RF test for the communication terminal or For RF performance test that automatically connects communication terminal and measurement equipment with user-generated path to automatically perform the specified test, and also performs calibration by directly measuring path loss for actual frequency used. It is an object to provide a switching device.

According to an aspect of the present invention, an RF performance test switching device includes at least one input port; At least two output ports; An intermediate port having at least one intermediate output port and at least one intermediate input port; At least one sub input port; Alternatively connect the input port to any one of the intermediate input port and the output port and alternatively connect the intermediate output port to any one of the output ports or directly connect the sub input port to the output port. It includes a plurality of RF switches to connect and a control unit for controlling the on / off of the RF switch and responsible for communication between the external measurement equipment.

In the above-described configuration, a synchronous input port for receiving a synchronous signal, a synchronous port having at least two or more synchronous output ports, and a power for distributing the power of the synchronous signal input through the synchronous input port and outputting the synchronous output port to the synchronous output port. It is characterized by including a splitter.

And a power splitter for combining or distributing signals of the input port, the output port, the intermediate port, and the sub-input port.

According to another aspect of the present invention, a switching device for testing RF performance includes at least one input port; At least two output ports; A plurality of RF switches for alternatively connecting the input port to any one of the output ports; A synchronization port having a synchronization input port for receiving a synchronization signal and at least two synchronization output ports; A power splitter for distributing the power of the sync signal input through the sync input port and outputting the power to the sync output port, and a control unit controlling on / off of the RF switch and performing communication with external measurement equipment. .

In the above configuration, it characterized in that it further comprises a power splitter for combining or distributing the signals of the input port, the output port, the intermediate port and the sub-input port.

According to the switching device for the RF performance test of the present invention, in performing an RF test for a communication terminal, one of a predetermined path or a user through a switch control in a state in which a communication terminal and a plurality of measurement equipments are connected to each port In addition to automatically connecting the communication terminal and the measurement equipment with a randomly generated path, it is possible not only to perform a predetermined test, but also to perform a calibration by directly measuring a path loss with respect to the actual frequency used.

1 is a block diagram of a general DVB-H terminal test apparatus.
2 is a block diagram of a switching device for RF performance test of the present invention.
Figure 3 is a block diagram of a SPDT switch in the switching device for RF performance test of the present invention.
4 is a configuration diagram for extracting calibration data for each path by connecting a network analyzer to the switching device for RF performance test of the present invention.
5 is a configuration diagram showing an actual connection state of the switching device for the RF performance test of the present invention by way of example.
6 is a graph showing the frequency-specific loss of the path of FIG. 4 described above in the switching device for RF performance test of the present invention.
7A and 7B are diagrams illustrating UI screens of a calibration program through a switching device for RF performance test of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the RF performance test switching device of the present invention.

2 is a block diagram of a switching device for RF performance test of the present invention, Figure 3 is a block diagram of a SPDT switch in the switching device for RF performance test of the present invention. First, as shown in FIG. 2, the RF performance test switching device 100 of the present invention includes at least one input port 110 (PORT1, PORT2), at least one sub-input port 140 (PORT7, PORT8), Intermediary port 130, input port 110 having at least one output port 120 (PORT9, PORT10), at least one intermediate input port PORT3, PORT4 and at least one intermediate output port PORT5, PORT6. , A plurality of RF switches (S1-S10) for properly connecting two or more ports among the sub-input port 140, the output port 120, and the intermediate port 130, and the power of the signal passing through them A plurality of power splitters or combiners (hereinafter referred to as 'splitters') (D1-D3) to distribute or combine, and control the on / off of the RF switch (S1-S10) and with external measuring equipment or calibration equipment. It is responsible for the communication between the users and performs the function of extracting calibration data. The control unit includes, for example, the MCU 170 and a power supply unit 150 for supplying DC power to each unit of the device, each of which may be installed in a rectangular case.

