JP2011171922A - High-frequency switch circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a high-frequency switch circuit that can suppress second order harmonics and third order harmonics from a transmission terminal to an antenna terminal and from the transmission terminal to a reception terminal, and can prevent an increase of a transmission loss of a fundamental frequency from the transmission terminal to the antenna terminal. <P>SOLUTION: A high-frequency switch circuit has at least one or more first short stubs 51 connected to a transmission terminal 11 and having an approximate 1/4 length to an equivalent wavelength of a fundamental frequency of a high-frequency signal, at least one or more second short stubs 52 connected to the transmission terminal 11 and having an approximate 1/6 length to the equivalent wavelength of the fundamental frequency of the high-frequency signal, and at least one or more open stubs 53 connected to the transmission terminal 11. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a high frequency switch circuit, and more particularly to a high frequency switch circuit suitable for use in a frequency band from a microwave band to a millimeter wave band.

  As a conventional high-frequency switch circuit, for example, there is one shown in Patent Document 1 below. In Patent Document 1, an antenna terminal and a transmission terminal are connected via a diode, and the length is 1/6 of the effective wavelength of a fundamental wave (hereinafter simply referred to as “fundamental wave”) of a high-frequency signal transmitted and received. A short stub having a stub is connected to the transmission terminal, the antenna terminal and the reception terminal are connected via a high-frequency line having a length of ¼ of the effective wavelength of the fundamental wave, and a diode is shunt connected to the reception terminal. A configuration is disclosed.

  In the high-frequency switch circuit disclosed in Patent Document 1, the above-described two diodes are forward-biased to be in an on state, thereby providing a passage between the transmission terminal and the antenna terminal, and between the transmission terminal and the reception terminal. The interval is used as a blocking path. On the other hand, the two diodes described above are reverse-biased so as to be in an off state, whereby a path between the antenna terminal and the receiving terminal is used as a passing path and a path between the antenna terminal and the transmitting terminal is used as a blocking path. That is, the high-frequency signal path is switched by simultaneously switching the bias states of the two diodes.

JP-A-8-162803

  In Patent Document 1, by connecting a short stub having a length of 1/6 of the effective wavelength of the fundamental wave to the transmission terminal, the third harmonic of the fundamental wave from the transmission terminal to the antenna terminal and from the transmission terminal to the reception terminal. Are suppressed (hereinafter simply referred to as “third harmonic”). However, since impedance mismatch occurs with respect to the fundamental wave of the high-frequency signal, there is a problem in that the fundamental wave passing loss from the transmission terminal to the antenna terminal increases.

  In Patent Document 1, one end of a high-frequency line having a length that is ¼ of the effective wavelength of the fundamental wave is grounded via a diode during transmission, so that the receiving terminal side is seen from the other end of the high-frequency line. The impedance to the fundamental wave is equivalent to infinity, blocking the fundamental wave from the transmission terminal to the reception terminal. At this time, the second harmonic of the fundamental wave of the high frequency signal viewed from the other end of the high frequency line having a length of ¼ of the effective wavelength of the fundamental wave (hereinafter simply referred to as “double wave”). The second harmonic from the transmission terminal to the antenna terminal is suppressed. Further, since the receiving terminal is grounded via a diode during transmission, the second harmonic wave that has passed through the high-frequency line from the transmitting terminal is suppressed. However, since the amount of suppression of the second harmonic from the transmission terminal to the antenna terminal and from the transmission terminal to the reception terminal depends only on the action of these high-frequency lines and diodes, the transmission terminal to the antenna terminal and the transmission terminal to the reception terminal There was a problem that the amount of suppression of the second harmonic wave was small.

  The present invention has been made in view of the above, and suppresses the second harmonic and the third harmonic from the transmission terminal to the antenna terminal and from the transmission terminal to the reception terminal, while suppressing the fundamental wave from the transmission terminal to the antenna terminal. An object of the present invention is to obtain a high-frequency switch that can prevent the deterioration of the passage loss.

