JPH1155156A - Antenna switch semiconductor integrated circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce as much as possible terminals which are exposed to the outside, to enable further miniaturization, in comparison with a conventional circuit and to prevent the occurrence of interference between an unused antenna and an antenna under use. SOLUTION: Corresponding to the setting of logic signals to 1st-3rd control input terminals 45-47, 1st-8th switches 5-12 using GaAs FETs are made conductive/non-conductive by a driver circuit 41, according to an output signal decoded by a decoder circuit 40. Especially while an internal reception antenna 32 is set in the unused state, it is grounded via the 7th switch 11, 7th capacitor 27 and 1st terminal resistor 35. When an internal transmission/reception antenna 3 is in the unused state, it is grounded via the 8th switch 12, 8th capacitor 28 and 2nd terminal resistor 36. As a result, the interference with the antenna under using is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called antenna switch for switching between an antenna and a transmission / reception circuit of a communication device such as a portable telephone or a mobile radio communication device, and more particularly to a device using a semiconductor integrated circuit. The present invention relates to a device that is reduced in size and improved in reliability.

[0002]

2. Description of the Related Art As a conventional antenna switch semiconductor integrated circuit, there is one having a configuration as shown in FIG. 5, for example. Hereinafter, the configuration and operation of this conventional antenna switch semiconductor integrated circuit will be described with reference to the same drawing. First, this antenna switch semiconductor integrated circuit includes a switch group 4A formed on a GaAs semiconductor chip 2. Then, this GaAs semiconductor chip 2
It is housed in the IC package 1.

The switch group 4A includes first to sixth switches 5 to 10, and is connected to the outside of the antenna switch semiconductor integrated circuit as described later. That is, one end of the first switch 5 is externally connected to, for example, an external receiving antenna terminal 30 provided in a casing of a mobile wireless communication device (not shown) via a first capacitor 21 for blocking direct current. It has become. A reception antenna (not shown) is connected to the external reception antenna terminal 30 as desired, and can be connected to a reception unit (not shown) via an antenna switch semiconductor integrated circuit.

[0004] One end of the second switch 6 is externally connected via a second capacitor 22 for blocking direct current to an internal receiver provided in, for example, a mobile radio communication device using the antenna switch semiconductor integrated circuit. The antenna 32 is connected to the antenna 32. One end of each of the third switch 7 and the fifth switch 9 is externally provided via a third capacitor 23 for blocking direct current, for example, an external receiving antenna provided in a housing of a mobile wireless communication device (not shown). The terminal 30 is connected to the terminal 30. The fourth switch 8 is externally connected to a receiving unit (not shown) via a fourth capacitor 24 for blocking direct current. The receiving unit includes first to sixth switches 5 to 5. 10, the internal receiving antenna 3
2. Any of the internal transmitting / receiving antenna 33, the external receiving antenna (not shown) attached to the external receiving antenna terminal 30, and the external transmitting / receiving antenna (not shown) attached to the external transmitting / receiving antenna terminal 31 Crabs are selectively connected.

[0005] Sixth switch 10 and third switch 7
Is connected to an external fifth capacitor 2 for DC blocking.
5, and is connected to a transmitting unit (not shown). The transmitting unit is connected to first to sixth switches 5 to 1
0 according to an operation described later, which is selectively performed on either the on-vehicle transmitting / receiving antenna (not shown) attached to the external receiving antenna terminal 30 or the internal transmitting / receiving antenna 33 described below. It is to be connected.

[0006] Fourth switch 8 and sixth switch 10
Are connected externally to a sixth capacitor 2 for blocking direct current.
6, the antenna switch semiconductor integrated circuit is connected to an internal transmission / reception antenna 33 provided in, for example, a mobile radio communication device.

The first to sixth switches 5 to 10
Are basically composed of the same semiconductor switch, and more specifically, for example, those composed of those shown in the basic configuration diagram in FIG. 6 are used. . Here, the configuration and operation of the semiconductor switch will be generally described with reference to FIG.
Gallium arsenide field effect transistor (hereinafter "GaAs
FET)), and this G is
The on / off operation of the aAs FET 60 is used as a switch function.

