JP2002261652A - High-frequency switch, 2band type high-frequency switch, 3band type high-frequency switch, and radio communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-loss high-frequency switch which is good in isolation. SOLUTION: A transmitting terminal 101 is connected to the anode of a first diode D101 via a first capacitor element C101. The anode side of the first transmitting terminal 101 is connected to a control terminal 102 via an inductor element L101 and a resistance element R101. A receiving terminal 103 is connected to the anode of a second diode D102 via a second capacitor element C102. The cathode of the second diode D102 is connected to a ground. The other separated end on the anode side of the second diode D102 is connected to a transmission line TL101 having one-fourth wave length in the used frequency electric length. The other end of the transmission line TL101 is connected to an antenna terminal via a third capacitor C103 as well as to the cathode of the first diode D101. The ON resistance in the first diode is lower than that in the second diode, and at the time of OFF, the capacity of the first diode is larger than of the second diode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency switch for switching high-frequency signals in a radio circuit of a radio communication device such as a portable telephone.

[0002]

2. Description of the Related Art A high-frequency switch circuit is often used for switching transmission and reception signals in a radio communication device such as a portable telephone using the TDMA system.

An example of the above-described conventional high-frequency switch circuit will be described below with reference to the drawings.

FIG. 13 is an equivalent circuit diagram of a conventional high frequency switch circuit. In FIG. 13, an anode of a first diode D1301 is connected to a transmission terminal 1301 via a first capacitor element C1301. Further, an inductor element L1301 and a resistor element R13 are provided on the anode side of the first diode D1301.
01 is connected to a control terminal 1302. The anode of the second diode D1302 is connected to the receiving terminal 1303 via the second capacitor element C1302, and the cathode is connected to the ground side.
On the anode side of the second diode D1302, a first transmission line TL13 having an electric length of 1/4 wavelength at the operating frequency is provided.
01 is connected to one end of the first diode D13.
01 and the third capacitor element C1303
Is connected to the antenna terminal 1304 via the. Here, the first diode D1301 and the second diode D130 are usually used in order to reduce the variety of parts used and to reduce the cost.
1302 has the same characteristics.

The operation of the high-frequency switch circuit configured as described above will be described.

When transmitting, the control terminal 1302
When a positive voltage is applied to the first diode D130,
First, the second diode D1302 is turned on. At this time, the capacitor elements C1301, C1302, C1303
Cuts the DC component. The transmission signal is sent to the transmission terminal 13
01 to the antenna terminal 1304 through the capacitor element C1301, the first diode D1301, and the capacitor element C1303. Where the transmission line TL
Since the second diode D1302 is ON, 1301 is a quarter-wave resonator with one end grounded. Therefore, the impedance of the line on the antenna terminal 1304 side becomes infinite, and the transmission signal is not transmitted to the reception side.

When receiving, the control terminal 130
Since no voltage is applied to the first diode D1
301 and the second diode D1302 are both in the OFF state, and the received signal is transmitted from the antenna terminal 1304 to the receiving terminal 1303 via the capacitor element C1303, the transmission line TL1301, and the capacitor element C1302.

[0008]

Here, PIN diodes are mainly used for the first diode D1301 and the second diode D1302, which are switching diodes. However, in general, a diode having a small ON resistance has a large capacitance between the cathode and anode terminals, and a diode having a small capacitance between the terminals when the diode is OFF has a trade-off relationship of a high ON resistance.

Therefore, if a diode having a small inter-terminal capacitance is selected to obtain high isolation while placing importance on isolation at the time of reception, the ON resistance increases and the loss in the signal path during transmission increases. .

On the other hand, with emphasis on insertion loss during transmission,
When a diode having a small ON resistance is selected, there is a problem that the capacitance between terminals is increased, the isolation is reduced, and the loss in the signal path at the time of reception is increased.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a high-frequency switch capable of favorably reducing loss in a signal path in both transmission and reception.

[0012]

According to a first aspect of the present invention (corresponding to claim 1), a transmitting terminal, a receiving terminal, an antenna terminal, and an anode are provided at the transmitting terminal. An anode is electrically connected to a first diode having a cathode electrically connected to the antenna terminal and an antenna terminal electrically connected to the reception terminal via a 波長 wavelength transmission line. A second diode whose cathode side is grounded, the transmission terminal, and the first diode.
And a control terminal provided at a connection point between the first and second diodes.
There is a trade-off between the resistance and the capacitance between the anode and the cathode. The ON resistance of the first diode is lower than the ON resistance of the second diode, and the capacitance when the second diode is OFF is lower. This is a high-frequency switch smaller than the capacitance of the first diode when it is turned off.

Further, a second aspect of the present invention (corresponding to claim 2)
Is a high-frequency switch according to a first aspect of the present invention, wherein a diode having an ON resistance of 1Ω or less is used as the first diode, and a capacitance between terminals when the second diode is OFF is 0.8 pF or less.

A third aspect of the present invention (corresponding to claim 3)
Is a high-frequency switch according to the first aspect of the present invention, wherein a diode having an ON resistance of 0.8Ω or less is used as the first diode, and a capacitance between terminals when the second diode is OFF is 0.5 pF or less. is there.

A fourth aspect of the present invention (corresponding to claim 4)
Is a high-frequency switch according to any one of the first to third aspects of the present invention, provided with an LC series circuit, provided in parallel with the first diode.

A fifth aspect of the present invention (corresponding to claim 5)
Is a high-frequency switch according to any one of the first to third aspects of the present invention provided with an LC parallel circuit connected in series to the second diode.