  In order to solve the above-described problems and achieve the object, the present invention outputs a high-frequency signal input from a transmission terminal from an antenna terminal, and outputs the high-frequency signal input from the antenna terminal from a reception terminal. A switch circuit having an anode connected to the antenna terminal, a cathode connected to the transmitting terminal, one end connected to the antenna terminal, the other end connected to the receiving terminal, A high-frequency line having a length of about ¼ of the effective wavelength of the fundamental wave of the high-frequency signal, a second diode having an anode connected to the other end of the high-frequency line, and one end of the second diode A capacitor connected to the cathode and grounded at the other end; an inductor connected in parallel to the capacitor; and at least one connected to the transmission terminal; The first short stub having a length of about 1/4 with respect to the effective wavelength of the fundamental wave of the high-frequency signal, and at least one connected to the transmission terminal, and with respect to the effective wavelength of the fundamental wave of the high-frequency signal And a second short stub having a length of approximately 1/6, and at least one open stub connected to the transmission terminal.

  According to the present invention, it is possible to prevent the fundamental wave passing loss from the transmission terminal to the antenna terminal while suppressing the second harmonic and the third harmonic from the transmission terminal to the antenna terminal and from the transmission terminal to the reception terminal. There is an effect that becomes possible.

FIG. 1 is a diagram of a configuration example of the high-frequency switch circuit according to the first embodiment. FIG. 2 is a diagram of a configuration example of the high-frequency switch circuit according to the second embodiment. FIG. 3 is a diagram of a configuration example of the high-frequency switch circuit according to the third embodiment. FIG. 4 is a diagram illustrating another configuration example of the high-frequency switch circuit according to the third embodiment. FIG. 5 is a diagram illustrating a characteristic example of the high-frequency switch circuit illustrated in FIG.

  Hereinafter, a high-frequency switch circuit according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment.

Embodiment 1 FIG.
FIG. 1 is a diagram of a configuration example of the high-frequency switch circuit according to the first embodiment. The high frequency switch circuit according to the first embodiment functions as a switch circuit that switches between transmission and reception of a high frequency signal.

  As shown in FIG. 1, the high-frequency switch circuit according to the first embodiment outputs a transmission signal and also outputs an antenna terminal 10 to which a reception signal is input, a transmission terminal 11 to which the transmission signal is input, and a reception signal. A receiving terminal 12, a bias terminal 13 to which a bias voltage is applied, an anode connected to the antenna terminal 10, a cathode connected to the transmitting terminal 11, and one end connected to the antenna terminal 10. The other end of the inductor 44 is connected to the bias terminal, one end is connected to the other end of the inductor 44, the other end is grounded, the one end is connected to the antenna terminal 10, and the other end is the receiving terminal 12. And a second diode having an anode connected to the other end of the high-frequency line 31 and a high-frequency line 31 having a length substantially ¼ of the effective wavelength of the fundamental wave connected to , A capacitor 41 having one end connected to the cathode of the second diode 22 and the other end grounded, an inductor 42 connected in parallel to the capacitor 41, and an effective fundamental wave connected to the transmission terminal 11. A first short stub 51 having a length of approximately ¼ of the wavelength, and a second short stub 52 having a length of approximately ６ of the effective wavelength of the fundamental wave connected to the transmission terminal 11 in the same manner; Similarly, an open stub 53 connected to the transmission terminal 11 is provided.

  Next, the operation of the high-frequency switch circuit according to the first embodiment will be described with reference to FIG. In the high-frequency switch circuit according to the first embodiment, when a positive voltage is applied to the bias terminal 13, the first diode 21 and the second diode 22 are forward biased and turned on. When a negative voltage is applied to the bias terminal 13, the first diode 21 and the second diode 22 are reverse-biased and turned off.

  At the time of transmission, a positive voltage is applied to the bias terminal 13 to turn on the first diode 21 and the second diode 22. At this time, the path between the transmission terminal 11 and the antenna terminal 10 is a passage path, and the path between the transmission terminal 11 and the reception terminal 12 is a blocking path. This is because the fundamental wave of the transmission signal input from the transmission terminal 11 passes through the first diode 21 to the antenna terminal 10 and is approximately ¼ of the effective wavelength of the fundamental wave to the reception terminal 12. Is grounded via the second diode 22 and the capacitor 41, the impedance of the high frequency line 31 with respect to the fundamental wave seen from the transmission terminal 11 side to the reception terminal 12 side is infinite. This is because they are equivalent.

