Transmitting-receiving circuit for radiocommunication apparatus, semiconductor integrated circuit device including the circuit, and radiocommunication apparatus including the same

• US 5,784,687 A
• Filed: 08/29/1995
• Issued: 07/21/1998
• Est. Priority Date: 08/30/1994
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Fujimoto, Kazuhisa, Itoh, Junji
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): LE, THANH C
• Application Number:
  US08/520,676
• Time in Patent Office: 1,057 Days
• Field of Search: 455/78, 455/80, 455/82, 455/83, 455/84, 455/89, 455/90, 455/129, 333/101, 333/103, 333/104, 333/118, 333/124, 333/126, 333/132
• US Class Current: 455/78
• CPC Class Codes: H01P 1/15 by semiconductor devices
• CPC Class Codes: H04B 1/48 in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter H04B1/46 takes precedence

Abstract

A changeover switch switches connection between an antenna and a transmitter amplifier and connection between the antenna and a receiver low noise amplifier, from one to the other. A first wire having characteristic impedance of 50 Ω connects the antenna and the changeover switch. A receiver matching circuit matches input impedance of the receiver low noise amplifier with the output impedance of the transmitter amplifier. An antenna side matching circuit matches the input impedance of the receiver low noise amplifier, which is matched with the output impedance of the transmitter amplifier by the receiver matching circuit, and the output impedance of the transmitter amplifier with the characteristic impedance of the first wire. The transmitter amplifier is connected with the changeover switch via a first coupling capacitance, and the receiver matching circuit is connected with the changeover switch via a second coupling capacitance.

Claims

1. A transmitting/receiving circuit for a radiocommunication apparatus comprising:

a transmitter amplifier for amplifying an input transmission signal and outputting the amplified transmission signal;

a receiver amplifier for amplifying an input received signal and outputting the amplified received signal;

a changeover switch having an antenna side input/output terminal through which the transmission signal is output to an antenna via a wire having prescribed characteristic impedance and the received signal is input from the antenna via the wire, for switching a first connection state for outputting the transmission signal received from the transmitter amplifier via no matching circuit to the antenna side input/output terminal and a second connection state for outputting the received signal received through the antenna side input/output terminal to the receiver amplifier, from one to the other;

a receiver matching circuit interposed between the changeover switch and the receiver amplifier for matching input impedance of the receiver amplifier with output impedance of the transmitter amplifier; and

an antenna side matching circuit interposed between the wire and the changeover switch for matching the characteristic impedance of the wire with the output impedance of the transmitter amplifier;

wherein the changeover switch has a transmitter through FET and a transmitter shunt FET connected in series to each other and a receiver through FET and a receiver shunt FET connected in series to each other,

the transmitter amplifier has at least one amplifier FET for amplifying the input transmission signal, and

the amplifier FET at a last stage of the transmitter amplifier also works as the transmitter shunt FET of the changeover switch.

2. A transmitting/receiving circuit for a radiocommunication apparatus comprising:

a transmitter amplifier for amplifying an input transmission signal and outputting the amplified transmission signal;

a receiver amplifier for amplifying an input received signal and outputting the amplified received signal;

a changeover switch having an antenna side input/output terminal through which the transmission signal is output to an antenna via a wire having prescribed characteristic impedance and the received signal is input from the antenna via the wire, for switching a first connection state for outputting the transmission signal received from the transmitter amplifier to the antenna side input/output terminal and a second connection state for outputting the received signal received through the antenna side input/output terminal to the receiver amplifier, from one to the other;

a transmitter matching circuit interposed between the transmitter amplifier and the changeover switch for matching output impedance of the transmitter amplifier with input impedance of the receiver amplifier; and

an antenna side matching circuit interposed between the wire and the changeover switch for matching the characteristic impedance of the wire with the input impedance of the receiver amplifier.

3. A transmitting/receiving circuit for a radiocommunication apparatus comprising:

a transmitter amplifier for amplifying an input transmission signal and outputting the amplified transmission signal;

a receiver amplifier for amplifying an input received signal and outputting the amplified received signal;

a changeover switch having an antenna side input/output terminal through which the transmission signal is output to an antenna via a wire having prescribed characteristic impedance and the received signal is input from the antenna via the wire, for switching a first connection state for outputting the transmission signal received from the transmitter amplifier to the antenna side input/output terminal and a second connection state for outputting the received signal received through the antenna side input/output terminal to the receiver amplifier, from one to the other;

a transmitter matching circuit interposed between the transmitter amplifier and the changeover switch for matching output impedance of the transmitter amplifier with optimal characteristic impedance of the changeover switch;

a receiver matching circuit interposed between the changeover switch and the receiver amplifier for matching input impedance of the receiver amplifier with the optimal characteristic impedance of the changeover switch; and

an antenna side matching circuit interposed between the wire and the changeover switch for matching the characteristic impedance of the wire with the optimal characteristic impedance of the changeover switch.