That is, the GaAs FET 60 has, at its gate, a predetermined voltage V applied to its drain and source.
When the same potential or a high voltage V2 as 1 is applied, a so-called ON state is established, which is a state equivalent to conduction between the terminals 61a and 61b at an AC level, while the gate voltage is lower than the predetermined voltage V1, for example. , At zero potential,
The GaAs FET 60 is in a so-called off state, and is in a state equivalent to an open state between the terminals 61a and 61b. As described above, the on / off control of the first to sixth switches 5 to 10 is performed by the gate potential, and in the antenna switch semiconductor integrated circuit shown in FIG. First to fourth control input terminals 45 to 48 to which control signals are input
Is provided.

In the antenna switch semiconductor integrated circuit having such a configuration, the first to fourth control input terminals 45 are provided.
Switches 5-1 for control signals input to
FIG. 7 is an explanatory diagram for explaining a connection state between the antenna 0 and the antenna, and a typical operation example will be described with reference to FIG. In FIG. 7, in the column of “switch conduction path”, the numbers written indicate the external connection terminals that are in a conductive state, for example, 5-3 indicates the fifth external connection terminal 19 and the third external connection terminal. This means that the external connection terminal 23 is brought into a conductive state. In the same figure, “H” indicates a logical value High, and “L” indicates a logical value Lo.
Let w denote each.

In the figure, the numbers "1", "2", "3", and "4" in the column of "control input terminal" indicate the first control input terminal 45 and the second control input terminal 45, respectively. The control input terminal 46, the third control input terminal 47, and the fourth control input terminal 48 mean “H” described in each row below,
"L" indicates the first to fourth control input terminals 45 to 45.
46 is a logical value to be set to 46, and a logical value H
high, which means logical value Low.

Further, the first control input terminal 45 is connected to the third control input terminal 45.
The second control input terminal 46 controls the fifth and sixth switches 9 and 10 simultaneously to the same operation state. And the third control input terminal 47
Controls the operation of the first switch 5, and the fourth control input terminal 48 controls the operation of the second switch 6. When the logical value High is applied to the first to fourth control input terminals 45 to 48, the corresponding switch is turned on. When the logical value Low is applied, the corresponding switch is turned on. It shall be off.

Under this assumption, for example, when transmission is performed using the internal transmission / reception antenna 33, in other words, in FIG.
In the case where the fifth external connection terminal 19 and the sixth external connection terminal 20 are brought into a conductive state, the first control input terminal 45 is provided with a logical value Low and the second control input terminal 4
6, it is necessary to apply a logical value High, and the third and fourth control input terminals 47 and 48 do not directly affect the connection between the transmitting unit and the antenna.
It may be set to either high or Low. By setting the signals to the respective control input terminals 45 to 48,
Since the sixth switch 10 is turned on, a transmitting unit (not shown) is connected to the internal transmission / reception antenna 33 via the sixth switch 10.

In the case where reception is performed by the internal transmission / reception antenna 33, in other words, in FIG. 7, when the fourth external connection terminal 18 and the sixth external connection terminal 20 are made conductive, 1 control input terminal 45 to logical value Hi.
gh and the second to fourth control input terminals 46 to 48 need to be set to a logical value Low, respectively. Since such setting causes the fourth switch 8 to be in a conductive state, it is not shown. The receiving unit is connected to the internal transmitting / receiving antenna 33.

Further, when the reception is performed by the internal receiving antenna 32, in other words, in FIG. 7, when the fourth external connection terminal 18 and the second external connection terminal 16 are brought into a conductive state, 4 has a logical value Hi.
gh and the first to third control input terminals 45 to 47 need to be set to the logical value Low, respectively. With such a setting, the second switch 6 becomes conductive, so that a reception signal not shown The unit will be connected to the internal receiving antenna 32.

As described above, in the antenna switch semiconductor integrated circuit, the first to sixth switches 5 to 10 operate according to the signal input to the first to fourth control input terminals 45 to 48, whereby , A transmitting unit or a receiving unit can be connected to a desired antenna.