  At the time of reception, a negative voltage is applied to the bias terminal 13 to turn off the first diode 21 and the second diode 22. At this time, the path between the antenna terminal 10 and the receiving terminal 12 is a passing path, and the path between the antenna terminal 10 and the transmitting terminal 11 is a blocking path. This is because the fundamental wave of the received signal input from the antenna terminal 10 is blocked because the first diode 21 is turned off to the transmitting terminal 11 and the second diode 22 is turned off to the receiving terminal 12. This is because it passes through the high-frequency line 31.

  In the high frequency switch circuit according to the first exemplary embodiment, the length of the first short stub 51 is set to approximately ¼ of the effective wavelength of the fundamental wave, so that the antenna terminal 10 side and the transmission terminal 11 side from the transmission terminal 11 side. Since the impedance to the second harmonic viewed from the side viewed from the reception terminal 12 side is substantially zero, the second harmonic from the transmission terminal 11 to the antenna terminal 10 and from the transmission terminal 11 to the reception terminal 12 can be suppressed. Further, the length of the second short stub 52 is set to approximately 1/6 of the effective wavelength of the fundamental wave, so that the antenna terminal 10 side is seen from the transmission terminal 11 side and the reception terminal 12 side is seen from the transmission terminal 11 side. Since the impedance to the third harmonic is substantially zero, the third harmonic from the transmission terminal 11 to the antenna terminal 10 and from the transmission terminal 11 to the reception terminal 12 can be suppressed.

  Here, by setting the length of the second short stub 52 to be approximately 1/6 of the effective wavelength of the fundamental wave, impedance mismatch with respect to the fundamental wave of the transmission signal viewed from the transmission terminal 11 side to the antenna terminal 10 side. Occurs. For this reason, impedance matching with respect to the fundamental wave of the transmission signal when the antenna terminal 10 side is viewed from the transmission terminal 11 side by the open stub 53 is achieved. Therefore, it is possible to suppress the deterioration of the fundamental wave passage loss during transmission, that is, when the route between the transmission terminal 11 and the antenna terminal 10 is a passage route.

  As described above, according to the high-frequency switch circuit according to the first embodiment, the first short stub having a length of approximately ¼ of the effective wavelength of the fundamental wave at the transmission terminal and the effective wavelength of approximately 1 of the fundamental wave. Since a second short stub having a length of / 6 is connected and an open stub for matching the impedance to the fundamental wave of the transmission signal viewed from the transmission terminal side when viewed from the antenna terminal side is connected, the transmission terminal While suppressing the second harmonic and the third harmonic from the transmission terminal to the antenna terminal and from the transmission terminal to the reception terminal, it is possible to suppress the deterioration of the passage loss from the transmission terminal to the antenna terminal.

  In the first embodiment, the case where one configuration including the high-frequency line between the antenna terminal and the reception terminal, the second diode, the inductor, and the capacitor is provided is described. Two or more terminals may be provided between the receiving terminal and a multi-stage configuration. Thereby, the fundamental wave from the transmission terminal to the reception terminal during transmission can be further suppressed.

  The first short stub having a length of about 1/4 of the effective wavelength of the fundamental wave at the connection point between the transmission terminal and the anode of the first diode and the length of about 1/6 of the effective wavelength of the fundamental wave By providing two or more second short stubs each having the above, the second harmonic and the third harmonic from the transmission terminal to the antenna terminal and from the transmission terminal to the reception terminal can be further suppressed.

Embodiment 2. FIG.
FIG. 2 is a diagram of a configuration example of the high-frequency switch circuit according to the second embodiment. Similar to the first embodiment, the high-frequency switch circuit according to the second embodiment functions as a switch circuit that switches between transmission and reception of a high-frequency signal.