The sixth invention (corresponding to claim 6)
Is a laminate formed by laminating a plurality of dielectrics, a transmission terminal, a reception terminal, an antenna terminal, a control terminal, a ground terminal, and an electrode pattern for connecting parts provided on the surface of the laminate. A first diode mounted on the surface, the anode being electrically connected to the transmission terminal, the cathode being electrically connected to the antenna terminal, and the antenna terminal being electrically connected to the reception terminal;
An anode is connected through a quarter-wave transmission line, and a second diode is connected to the cathode side of the second diode.
And the second diode has a trade-off relationship between the ON resistance and the capacitance between the anode and the cathode, and the ON resistance of the first diode is lower than the ON resistance of the second diode; Is a high-frequency switch in which the off-state capacity of the diode is smaller than the off-state capacity of the first diode.

The seventh invention (corresponding to claim 7)
Is a high-frequency switch according to any one of the first to fifth aspects of the present invention constituted by using a laminate.

An eighth aspect of the present invention (corresponding to claim 8)
Are a first high-frequency switch for a first frequency band and a first high-frequency switch.
A second high-frequency switch for a second frequency band higher than the first frequency band, an antenna terminal of the first high-frequency switch, and an antenna terminal of the second high-frequency switch; And a demultiplexer for demultiplexing and multiplexing the second frequency band and the second frequency band, and sharing the same antenna with the first high-frequency switch and the second high-frequency switch. A first high-frequency switch and a second high-frequency switch
Is a two-band high-frequency switch using the high-frequency switch according to any one of claims 1 to 5.

A ninth aspect of the present invention (corresponding to claim 9)
Is the first resistance of the second high-frequency switch from the ON resistance of the first diode of the first high-frequency switch.
And the ON resistance of the diode of the first high-frequency switch is set lower than the capacitance of the second diode when the second diode is OFF.
O2 of the second diode of the second high-frequency switch
An eighth high-frequency switch according to the eighth aspect of the present invention in which the capacitance at the time of FF is reduced.

According to a tenth aspect of the present invention (corresponding to claim 10), the ON resistance of the first diode of the first high-frequency switch is 1Ω or less and the first diode of the second high-frequency switch is Is ON resistance of 0.8Ω or less,
O2 of the second diode of the first high-frequency switch
The capacitance at the time of FF is 0.8 pF or less, and the capacitance of the second diode of the second high-frequency switch at the time of OFF is 0.
A ninth embodiment of the present invention is the two-band high-frequency switch of 5 pF or less.

An eleventh aspect of the present invention (corresponding to claim 11) relates to a transmission terminal, a reception terminal and a control terminal of the first high-frequency switch, and a transmission terminal, a reception terminal and a control terminal of the second high-frequency switch. A terminal and an antenna terminal common to the first high-frequency switch and the second high-frequency switch are provided on a surface of a laminate in which a plurality of dielectrics are laminated as an electrode pattern for component connection together with a ground terminal; An electrode pattern for constituting the first high-frequency switch, the second high-frequency switch, and the duplexer is provided inside the laminate,
The first diode and the second diode are:
The two-band high-frequency switch according to any one of the eighth to tenth aspects of the present invention mounted on the surface of the multilayer body.

According to a twelfth invention (corresponding to claim 12), a first high-frequency switch for a first frequency band,
A second high-frequency switch for a second frequency band higher than the first frequency band, a third high-frequency switch for a third frequency band higher than the first frequency band, and an antenna of the first high-frequency switch A terminal and an antenna terminal of the second high-frequency switch are electrically connected, and the first frequency band;
The second frequency band and the second frequency band are demultiplexed and combined, and the same antenna is shared by the first high-frequency switch, the second high-frequency switch, and the third high-frequency switch. A high-frequency switch according to any one of claims 1 to 5 as the first high-frequency switch and the second high-frequency switch. A high-frequency switch, a third diode having a cathode connected between the antenna terminal and a connection point between the cathode of the first diode and the transmission line, and an anode connected to a second reception terminal; A second control terminal connected between the third diode and the second reception terminal, and a reception terminal using the transmission terminal of the first high-frequency switch as a second transmission terminal; Is a 3-band high-frequency switch for operating with the second diode of said second high-frequency switch on the side.

According to a thirteenth aspect of the present invention (corresponding to claim 13), the first diode and the first diode of the second high-frequency switch are turned on by the ON resistance of the first diode of the first high-frequency switch. The ON resistance of the third diode of the third high-frequency switch is reduced, and the capacitance of the second diode of the first high-frequency switch when the second diode is turned off is set lower than the ON resistance of the second diode of the second high-frequency switch. A twelfth band-type high-frequency switch according to the present invention in which the capacitance at the time of OFF is reduced.

According to a fourteenth aspect of the present invention (corresponding to claim 14), the ON resistance of the third diode of the third high-frequency switch is the ON resistance of the first diode of the second high-frequency switch. A thirteenth three-band high-frequency switch according to the present invention having lower resistance than the resistance.

According to a fifteenth aspect of the present invention (corresponding to claim 15), the ON resistance of the first diode of the first high-frequency switch is 1Ω or less and the first high-frequency switch of the second high-frequency switch is not connected to the first high-frequency switch. The ON resistance of the diode and the third diode of the third high-frequency switch is 0.8Ω or less, and the off-state capacitance of the second diode of the first high-frequency switch is 0.8 pF or less. A three-band high-frequency switch according to a thirteenth or fourteenth invention, wherein the capacitance of the second high-frequency switch when the second diode is OFF is 0.5 pF or less.

