Unpowered switch and bleeder circuit

• US 20060199563A1
• Filed: 02/09/2006
• Published: 09/07/2006
• Est. Priority Date: 02/09/2005
• Status: Active Grant

• Current Assignee: pSemi Corporation (Murata Manufacturing Co Limited)
• Original Assignee: Peregrine Semiconductor Corporation (Murata Manufacturing Co Limited)
• Inventors: Kelly, Dylan J., Kemerling, Clint L.
• Granted Patent: US 7,619,462 B2
• Time in Patent Office: Days
• US Class Current: 455/333
• 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 novel RF switch for switching radio frequency (RF) signals is disclosed. The RF switch may comprise both enhancement and depletion mode field-effect transistors (E-FETs and D-FETs) implemented as a monolithic integrated circuit (IC) on a silicon-on-insulator (SOI) substrate. The disclosed RF switch, with a novel bleeder circuit, may be used in RF applications wherein a selected switch state and performance are required when the switch and bleeder circuits are not provided with operating power (i.e., when the switch and bleeder circuits are “unpowered”).

Claims

1. A monolithic integrated circuit RF switch comprising at least one RF switch selected from the following RF switch types:

a depletion-enhancement (D-E) RF switch, an enhancement-depletion (E-D) RF switch, a depletion switch (D-sw) RF switch, and a depletion shunt (D-sh) RF switch, wherein;

(a) the D-E RF switch comprises;

(1) a depletion-mode switch (D-Sw) circuit operatively coupled to receive an RF signal from an RF input of the D-E RF switch, wherein the D-Sw circuit selectively conveys the RF signal to an output of the D-E RF switch, and wherein the D-Sw circuit is controlled by control signals conveyed by a first control line C1; and

(2) an enhancement-mode shunt (E-Sh) circuit operatively coupled to receive the RF signal from the RF input of the D-E RF switch, wherein the E-Sh circuit selectively conveys the RF signal to ground, and wherein the E-Sh circuit is controlled by control signals conveyed by a second control line C1x;

(b) and wherein the E-D RF switch comprises;

(1) an enhancement-mode switch (E-Sw) circuit operatively coupled to receive the RF signal from an input of the E-D RF switch, wherein the E-Sw circuit selectively conveys the RF signal to an output of the E-D RF switch, and wherein the E-Sw circuit is controlled by control signals conveyed by a third control line C2; and

(2) a depletion-mode shunt (D-Sh) circuit operatively coupled to receive the RF signal from the input of the E-D RF switch, wherein the D-Sh circuit selectively conveys the RF signal to ground, and wherein the D-Sh circuit is controlled by control signals conveyed by a fourth control line C2x;

(c) and wherein the D-sw RF switch comprises a depletion-mode switch (D-Sw) circuit operatively coupled to receive the RF signal from an input of the D-sw RF switch, wherein the D-Sw circuit selectively conveys the RF signal to an output of the D-sw RF switch, and wherein the D-Sw circuit is controlled by control signals conveyed by the first control line C1;

(d) and wherein the D-sh RF switch comprises a depletion-mode shunt (D-Sh) circuit operatively coupled to receive the RF signal from an input of the D-sh RF switch, wherein the D-Sh circuit selectively conveys the RF signal to ground, and wherein the D-Sh circuit is controlled by control signals conveyed by the fourth control line C2x.

2. The RF switch of claim 1, wherein when the switch is not provided with operating power it operates in an UNPOWERED-STATE, and wherein when the switch is provided with operating power it operates in a POWERED-STATE, further comprising at least one bleeder circuit operatively coupled to ground and to at least one of the control lines, wherein the at least one bleeder circuit has a first impedance between ground and the at least one of the control lines when the RF switch operates in the POWERED-STATE, and wherein the at least one bleeder circuit has a second impedance between ground and the at least one of the control lines when the RF switch operates in the UNPOWERED-STATE, and wherein the second impedance is less than the first impedance.