  As shown in FIG. 2, the high-frequency switch circuit according to the second embodiment outputs a transmission signal and also outputs an antenna terminal 10 to which a reception signal is input, a transmission terminal 11 to which the transmission signal is input, and a reception signal. A receiving terminal 12, a bias terminal 13 to which a bias voltage is applied, an anode connected to the antenna terminal 10, a cathode connected to the transmitting terminal 11, and one end connected to the antenna terminal 10. The other end of the inductor 44 connected to the bias terminal, one end connected to the other end of the inductor 44, the other end connected to the ground, and the other end of the effective wavelength of the fundamental wave connected to the antenna terminal 10. A first high-frequency line 31 having a length of approximately 1/4, a second diode 22 having an anode connected to the other end of the first high-frequency line 31, and one end A capacitor 41 connected to the cathode of the second diode 22 and having the other end grounded; an inductor 42 connected in parallel to the capacitor 41; one end connected to the other end of the first high-frequency line 31; A second high-frequency line 32 having a length of about ¼ of the effective wavelength of the fundamental wave connected to the reception terminal 12, a third diode 23 whose anode is connected to the reception terminal 12, and a third diode A short stub 54 connected to the cathode of the third diode and an open stub 55 connected to the cathode of the third diode.

  Next, the operation of the high frequency switch circuit according to the second embodiment will be described with reference to FIG. In the high-frequency switch circuit according to the second embodiment, when a positive voltage is applied to the bias terminal 13, the first diode 21, the second diode 22, and the third diode 23 are forward biased and turned on. Further, when a negative voltage is applied to the bias terminal 13, the first diode 21, the second diode 22, and the third diode 23 are reverse-biased and turned off.

  At the time of transmission, a positive voltage is applied to the bias terminal 13 to turn on the first diode 21, the second diode 22, and the third diode 23. At this time, the path between the transmission terminal 11 and the antenna terminal 10 is a passage path, and the path between the transmission terminal 11 and the reception terminal 12 is a blocking path. This is because the fundamental wave of the transmission signal input from the transmission terminal 11 passes through the first diode 21 to the antenna terminal 10 and is approximately ¼ of the effective wavelength of the fundamental wave to the reception terminal 12. Is grounded via the second diode 22 and the capacitor 41, the impedance of the high-frequency line 31 with respect to the fundamental wave seen from the transmission terminal 11 side to the reception terminal 12 side is reduced. This is because it is equivalent to infinity.

  At the time of reception, a negative voltage is applied to the bias terminal 13 to turn off the first diode 21, the second diode 22, and the third diode 23. At this time, the path between the antenna terminal 10 and the receiving terminal 11 is a passing path, and the path between the antenna terminal 10 and the transmitting terminal 11 is a blocking path. This is because the fundamental wave of the reception signal input from the antenna terminal 10 is cut off to the transmission terminal 11 because the first diode 21 is turned off, and the second diode 22 and the third diode 23 to the reception terminal 12. This is because the signal passes through the first high-frequency line 31 and the second high-frequency line 32 by being turned off.

  In the high frequency switch circuit according to the second embodiment, at the time of transmission, that is, when the third diode 23 is in the on state, the reception terminal 12, the short stub 54, and the open stub 55 are connected via the third diode 23. Connected. Therefore, by setting the length of the short stub 54 to approximately ¼ of the effective wavelength of the fundamental wave, the impedance with respect to the double wave when the receiving terminal 12 side is viewed from the transmitting terminal 11 side becomes substantially zero. The second harmonic from the terminal 11 to the receiving terminal 12 can be suppressed, and the length of the open stub 55 is set to approximately 1/12 of the effective wavelength of the fundamental wave, so that the receiving terminal 12 side can be seen from the transmitting terminal 11 side. In addition, since the impedance with respect to the third harmonic becomes substantially zero, the third harmonic from the transmission terminal 11 to the reception terminal 12 can be suppressed.

  Alternatively, by setting the length of the short stub 54 to approximately ６ of the effective wavelength of the fundamental wave, the third harmonic wave from the transmission terminal 11 to the reception terminal 12 is suppressed, and the length of the open stub 55 is reduced to that of the fundamental wave. By setting the effective wavelength to approximately 1/8, the second harmonic from the transmission terminal 11 to the reception terminal 12 can be suppressed.

