KR20080028254A - Rf switch combined microstripline/slotline and switch module using thereof - Google Patents

Abstract

An RF(Radio Frequency) switch combined with a microstripline and a slot line and a switch module using the same are provided to improve isolation by preventing the slot line from being electromagnetically connected to the microstriplines. An RF switch(200) includes first and second microstriplines(202,203), a slot line(204), at least one switching element(206), and a dielectric substrate(201). The first microstripline is formed at one side of a top surface of the dielectric substrate in a conductor pattern to receive an RF signal. The second microstripline is formed at the other side of the top surface of the dielectric substrate to transmit the RF signal. The slot line is formed on a bottom surface of the dielectric substrate and electromagnetically connected to the first and second microstriplines. The at least one switching element is installed in a predetermined position of the slot line and turned on/off by a control signal.

Description

High frequency switch by combining microstripline and slot line and switch module using same {RF switch combined microstripline / slotline and switch module using kind}

1 is a view showing the basic structure of a high frequency switch by the combination of a microstrip line and a slot line according to the present invention.

2 is an enlarged view of a portion A of FIG. 1;

3 is a view showing a structure of a high frequency switch by combining a microstrip line and a slot line according to the first embodiment of the present invention.

4 is a front and rear pattern view of FIG.

5 is a view showing a structure of a high frequency switch by combining a microstrip line and a slot line according to a second embodiment of the present invention.

6 is a view showing various shapes of a slot line according to the present invention.

7 illustrates a bias circuit of a high frequency switch according to the present invention.

8 is a block diagram showing a structure of a first embodiment of a system using a high frequency switch module according to the present invention;

Figure 9 illustrates a structure of a second embodiment of a system using a high frequency switch module according to the present invention.

10 is a view of a structure of a third embodiment of a system using a high frequency switch module according to the present invention;

※ Explanation of code for main part of drawing

201, 402: printed board 202: first microstripline

203: first microstrip line 204: slot line

205: slot line termination 206: first switching element

207: upper ground plane 208: lower ground plane

209: second switching element 301, 401: antenna

302: bandpass filter 303: circulator

304, 403: first switch 305: low noise amplifier

306: power amplifier 307, 405: second switch

308: controller 310, 410: switch module

402: circuit board 404: first pin diode

406: second pin diode

      The present invention relates to a high frequency switch for switching a high frequency line of a communication system, and more particularly, a microstrip line and a slot line are respectively formed on an upper portion and a lower portion of a dielectric substrate, and a switching element is provided at a predetermined position of the slot line. The present invention relates to a high frequency switch and a switch module using the same by combining a microstrip line and a slot line to turn on / off a high frequency signal.

      In general, a high frequency switch used to turn on or off a path of a high frequency signal such as RF (Radio Frequency) and Microwave (Microwave) is a high-power mechanical switch that turns a line on or off by a magnetized solenoid, or a pin A device such as a diode is classified into a low-power electronic switch for turning a line on and off.

      In the conventional switch, the mechanical switch has the advantage of switching high-power signals, while the switching speed is slow and the life is limited by wear of components due to repetitive switching. There is a problem that may cause noise in the peripheral circuit due to the magnetization action of.

      In addition, a conventional electronic switch normally connects pin diodes in series or in parallel to turn on / off a line by a bias applied thereto. In addition to being affected, there is another problem that high-power signals cannot be turned on and off, and that isolation is not sufficiently secured during switching.

      The present invention is to solve the problems of the prior art as described above, the microstrip line and the slot line is formed on the upper and lower portions of the dielectric substrate, respectively, and provided with a switching element at a predetermined position of the slot line to turn on the high-frequency signal It is a technical object of the present invention to provide a high frequency switch and a switch module using the same, which facilitate implementation of a high frequency line and improve isolation at the time of turning off.

      In order to solve the technical problem as described above, the high frequency switch 200 by combining the microstrip line and the slot line according to the present invention includes a first pattern and a first pattern formed on the upper portion of the dielectric substrate 201 having a predetermined dielectric constant. 2 microstrip lines 202 and 203; and a slot line 204 formed to be electromagnetically coupled to the microstrip lines below the dielectric substrate; and one provided at a predetermined position of the slot line. And the switching elements 206 and 209; and a dielectric substrate 201 having the microstrip line formed thereon and the slot line and the switching element disposed thereunder.