[0016]

However, the above-described conventional antenna switch semiconductor integrated circuit has the following problems. First, as described above, each of the switches 5-1
Although four control input terminals are required for the operation control of 0, there is a demand that even one such terminal be reduced in the present situation where further miniaturization of the package is required. The need for as many as four control input terminals is one of the major factors that hinder miniaturization, and it is necessary to provide four wirings between the antenna switch semiconductor integrated circuit and the external circuit. This means that there is a problem that the number of wirings of a device in which the antenna switch semiconductor integrated circuit is used, for example, a mobile radio communication device or a mobile phone is increased, and that miniaturization of these devices is also prevented. .

As a measure for reducing the number of control input terminals, for example, first to fourth control input terminals 45 to 48 are used.
Instead of directly controlling the operations of the first to sixth switches 5 to 10 by applying a predetermined signal to the semiconductor device, a decoder circuit is provided on the semiconductor chip 2 made of GaAs, and the number of control terminals going out is set. However, since the GaAs material is expensive, providing a decoder circuit on the same chip increases the chip area, which leads to an increase in price, which is not always a good idea.

Further, in the conventional circuit shown in FIG. 5, depending on the operation state, a specific antenna is electrically floated from the ground, and thus there is a problem that the antenna in operation is affected. . That is, for example,
When transmitting with the internal transmitting / receiving antenna 33,
7, the second state of the switch conduction path (the fifth external connection terminal 19 and the sixth external connection terminal 2
0) and the fourth control input terminal 48 is in a state where the logical value is set to Low, the second
Is turned off, the internal receiving antenna 32 is in an electrically floating state. Therefore, in this case, a transmission wave from the internal transmitting / receiving antenna 33 in the operating state is picked up, and not only does the efficiency of the internal transmitting / receiving antenna 33 decrease, but also the picked-up radio wave is re-emitted to cause a trouble to the surrounding electronic devices. There is a problem that may give.

In the case where reception is performed by the internal transmitting / receiving antenna 33, that is, in FIG. 7, the fourth state of the switch conduction path (the fourth external connection terminal 18 and the sixth external connection terminal 20 In the conductive state), the second
Since the switch 6 is turned off, the internal receiving antenna 32 is in an electrically floating state, and interacts with the internal transmitting / receiving antenna 33 in a manner similar to the above case, and the receiving antenna of the internal transmitting / receiving antenna 33 However, there is a problem that the efficiency may be lowered. Further, in the case where reception is performed by the internal receiving antenna 32, that is, in the case of FIG. 7, the fifth state of the switch conduction path (the conduction state between the fourth external connection terminal 18 and the second external connection terminal 16). )), The fourth and sixth switches 8,
10 becomes non-conductive, the internal transmitting / receiving antenna 33
Is in an electrically floating state, causing a so-called interaction in the same manner as described above, which causes a problem that the efficiency of the internal receiving antenna 32 may be reduced.

Further, in order to completely block or pass the transmission power of 1 Watt or more by the GaAs FET, 5 V or more is required as the voltages V1 and V2 shown in the circuit of FIG. However, lithium batteries, which have been widely used in portable electronic devices in recent years,
The above voltage supply is impossible. Therefore, for example, 5
When a battery capable of supplying a voltage of v or more is used, there arises a problem that advantages of small size and light weight cannot be enjoyed as compared with a lithium battery.
Further, for example, as a measure for enabling the use of a lithium battery, it is conceivable to separately provide a booster circuit for boosting the voltage of the lithium battery in a portable communication device using the antenna switch semiconductor integrated circuit. In recent years, where there is a strong demand for more compact mobile communication devices, there is a problem that such measures cannot provide products that satisfy market requirements.

The present invention has been made in view of the above situation, and has an antenna switch semiconductor integrated circuit using a gallium arsenide field effect transistor which has as few terminals as possible to the outside and which can be made smaller than conventional ones. Is provided. Another object of the present invention is to increase the chip area on which gallium arsenide field effect transistors are formed,
An object of the present invention is to provide an antenna switch semiconductor integrated circuit in which the number of external terminals can be reduced as much as possible. It is another object of the present invention to provide an antenna switch semiconductor integrated circuit having high operation stability and high reliability without causing interference between an unused antenna and a used antenna. It is another object of the present invention to provide an antenna switch semiconductor integrated circuit using a gallium arsenide field effect transistor that can be used in a lithium battery while reducing the size.