  On the other hand, at the time of reception, that is, when the third diode 23 is in the off state, the reception terminal 12, the short stub 54, and the open stub 55 are disconnected. Therefore, at the time of reception, that is, when the path between the antenna terminal 10 and the reception terminal 12 is a passing path, the transmission loss of the fundamental wave is not deteriorated, that is, between the transmission terminal 11 and the reception terminal 12. The second harmonic and the third harmonic from the transmission terminal 11 to the reception terminal 12 in the case where the above path is the cutoff path can be suppressed.

  As described above, according to the high frequency switch circuit according to the second embodiment, the anode of the third diode is connected to the reception terminal, and the effective wavelength of the fundamental wave is approximately ¼ of the effective wavelength of the cathode of the third diode. Since a short stub having a length and an open stub having a length approximately 1/12 of the effective wavelength of the fundamental wave are connected, the second and third harmonics of the fundamental wave from the transmission terminal to the reception terminal at the time of transmission are connected. While suppressing the harmonics of the wave, it is possible to suppress the deterioration of the fundamental wave passing loss from the antenna terminal to the receiving terminal during reception. Alternatively, the same effect can be obtained by setting the length of the short stub to approximately 1/6 of the effective wavelength of the fundamental wave and the length of the open stub to approximately 1/8 of the effective wavelength of the fundamental wave.

  In the second embodiment, the case where one configuration having the first high-frequency line, the second diode, the inductor, and the capacitor between the antenna terminal and the second high-frequency line is described. It is possible to provide a multi-stage configuration by providing two or more of the above configuration between the antenna terminal and the second high frequency line. Thereby, similarly to the first embodiment, the fundamental wave from the transmission terminal to the reception terminal at the time of transmission can be further suppressed.

Embodiment 3 FIG.
FIG. 3 is a diagram of a configuration example of the high-frequency switch circuit according to the third embodiment. The high-frequency switch circuit according to the third embodiment functions as a switch circuit that switches between transmission and reception of a high-frequency signal, as in the first and second embodiments.

  As shown in FIG. 3, the high-frequency switch circuit according to the third embodiment outputs a transmission signal and outputs an antenna terminal 10 to which a reception signal is input, a transmission terminal 11 to which the transmission signal is input, and a reception signal. A receiving terminal 12, a bias terminal 13 to which a bias voltage is applied, an anode connected to the antenna terminal 10, a cathode connected to the transmitting terminal 11, and one end connected to the antenna terminal 10. The other end of the inductor 44 connected to the bias terminal, one end connected to the other end of the inductor 44, the other end connected to the ground, and the other end of the effective wavelength of the fundamental wave connected to the antenna terminal 10. A first high-frequency line 31 having a length of approximately 1/4, a second diode 22 having an anode connected to the other end of the first high-frequency line 31, and one end A capacitor 41 connected to the cathode of the second diode 22 and having the other end grounded, an inductor 42 connected in parallel to the capacitor 41, and approximately ¼ of the effective wavelength of the fundamental wave connected to the transmission terminal 11. The first short stub 51 having a length, the second short stub 52 having a length of about 1/6 of the effective wavelength of the fundamental wave connected to the transmission terminal 11, and the transmission terminal 11 similarly. The connected first open stub 53 and one end connected to the other end of the first high-frequency line 31 and the other end connected to the receiving terminal 12 have a length of about ¼ of the effective wavelength of the fundamental wave. The second high-frequency line 32, the third diode 23 whose anode is connected to the reception terminal 12, the third short stub 54 connected to the cathode of the third diode, and the third diode Catho And a second open stub 55 connected to the.

  In the high-frequency switch circuit according to the third embodiment, as in the first embodiment, the first short stub 51 having a length of approximately ¼ of the effective wavelength of the fundamental wave causes the antenna terminal 10 to The second short stub 52 that can suppress the second harmonic from the transmission terminal 11 to the reception terminal 12 and has a length of about 1/6 of the effective wavelength of the fundamental wave is used to transmit the antenna terminal 10 from the transmission terminal 11. , And the third harmonic from the transmission terminal 11 to the reception terminal 12 can be suppressed. Similarly to the first embodiment, the first open stub 53 matches the impedance of the transmission signal viewed from the transmission terminal 11 side with respect to the fundamental wave of the transmission terminal 11 side, and at the time of transmission, that is, the transmission terminal 11 and the antenna. It is possible to suppress the deterioration of the fundamental wave passage loss when the route to the terminal 10 is a passage route.