A sixteenth aspect of the present invention (corresponding to claim 16) is the three-band type of the fifteenth aspect of the present invention wherein the ON resistance of the third diode of the third high-frequency switch is set to 0.5Ω or less. It is a high frequency switch.

A seventeenth aspect of the present invention (corresponding to claim 17) relates to a transmission terminal, a reception terminal and a control terminal of the first high-frequency switch, and a transmission terminal, a reception terminal and a control terminal of the second high-frequency switch. A terminal, a receiving terminal and a control terminal of the third high-frequency switch, and an antenna terminal common to the first high-frequency switch, the second high-frequency switch, and the third high-frequency switch;
An electrode pattern for connecting components together with a ground terminal is provided on a surface of a laminated body in which a plurality of dielectrics are laminated, and a first high-frequency switch, a second high-frequency switch, and a third high-frequency switch are provided inside the laminated body. An electrode pattern for configuring the high-frequency switch and the duplexer is provided,
The first diode, the second diode, and the third diode are the three-band high-frequency switch according to any one of the twelfth to seventeenth aspects of the present invention mounted on the surface of the multilayer body.

An eighteenth aspect of the present invention (corresponding to claim 18) is an antenna, a transmitting unit for transmitting a signal from the antenna, a receiving unit for receiving a signal from the antenna, and the antenna And a switch unit for switching connection between the transmission unit and the reception unit. A wireless communication device using the high-frequency switch according to any one of the first to seventeenth aspects of the invention as the switch unit.

As described above, the high-frequency switch circuit of the present invention uses a diode on the transmission side that has a lower high-frequency resistance when turned on than a diode used on the reception side, and is turned off on the reception side than the diode on the transmission side. Low loss and high isolation characteristics are realized by using diodes with different characteristics with small inter-terminal capacitance in the high frequency range at the time.

[0031]

(Embodiment 1) Hereinafter, a high-frequency switch circuit according to Embodiment 1 of the present invention will be described.
Description will be made using an antenna switching circuit that is often used when performing communication by the DMA method. FIG. 1 shows Embodiment 1
3 shows an equivalent circuit of the high-frequency switch circuit in FIG. In FIG. 1, an anode of a first diode D101 is connected to a transmission terminal 101 via a first capacitor element C101. Also, the first diode D101
The inductor element L101 and the resistance element R
A control terminal 102 is connected via 101. The receiving terminal 103 has a second capacitor element C102
The anode of the second diode D102 is connected via the second diode D102, and the cathode is connected to the ground side.

A transmission line TL101 having an electrical length of 1/4 wavelength at the operating frequency is connected to one of the anode sides of the second diode D102, and the other end is connected to the cathode of the first diode D101 and the third capacitor. Element C10
3 and connected to the antenna terminal 104. Here, the ON resistance of the first diode D101 is lower than the ON resistance of the second diode D102.
The capacitance at the time of OFF of the first diode D101
It is smaller than the capacity at the time of OFF.

The operation of the high-frequency switch circuit configured as described above will be described.

In transmission, when a positive voltage is applied to the control terminal 102, the first diode D101 and the second diode D102 are turned on. At this time, the capacitor elements C101, C102, and C103 cut the DC component, and no current flows through each terminal. Further, the inductor element L101 is used as a high-frequency choke to prevent high-frequency from flowing to the control terminal 102. The resistance element R101 is a diode D1.
01 and D102 are used to supply a bias current.

The transmission signal transmitted from the transmission terminal 101 is composed of a capacitor element C101 and a first diode D10.
1 and transmitted to the antenna terminal 104 via the capacitor element C103. At this time, the transmission line TL101 is a grounded-type resonator because the second diode D102 is turned on and grounded. Therefore, the impedance on the antenna side is close to infinity, the receiving side is cut off at high frequencies, and no transmission signal is transmitted. Since the first diode D101 has a low ON resistance, the signal path through which the transmission signal flows is a low-loss path.

Next, at the time of reception, the control terminal 102
No voltage is applied to the first diode D10
First, the second diode D102 is OFF.
The received signal is transmitted from the antenna terminal 104 to the capacitor element C1.
03, the transmission line TL101, the capacitor element C1
02 to the receiving terminal 103. Here the second
The diode D102 has a high isolation because it has a small inter-terminal capacitance when OFF.
The received signal is transmitted to the receiving terminal 103 side without leaking to the ground side to which the second diode D102 is connected. Therefore, the signal path through which the received signal flows is a low-loss path.

FIG. 2 is a top view showing an example in which the circuit of FIG. 1 is formed on a printed circuit board. Printed circuit board P201
Is made of glass epoxy or the like, and a ground electrode is provided on the back surface although not shown. Transmission line TL2
01 to L205 are microstrip lines formed on the printed circuit board P201. Inductor element L201 realized by an air-core coil or the like, and capacitor elements C201 to C20 realized by a chip capacitor or the like
3, a resistance element R201 realized by a chip resistor or the like;
Both the first diode D201 and the second diode D202 are mounted on the printed circuit board P201 by soldering or the like.
G200 is an electrode provided for grounding the cathode side of the second diode D202, and is electrically connected to a ground electrode on the back surface of the printed circuit board P201 through a through hole. The transmission terminal 20 is provided on the printed circuit board P201.
1, a control terminal 202, a receiving terminal 203, and an antenna terminal 204 are provided.

As described above, in the present embodiment, a diode having a low ON resistance is used for the diode on the transmission side, and a diode having a small inter-terminal capacitance when OFF is used for the reception side. In this case, a high-frequency switch circuit having a low-loss signal path through which a transmission signal or a reception signal passes can be realized.