In the above-described configuration, the power supply unit 150 supplies the DC power required for each part of the device by decompressing, rectifying, and smoothing the commercial AC power. Alternatively, the power supply unit 150 may be implemented as an independent DC power source. Next, the input port 110, the intermediate port 130, the sub input port 140 and the output port 120 may be arranged to be exposed to the side or top surface of, for example, a rectangular case, all of which are coaxial. It may be made of a cable connector.

Meanwhile, the path from the input port 110 to the output port 120 is a path (hereinafter, referred to as a “direct path”) directly from the input port 120 to the output port 120 and an intermediate port from the input port 120. Via 130 to the output port 120, ie indirectly connected paths (hereinafter referred to as 'indirect path'), RF switch (S1-S10) or power splitter (D1-D3) these direct It may be interposed between the path and the indirect path. On the other hand, the path from the sub input port 140 to the output port 120 is connected directly to the output port 120 without passing through the intermediate port 130 (of course, there may be an RF switch or a power splitter intervening). Only direct paths may be used.

The apparatus of the present invention also receives an arbitrary synchronization signal, for example, a synchronization signal of a predetermined frequency into the synchronization input port IN, and then distributes its power to output to the plurality of synchronization output ports OUT1, OUT2, OUT3. The synchronous output power splitter D4 may be further provided. The synchronous input port IN and the synchronous output ports OUT1 through OUT3 are collectively referred to as the synchronous port 160. The user can accurately synchronize the plurality of measurement equipment by a simple operation of connecting the plurality of measurement equipment to the synchronization output port 160. In the drawings, reference numeral 200 denotes a control computer.

Meanwhile, in the present invention, the RF switches S1-S10 may be implemented as relays of a single pole double throw (SPDT) method, which is a three-way switch. Specifically, the SPDT switch adopted as the RF switch S1-S10 in the present invention has one common contact (C) and two branch contacts (1, 2), as shown in FIG. By means of two switch contacts the common contact C is alternatively connected to each branch contact 1, 2. Each of the branch contacts 1 and 2 of the SPDT switch is usually connected with a terminating resistor of 50 ohms. The common contact C is connected to one branch contact (branch contact 1 in the embodiment of FIG. 3). When connected, the other branch contact (branch contact 2 in the embodiment of FIG. 3) is grounded through a 50Ω termination resistor.

4 is a configuration diagram for extracting calibration data for each path by connecting a network analyzer to a switching device for RF performance test of the present invention. In the example of FIG. 4, the first input port PORT1 is selected from the input ports 110. A process of performing calibration for each frequency used for the path from the output port 120 to the first output port PORT9 is illustrated (see a thick line).

To this end, the network analyzer 300 transmits a calibration RF signal for each frequency used to the first input port PORT1, receives the signal to the first output port PORT9, and checks the path loss to extract calibration data. The control computer 200 stores the calibration data for each path in a table. In addition, the control computer 200 may store the loss of all paths and calibration data for correcting the data in the form of a table in the above-described manner, which will be described later.

5 is a configuration diagram showing an actual connection state of the switching device for the RF performance test of the present invention by way of example, reference numeral 400 in FIG. 5 represents a base station emulator (BSE) for generating a base station signal, 500 A fading simulator, 600 and 700, a signal generator (S / G) and a signal analyzer (S / A), and 800 and 850, a user equipment.

In the above-described configuration, two base station signals TX1 and TX2 generated by the base station emulator 400 are respectively input to the first input port PORT1 and the second input port PORT1 constituting the input port 100. Can be. The base station signal input through the first input port PORT1, for example, TX1, may be output to the user terminal 800 through S1-> S3-> D2-> S6-> S7, and the second input port. The base station signal input through PORT2, for example TX2, may also be output to the user terminal 850 via S2-> S5-> S8.

Unlike this, the base station signal input to the first input port PORT1 is input to the intermediate input port PORT3 via the RF switch S1, and then fading in which the intensity of the radio wave is changed in the fading simulator 500 as in the actual propagation environment. The fading signal may be converted into a signal and then provided to the user terminal 800 through S3-> D2-> S6-> S7 after the fading signal is output through the intermediate output port PORT5. The base station signal input to the second input port PORT2 may also be output to the user terminal 850 via S2-> PORT4-> fading simulator 500-> PORT6-> S2-> S5-> S8.