  Further, in the high frequency switch circuit according to the third embodiment, as in the second embodiment, at the time of transmission, that is, when the third diode 23 is in the ON state, the reception terminal 12 and the third short stub 54 and The second open stub 55 is connected via the third diode 23. Therefore, by setting the length of the third short stub 54 to approximately ¼ of the effective wavelength of the fundamental wave, the second harmonic from the transmission terminal 11 to the reception terminal 12 is suppressed, and the second open stub 55 By setting the length to approximately 1/12 of the effective wavelength of the fundamental wave, the third harmonic wave from the transmission terminal 11 to the reception terminal 12 can be suppressed.

  Alternatively, the third harmonic wave from the transmission terminal 11 to the reception terminal 12 is suppressed by setting the length of the third short stub 54 to approximately 1/6 of the effective wavelength of the fundamental wave, as in the second embodiment. By setting the length of the second open stub 55 to approximately 1/8 of the effective wavelength of the fundamental wave, it is possible to suppress the second harmonic wave from the transmission terminal 11 to the reception terminal 12.

  On the other hand, at the time of reception, that is, when the third diode 23 is in the OFF state, the reception terminal 12 is disconnected from the third short stub 54 and the second open stub 55. Therefore, at the time of reception, that is, when the path between the antenna terminal 10 and the reception terminal 12 is a passing path, the transmission loss of the fundamental wave is not deteriorated, that is, between the transmission terminal 11 and the reception terminal 12. The second harmonic and the third harmonic from the transmission terminal 11 to the reception terminal 12 in the case where the above path is the cutoff path can be suppressed.

  FIG. 4 is a diagram illustrating another configuration example of the high-frequency switch circuit according to the third embodiment. In the high-frequency switch circuit shown in FIG. 4, in addition to the configuration shown in FIG. 3, the anode is connected to the connection point between the receiving terminal 12 and the second high-frequency line 32, and one end is connected to the cathode of the diode 24. The other end of the capacitor 45 is grounded, and the inductor 46 is connected to the capacitor 45 in parallel. With the configuration including these diode 24, capacitor 45, inductor 46, and second high-frequency line 32, the fundamental wave from the transmission terminal to the reception terminal is further suppressed as in the first and second embodiments. it can.

  FIG. 5 is a diagram illustrating a characteristic example of the high-frequency switch circuit illustrated in FIG. FIG. 5A is a diagram illustrating pass characteristics between the transmission terminal 11 and the antenna terminal 10. In FIG. 5A, the horizontal axis indicates the frequency, and the vertical axis indicates the passing signal amplitude between the transmission terminal 11 and the antenna terminal 10.

  FIG. 5B is a diagram illustrating the isolation characteristics between the transmission terminal 11 and the reception terminal 12. In FIG. 5B, the horizontal axis indicates the frequency, and the vertical axis indicates the passing signal amplitude between the transmission terminal 11 and the reception terminal 12. In addition, fo shown on the horizontal axis of FIGS. 5A and 5B is the frequency of the fundamental wave, 2fo is the frequency of the second harmonic, and 3fo is the frequency of the third harmonic.

  As shown in FIG. 5A, in the pass characteristic between the transmission terminal 11 and the antenna terminal 10, the deterioration of the fundamental wave pass loss from the transmission terminal 11 to the antenna terminal 10 is suppressed, and the transmission terminal 11 is connected to the antenna. The second and third harmonics to the terminal 10 are suppressed.

  Further, as shown in FIG. 5B, in the isolation characteristic between the transmission terminal 11 and the reception terminal 12, the fundamental wave from the transmission terminal 11 to the reception terminal 12 is suppressed, and the transmission terminal 11 to the reception terminal 12 is suppressed. The second harmonic and the third harmonic are also suppressed.