(Embodiment 2) Next, Embodiment 2 of the present invention will be described with reference to the drawings. Figures 3, 4,
5 is a perspective view, an exploded perspective view, and a circuit diagram of a laminate forming a high-frequency switch circuit according to Embodiment 2 of the present invention. In FIG. 3, a transmission terminal 301, a ground terminal 302, a reception terminal 303, a ground terminal 304, an antenna terminal 305, and a control terminal 3 are provided on the side surface and the upper and lower surfaces near the side surface of a laminate 300 in which a plurality of dielectric sheets are laminated.
06 terminal electrodes are provided. Electrodes 307, 30
8, 309, 310, 311 and 312 are electrodes provided on the surface of the laminate 300.

The first diode D301 includes an electrode 310,
312, the second diode D302 is connected to the electrodes 302 and 3;
11 is connected by solder or the like. Similarly, the inductor element L301 is connected to the electrodes 307 and 308, and the resistance element R301 is connected to the electrodes 308 and 309.

FIG. 4 is an exploded perspective view of the high frequency switch of FIG. The dielectric sheets 400A, 400B, 400C,
A transmission terminal 40 is provided on the side surface and the upper and lower surfaces near the side surface of 400D.
1, ground terminal 402, receiving terminal 403, ground terminal 40
4, an antenna terminal 405 and a control terminal 406 are provided. The electrode patterns 407, 408, 409, 410, 41 are provided on the upper surface of the dielectric sheet 400A.
1,412 are provided. The dielectric sheet 400B is provided with a transmission line TL401 extending from the transmission terminal 401, and is electrically connected to the electrode pattern 407 by a control voltage supply via V401. The transmission line TL401 is further connected to the electrode pattern 410 by a via V402.

A TL 402 is provided on the dielectric sheet 400C, and the antenna terminal 405 is connected to the reception terminal 40C.
3 and further electrically connected to the electrode patterns 411 and 412 through vias V403 and V404, respectively. 400D is provided with a ground electrode G401, and a ground terminal 402 and a control terminal 406.
Grounded through.

In the configuration example of the laminated body in FIG.
The circuit elements surrounded by the dotted line in the circuit diagram of FIG. 5 are realized therein. Further, a capacitor element C501 for blocking DC current is provided on a wiring board on which this laminate is mounted.
By providing C502 and C503, a high-frequency switch circuit module is configured.

In the embodiment shown in FIG. 3, the control resistor R301 and the inductor element L301 are described as individual components mounted on the surface of the multilayer body 300. However, the resistor element is a printed resistor, and the inductor element is a high impedance. The same effect can be obtained even if the transmission line is built in the laminate 300.

Further, in FIG. 5, capacitor elements C501, C502, C
Although the transmission terminal 501, the reception terminal 503, and the antenna terminal 504 are provided in each of the transmission terminal 501, the same effect can be obtained by incorporating them in the laminate 300.
By configuring each element constituting the high-frequency switch in the laminated body as described above, miniaturization can be achieved, and high reliability can be obtained.

Embodiment 3 Next, Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 6 is an equivalent circuit diagram of the high-frequency switch circuit according to Embodiment 3 of the present invention. The difference from the first embodiment is that a series circuit including a capacitor element C604 and an inductor element L602 is provided in parallel with the first diode D601. This is because of the inter-terminal capacitance of the first diode D601 when it is OFF and the inductor element L602.
This is to increase the isolation between the antenna terminal 604 and the transmission terminal 601 during reception.

Here, the capacitor element C604 is provided to block a DC component from the control terminal 602, and has a capacity of a value large enough to prevent resonance in the frequency band used when the first diode is ON. I have.

As a result, in the high-frequency switch circuit of the present embodiment, it is possible to reduce the loss of the path of the transmission signal at the time of transmission and to increase the isolation of the signal path on the transmission side at the time of reception. A higher performance switch circuit can be provided.

In the above embodiment, the description has been made assuming that a series circuit including the capacitor element C604 and the inductor element L602 is provided. However, a single inductor element may be used.

(Embodiment 4) Next, Embodiment 4 of the present invention will be described with reference to the drawings. FIG. 7 is an equivalent circuit diagram of the high-frequency switch circuit according to Embodiment 4 of the present invention. The difference from the third embodiment is that a parallel circuit including an inductor element L703 and a capacitor element C705 is further provided in series with the second diode D702. This means that the second diode D702 is ON
Inductor component between terminals and capacitor element C7
05 is provided for the purpose of reducing the ground resistance by causing series resonance during transmission.

As a result, a high-frequency switch circuit having a low-loss signal path and high isolation can be provided as compared with the third embodiment.

FIG. 8 is a characteristic example showing the relationship between the ON resistance of the PIN diode and the inter-terminal capacitance. As shown here, those with low ON resistance have large inter-terminal capacitance, and those with small inter-terminal capacitance have high ON resistance. The first diode has a ON resistance of 1 Ω or less, and preferably has a ON resistance of 0.1Ω or less.
The resistance between the terminals of the second diode is preferably 0.8 pF or less, preferably 0.5 pF or less. The relationship between the first diode and the second diode is the same in the first to third embodiments.

In the above embodiment, the description has been made assuming that the parallel circuit including the capacitor element C705 and the inductor element L703 is provided, but a single capacitor element may be used.

In the above-described embodiment, the parallel circuit including the capacitor element C705 and the inductor element L703 has been described as being added to the configuration of the third embodiment. Is also good.