4. A transmitting/receiving circuit for a radiocommunication apparatus comprising:

a transmitter amplifier having at least one amplifier FET for amplifying an input transmission signal;

a receiver amplifier for amplifying an input received signal and outputting the amplified received signal; and

a changeover switch having an antenna input/output terminal through which the transmission signal is output to an antenna and the received signal is input from the antenna, a transmitter through FET and a transmitter shunt FET connected in series to each other, and a receiver through FET and a receiver shunt FET connected in series to each other, for switching a first connection state for outputting the transmission signal received from the transmitter amplifier to the antenna side input/output terminal and a second connection state for outputting the received signal received through the antenna side input/output terminal to the receiver amplifier, from one to the other,

wherein the amplifier FET at a last stage of the transmitter amplifier works also as the transmitter shunt FET of the changeover switch.

5. A semiconductor integrated circuit device comprising:

a semiconductor substrate;

a transmitter amplifier formed on the semiconductor substrate for amplifying an input transmission signal and outputting the amplified transmission signal;

a receiver amplifier formed on the semiconductor substrate for amplifying an input received signal and outputting the amplified received signal;

a changeover switch formed on the semiconductor substrate having an antenna side input/output terminal through which the transmission signal is output to an antenna via a wire having prescribed characteristic impedance and an antenna side matching circuit for matching the characteristic impedance of the wire with output impedance of the transmitter amplifier and the received signal is input from the antenna via the wire and the antenna side matching circuit, for switching a first connection state for outputting the transmission signal received from the transmitter amplifier via no matching circuit to the antenna side input/output terminal and a second connection state for outputting the received signal received through the antenna side input/output terminal to the receiver amplifier, from one to the other; and

a receiver matching circuit formed on the semiconductor substrate and interposed between the receiver amplifier and the changeover switch for matching input impedance of the receiver amplifier with the output impedance of the transmitter amplifier;

wherein the changeover switch has a transmitter through FET and a transmitter shunt FET connected in series to each other and a receiver through FET and a receiver shunt FET connected in series to each other,

the transmitter amplifier has at least one amplifier FET for amplifying the input transmission signal; and

the amplifier FET at a last stage of the transmitter amplifier works also as the transmitter shunt FET of the changeover switch.

6. A semiconductor integrated circuit device comprising:

a semiconductor substrate;

a transmitter amplifier formed on the semiconductor substrate and having at least one amplifier FET for amplifying an input transmission signal; and

a changeover switch formed on the semiconductor substrate and having an antenna input/output terminal through which the transmission signal is output to an antenna and a received signal is input from the antenna, a transmitter through FET and a transmitter shunt FET connected in series to each other, a receiver through FET and a receiver shunt FET connected in series to each other, for switching a first connection state for outputting the transmission signal received from the transmitter amplifier to the antenna side input/output terminal and a second connection state for outputting the received signal received through the antenna side input/output terminal to the receiver amplifier, from one to the other,

wherein the amplifier FET at a last stage of the transmitter amplifier works also as the transmitter shunt FET of the changeover switch.

7. A radiocommunication apparatus comprising:

an antenna;

a wire connected to the antenna and having prescribed characteristic impedance;

a transmitter amplifier for amplifying an input transmission signal and outputting the amplified transmission signal;

a receiver amplifier for amplifying an input received signal and outputting the amplified received signal;

a changeover switch having an antenna side input/output terminal through which the transmission signal is output to the antenna via the wire and the received signal is input from the antenna via the wire, for switching a first connection state for outputting the transmission signal received from the transmitter amplifier to the antenna side input/output terminal and a second connection state for outputting the received signal received through the antenna side input/output terminal to the receiver amplifier via no matching circuit, from one to the other;

a transmitter matching circuit interposed between the transmitter amplifier and the changeover switch for matching output impedance of the transmitter amplifier with input impedance of the receiver amplifier; and

an antenna side matching circuit interposed between the wire and the changeover switch for matching the characteristic impedance of the wire with the input impedance of the receiver amplifier.

8. A radiocommunication apparatus comprising:

an antenna;

a wire connected to the antenna and having prescribed characteristic impedance;

a transmitter amplifier for amplifying an input transmission signal and outputting the amplified transmission signal;

a receiver amplifier for amplifying an input received signal and outputting the amplified received signal;

a changeover switch having an antenna side input/output terminal through which the transmission signal is output to the antenna via the wire and the received signal is input from the antenna via the wire, for switching a first connection state for outputting the transmission signal received from the transmitter amplifier to the antenna side input/output terminal and a second connection state for outputting the received signal received through the antenna side input/output terminal to the receiver amplifier, from one to the other;

a transmitter matching circuit interposed between the transmitter amplifier and the changeover switch for matching output impedance of the transmitter amplifier with optimal characteristic impedance of the changeover switch;

a receiver matching circuit interposed between the changeover switch and the receiver amplifier for matching input impedance of the receiver amplifier with the optimal characteristic impedance of the changeover switch; and

an antenna side matching circuit interposed between the wire and the changeover switch for matching the characteristic impedance of the wire with the optimal characteristic impedance of the changeover switch.