High-frequency switch circuit and high-frequency transmitting/receiving apparatus
First Claim
1. A high-frequency switch circuit which switches between a transmitting mode of inputting and outputting a transmission signal and a receiving mode of inputting and outputting a reception signal, said circuit comprising:
- a first terminal which receives the transmission signal;
a first FET (field-effect transistor) which makes a path of the transmission signal conductive or cut off;
a second terminal which receives a control signal that is inactive in the transmitting mode and is active in the receiving mode;
a ground terminal which is grounded via a first capacitor; and
a second FET which has a drain electrode, a source electrode and a gate electrode, the drain or source electrode being connected to the ground terminal, the source or drain electrode being connected to first terminal, and the gate electrode being connected to the second terminal, and which has a greater off-capacitance for unit gate width than the first FET.
1 Assignment
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Accused Products
Abstract
A high-frequency switch circuit includes a first terminal which receives a transmission signal, a first FET which makes a path of the transmission signal conductive or cut off, a second terminal which receives a control signal that is inactive in a transmitting mode and is active in a receiving mode, a ground terminal which is grounded via a first capacitor, and a second FET which has a drain electrode, a source electrode and a gate electrode, the drain or source electrode being connected to the ground terminal, the source or drain electrode being connected to first terminal, and the gate electrode being connected to the second terminal, and which has a greater off-capacitance for unit gate width than the first FET.
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Citations
20 Claims
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1. A high-frequency switch circuit which switches between a transmitting mode of inputting and outputting a transmission signal and a receiving mode of inputting and outputting a reception signal, said circuit comprising:
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a first terminal which receives the transmission signal;
a first FET (field-effect transistor) which makes a path of the transmission signal conductive or cut off;
a second terminal which receives a control signal that is inactive in the transmitting mode and is active in the receiving mode;
a ground terminal which is grounded via a first capacitor; and
a second FET which has a drain electrode, a source electrode and a gate electrode, the drain or source electrode being connected to the ground terminal, the source or drain electrode being connected to first terminal, and the gate electrode being connected to the second terminal, and which has a greater off-capacitance for unit gate width than the first FET. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A high-frequency transmitting/receiving apparatus comprising:
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a dielectric substrate;
a high-frequency power amplifier which is provided on the dielectric substrate and which amplifies a transmission signal;
an inductor connected at one end to a power-supply voltage and at the other end connected to an output of the high-frequency power amplifier; and
a high-frequency switch circuit which is provided on the dielectric substrate, which is sealed in a package substrate and which switches between a transmitting mode of inputting and outputting the transmission signal and a receiving mode of inputting and outputting a reception signal, said switch circuit comprising;
a first terminal which receives the transmission signal;
a wiring portion which connects a first node to the first terminal;
a first FET which has a drain electrode, a source electrode and a gate electrode, the drain or source electrode being connected to the first node, and which makes a path of the transmission signal conductive or cut off;
a second terminal which receives a control signal that is inactive in the transmitting mode and is active in the receiving mode;
a ground terminal which is grounded via a first capacitor; and
a second FET which has a drain electrode, a source electrode and a gate electrode, the drain or source electrode being connected to the first node, the source or drain electrode being connected to the ground terminal, and the gate electrode being connected to the second terminal, and which has a greater off-capacitance for unit gate width than the first FET, the second FET having an off-capacitance, and the wiring portion having inductance, said off-capacitance and said inductance performing impedance matching on the high-frequency power amplifier. - View Dependent Claims (18, 19)
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20. A high-frequency transmitting/receiving apparatus comprising:
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a dielectric substrate;
a high-frequency power amplifier which is provided on the dielectric substrate and which amplifies a transmission signal;
an inductor connected at one end to a power-supply voltage and at the other end connected to an output of the high-frequency power amplifier; and
a high-frequency switch circuit which is provided on the dielectric substrate and which switches between a transmitting mode of inputting and outputting the transmission signal and a receiving mode of inputting and outputting a reception signal, said switch circuit comprising;
a first terminal which receives the transmission signal;
a first FET which makes a path of the transmission signal conductive or cut off;
a second terminal which receives a control signal that is inactive in the transmitting mode and is active in the receiving mode;
a ground terminal which is grounded via a first capacitor;
a second FET which has a drain electrode, a source electrode and a gate electrode, the drain or source electrode being connected to the first terminal, the source or drain electrode being connected to the ground terminal, and the gate electrode being connected to the second terminal, and which has a greater off-capacitance for unit gate width than the first FET, and a wiring portion which connects the first terminal to the output of the high-frequency power amplifier, the second FET having an off-capacitance, and the wiring portion having inductance, said off-capacitance and said inductance performing impedance matching on the high-frequency power amplifier.
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Specification