(Embodiment 5) FIG. 9 is an equivalent circuit diagram of a two-band high-frequency switch circuit using the high-frequency switch circuit of the present invention. The two-band type high-frequency switch circuit according to the present embodiment includes a first high-frequency switch 900A for the first frequency band f1 and a second high-frequency switch 900B for the second frequency band f2 higher than the first frequency. Has two,
Further, the respective antenna terminals 904 and 9
14 are combined into one by using a duplexer 920, so that the same antenna (not shown) connected to the antenna terminal 930 is shared.

Hereinafter, as for the two-band high-frequency switch according to the fifth embodiment of the present invention, f1 will be expressed as GSM and DCS, which are used in mobile communications in Europe.
880-960M which is the frequency band of transmission and reception of SM system
Hz, f2 is 1 which is a frequency band for transmission and reception of the DCS method.
710-1880 MHz will be described. In addition, here, description will be made using an example in which the duplexer 920 is configured by a low-pass filter and a high-pass filter having characteristics as shown in FIG. Note that the duplexer 920 can also be configured by combining two types of band-pass filters having different pass bands from each other.

When transmitting, the transmission signal in the GSM band is the first signal.
By applying a voltage to the control terminal 902 of the high-frequency switch 900A of FIG.
2 is turned on and the capacitor element C9 is transmitted from the transmission terminal 901
01, the diode D901, and the capacitor element C903, and are input to the terminal 904 of the duplexer 920 on the low-pass filter (LPF) side.

The DCS band transmission signal is supplied with a voltage to the control terminal 912 of the second high-frequency switch 900B, turning on the diodes D911 and 912, and causing the capacitor C911, the diode D911 and the capacitor C913 to pass through the transmission terminal 911. As described above, the signal is input to the terminal 914 on the high-pass filter (HPF) side of the duplexer 920. Each of the transmission signals input to the duplexer 920 has an isolation in a cross band as shown in FIG. 9, so that none of the transmission signals is output to the other high-frequency switch side and is output to the antenna terminal 930.

When receiving, set the control terminal to OF
F, the signal is received by the antenna and the antenna terminal 930
Are input to the LPF-side antenna terminal 904 in the case of the GSM band and to the HPF-side antenna terminal 914 in the case of the DCS band by the demultiplexer 920.

The signal in the GSM band is output from the antenna terminal 904 to the GSM band receiving terminal 903 through the capacitor element C903, the transmission line TL901, and the capacitor element C902. The signal in the DCS band is supplied to the antenna terminal 914.
Through the capacitor element C913, the transmission line TL911, and the capacitor element C912, the DCS band receiving terminal 91
3 is output.

In such a configuration, in each of the first high-frequency switch 900A and the second high-frequency switch 900B, the first diodes D901 and D911 on the transmission terminals 901 and 911 side are on the reception terminals 903 and 913 side. A diode having lower ON resistance than the second diodes D902 and D912 is used, and a diode D902 and D912 on the receiving terminals 903 and 913 side have a smaller terminal capacitance than the diodes D901 and D911 on the transmitting terminal side when OFF. As a result, a low-loss high-frequency switch is obtained as in the first embodiment. Therefore, the present embodiment is a low-loss two-band high-frequency switch. At this time, the diode D901 has an ON resistance of 1Ω or less and the diode D9
11 is 0.8Ω or less, the capacitance between the terminals of the diode D902 is 0.8pF or less, and the diode D912 is 0.1Ω or less.
5 pF or less is desirable.

With the above configuration, the loss on the transmission side is slightly larger on the lower frequency side, but the isolation at the time of reception is increased, and the signal leaking to the transmission terminal side is reduced. In general, the ON resistance is set lower because a higher loss is desired on the higher frequency side during transmission. By using such a two-band type high frequency switch, the power consumption of the wireless communication device can be reduced.

Also, in this configuration, various operations can be performed according to the requirements of the communication system, such as simultaneous transmission and reception of two waves or reception at the time of transmission on one side by using the demultiplexer 920.

(Embodiment 6) FIG. 11 shows a three-band high-frequency switch circuit using the high-frequency switch circuit of the present invention. The three-band high-frequency switch circuit according to the present embodiment includes a first high-frequency switch 11 for the first frequency band f1.
00A, a second high frequency switch 1100B for a second frequency band f2 higher than the first frequency, and a third high frequency switch 1 for a third frequency band f3 higher than the first frequency.
100C, and each antenna terminal 40
4. The same antenna (not shown) connected to the antenna terminal 1130 is shared by combining the antenna terminals 1114 with one another using the duplexer 1120.

The first high-frequency switch 1100A and the second high-frequency switch 1100B have the same configuration as the high-frequency switch of the first embodiment.

The third high-frequency switch 1100C
Has a transmission terminal 1111, a capacitor element C1111, an inductor element L1111, a resistance element R1111, a control terminal 1112, and a first diode D1111 shared with a second high-frequency switch 1100B as a transmission-side configuration. Antenna terminal 1114 and capacitor 111 serving as any signal path of
3 is also shared with the second high-frequency switch 1100B, and the transmission line TL1111 and the second
Of the second high frequency switch 111
Shared with 0B.

On the receiving side of the third high-frequency switch 1100C, the anode is connected between the capacitor element C1113 and the connection point between the first diode D1111 and the transmission line TL1111. The cathode is connected to the capacitor element C1122. Connected to the receiving terminal 1123 via
Diode D1121 and the third diode D112
1 is connected to the resistor element R1121 and the inductor element L11
Control terminal 1 connected via 22 series circuits
122, a capacitor element C1121 and an inductor element L connected in parallel with the third diode D1121.
1121 series circuit.