[0022]

According to a first aspect of the present invention, there is provided an antenna switch semiconductor integrated circuit wherein a plurality of gallium arsenide field effect transistors are controlled in conduction and non-conduction according to a control signal from outside, and an external connection terminal is provided. Antenna switch integrated on a gallium arsenide semiconductor chip so that connection between an external receiving antenna, an external transmitting / receiving antenna, an internal receiving antenna, an internal transmitting / receiving antenna, and a receiving unit and a transmitting unit can be switched through In the semiconductor integrated circuit, on the gallium arsenide semiconductor chip,
A switch comprising a gallium arsenide field effect transistor for setting the internal receiving antenna to a circuit ground state when the transmitting unit and the internal transmitting / receiving antenna are connected, or when the receiving unit and the internal transmitting / receiving antenna are connected; A switch comprising a gallium arsenide electric field transistor for setting the internal transmission / reception antenna to a circuit ground state when the reception unit and the external reception antenna are connected, and the gallium arsenide semiconductor chip according to a control signal from the outside. A decoder circuit for outputting a signal for selecting a gallium arsenide field effect transistor to be brought into a conductive state from among the plurality of gallium arsenide field effect transistors provided above, and the gallium arsenide semiconductor according to an output signal of the decoder circuit A plurality of gallium arsenide field effect transformers mounted on a chip A drive circuit that outputs a signal for bringing the star into a conductive state and a non-conductive state, an oscillation circuit that outputs a signal of a predetermined frequency, and a DC voltage applied from the outside using a output signal of the oscillation circuit to a predetermined level. And a voltage doubler generating circuit for converting the voltage to a voltage. The decoder circuit, the drive circuit, the oscillating circuit, and the doubler generating circuit are integrated into a MOS integrated circuit, and are mounted on a chip separate from the gallium arsenide semiconductor chip. And housed in the same IC package together with the gallium arsenide semiconductor chip.

In this configuration, especially when the internal receiving antenna or the internal transmitting / receiving antenna is not used, the circuit is grounded by a switch made of a newly provided GaAs FET, and is electrically floated. Therefore, interference with other in-use antennas caused by this is avoided. In addition, by providing the decoder circuit and the drive circuit separately from the GaAs semiconductor chip and in an integrated circuit in the same IC package, externally input control for controlling the operation of the GaAs FET switch is performed. The number of signals can be reduced as compared with the related art. The integration of decoder circuits and drive circuits into MOs
S integrated circuit, silicon bipolar integrated circuit, or
A silicon BiCMOS integrated circuit is preferred.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. Note that the members, arrangements, and the like described below do not limit the present invention,
Various modifications can be made within the scope of the present invention. First, a first example will be described with reference to FIGS. Note that the same components as those of the conventional device shown in FIG. 5 are denoted by the same reference numerals. First, the configuration of the antenna switch semiconductor integrated circuit in the first example will be described with reference to FIG. 1. This antenna switch semiconductor integrated circuit includes a GaAs semiconductor made of gallium arsenide (GaAs) in a so-called IC package 1. A chip 2 is provided, and the GaAs
A switch group using GaAs FETs is formed on a semiconductor chip 2 in the same manner as in the related art, but a MOS (Metal-Oxide-Semiconductor) integrated circuit semiconductor chip 3 is mounted in an IC package 1. Is different from the first embodiment.

More specifically, the GaAs semiconductor chip 2 has a switch group 4 including first to eighth switches 5 to 12 using GaAs FETs. That is, the first and second switches 5 and 6 are connected to each other at one end thereof, while the other end of the first switch 5 is provided at the IC package 1 so as to be connectable to the outside. The first external connection terminal 15 is connected to the external reception antenna terminal 30 via the first external connection terminal 15 and the first capacitor 21 for blocking a DC component. The external receiving antenna terminal 30 is provided, for example, in a housing of a mobile radio communication device (not shown), and an on-vehicle receiving antenna is attached when the vehicle is mounted on a vehicle.

The other end of the second switch 6 is connected together with one end of the seventh switch 11 to a second external connection terminal 16 provided on the IC package 1 so as to be connectable to the outside. The antenna switch semiconductor integrated circuit is connected to, for example, an internal reception antenna 32 provided in a mobile radio communication device, via the second external connection terminal 16 and the second capacitor 22 for blocking a DC component. It has become so. The other end of the seventh switch 11 is grounded via a seventh capacitor 27 for blocking a DC component and a first terminating resistor 35.