      In addition, the switch module 310 according to the present invention, the asymmetric three-terminal circulator 303 for passing the input downlink high-frequency signal only in one direction, and is configured by the combination of the microstrip line and the slot line is the circular A first switch 304 for turning on / off a downlink high frequency signal passing through the radar, a low noise amplifier 305 for low noise amplifying the downlink high frequency signal passing through the first switch with a predetermined gain, a microstrip line; A second switch 307 configured by a combination of slot lines to turn on / off an uplink high frequency signal input from an external power amplifier 306, and to control on / off operations of the first and second switches. The controller 308 is characterized in that it is configured integrally.

      Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding members will be denoted by the same reference numerals and detailed description thereof will be omitted.

      1 is a view showing a basic structure of a high frequency switch by combining a microstrip line and a slot line according to the present invention, Figure 2 is an enlarged view of portion A of FIG. As shown, according to the present invention, the first microstrip line 202 to which a high frequency signal is input and the second microstrip line 203 to which the high frequency signal is output are conductor patterns. And a slot line 204 formed at a lower portion of the dielectric substrate so as to be electromagnetically coupled to the first and second microstrip lines.

Here, referring to FIG. 2A, the length L _ST and the slot line of the first and second microstrip lines intersect the first microstrip line and the slot line or the second microstrip line and the slot line. The length L _SL is each 1/4 wavelength of the high frequency signal. This illustrates the structure of an open stub in which the first and second microstrip lines extend one quarter wavelength from the intersection point, but the present invention is not limited thereto.

      That is, as illustrated in FIG. 2B, a shorted stub formed by shorting the first and second microstrip lines without extending by a quarter wavelength from the intersection may be further used. Such a stub shape may be selectively applied according to various embodiments of the present invention and the requirements of the system.

      3 is a view showing a structure of a high frequency switch by combining a microstrip line and a slot line according to a first embodiment of the present invention, and FIG. 4 is a front and rear pattern diagram of FIG. 3 (a). In FIG. 3, the high frequency switch 200 by combining the microstrip line and the slot line according to the present invention has a first and second microstrip lines 202 and 203 formed on the dielectric substrate 201 having a predetermined dielectric constant. Is formed in a conductor pattern, a slot line 204 is formed in the lower portion of the dielectric substrate to be electromagnetically coupled to the microstrip lines, one or more switching elements (206) at a predetermined position, preferably in the center of the slot line ) Is provided to receive a control signal from an external controller is turned on / off. Here, the slot line end portion 205 may be manufactured in a form in which one side is opened as shown in (a) of FIG. 3, or may be manufactured in a form without an opening as shown in (b) of FIG. 3.

      Figure 4 is for showing the structure of Figure 3 (a) in more detail, (a) shows a front pattern diagram (b) shows a rear pattern diagram, (c) is an X-Y side view. In FIG. 4A, first and second microstrip lines 202 and 203 are formed in a conductor pattern on an upper portion of the dielectric substrate 201, and in the lower portion of the dielectric substrate in FIG. The slot line 204 is formed to have the conductor pattern removed to be electromagnetically coupled to the strip lines, and the first switching element 206 is provided at the center of the slot line.

      Here, the slot line is preferably formed in the left and right end of the slot line end portion 205 of a predetermined shape, the hatched portion in Figure 4 represents a conductor pattern. In the high frequency switch 200, when the reverse bias is applied as the control signal to the first switching element 206, the first switching element is turned off, and the slot line is connected to the first and second microstrip lines by electromagnetic coupling. Therefore, a high frequency signal is transmitted from the first microstrip line to the second microstrip line. On the contrary, when a forward bias is applied as a control signal to the first switching element, the first switching element is turned on, so that the upper ground plane 207 and the lower ground plane are turned on. Since 208 is conductive and becomes a ground plane, the slotline is incapable of electromagnetic coupling with the first and second microstrip lines. Therefore, the high frequency signal is not transmitted from the first microstrip line to the second microstrip line.

      FIG. 5 is a view illustrating a structure of a high frequency switch by combining a microstrip line and a slot line according to a second embodiment of the present invention, and further extending the first embodiment of FIG. Configure a second microstripline 203 at 205 parallel to the slotline and further include a second switching element 209 at the slotline termination 205 to improve isolation at off time. It is. At this time, the slot line end portion 205 has a semicircle length of 1/4 wavelength as shown in the drawing, and thus has a second switching element at a quarter wavelength, so that when the forward bias is applied And the first and second microstrip lines are electromagnetically coupled, and when the reverse bias is applied, the signals of the slot lines are not transmitted to the first and second microstrip lines. This further improves. Since the operation principle of FIG. 5 is the same as that of FIG. 4, a detailed description thereof will be omitted.