That is, the third high-frequency switch 1100
C is a third diode D1121, a receiving circuit including a peripheral circuit, a first diode D1111 and a transmitting circuit including a peripheral circuit and shared in high frequency with the second high-frequency switch 1100B, A second high-frequency switch 11 including a diode D1112 and a transmission line TL111;
00B and a circuit shared in a DC manner.

Hereinafter, the three-band high-frequency switch according to the sixth embodiment of the present invention will be described with specific examples of the GSM and DCS systems used in mobile communications in Europe and the PCS system used in the United States as f1. Is 880-960 MHz, which is a frequency band for GSM transmission / reception, and f2 is 1711-1880 MH, which is a frequency band for transmission / reception of DCS.
z, f3 is the frequency band of PCS transmission / reception, 18
The description will be made on the assumption that the frequency is 60 to 1990 MHz.

When transmitting, the transmission signal in the GSM band is the first
Control terminal 110 of high frequency switch 1100A
2 to the first diode D1
101, the second diode 1102 is turned on, and the signal input to the transmission terminal 1101 is the capacitor element C110
1, first diode D1101, capacitor element C1
103, the low-pass filter (LP) of the duplexer 1120
The signal is input to the antenna terminal 1104 on the F) side.

The transmission signals in the DCS band and the PCS band are turned on by applying a voltage to the control terminal 1112 of the second high-frequency switch 1100B (third high-frequency switch 1100C) to turn on the diodes D1111 and 1112.
From the transmission terminal 1111 to the capacitor element C111.
1, the first diode D1111, the capacitor element C1
113, the high-pass filter (HP) of the duplexer 1130
F) to the terminal 1114.

As shown in FIG. 9 quoted in the fifth embodiment, since the demultiplexer 1120 has isolation in the cross band, the transmission signals input to the respective demultiplexers 1120 are transmitted to different high-frequency switches. It is not output but output to the antenna terminal 1130.

When receiving, the control terminal 110
2, 1112 and 1122 are turned off, the GSM band signal input from the antenna terminal 930 is input to the LPF side antenna terminal 1104 by the demultiplexer 1120, and the DCS and PCS band signals are input to the HPF side. The signal is output to the antenna terminal 1114.

The signal in the GSM band is transmitted from the antenna terminal 1104 to the capacitor element C1103, the transmission line TL1101,
The signal is output to the GSM band receiving terminal 1103 through the capacitor element C1102.

The signal in the DCS band passes from terminal 1114 through capacitor element C1113, transmission line TL1111, and capacitor element C1112 to receive terminal 11 for the DCS band.
13 is output.

Further, when receiving the PCS band, by applying a voltage to the control terminal 1122, the operation of the third high-frequency switch 1100C causes the third diode D1121 and the second diode D1112 to be turned off.
N, the received signal is transmitted from the antenna terminal 1114 to the capacitor element C1113, the third diode D1121,
PCS receiving terminal 11 via capacitor element C1122
23.

Note that the third diode D1121 is turned off.
, Ie, the second high-frequency switch 1110B
When receiving DCS band signals by operating as
Of the diode D1121 and the inductor element L1121 in parallel resonance to ensure isolation between the band of DCS and PCS and prevent signals from flowing to the receiving terminal 1123 side of PCS.

In such a configuration, the transmission terminal 110
The first diodes D11 on the side of
01, D1111 and the third diode D1121 for PCS band reception are turned on by the second diodes D1102, D1112 on the reception terminal 1103, 1113 side, respectively.
The second diodes D1102 and D1112 on the side of the receiving terminals 1103 and 1113 are of low resistance.
Since the inter-terminal capacitance at the time of F is smaller than the inter-terminal capacitance of the diodes D1101 and D1111 on the transmission terminals 1101 and 1111 side, a low-loss high-frequency switch is obtained.

The diodes used for the second high-frequency switch 1100B and the third high-frequency switch 1100C on the higher frequency side may be selected so as to have lower loss than the first high-frequency switch 1100A on the lower frequency side. desirable. Further, the third diode D11
It is desirable that the ON resistance of 21 is lower than the ON resistance of the first diode D1101 on the transmission terminal 1101 side of the first high-frequency switch 1100A.

For example, at this time, the first diode D110
1 indicates that the ON resistance is 1Ω or less and the first diode D1111
Is 0.8Ω or less, and the third diode D1121
The ON resistance of the second diode D11 is 0.5Ω or less.
02 and D1112 preferably have an inter-terminal capacitance of 0.8 pF or less when OFF.

By using the three-band high-frequency switch having the above-described configuration, it is turned on at the time of reception on the PCS side.
Since a diode having a low resistance is used, the loss is low, and sufficient isolation can be obtained by connecting an inductor element in parallel with the diode D1121.

In other circuit portions, low loss and high isolation characteristics can be obtained as in the two-band high-frequency switch. When a three-band high-frequency switch having such a configuration is used, the power consumption of the wireless communication device can be reduced because the loss on the transmitting side is small. Since a duplexer is used, the GS is the same as the two-band high-frequency switch.
The M side and the DCS and PCS sides can individually perform operations such as transmission and reception at the same time. Further, by forming a three-band high-frequency switch by using a laminated structure, the size of the wireless communication device can be reduced.

The series circuit of the capacitor element C1121 and the inductor element L1121 connected in parallel to the third diode D1121 may be omitted.