The fifth switch 9 has one end connected to the third switch 9.
The third external connection terminal 17 together with one end of the switch 7
And is connected to the external transmitting / receiving antenna terminal 31 via the third external connection terminal 17 and the third capacitor 23 for blocking DC components. The external transmission / reception antenna terminal 31 is provided, for example, in a casing of a mobile radio communication device (not shown), and is provided with a vehicle-mounted transmission / reception antenna (not shown) when mounted on a vehicle. This fifth switch 9
Is connected to the mutual connection point of the first and second switches 5 and 6 and one end of the fourth switch 8, and is also connected to a fourth external connection terminal 18. Via the fourth external connection terminal 18 and the fourth capacitor 24 for blocking a DC component, it is connected to a receiving unit (not shown).

One end of the sixth switch 10 is connected to the fifth external connection terminal 1 together with the other end of the third switch 7.
9 and is connected to a transmitting unit (not shown) via the fifth external connection terminal 19 and the fifth capacitor 25 for blocking a DC component. The other end of the sixth switch 10 is connected to the other end of the fourth switch 8 and one end of the eighth switch 12, and is also connected to a sixth external connection terminal 20. The internal transmission / reception antenna 33 is connected via the sixth external connection terminal 20 and the sixth capacitor 26 for blocking a DC component. The other end of the eighth switch 12 is grounded via an eighth capacitor 28 for blocking a DC component and a second terminating resistor 36.

The above-mentioned first to eighth switches 5 to 12
Uses a GaAs FET as in the prior art, and its basic configuration is the same as the conventional one described with reference to FIG. 6, so that the detailed description is omitted here. On the other hand, a decoder circuit (denoted as "DEC" in FIGS. 1 and 4) is provided on the MOS integrated circuit semiconductor chip 3.
40 and a drive circuit ("DR" in FIGS. 1 and 4).
V) 41, an oscillation circuit (denoted as "OSC" in FIGS. 1 and 4) 42, and a voltage doubler generation circuit (denoted as "PUMP" in FIGS. 1 and 4) 43. These are formed by MOS integrated circuit technology, which is a well-known and well-known IC manufacturing technology.

The decoder circuit 40 is provided with a drive circuit 41 based on signals input to the three control input terminals 45 to 47.
And outputs six signals for controlling the first to eighth switches 5 to 12 to the drive circuit 41 through the same. The circuit configuration is the same as that of a known / known decoder circuit. I have. The drive circuit 41 outputs the first to eighth switches 5 based on the output signal from the decoder circuit 40.
To output the signals necessary to make the 〜12 conductive or non-conductive state.
It is extracted to the first to eighth switches 5 to 12 of the s semiconductor chip 2. The wiring between the MOS integrated circuit semiconductor chip 3 and the GaAs semiconductor chip 2 is performed by so-called wire bonding.

The drive circuit 41 is constituted by a MOS analog switch, and if an example of a circuit configuration for one output is shown, for example, it is as shown in FIG. That is, referring to FIG.
The output contact 50a of the analog switch 50 is connected to the gate of the GaAs FET constituting the first to eighth switches 5 to 12, and the first contact 50b is connected to the ground.
The second contact 50c has a predetermined voltage, that is, GaAs F
A conduction gate voltage Vgon necessary for bringing ET into a conduction state (on state) is applied.
Here, the conduction gate voltage Vgon is supplied from a voltage doubler generation circuit 43 described later.

The connection between the output contact 50a and the first contact 50b or the second contact 50c can be switched according to a control signal from the decoder circuit 40, for example, switching of the logic level of the logic signal. In the case of this example, when the signal of the logical value High is input from the decoder circuit 40, the output contact 50
a is connected to the second contact 50c, and the logical value is Low.
Is input, the output contact 50a and the first contact 50b are connected.