      Meanwhile, in FIG. 5, the high frequency switch according to the present invention configures the second microstrip line 203 to be parallel to the slot line at one side of the slot line end portion 205 and is formed at the end of the slot line end portion 205. It may be configured to include only two switching elements 209. That is, the use of only the second switching element 209 instead of the first switching element 206 in FIG. 5 is included in the embodiment of the present invention.

      In addition, in the embodiments of the present invention, a pin diode is used as the switching element. However, the present invention is not limited thereto, and high-frequency monolithic integrated circuits (MMICs) and field effect transistors are used to electronically switch high-frequency signals. (FET; Field Effect Transistor) or the like may be used.

      The effect of the isolation is improved by the switching elements including the pin diode as compared to the prior art as follows. That is, the isolation of the conventional switch is determined only by the switching element itself at the time of off, whereas in the present invention, the upper ground plane 207 and the lower ground plane 208 of the dielectric substrate are conducted by the switching element at the time of off. By being one ground plane, the slot line cannot be electromagnetically coupled with the first and second microstrip lines, thereby greatly improving the isolation.

      In addition, since the switching element does not have to have the same operating frequency as the frequency of the high frequency signal applied to the first microstrip line, there is no need to use expensive components, and thus the manufacturing cost can be reduced. That is, since the switching element does not directly switch the high frequency signal, the frequency of the switched high frequency signal and the operating frequency of the switching element are irrelevant.

      6 is a view showing various shapes of a slot line according to the present invention. 6 (a) shows a slot line having a straight shape, FIG. 6 (b) shows a slot line having a circular end portion, and FIG. 6 (c) shows a slot line having a rectangular end portion. Indicates. In addition, Figure 6 (d) is a slot line of a structure in which a half of the circle in the taper (Taper) connected to a straight line in Figure 6 (b), Figure 6 (e) is the Figure 6 (c) Half of the square represents the slot line of the structure connected with the straight line in the form of taper.

      In addition, although not shown in FIG. 6, the shape of the microstrip line according to the present invention may also be variously configured as in the slot line. Therefore, in the implementation of the high frequency switch according to the present invention, various embodiments can be configured by combining the microstrip line and the slot line having the shape as shown in FIGS. 6A to 6E.

      7 is a diagram illustrating a bias circuit of a high frequency switch according to the present invention, by forming a loop connected to a slot line 204 by a branch slot 210 branching a predetermined position of a slot line under the dielectric substrate. A bias circuit for supplying power to the switching device may be easily configured by using a separate ground part 211 formed by the loop. That is, a ground plane is required above and below the center of the slot line due to the structure of the slot line. Since the bias supply is essential for driving the switching element, a bias circuit is provided through the ground part 211 formed by the branch slot 210 as shown in FIG. Configure At this time, by connecting the capacitor 212 to the ground portion is extended to the ground plane in high frequency, but is cut off in DC.

      Although the shape of the grounding portion formed by the slot line and the branch slot is shown in a square shape in the embodiment of the present invention, various shapes such as a semicircle or a triangular shape with one slot line as one side may be used.

      8 is a block diagram showing a structure of a first embodiment of a system using a high frequency switch module according to the present invention, showing that the high frequency switch module according to the present invention is used in a time division duplex (TDD) system. As shown in Figure 8 (a) shows a high frequency switch module of the present invention applied to a time division duplex communication system, Figure 8 (b) is a simplified illustration of the high-frequency switch module.

      In FIG. 8, the downlink path, that is, the high frequency signal path transmitted from the base station or the repeater to the terminal (denoted as Rx in FIG. 8) and the uplink path, that is, the high frequency signal path transmitted from the terminal to the base station or the repeater (Tx in FIG. 8). In the display), an integrated high frequency switch module 310 according to the present invention is used. Such a high frequency switch module 310 includes an asymmetric three-terminal circulator 303 for passing an input downlink high frequency signal only in one direction. And a first switch 304 configured by the combination of the microstrip line and the slot line to turn on / off the downlink high frequency signal passing through the circulator, and the downlink high frequency signal passing through the first switch. A low noise amplifier 305 for low noise amplification at a gain, and a combination of a microstripline and a slotline to input from an external power amplifier 306 A second switch 307 for turning on / off the output uplink high frequency signal and a controller 308 for controlling the on / off operation of the first and second switches are integrally formed.

