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US 2004/0171356 A1Published application
High frequency switch, radio communication apparatus, and high frequency switching method
AssigneePanasonic Corporation
InventorsKazuhide Uriu, Toru Yamada, Hideaki Nakakubo, Masaharu Tanaka
Life of this patent
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Abstract
For example, in a conventional high frequency switch used for a mobile phone and so on, high frequency distortion is caused by a diode which is turned off upon transmission. A high frequency switch includes a switch circuit 2 for switching transmission and reception performed via a transmitting terminal Tx2 and receiving terminals Rx2 and Rx3, said switch circuit having a diode D1 turned off upon transmission, and a low-pass filter 11 for suppressing high frequency distortion caused by the diode D1 upon transmission.
Claims17
A high frequency switch, comprising:
- a first transmit-receive switch (2) which switches transmission and reception performed via a first transmitting terminal (Tx2) and first (Rx2) and second (Rx3) receiving terminals and has a first diode (D1) being turned off at the time of said transmission;
- and
- a first low-pass filter (11) for suppressing high frequency distortion caused by said first diode (D1) at the time of said transmission,
- said first transmitting terminal (Tx2) is connected to said antenna (ANT) via a second diode (D3) and said first low-pass filter (11), said diode being in a forward direction at the time of said transmission,
- characterized in that
- a second low-pass filter (13) is further provided, said second low-pass filter being inserted between said first transmitting terminal (Tx2) and an anode of said second diode (D3) to suppress high frequency distortion occurring at the time of said transmission, and
- said second low-pass filter suppresses high frequency distortion occurring at the time of said transmission, in cooperation with said first low-pass filter (11).
4 more elements
A high frequency switch, comprising:
- a plurality of transmit-receive switches for switching transmission and reception performed via transmitting terminals and receiving terminals;
- and
- branching filter means of connecting said plurality of transmit-receive switches to an antenna (ANT), and
- said receiving terminals are each connected to said antenna and are each grounded via a diode in a forward direction and a ground resistor, and
- said ground resistor used for grounding is shared by a single resistor,
- characterized in that
- said ground resistor is grounded via an inductor.
4 more elements
A high frequency switch comprising:
- a first transmit-receive switch (2) which switches transmission and reception performed via a first transmitting terminal (Tx2) and first (Rx2) and second (Rx3) receiving terminals and has a first diode (D1) being turned off at the time of said transmission;
- a first low-pass filter (11) for suppressing high frequency distortion caused by said first diode (D1) at the time of said transmission;
- said first transmitting terminal (Tx2) is connected to said antenna (ANT) via a second diode (D3) and said first low-pass filter (11), said diode being in a forward direction at the time of said transmission,
- a second transmit-receive switch (1) for switching transmission and reception performed via a third transmitting terminal and a third receiving terminal;
- and
- branching filter means (3) of connecting said first (2) and second (1) transmit-receive switch to an antenna (ANT), and
- said second and third receiving terminals are connected to said antenna (ANT) and are grounded respectively via a diode in a forward direction and a ground resistor, and said ground resistor used for grounding is shared by a single resistor,
- characterized in that
- a second low-pass filter (13) is further provided, said second low-pass filter being inserted between said first transmitting terminal (Tx2) and an anode of said second diode (D3) to suppress high frequency distortion occurring at the time of said transmission, and
- said second low-pass filter suppresses high frequency distortion occurring at the time of said transmission, in cooperation with said first low-pass filter (11), and
- said ground resistor is grounded via an inductor.
8 more elements
A high frequency switching method, comprising:
- a switching step of switching transmission and reception by using a first transmit-receive switch (2) having a first diode (D1) which is turned off at the time of said transmission, said transmit-receive switch being used for switching transmission and reception performed via a first transmitting terminal (Tx2) and first (Rx2) and second (Rx3) receiving terminals;
- and
- a filtering step of performing filtering by using a first low-pass filter (11) for suppressing high frequency distortion caused by said first diode (D1) at the time of said transmission,
- a transmission step using said first transmitting terminal (Tx2), which is connected to said antenna (ANT) via a second diode (D3) and said low-pass filter (11), said diode being in a forward direction at the time of said transmission,
- characterized by the steps of
- suppressing high frequency distortion occurring at the time of said transmission using a second low-pass filter (13), said second low-pass filter being inserted between said first transmitting terminal (Tx2) and an anode of said second diode (D3), and
- suppressing high frequency distortion occurring at the time of said transmission by using said second low-pass filter in cooperation with said first low-pass filter (11).
4 more elements
A high frequency switching method, comprising:
- a switching step of switching transmission and reception by using a plurality of transmit-receive switches for switching transmission and reception performed via transmitting terminals and receiving terminals, and
- said receiving terminals are each connected to an antenna and are respectively ground via a diode in a forward direction and ground resistors, said plurality of transmit-receive switches being connected to said antenna via branching filter means, and
- said grounded resistors used for grounding are shared by a single resistor,
- characterised in that
- said ground resistor is grounded via an inductor.
2 more elements
A high frequency switching method comprising:
- a first switching step of switching transmission reception by using a first transmit-receive switch (2) having a first diode (D1) which is turned off at the time of said transmission, said transmit-receive switch being used for switching transmission and reception performed via a first transmitting terminal (Tx2) and first (Rx2) and second (Rx3) receiving terminals,
- a filtering step of performing filtering by using a first low-pass filter (11) for suppressing high frequency distortion caused by said first diode (D1) at the time of said transmission;
- a transmission step using said first transmitting terminal (Tx2), which is connected to said antenna (ANT) via a second diode (D3) and said low-pass filter (11), said diode being in a forward direction at the time of said transmission,
- a second switching step of switching transmission and reception by using a second transmission reception switching circuit for switching transmission and reception performed via a third transmitting terminal and a third receiving terminal, and
- said second and third receiving terminals are connected to an antenna and are respectively grounded via a diode in a forward direction and a ground resistor, said first and second transmit-receive switches being connected to said antenna via branching filter means, and said ground resistors used for grounding are shared by a single resistor,
- characterized by the steps of
- suppressing high frequency distortion occurring at the time of said transmission using a second low-pass filter (13), said second low-pass filter being inserted between said first transmitting terminal (Tx2) and an anode of said second diode (D3), and
- suppressing high frequency distortion occurring at the time of said transmission by using said second low-pass filter in cooperation with said first low-pass filter (11), and
- said ground resistor is grounded via an inductor.
6 more elements
Dependencies are inferred from the claim text.