The voltage doubler 43 is connected to an external DC power supply 5.
2 for boosting the power supply voltage supplied to the antenna switch semiconductor integrated circuit to a predetermined voltage based on the power supply voltage supplied to the antenna switch semiconductor integrated circuit, and functions together with the oscillation circuit 42 as a known / known so-called DC-DC converter. It is something like that. Therefore, as the DC power supply 52,
It is possible to use a lithium battery having a voltage lower than the voltage required for the operation of the first to eighth switches 5 to 12. 12.
The doubler voltage generation circuit 43 also supplies a power supply voltage to the decoder circuit 40 and the drive circuit 41. The oscillating circuit 42 outputs a sine wave signal having a predetermined frequency.
As described above, it is used for the boosting operation in the voltage doubler generation circuit 43.

Next, the operation of the above configuration will be described with reference to FIG. FIG. 6 shows how the first to sixth external connection terminals 15 to 20 become conductive with respect to the operation states of the first to eighth switches 5 to 12, and FIG. The numbers in the “switch conduction path” column are the first to sixth external connection terminals 15 to 2 that are brought into conduction by the setting in the “control input terminal” column in the right column.
0, for example, “5-3” in the first line
Are the fifth external connection terminal 19 and the third external connection terminal 17
Are in a conductive state.

In the figure, the numbers "1", "2", and "3" described in the column of "control input terminal" are the first control input terminal 45 and the second control input terminal 46, respectively. ,
The “H” and “L” described in the respective rows below the third control input terminal 47 are logical values to be set in the first to third control input terminals 45 to 47. And mean a logical value High and a logical value Low, respectively. Further, 1 to 8 described in the “switch” column
Means the first to eighth switches 5 to 12, respectively, and “H” and “L” described in each row below the switches are
The operating states of the first to eighth switches 5 to 12 are represented by a conducting state (on state) and a non-conducting state (off state), respectively.

Under the above assumption, a specific connection state will be described. For example, when a transmitting unit (not shown) is connected to an external transmitting / receiving antenna (not shown), in other words, when the fifth external connecting terminal 19 and the third external connecting terminal 17 are brought into a conductive state, The first control input terminal 45 is set to a logical value Low, and the second and third control input terminals 46 and 47 are set to a logical value High. Decoder circuit 4
At 0, decoding according to this input signal is performed,
As a result of driving the corresponding driver of the drive circuit 41, the first and second switches 5, 6 and the fifth and sixth switches
Switches 9 and 10 become non-conductive, and the third and fourth switches
Switches 7, 8 and the seventh switch 11 are turned on (see FIG. 3). Therefore, the transmitting unit is connected to the third switch 7 and the external transmitting / receiving antenna terminal 3 in the conductive state.
1 is connected to an external transmitting / receiving antenna (not shown).

Similarly, when the transmitting section is connected to the internal transmitting / receiving antenna 33, the fifth external connection terminal 1
The first to fourth control input terminals 45 to 47 may be set to the input settings as shown in FIG. 3 so that the 9 and the sixth external connection terminal 20 are electrically connected. In the conductive state between the fifth external connection terminal 19 and the sixth external connection terminal 20, the seventh switch 11 is in a conductive state (see FIG. 3). 7
Since the circuit is grounded via the switch 11, the seventh capacitor 27, and the first terminating resistor 35, unlike the related art, it is ensured that the internal receiving antenna 32 affects the operation of the internal transmitting / receiving antenna 33. Operating state to be avoided.

When a receiving unit (not shown) is connected to an external transmitting / receiving antenna, the first to fourth terminals are connected so that the fourth external connecting terminal 18 and the third external connecting terminal 17 are electrically connected. The control input terminals 45 to 47 may have input settings as shown in FIG. Further, when the receiving unit is connected to the internal transmitting / receiving antenna 33, the first to fourth control input terminals 45 are connected so that the fourth external connection terminal 18 and the sixth external connection terminal 20 are electrically connected. 3 to 47
In the case where the receiving unit is connected to the internal receiving antenna 32, the fourth external connection terminal 18 and the second external connection terminal 16 are set to be in a conductive state. , The first to fourth control input terminals 45 to 47
May be set as shown in FIG.