3. The RF switch of claim 2, wherein the at least one bleeder circuit comprises:

a) a first depletion-mode p-type transistor (DP1), wherein a first channel node of the DP1 is operatively coupled to the at least one of the control lines;

b) a first depletion-mode n-type (DN1) transistor, wherein a first channel node of the DN1 is operatively coupled to a second channel node of the DP1, and wherein a second channel node of the DN1 is operatively coupled to the ground;

c) a second depletion-mode p-type transistor (DP2), wherein a first channel node of the DP2 is operatively coupled to a gate of the DP1, and wherein a second channel node of the DP2 is operatively coupled to a gate of the DN1, and wherein a gate of the DP2 is operatively coupled to a bias supply voltage VDD;

d) a VDD voltage divider circuit operatively coupled to the VDD, the ground, the gate of the DP1, and the first channel node of the DP2, wherein the VDD voltage divider circuit conveys a divided voltage level of the VDD to the gate of the DP1 and to the first channel node of the DP2; and

e) a VSS voltage divider circuit operatively coupled to a bias supply voltage VSS, the ground, the gate of the DN1, and the second channel node of the DP2, wherein the VSS voltage divider circuit conveys a divided voltage level of the VSS to the gate of the DN1 and to the second channel node of the DP2.

4. The RF switch of claim 3, wherein the at least one bleeder circuit further comprises:

a) a third depletion-mode p-type transistor (DP3) interposed between the first channel node of the DP1 and the at least one of the control lines, wherein the first channel node of the DP1 is operatively coupled to a second channel node of the DP3, and wherein a first channel node of the DP3 is operatively coupled to the at least one of the control lines, and wherein a gate of the DP3 is operatively coupled to ground;

b) a second depletion-mode n-type transistor (DN2) interposed between the second node of the DP1 and the first channel node of the DN1, wherein a second channel node of the DN2 is operatively coupled to the first channel node of the DN1, and wherein a first channel node of the DN2 is operatively coupled to the second channel node of the DP1, and wherein a gate of the DN2 is operatively coupled to ground; and

c) a fourth depletion-mode p-type transistor (DP4) interposed between the second channel node of the DP2 and both the gate of the DN1 and the VSS voltage divider circuit, wherein a first channel node of the DP4 is operatively coupled to the second channel node of the DP2, and wherein a second channel node of the DP4 is operatively coupled to the gate of the DN1 and to the VSS voltage divider circuit, and wherein a gate of the DP4 is operatively coupled to the VDD voltage divider circuit to receive the divided voltage level of the VDD.

5. The RF switch of claim 4, wherein the at least one bleeder circuit further comprises:

a) a fifth depletion-mode p-type transistor (DP5), wherein a first channel node of the DP5 is operatively coupled to the VSS, and wherein a second channel node of the DP5 is operatively coupled to ground, and wherein a gate of the DP5 is operatively coupled to the VDD voltage divider circuit to receive the divided voltage level of the VDD; and

b) a capacitor, wherein a first node of the capacitor is operatively coupled to the first channel node of the DP5 and to the bias supply voltage VSS, and wherein a second node of the capacitor is operatively coupled to ground.

6. The RF switch of claim 1, wherein the RF switch comprises one of the following switch types:

a single-pole, single-throw switch;

a single-pole, multi-throw switch;

a multi-pole, single-throw switch; and

a multi-pole, multi-throw switch.

7. The RF switch of claim 1, wherein the RF switch comprises at least one circuit comprising a plurality of D-E RF switches coupled together in a cascaded series-shunt configuration.

8. The RF switch of claim 1, wherein the RF switch comprises at least one circuit comprising a plurality of E-D RF switches coupled together in a cascaded series-shunt configuration.

9. The RF switch of claim 1, wherein at least one of the D-Sw circuit, E-Sh circuit, E-Sw circuit, and D-Sh circuit components comprises one or more transistors coupled together in a stacked or serial configuration.

10. The RF switch of claim 9, wherein the one or more transistors are configured in a symmetrically stacked configuration.

11. The RF switch of claim 9, wherein the one or more transistors are configured in an asymmetrically stacked configuration.

12. The RF switch of claim 1, wherein the RF switch is fabricated using at least one of the following technologies:

SIMOX, bonded wafers having a thin silicon layer bonded to an insulating layer, silicon-on-sapphire, ultrathin silicon-on-sapphire, and GaAs.