  As described above, according to the high frequency switch circuit according to the third embodiment, as in the first embodiment, the first short stub having a length approximately ¼ of the effective wavelength of the fundamental wave at the transmission terminal, A second short stub having a length of about 1/6 of the effective wavelength of the fundamental wave and a first open stub for matching the impedance of the transmission signal to the fundamental wave viewed from the transmission terminal side to the antenna terminal side are connected. As in the second embodiment, the anode of the third diode is connected to the receiving terminal, and the third short stub having the length of about ¼ of the effective wavelength of the fundamental wave is connected to the cathode of the third diode. And the second open stub having a length of approximately 1/12 of the effective wavelength of the fundamental wave is connected, so that the fundamental wave pass loss from the transmission terminal to the antenna terminal and from the transmission terminal to the reception terminal is deteriorated. It suppresses, it is possible to further suppress the second harmonic wave and third harmonic wave to the receiving terminal from the transmitting terminal. Alternatively, as in the second embodiment, the length of the third short stub is set to approximately 1/8 of the effective wavelength of the fundamental wave, and the length of the second open stub is set to approximately 1/6 of the effective wavelength of the fundamental wave. However, the same effect can be obtained.

  Note that the configuration shown in the above embodiment is an example of the configuration of the present invention, and can be combined with another known technique, and a part thereof is omitted without departing from the gist of the present invention. Needless to say, it is possible to change the configuration.

  As described above, the high-frequency switch circuit according to the present invention suppresses the second and third harmonics from the transmission terminal to the antenna terminal and from the transmission terminal to the reception terminal, while suppressing the fundamental wave from the transmission terminal to the antenna terminal. This is useful as an invention that can prevent the deterioration of the passage loss.

DESCRIPTION OF SYMBOLS 10 Antenna terminal 11 Transmission terminal 12 Reception terminal 13 Bias terminal 21, 22, 23, 24 Diode 31, 32 High frequency line 41, 43, 45 Capacitor 42, 44, 46 Inductor 51, 52, 54 Short stub 53, 55 Open stub

Claims (5)