(Embodiment 7) FIG. 12 is a block diagram of a radio section of a radio communication device equipped with the high-frequency switch circuit of the present invention. The transmission signal from the power amplifier PA constituting the means of the present invention together with the oscillator OSC, the mixer MIX, and the band-pass filter BPF is transmitted to the control terminal 1201.
When a voltage is applied to the first diode D1201, the second diode D1201,
Of the transmission terminal 121 is turned on.
1, the capacitor element C1201, the diode D12
01, the antenna 121 via the capacitor element C1203.
Sent from 0.

The received signal is sent to the control terminal 1201.
The first diode D1201 and the second diode D1202 are turned off when the control voltage is not applied to the oscillator OSC of the receiving side via the receiving terminal 1212 via the antenna element 1210, the capacitor element C1203, the transmission line TL1201, and the capacitor element C1202. The signal is input to the low-noise amplifier LNA which constitutes the receiving means of the present invention together with the mixer MIX and the band-pass filter BPF.

At the time of transmission, the first diode D1201 is O
Since the N resistance is low, the transmission signal from the power amplifier PA can be transmitted with little loss, and the transmission signal is not transmitted to the reception terminal because one end of the transmission line TL1201 is grounded. At the time of reception, the second diode D1202 can transmit the received signal to the low-noise amplifier LNA without attenuating because the capacitance between the terminals when the second diode D1202 is OFF is small.

In the second embodiment, the circuit using the laminated body is the circuit of the first embodiment. However, the circuit of the third, fourth, fifth and sixth embodiments can of course be realized. Further, although the transmission lines in the laminate are each one layer, a similar effect can be obtained by using a plurality of structures of two or more layers.

[0088]

As described above, according to the present invention, a high-frequency switch with low loss and high isolation can be provided. Further, by using a laminated structure, miniaturization and high reliability can be achieved, and further, miniaturization and low power consumption of a wireless communication device using the same can be achieved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a high-frequency switch circuit according to a first embodiment of the present invention.

FIG. 2 is a mounting diagram according to the first embodiment of the present invention;

FIG. 3 is a perspective view of a multilayer high-frequency switch according to a second embodiment of the present invention;

FIG. 4 is an exploded perspective view of the multilayer high-frequency switch according to the second embodiment of the present invention.

FIG. 5 is a circuit diagram according to a second embodiment of the present invention.

FIG. 6 is a circuit diagram according to a third embodiment of the present invention.

FIG. 7 is a circuit diagram according to a fourth embodiment of the present invention.

FIG. 8 is a diagram showing a characteristic example of a PIN diode;

FIG. 9 is a circuit diagram according to a fifth embodiment of the present invention.

FIG. 10 is a diagram showing an example of transmission characteristics of a duplexer.

FIG. 11 is a circuit diagram according to a sixth embodiment of the present invention.

FIG. 12 is a block circuit diagram of a wireless communication device using the high-frequency switch circuit of the present invention.

FIG. 13 is a circuit diagram of a conventional high-frequency switch circuit.

[Explanation of symbols]

111, 201, 301, 401, 501, 601, 7
01,801,811,1101,1111,1301
Transmission terminals 112, 202, 302, 402, 502, 602, 7
02,802,812,1102,1112,1302
Control terminals 113, 203, 303, 403, 503, 603, 7
03,803,813,1103,1113,112
3,1303 receiving terminal 114,204,304,404,504,604,7
04,804,814,1104,1114,1304
Antenna terminal C Capacitor element D Diode G Ground electrode L Inductor element R Resistance element TL Transmission line V Via electrode 300,400 Stack 400A, 400B, 400C, 400D Dielectric sheet

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshio Ishizaki 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Term (reference) 5J012 BA03 BA04 5K011 DA02 DA22 DA25 DA27 EA06 FA01 GA04 JA01

Claims (18)