When the receiving section is connected to the internal transmitting / receiving antenna 33, the fifth external connection terminal 19 is used.
Similarly to the case where the third external connection terminal 20 and the sixth external connection terminal 20 are in a conductive state, the seventh switch 11 is in a conductive state (see FIG. 3). 7 and the first terminating resistor 3
5, the circuit is grounded, and unlike the related art, the internal receiving antenna 32 is in an operating state in which the operation of the internal transmitting and receiving antenna 33 is reliably prevented from being affected. When the receiving section is connected to the internal receiving antenna 32, the eighth switch 12 is turned on (see FIG. 3), so that the internal transmitting / receiving antenna 33 is connected to the eighth switch 12, the eighth capacitor. 28 and the second terminating resistor 36, the circuit is grounded, and unlike the related art, the operating state is such that the internal transmitting / receiving antenna 33 is reliably prevented from affecting the operation of the internal receiving antenna 32. .

Further, when the receiving section is connected to an external receiving antenna (not shown), the first to third external connection terminals 18 and the first external connection terminal 15 are brought into conduction so that the first to the first external connection terminals 15 are brought into conduction. The fourth control input terminals 45 to 47 may have input settings as shown in FIG.

Next, a second example will be described with reference to FIG. This second example corresponds to the first example shown in FIG.
1 has basically the same configuration as the configuration shown in FIG. 1 except that the oscillation circuit 42 is not provided. Therefore, in FIG. 2, the same components as those in the first example shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. Hereinafter, different points will be mainly described. And In the second example, a clock input terminal 53 is provided in the IC package 1 in order to obtain the same signal from the outside as obtained from the oscillation circuit 42 (see FIG. 1). The signal of the predetermined frequency applied to the input terminal 53 is input to the voltage doubler 43 in the same manner as in the first example.

Therefore, the operation of the voltage doubler generation circuit 43 is not different from that of the first example, and a predetermined voltage is output and supplied to other circuit parts. Also,
The operations of the decoder circuit 40 and the drive circuit 41 are not different from those of the first example, and therefore, the operations of the first to eighth switches 5 to 12 are also the same. I decided to.

In the embodiment of the invention described above, the decoder circuit 40, the drive circuit 41, and the oscillation circuit 4
Although the 2 and double voltage generation circuit 43 is formed as a MOS integrated circuit, a silicon bipolar integrated circuit or a silicon Bi
It may be formed by a CMOS integrated circuit.

[0044]

As described above, according to the present invention,
Antenna switch using GaAs FET In a semiconductor integrated circuit, when an internal receiving antenna or an internal transmitting / receiving antenna is in a non-use state, a switch composed of a GaAs FET for grounding each antenna is provided. To provide an antenna switch semiconductor integrated circuit that is stable in operation, has high reliability, does not cause electrical floating between the antenna and the internal transmission / reception antenna, and does not cause interference with other antennas in use. Can be. Ga in the IC package
A decoder circuit and a drive circuit are provided on a semiconductor chip provided separately from the AS semiconductor chip.
An external control signal for controlling the operation of the switch composed of ET is transmitted to G through this decoder circuit and drive circuit.
Since the operation can be controlled by applying the voltage to a switch composed of aAs FET, the number of control signals that need to be input from the outside can be reduced as compared with the related art. It is possible to provide an antenna switch semiconductor integrated circuit that requires a smaller number than in the past and can be further reduced in size. further,
Since a voltage doubler generation circuit is provided in the same package so that an external voltage can be converted to a desired voltage, it is possible to use a lithium battery which has been widely used in portable communication devices in recent years. Unlike the case where a so-called booster circuit is provided separately from the antenna switch semiconductor integrated circuit, there is no hindrance to downsizing the device.

[Brief description of the drawings]

FIG. 1 is a circuit diagram illustrating a first circuit configuration example according to an embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram showing an example of an equivalent circuit for one output of a drive circuit.

FIG. 3 is an explanatory diagram illustrating operations of first to eighth switches in response to a logic signal input to a control input terminal.

FIG. 4 is a circuit diagram illustrating a second circuit configuration example according to the embodiment of the present invention.

FIG. 5 is a circuit diagram showing a circuit configuration example of a conventional antenna switch semiconductor integrated circuit.