A high-frequency switch circuit that outputs a high-frequency signal input from a transmission terminal from an antenna terminal, and outputs the high-frequency signal input from the antenna terminal from a reception terminal,
A first diode having an anode connected to the antenna terminal and a cathode connected to the transmitting terminal;
A high-frequency line having one end connected to the antenna terminal and the other end connected to the receiving terminal and having a length of about ¼ of the effective wavelength of the fundamental wave of the high-frequency signal;
A second diode having an anode connected to the other end of the high-frequency line;
A capacitor having one end connected to the cathode of the second diode and the other end grounded;
An inductor connected in parallel to the capacitor;
A first short stub connected to at least one of the transmission terminals and having a length of about ¼ of an effective wavelength of the fundamental wave of the high-frequency signal;
A second short stub connected to at least one of the transmission terminals and having a length of about 1/6 with respect to the effective wavelength of the fundamental wave of the high-frequency signal;
At least one open stub connected to the transmission terminal;
A high-frequency switch circuit comprising: A high-frequency switch circuit that outputs a high-frequency signal input from a transmission terminal from an antenna terminal, and outputs the high-frequency signal input from the antenna terminal from a reception terminal,
A first diode having an anode connected to the antenna terminal and a cathode connected to the transmitting terminal;
A first high-frequency line having one end connected to the antenna terminal and having a length of about ¼ of the effective wavelength of the fundamental wave of the high-frequency signal;
A second diode having an anode connected to the other end of the first high-frequency line;
A capacitor having one end connected to the cathode of the second diode and the other end grounded;
An inductor connected in parallel to the capacitor;
A second high-frequency wave having one end connected to the other end of the first high-frequency line and the other end connected to the receiving terminal, and having a length of about ¼ of the effective wavelength of the fundamental wave of the high-frequency signal. Tracks,
A third diode having an anode connected to the receiving terminal;
A short stub connected to the cathode of the third diode and having a length of approximately 1/4 with respect to the effective wavelength of the fundamental wave of the high-frequency signal;
An open stub connected to the cathode of the third diode and having a length of approximately 1/12 of the effective wavelength of the fundamental wave of the high-frequency signal;
A high-frequency switch circuit comprising: A high-frequency switch circuit that outputs a high-frequency signal input from a transmission terminal from an antenna terminal, and outputs the high-frequency signal input from the antenna terminal from a reception terminal,
A first diode having an anode connected to the antenna terminal and a cathode connected to the transmitting terminal;
A first high-frequency line having one end connected to the antenna terminal and having a length of about ¼ of the effective wavelength of the fundamental wave of the high-frequency signal;
A second diode having an anode connected to the other end of the first high-frequency line;
A capacitor having one end connected to the cathode of the second diode and the other end grounded;
An inductor connected in parallel to the capacitor;
A second high-frequency wave having one end connected to the other end of the first high-frequency line and the other end connected to the receiving terminal, and having a length of about ¼ of the effective wavelength of the fundamental wave of the high-frequency signal. Tracks,
A third diode having an anode connected to the receiving terminal;
A short stub connected to the cathode of the third diode and having a length of about 1/6 with respect to the effective wavelength of the fundamental wave of the high-frequency signal;
An open stub connected to the cathode of the third diode and having a length of about 1/8 with respect to the effective wavelength of the fundamental wave of the high-frequency signal;
A high-frequency switch circuit comprising: A high-frequency switch circuit that outputs a high-frequency signal input from a transmission terminal from an antenna terminal, and outputs the high-frequency signal input from the antenna terminal from a reception terminal,
A first diode having an anode connected to the antenna terminal and a cathode connected to the transmitting terminal;
A first high-frequency line having one end connected to the antenna terminal and having a length of about ¼ of the effective wavelength of the fundamental wave of the high-frequency signal;
A second diode having an anode connected to the other end of the first high-frequency line;
A capacitor having one end connected to the cathode of the second diode and the other end grounded;
An inductor connected in parallel to the capacitor;
A first short stub connected to at least one of the transmission terminals and having a length of about ¼ of an effective wavelength of the fundamental wave of the high-frequency signal;
A second short stub connected to at least one of the transmission terminals and having a length of about 1/6 with respect to the effective wavelength of the fundamental wave of the high-frequency signal;
A first open stub connected to at least one of the transmission terminals;
A second high-frequency wave having one end connected to the other end of the first high-frequency line and the other end connected to the receiving terminal, and having a length of about ¼ of the effective wavelength of the fundamental wave of the high-frequency signal. Tracks,
A third diode having an anode connected to the other end of the second high-frequency line;
A third short stub connected to the cathode of the third diode and having a length of approximately ¼ of the effective wavelength of the fundamental wave of the high-frequency signal;
A second open stub connected to the cathode of the third diode and having a length of approximately 1/12 of the effective wavelength of the fundamental wave of the high-frequency signal;
A high-frequency switch circuit comprising: A high-frequency switch circuit that outputs a high-frequency signal input from a transmission terminal from an antenna terminal, and outputs the high-frequency signal input from the antenna terminal from a reception terminal,
A first diode having an anode connected to the antenna terminal and a cathode connected to the transmitting terminal;
A first high-frequency line having one end connected to the antenna terminal and having a length of about ¼ of the effective wavelength of the fundamental wave of the high-frequency signal;
A second diode having an anode connected to the other end of the first high-frequency line;
A capacitor having one end connected to the cathode of the second diode and the other end grounded;
An inductor connected in parallel to the capacitor;
A first short stub connected to at least one of the transmission terminals and having a length of about ¼ of an effective wavelength of the fundamental wave of the high-frequency signal;
A second short stub connected to at least one of the transmission terminals and having a length of about 1/6 with respect to the effective wavelength of the fundamental wave of the high-frequency signal;
A first open stub connected to at least one of the transmission terminals;
A second high-frequency wave having one end connected to the other end of the first high-frequency line and the other end connected to the receiving terminal, and having a length of about ¼ of the effective wavelength of the fundamental wave of the high-frequency signal. Tracks,
A third diode having an anode connected to the other end of the second high-frequency line;
A third short stub connected to the cathode of the third diode and having a length of about 1/6 with respect to the effective wavelength of the fundamental wave of the high-frequency signal;
A second open stub connected to the cathode of the third diode and having a length of about 1/8 of the effective wavelength of the fundamental wave of the high-frequency signal;
A high-frequency switch circuit comprising:

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