RF switch

• US 9,312,909 B2
• Filed: 06/26/2014
• Issued: 04/12/2016
• Est. Priority Date: 12/27/2013
• Status: Active Grant

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Kang, Suk Chan, Choi, Kyu Jin, Choi, Jae Hyouck, Kim, Jeong Hoon
• Primary Examiner(s): Vuong, Quochien B
• Application Number:
  US14/316,505
• Publication Number:
  US 20150188597A1
• Time in Patent Office: 656 Days
• Field of Search: 455/78, 455/79, 455/552.1, 455/553.1, 455/63.1, 455/67.11, 455/67.13
• US Class Current: 1/1
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver

Abstract

A RF (Radio Frequency) switch may include: a common port; a first switching unit including a plurality of first switching devices; a second switching; a negative voltage generating unit sensing the high frequency signal from the common port and rectifying the sensed high frequency signal to generate a negative voltage; and a logic circuit unit controlling switching operations of the first and second switching units using the negative voltage provided from the negative voltage generating unit and a positive voltage provided from the outside.

Claims

1. A RF(Radio Frequency) switch comprising:

a common port transmitting and receiving high frequency signals;

a first switching unit including a plurality of first switching devices connected to each other in series and conducting or blocking a signal transfer path between a first port to and from which the high frequency signal is input and output and the common port;

a second switching unit including a plurality of second switching devices connected to each other in series and conducting or blocking a signal transfer path between a second port to and from which the high frequency signal is input and output and the common port;

a negative voltage generating unit sensing the high frequency signal from the common port and rectifying the sensed high frequency signal to generate a negative voltage; and

a logic circuit unit controlling switching operations of the first and second switching units using the negative voltage provided from the negative voltage generating unit and a positive voltage provided from outside of the RF switch.

2. The RF switch of claim 1, wherein the negative voltage generating unit includes:

a sensing circuit unit sensing the high frequency signal from the common port;

an amplifying circuit unit amplifying a level of the sensed high frequency signal to a present level; and

a rectifying circuit unit rectifying the amplified high frequency signal.

3. The RF switch of claim 2, wherein the negative voltage generating unit further includes a filter circuit unit removing ripples from the rectified high frequency signal.

4. The RF switch of claim 1, further comprising:

a first shunting unit connected between the second port and the second switching unit to conduct or block a signal transfer path between the second port and a ground; and

a second shunting unit connected between the first port and the first switching unit to conduct or block a signal transfer path between the first port and a ground,

wherein the first shunting unit includes a plurality of first switching devices connected to each other in series, and the second shunting unit includes a plurality of second switching devices connected to each other in series.

5. The RF switch of claim 4, wherein the logic circuit unit applying a first gate signal to control terminals of the first switching devices included in each of the first switching unit and the first shunting unit to control a switching operation, and applying a second gate signal to control terminals of the second switching devices included in each of the second switching unit and the second shunting unit to control a switching operation.

6. The RF switch of claim 1, wherein each of the plurality of first and second switching devices is a field effect transistor (FET) or a bipolar junction transistor (BJT).

7. A RF switch comprising:

a common port connected to an antenna;

a first switching unit including a plurality of first switching devices connected to each other in series between the common port and a first port;

a second switching unit including a plurality of second switching devices connected to each other in series between the common port and a second port;

a logic circuit unit applying a first gate signal to control terminals of the plurality of first switching devices included in the first switching unit and applying a second gate signal to control terminals of the plurality of second switching devices included in the second switching unit to control the second switching unit to be blocked in the case in which the first switching unit is conducted and to control the second switching unit to be conducted in the case in which the first switching unit is blocked; and

a negative voltage generating unit including at least one resistor connected in series with the common port and a rectifying circuit unit connected in series with the at least one resistor and the logic circuit unit between the at least one resistor and the logic circuit unit,

wherein the negative voltage generating unit senses an output signal of the common port using the at least one resistor and provides a negative voltage generated by rectifying the sensed output signal by the rectifying circuit unit to the logic circuit unit, and the logic circuit unit generates the first and second gate signals using the negative voltage and a positive voltage provided from outside of the RF switch.

8. The RF switch of claim 7, wherein the negative voltage generating unit further includes at least one amplifier connected between the at least one resistor and the rectifying circuit unit,

the amplifier amplifying a level of the sensed output signal to a present level and providing the signal having the amplified level to the rectifying circuit unit.

9. The RF switch of claim 7, wherein the negative voltage generating unit further includes at least one capacitor connected in series with a ground between the rectifying circuit unit and the logic circuit unit,

the at least one capacitor removing ripples from the rectified output signal and providing the output signal from which the ripple is removed to the logic circuit unit.

10. The RF switch of claim 7, further comprising:

a first shunting unit including a plurality of first switching devices connected to each other in series and conducting or blocking a signal transfer path between the second port and a ground; and

a second shunting unit including a plurality of second switching devices connected to each other in series and conducting or blocking a signal transfer path between the first port and a ground.

11. The RF switch of claim 10, wherein the logic circuit unit applying the first gate signal to control terminals of the plurality of first switching devices included in the first shunting unit and applying the second gate signal to control terminals of the plurality of second switching devices included in the second shunting unit.

12. The RF switch of claim 7, wherein each of the plurality of first and second switching devices is an FET or a BJT.