On the other hand, after generating the signal generator 600 after combining the noise signal passing through PORT7-> D1-> S10-> S4 from the base station signal inputted via PORT1-> S1-> S3 and the power splitter (D2), and then S6- By outputting through < RTI ID = 0.0 > S7, < / RTI > the base station signal into which the noise is forcibly mixed may be output to the user terminal 800.

FIG. 6 is a graph showing the frequency-specific loss of the path (see solid line) of FIG. 4 described above in the switching device for RF performance test of the present invention, and shows a loss of 3GPP LTE system downlink frequency. In Figure 6, the vertical axis represents loss (dB), and the horizontal axis represents frequency.

As shown in FIG. 6, in the present invention, after a loss is measured for each predetermined frequency step for a specific path, the frequency other than that is not indirectly estimated by loss by interpolation. By calibrating path loss directly to create a table and then performing calibration, accurate calibration is possible. Table 1 below is a calibration table in which the frequency loss and corresponding calibration data shown in FIG. 6 are recorded.

Frequency [Hz] Loss of Path 1 [dB] Compensation value for path 1 [dB] 869000000 -4.347 +4.347 894000000 -4.343 +4.343 925000000 -4.367 +4.367 960000000 -4.368 +4.368 1805000000 -4.832 +4.832 1880000000 -4.818 +4.818 2110000000 -4.924 +4.924 2170000000 -4.347 +4.347 2620000000 -4.934 +4.934 2690000000 -5.086 +5.086

7A and 7B are diagrams illustrating UI screens of a calibration program through a switching device for RF performance test of the present invention, and are diagrams illustrating screen selection modes and individual switch control modes, respectively. First, when the user selects a predetermined path selection mode (Pre-RCT) as shown by a dotted line in FIG. 7A as a selection mode, all paths that are predetermined and selectable by the user are listed together with the alternative selection button. The user can designate a desired path by selecting (clicking) one of the buttons, and the MCU 170 controls the related RF switches S1-S10 in accordance with the specified path.

Alternatively, the user may select an individual switch control mode (Manual S / W Control) as shown by a dotted line in FIG. 7B as a selection mode. In this case, all selectable RF switches (S1-S10) at the bottom thereof are multiplied. Listed together with the enemy selection button, the user can arbitrarily generate a desired path by selecting (clicking) a plurality of desired RF switches. In this case, the input port may function as an output port while the output port may function as an input port.

The switching device for RF performance test of the present invention is not limited to the above-described embodiment, and may be variously modified and implemented within the range permitted by the technical idea of the present invention.

100: switching device, 110, PORT1, PORT2: input port,
120, PORT9, PORT10: output port,
130, PORT3, PORT4, PORT5, PORT6: intermediary ports,
140: PORT7, PORT8: sub input port, D1-D4: power splitter,
150: power supply, 160: sync port,
170: MCU, 200: control computer,
300: network analyzer

Claims (5)

At least one input port;
At least two output ports;
An intermediate port having at least one intermediate output port and at least one intermediate input port;
At least one sub input port;
Positioned on a path extending from the input port to the intermediate input port or to one of the output ports for selectively connecting the input port to either the intermediate input port or the output port; A first group of RF switches and a second group for alternatively connecting the intermediate output port to any one of the output ports on a path extending from the intermediate output port to any one of the output ports A plurality of RF switches including an RF switch and a third group of RF switches positioned on a path extending from the sub input port to any one of the output ports to connect the sub input ports to the output ports With;
And a control unit for controlling on / off of the RF switches and communicating with the external measurement device according to external measurement device connected to some or all of the ports. The method of claim 1,
A sync port having a sync input port for receiving a sync signal and at least two sync output ports;
And a power splitter for distributing power of the sync signal input through the sync input port and outputting the power to the sync output port. 3. The method of claim 2,
And a power splitter for combining or distributing signals of the input port, the output port, the intermediate port, and the sub-input port. delete delete

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