[Claims] A first diode having an anode electrically connected to the transmission terminal and a cathode electrically connected to the antenna terminal; a reception terminal; a reception terminal; an antenna terminal; An anode connected to an antenna terminal electrically connected to a second diode via a transmission line of 1/4 wavelength, and a second diode having a cathode grounded; and a second diode connected between the transmission terminal and the first anode. A control terminal provided at a connection point; wherein the first and second diodes have a trade-off relationship between ON resistance and capacitance between the anode and the cathode; ON resistance is ON of the second diode
A high-frequency switch having a lower resistance than the resistance and a capacitance when the second diode is turned off is smaller than a capacitance when the first diode is turned off. 2. The first diode has an ON resistance of 1
Ω or less, and the second diode is O
2. The method according to claim 1, wherein the inter-terminal capacitance at the time of FF is 0.8 pF or less.
2. The high frequency switch according to item 1. 3. The device according to claim 1, wherein a diode having an ON resistance of 0.8Ω or less is used as the first diode, and a capacitance between terminals when the second diode is OFF is 0.5 pF or less. High frequency switch. 4. The high-frequency switch according to claim 1, further comprising an LC series circuit provided in parallel with said first diode. 5. The high-frequency switch according to claim 1, further comprising an LC parallel circuit connected in series to said second diode. 6. A laminate in which a plurality of dielectrics are laminated, and a transmission terminal, a reception terminal, an antenna terminal, a control terminal, a ground terminal, and an electrode pattern for component connection provided on the surface of the laminate. A first diode mounted on the surface of the multilayer body, the first terminal having an anode electrically connected to the transmission terminal, the cathode being electrically connected to the antenna terminal, and the antenna being electrically connected to the reception terminal; An anode is connected to the terminal via a 波長 wavelength transmission line, and a second diode is provided, the cathode side of which is grounded. The first and second diodes are provided with an ON resistor and a connection between the anode and the cathode. There is a trade-off relationship between the capacitance of the first diode and the ON resistance of the second diode.
A high-frequency switch having a lower resistance than the resistance and a capacitance when the second diode is turned off is smaller than a capacitance when the first diode is turned off. 7. The method according to claim 1, wherein the laminated body is used.
The high frequency switch according to any one of the above. 8. A first high frequency switch for a first frequency band and a second high frequency switch for a second frequency band higher than the first frequency band.
The high frequency switch, the antenna terminal of the first high frequency switch, and the antenna terminal of the second high frequency switch are electrically connected, and the first frequency band and the second frequency band are demultiplexed. The first high-frequency switch and the second high-frequency switch are provided with a duplexer for sharing the same antenna, and the first high-frequency switch and the second high-frequency switch are provided as a first high-frequency switch and a second high-frequency switch. Item 6. A two-band high-frequency switch using the high-frequency switch according to any one of Items 1 to 5. 9. An on-resistance of the first diode of the second high-frequency switch is made lower than an on-resistance of the first diode of the first high-frequency switch.
9. The two-band high-frequency switch according to claim 8, wherein the off-time capacitance of the second diode of the second high-frequency switch is smaller than the off-time capacitance of the second diode of the high-frequency switch. 10. The first high-frequency switch of the first high-frequency switch
And the ON resistance of the first diode of the second high-frequency switch is 0.8Ω.
In the following, the off-state capacitance of the second diode of the first high-frequency switch is 0.8 pF or less, and the off-state capacitance of the second diode of the second high-frequency switch is 0.5 pF or less. The two-band high-frequency switch according to claim 9. 11. The transmission terminal, reception terminal and control terminal of the first high-frequency switch, the transmission terminal, reception terminal and control terminal of the second high-frequency switch, the first high-frequency switch and the second An antenna terminal common to the high-frequency switch is provided on the surface of a laminated body in which a plurality of dielectrics are laminated together with a ground terminal as an electrode pattern for component connection, and a first high-frequency switch is provided inside the laminated body. 2
An electrode pattern for configuring the high-frequency switch and the duplexer is provided, wherein the first diode and the second diode are:
The two-band high-frequency switch according to any one of claims 8 to 10, which is mounted on the surface of the multilayer body. 12. A first high frequency switch for a first frequency band, a second high frequency switch for a second frequency band higher than the first frequency band, and a third high frequency switch for a higher frequency band than the first frequency band. A third high-frequency switch for a frequency band; an antenna terminal of the first high-frequency switch;
The first high frequency switch is electrically connected to an antenna terminal of the first high frequency switch, and the first frequency band, the second frequency band, and the second frequency band are demultiplexed and multiplexed. A second high-frequency switch, and a duplexer for sharing the same antenna with the third high-frequency switch, wherein the first high-frequency switch and the second high-frequency switch are used as the first high-frequency switch and the second high-frequency switch. The high-frequency switch according to any one of the above, wherein the third switch has a cathode disposed between the antenna terminal of the second high-frequency switch and a connection point between the cathode of the first diode and the transmission line. A third diode having an anode connected to a second receiving terminal, and a second diode connected between the third diode and the second receiving terminal.
And a transmission terminal of the first high-frequency switch is used as a second transmission terminal,
A three-band high-frequency switch that operates on the receiving side using the second diode of the second high-frequency switch. 13. The first high-frequency switch according to claim 1, wherein:
The on-resistance of the first diode of the second high-frequency switch and the third resistance of the third diode of the third high-frequency switch are made lower than the on-resistance of the diode of the second high-frequency switch. O of the diode
2. The capacity of the second high-frequency switch when the second diode is turned off is smaller than the capacity when the FF is used.
3. The three-band high-frequency switch according to 2. 14. The third high-frequency switch according to claim 3, wherein
2. The ON resistance of the first diode of the second high frequency switch is lower than the ON resistance of the first diode of the second high frequency switch.
3. The three-band high-frequency switch according to 3. 15. The first high-frequency switch of the first high-frequency switch
And the ON resistance of the first diode of the second high-frequency switch and the ON resistance of the third diode of the third high-frequency switch are 0.8Ω.
The following: O of the second diode of the first high-frequency switch
The capacitance at the time of FF is 0.8 pF or less, and the capacitance at the time of OFF of the second diode of the second high-frequency switch is 0.
The three-band high-frequency switch according to claim 13 or 14, wherein the high-frequency switch is 5 pF or less. 16. The third high-frequency switch of the third high-frequency switch
16. The diode according to claim 15, wherein the ON resistance of said diode is 0.5 or less.
3. The three-band high-frequency switch according to item 1. 17. A transmission terminal, a reception terminal, and a control terminal of the first high-frequency switch, and a transmission terminal, a reception terminal, and a control terminal of the second high-frequency switch.
A receiving terminal and a control terminal of the third high-frequency switch, and an antenna terminal common to the first high-frequency switch, the second high-frequency switch, and the third high-frequency switch are connected to a ground terminal and an electrode pattern for component connection. A first high-frequency switch, a second high-frequency switch, and a second high-frequency switch inside the multilayer body.
And an electrode pattern for configuring the third high-frequency switch, the third high-frequency switch, and the duplexer. The first diode, the second diode, and the third diode are provided in the stacked body. 18. The three-band high-frequency switch according to claim 12, which is mounted on a surface. 18. An antenna, a transmitting unit for transmitting a signal from the antenna, a receiving unit for receiving a signal from the antenna, and a switch for switching a connection between the antenna and the transmitting unit or the receiving unit. 18. A wireless communication device using the high-frequency switch according to claim 1 as said switch means.