US 2003/0201826 A1 · High frequency switch, amplifying circuit, and mobile communication terminal

Abstract

In order to provide a high frequency switch in which the setting range of the control voltage is expanded, the high frequency switch is constructed from a switch and a reference voltage generation circuit. The switch comprises first and second field effect transistors. In the first field effect transistor, the source electrode is connected to a signal input terminal, while the drain electrode is connected to a signal output terminal, and while the source electrode is connected to a control terminal. In the second field effect transistor, the source electrode is connected to the signal input terminal, while the drain electrode is connected to the signal output terminal, and while the gate electrode is connected to the control terminal. The reference voltage generation circuit generates two reference voltages the values of which are different from each other, then provides the lower reference voltage to the gate electrode of the first field effect transistor, and then provides the higher reference voltage to the source electrode of the second field effect transistor.

Claims17

Dependent claims

A high frequency switch comprising:

a signal input terminal;
first and second signal output terminals;
a control terminal to which a control voltage is applied;
a switch provided with a first switch element having one and the other signal electrodes and a control electrode, said signal input terminal being connected to the one signal electrode, said first signal output terminal being connected to the other signal electrode, and said control terminal being connected to any one of the one and the other signal electrodes, and with a second switch element having one and the other signal electrodes and a control electrode, said signal input terminal being connected to the one signal electrode, said second signal output terminal being connected to the other signal electrode, and said control terminal being connected to the control electrode;
and
a reference voltage generation circuit for generating first and second reference voltages the values of which are different from each other, then providing said first reference voltage to the control electrode of said first switch element, and then providing said second reference voltage to any one of the one and the other signal electrodes of said second switch element;
wherein
on the basis of the relation between said control voltage and said first reference voltage and the relation between said control voltage and said second reference voltage, depending on the value of the control voltage, said first and second switch elements are selectively made conductive.

5 more elements

An amplifying circuit comprising:

a signal input terminal;
first and second signal output terminals;
a control terminal to which a control voltage is applied;
a switch provided with a first switch element having one and the other signal electrodes and a control electrode, said signal input terminal being connected to the one signal electrode, and said control terminal being connected to any one of the one and the other signal electrodes, and with a second switch element having one and the other signal electrodes and a control electrode, said signal input terminal being connected to the one signal electrode, and said control terminal being connected to the control electrode;
a first amplifier an input terminal of which is connected to the other signal electrode of said first switch element and an output terminal of which is connected to said first signal output terminal;
a second amplifier an input terminal of which is connected to the other signal electrode of said second switch element and an output terminal of which is connected to said second signal output terminal;
and
a reference voltage generation circuit for generating first and second reference voltages, then providing said first reference voltage to the control electrode of said first switch element, and then providing said second reference voltage to any one of the one and the other signal electrodes of said second switch element;
wherein
on the basis of the relation between said control voltage and said first reference voltage and the relation between said control voltage and said second reference voltage, depending on the value of the control voltage, said first and second switch elements are selectively made conductive, and wherein:
when said first switch element is conductive, said first amplifier is made active while said second amplifier is made inactive;
and when said second switch element is conductive, said first amplifier is made inactive while said second amplifier is made active.

9 more elements

A mobile communication terminal comprising an amplifying circuit having the function of selecting the path of a high frequency signal,

said amplifying circuit comprising:
a signal input terminal;
first and second signal output terminals;
a control terminal to which a control voltage is applied;
a switch provided with a first switch element having one and the other signal electrodes and a control electrode, said signal input terminal being connected to the one signal electrode, and said control terminal being connected to any one of the one and the other signal electrodes, and with a second switch element having one and the other signal electrodes and a control electrode, said signal input terminal being connected to the one signal electrode, and said control terminal being connected to the control electrode;
a first amplifier an input terminal of which is connected to the other signal electrode of said first switch element and an output terminal of which is connected to said first signal output terminal;
a second amplifier an input terminal of which is connected to the other signal electrode of said second switch element and an output terminal of which is connected to said second signal output terminal;
and
a reference voltage generation circuit for generating first and second reference voltages, then providing said first reference voltage to the control electrode of said first switch element, and then providing said second reference voltage to any one of the one and the other signal electrodes of said second switch element;
wherein
on the basis of the relation between said control voltage and said first reference voltage and the relation between said control voltage and said second reference voltage, depending on the value of the control voltage, said first and second switch elements are selectively made conductive, and wherein:
when said first switch element is conductive, said first amplifier is made active while said second amplifier is made inactive;
and when said second switch element is conductive, said first amplifier is made inactive while said second amplifier is made active.

10 more elements

A mobile communication terminal comprising an amplifying circuit having the function of selecting the path of a high frequency signal,

said amplifying circuit comprising:
a signal input terminal;
first and second signal output terminals;
a control terminal to which a control voltage is applied;
a switch provided with a first switch element having one and the other signal electrodes and a control electrode, said signal input terminal being connected to the one signal electrode, said first signal output terminal being connected to the other signal electrode, and said control terminal being connected to any one of the one and the other signal electrodes, and with a second switch element having one and the other signal electrodes and a control electrode, said signal input terminal being connected to the one signal electrode, said second signal output terminal being connected to the other signal electrode, and said control terminal being connected to the control electrode;
a reference voltage generation circuit for generating first and second reference voltages the values of which are different from each other, then providing said first reference voltage to the control electrode of said first switch element, and then providing said second reference voltage to any one of the one and the other signal electrodes of said second switch element;
and
an amplifier an output terminal of which is connected to said signal input terminal;
wherein
on the basis of the relation between said control voltage and said first reference voltage and the relation between said control voltage and said second reference voltage, depending on the value of the control voltage, said first and second switch elements are selectively made conductive, and wherein:
a signal inputted to an input terminal of said amplifier is amplified and then provided to said signal input terminal;
and a power supply terminal of said amplifier is connected in common with a power supply terminal of said reference voltage generation circuit.

9 more elements

Dependencies are inferred from the claim text.

High frequency switch, amplifying circuit, and mobile communication terminal

Life of this patent

High frequency switch, amplifying circuit, and mobile communication terminal

Life of this patent

Abstract

Claims17