      First, referring to the downlink path, the downlink signal received through the antenna 301 is passed through only the required frequency band by the bandpass filter 302 and is input to the first terminal A of the circulator 303. The circulator outputs the downlink high frequency signal to the second terminal B in one direction, and the downlink high frequency signal passing through the circulator is turned on / off by the first switch 304, and the first switch. The downlink high frequency signal passing through is also low noise amplified and output by the low noise amplifier 305 at a predetermined gain.

      Alternatively, in the uplink path, the uplink high frequency signal input from the power amplifier 306 is turned on / off by the second switch 307, and the uplink high frequency signal passing through the second switch is the third of the circulator. After being input to the terminal C and output to the first terminal A in one direction, only the required frequency band is passed by the bandpass filter 302 and transmitted through the antenna 301. At this time, the on / off operation of the first and second switches is performed by the controller 308 opposite to each other. On the other hand, Figure 8 (b) is a simplified view to show that the transmission and reception path is separated in the state except the low noise amplifier and the controller in Figure 8 (a).

      In FIG. 8, the high frequency switch module 310 according to the present invention includes a circulator 303 through which a downlink high frequency signal is input and passed only in one direction, and a downlink high frequency signal passed through the circulator. A first switch 304 for turning on / off, a low noise amplifier 305 for low noise amplifying the downlink high frequency signal passing through the first switch with a predetermined gain, and an uplink high frequency signal input from the power amplifier 306 The second switch 307 for turning on / off and the controller 308 for controlling the on / off operation of the first and second switches are integrally formed, thereby reducing the manufacturing cost of the individual devices and Line loss and intermodulation distortion (IMD) caused by the coupling can be reduced.

      9 is a view showing the structure of a second embodiment of a system using a high frequency switch module according to the present invention, and does not use the circulator. As shown, the first and second switches 403 and 405 are integrally manufactured on one circuit board 402 so that the Rx path (downlink path) is connected to the antenna 401 by the on / off operation of the first switch. The Tx path (uplink path) is connected / disconnected with the antenna 401 by the on / off operation of the second switch. 9 is a high frequency switch according to the first embodiment of the present invention.

      10 is a view showing the structure of a third embodiment of a system using a high frequency switch module according to the present invention. Referring to FIG. 10, as shown in FIG. 9, the first and second switches 403 and 405 are integrally manufactured on one circuit board 402 so that the Rx path (downlink) is turned on by the on / off operation of the first switch. Path) is connected / disconnected with the antenna 401, and similarly, the Tx path (uplink path) is connected / disconnected with the antenna 401 by the on / off operation of the second switch. 10 is a high frequency switch according to the second embodiment of FIG.

      In the above described and illustrated with respect to the preferred embodiment of the present invention is not limited only to the above embodiments and various modifications carried out by those skilled in the art within the scope not departing from the technical gist of the present invention. Can be.

      According to the above configuration, the present invention provides a high frequency signal input to the first microstrip line and output to the second microstrip line through the slot line by turning on / off the switching element provided at a predetermined position of the slot line. There is an effect of providing a high frequency switch that is easy to implement a high frequency line and the isolation is improved when off.

      The present invention also provides a circulator for inputting a high frequency signal and passing in only one direction, a first switch for turning on / off a downlink high frequency signal passing through the circulator, and a downlink high frequency passing through the first switch. A low noise amplifier for low noise amplifying the signal with a predetermined gain, a second switch for turning on / off an uplink high frequency signal input from a power amplifier, and a controller for controlling on / off operation of the first and second switches. As a result, there is an effect of providing a high frequency switch module that reduces manufacturing costs according to the manufacture of individual devices and reduces line loss and intermodulation distortion caused by coupling between individual devices.