FIG. 6 is a configuration diagram showing a configuration example of a semiconductor switch constituting first to sixth switches used in the antenna switch semiconductor integrated circuit shown in FIG. 5;

FIG. 7 is an explanatory diagram for explaining a relationship between a control signal input and an operation of each switch in the antenna switch semiconductor integrated circuit shown in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... IC package 2 ... GaAs semiconductor chip 3 ... MOS integrated circuit semiconductor chip 5 ... 1st switch 6 ... 2nd switch 7 ... 3rd switch 8 ... 4th switch 9 ... 5th switch 10 ... 6th Switch 11 ... seventh switch 12 ... eighth switch 40 ... decoder circuit 41 ... drive circuit 42 ... oscillation circuit 43 ... double voltage generation circuit 45 ... first control input terminal 46 ... second control input terminal 47 ... Third control input terminal 48... Fourth control input terminal

Claims (4)

[Claims] 1. A plurality of gallium arsenide field effect transistors, the conduction and non-conduction of which are controlled according to a control signal from outside, and an external receiving antenna, an external transmitting / receiving antenna, and an internal receiving connected via an external connection terminal. An antenna switch semiconductor integrated circuit integrated on a gallium arsenide semiconductor chip so that a connection between an antenna and an internal transmission / reception antenna and a reception unit and a transmission unit can be switched. A switch comprising a gallium arsenide field-effect transistor for bringing the internal receiving antenna into a circuit ground state when the internal transmitting / receiving antenna is connected or when the receiving unit and the internal transmitting / receiving antenna are connected; And the external receiving antenna is connected,
A switch formed of a gallium arsenide field transistor for setting an internal transmission / reception antenna to a circuit ground state, and a switch among a plurality of gallium arsenide field effect transistors provided on the gallium arsenide semiconductor chip in response to a control signal from the outside; A decoder circuit for outputting a signal for selecting a gallium arsenide field effect transistor to be in a state, and conducting a plurality of gallium arsenide field effect transistors provided on the gallium arsenide semiconductor chip in accordance with an output signal of the decoder circuit; A drive circuit that outputs a signal for bringing the circuit into a non-conducting state, an oscillation circuit that outputs a signal of a predetermined frequency, and a DC voltage applied from outside is converted into a predetermined voltage using an output signal of the oscillation circuit. A voltage doubler generation circuit, wherein the decoder circuit, the drive circuit, And MOS integrated circuits of the circuit and the multiplying voltage generating circuit, and the gallium arsenide semiconductor chip formed on a separate chip,
An antenna switch semiconductor integrated circuit housed in the same IC package together with the gallium arsenide semiconductor chip. 2. A plurality of gallium arsenide field effect transistors, the conduction and non-conduction of which are controlled according to a control signal from the outside, and an external receiving antenna, an external transmitting / receiving antenna, and an internal receiving antenna connected via an external connection terminal. An antenna switch semiconductor integrated circuit integrated on a gallium arsenide semiconductor chip so that a connection between an antenna and an internal transmission / reception antenna and a reception unit and a transmission unit can be switched. A gallium arsenide field-effect transistor that sets the internal receiving antenna to a circuit ground state when the internal transmitting / receiving antenna is connected or when the receiving unit and the internal transmitting / receiving antenna are connected; When the antenna is connected,
A gallium arsenide field-effect transistor for setting the internal transmission / reception antenna to a circuit ground state; and a conductive state among a plurality of gallium arsenide field-effect transistors provided on the gallium arsenide semiconductor chip in response to a control signal from the outside. A decoder circuit that outputs a signal for selecting a gallium arsenide field effect transistor; and a plurality of gallium arsenide field effect transistors provided on the gallium arsenide semiconductor chip in a conductive state and a non-conductive state according to an output signal of the decoder circuit. A drive circuit that outputs a signal for performing the following operation; and a voltage doubler generation circuit that converts a DC voltage applied from the outside into a predetermined voltage using a signal of a predetermined frequency applied from the outside. Circuit, the drive circuit, the oscillation circuit, and the voltage doubler generation circuit And formed on a chip separate from the gallium arsenide semiconductor chip,
An antenna switch semiconductor integrated circuit housed in the same IC package together with the gallium arsenide semiconductor chip. 3. The antenna switch semiconductor integrated circuit according to claim 1, wherein a silicon bipolar integrated circuit is used instead of the MOS integrated circuit. 4. Silicon BiC instead of MOS integrated circuit
3. The antenna switch semiconductor integrated circuit according to claim 1, wherein a MOS integrated circuit is used.