Claims (17)

In the switch for turning on / off the path of a high frequency signal, A first microstrip line formed in a conductive pattern on an upper side of the dielectric substrate having a predetermined dielectric constant to receive the high frequency signal; A second microstrip line formed in a conductor pattern on the other side of the dielectric substrate to output the high frequency signal; A slot line formed under the dielectric substrate and electromagnetically coupled to the first and second microstrip lines; At least one switching element provided at a predetermined position of the slot line and turned on / off by a control signal; And The microstrip line is formed at an upper portion thereof and a dielectric substrate having the slot line and the switching element at the lower portion thereof. In the high frequency module including a switch for turning on / off the path of a high frequency signal, An asymmetric three-terminal circulator for passing the input downlink high frequency signal in only one direction; A first microstripline formed in a conductive pattern on one side of the dielectric substrate having a predetermined dielectric constant and receiving the downlink high frequency signal, and a conductive pattern formed on the other side of the dielectric substrate in order to output the downlink high frequency signal A second microstrip line, a slot line formed under the dielectric substrate to be electromagnetically coupled to the first and second microstrip lines, and provided at a predetermined position of the slot line to be turned on / off by a control signal. A first switch composed of one or more switching elements turned off to turn on / off a downlink high frequency signal passing through the circulator; A low noise amplifier for low noise amplifying the downlink high frequency signal passing through the first switch with a predetermined gain; A first microstrip line formed with a conductor pattern on one side of the dielectric substrate having a predetermined dielectric constant and receiving an uplink high frequency signal from an external power amplifier; and a uplink high frequency formed with a conductor pattern on the other side of the dielectric substrate A second microstrip line to which a signal is output, a slot line formed under the dielectric substrate to be electromagnetically coupled to the first and second microstrip lines, and provided at a predetermined position of the slot line to control signals. A second switch composed of one or more switching elements turned on and off by turning on / off the uplink high frequency signal; And And a controller for controlling on / off operations of the first and second switches. The high frequency switch module is a combination of a microstrip line and a slot line. In the high frequency module including a switch for turning on / off the path of a high frequency signal, The first and second high frequency switches are symmetrically disposed about one common terminal to have first and second input / output terminals, respectively, And selectively connecting the common terminal and the first or second input / output terminal by selectively turning on / off the first and second high frequency switches according to a control signal. By high frequency switch module. The method according to claim 1 or 2, At the point where the first microstrip line and the slot line or the second microstrip line and the slot line cross each other, the length L _ST of the first and second microstrip lines and the length L _SL of the slot line are each 1 of the high frequency signal. High frequency switch by combining the microstrip line and the slot line, characterized in that the / 4 wavelength. The method according to claim 1 or 2, wherein the slot line, A high frequency switch by combining a microstrip line and a slot line comprising at least one switching element. The method according to claim 1 or 2, wherein the slot line, A slot line end portion having a predetermined shape is formed at an end thereof, and at least one switching element is further provided at the end portion of the slot line. The method according to claim 1 or 2, wherein the slot line, A slot line termination having a predetermined shape is formed at an end thereof, and at least one switching element is provided only at the slot line termination. The method of claim 6 or 7, wherein the slot line end portion, A high frequency switch by combining a microstrip line and a slot line, wherein the semicircle is 1/4 wavelength of the high frequency signal. The method of claim 6, wherein And a microstrip line configured to be parallel to the slot line at the end of the slot line. The method according to any one of claims 6 to 9, wherein the slot line end portion, High frequency by the combination of a microstrip line and a slot line, wherein the shape is any one of a figure consisting of a straight line shape, a circular shape, a square shape, a half tapered structure, and a half tapered shape. switch. The method of claim 1, wherein the first and second micro stripline, High frequency by the combination of a microstrip line and a slot line, wherein the shape is any one of a figure consisting of a straight line shape, a circular shape, a square shape, a half tapered structure, and a half tapered shape. switch. The method according to any one of claims 1, 2 and 4, wherein the first and second microstriplines, Combination of the microstrip line and the slot line characterized in that the open stub structure extending by a quarter wavelength of the high frequency signal from the intersection of the first microstrip line and the slot line or the second microstrip line and the slot line. By high frequency switch. The method according to any one of claims 1, 2 and 4, wherein the first and second microstriplines, And a short stub structure formed by shorting the first and second microstrip lines without extending a quarter wavelength from the intersection point. The method according to claim 1 or 2, Forming a loop connected to the slot line by a branch slot branching a predetermined position of the slot line, And a bias circuit for supplying power to the switching element by using the ground formed by the loop. The method of claim 14, wherein the bias circuit, And a capacitor connected to the ground portion formed by the branch slot so as to extend to the ground plane at high frequency but cut off at DC. The method of claim 14, wherein the ground portion, A high frequency switch, characterized in that the shape is a shape having the slot line as one side. The method according to claim 1, 2, 5, 6 and 7, wherein the switching element, A high frequency switch by combining a microstrip line and a slot line, which is any one of an electronic switching element including a pin diode, a high frequency single integrated circuit (MMIC), and a field effect transistor (FET).

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