13. A monolithic integrated circuit single-pole double-throw (SPDT) RF switch, comprising:

(a) a D-E RF switch selectively conveying a first RF signal between a first RF input node and an RF common node (RFcommon), wherein the D-E RF switch comprises;

(1) a depletion-mode switch (D-Sw) circuit operatively coupled to receive the first RF signal, wherein the D-Sw circuit selectively conveys the first RF signal to the RFcommon, and wherein the D-Sw circuit is controlled by control signals conveyed by a first control line C1; and

(2) an enhancement-mode shunt (E-Sh) circuit operatively coupled to receive the first RF signal, wherein the E-Sh circuit selectively conveys the first RF signal to ground, and wherein the E-Sh circuit is controlled by control signals conveyed by a second control line C1x; and

(b) an E-D RF switch selectively conveying a second RF signal between a second RF input node and the RFcommon, wherein the E-D RF switch comprises;

(1) an enhancement-mode switch (E-Sw) circuit operatively coupled to receive the second RF signal, wherein the E-Sw circuit selectively conveys the second RF signal to the RFcommon, and wherein the E-Sw circuit is controlled by control signals conveyed by a third control line C2; and

(2) a depletion-mode shunt (D-Sh) circuit operatively coupled to receive the second RF signal, wherein the D-Sh circuit selectively conveys the second RF signal to ground, and wherein the D-Sh circuit is controlled by control signals conveyed by a fourth control line C2x.

14. The SPDT RF switch of claim 13, wherein when the switch is not provided with operating power it operates in an UNPOWERED-STATE, and wherein when the switch is provided with operating power it operates in a POWERED-STATE, further comprising at least one bleeder circuit operatively coupled to ground and to at least one of the control lines, wherein the at least one bleeder circuit has a first impedance between ground and the at least one of the control lines when the RF switch operates in the POWERED-STATE, and wherein the at least one bleeder circuit has a second impedance between ground and the at least one of the control lines when the RF switch operates in the UNPOWERED-STATE, and wherein the second impedance is less than the first impedance.

15. The SPDT RF switch of claim 13, wherein at least one of the D-Sw circuit, E-Sh circuit, E-Sw circuit, and D-Sh circuit components comprises one or more transistors coupled together in a stacked or serial configuration.

16. The SPDT RF switch of claim 15, wherein the one or more transistors are configured in a symmetrically stacked configuration.

17. The SPDT RF switch of claim 15, wherein the one or more transistors are configured in an asymmetrically stacked configuration.

18. The SPDT RF switch of claim 13, wherein the SPDT RF switch is fabricated using at least one of the following technologies:

SIMOX, bonded wafers having a thin silicon layer bonded to an insulating layer, silicon-on-sapphire, ultrathin silicon-on-sapphire, and GaAs.

19. The SPDT RF switch of claim 13, further comprising a plurality of cascaded D-E RF switches selectively conveying the first RF signal between the first RF input node and the RFcommon.

20. The SPDT RF switch of claim 13, further comprising a plurality of cascaded E-D RF switches selectively conveying the second RF signal between the second RF input node and the RFcommon.

21. A monolithic integrated circuit single-pole double-throw (SPDT) RF switch, comprising:

(a) a first E-D RF switch selectively conveying a first RF signal between a first RF input node and an RF common node (RFcommon), wherein the first E-D RF switch comprises;

(1) a first enhancement-mode switch (E-Sw) circuit operatively coupled to receive the first RF signal, wherein the first E-Sw circuit selectively conveys the first RF signal to the RFcommon, and wherein the first E-Sw circuit is controlled by control signals conveyed by a first control line C1; and

(2) a first depletion-mode shunt (D-Sh) circuit operatively coupled to receive the first RF signal, wherein the first D-Sh circuit selectively conveys the first RF signal to ground, and wherein the first D-Sh circuit is controlled by control signals conveyed by a second control line C1x; and

(b) a second E-D RF switch selectively conveying a second RF signal between a second RF input node and the RFcommon, wherein the second E-D RF switch comprises;

(1) a second enhancement-mode switch (E-Sw) circuit operatively coupled to receive the second RF signal, wherein the second E-Sw circuit selectively conveys the second RF signal to the RFcommon, and wherein the second E-Sw circuit is controlled by control signals conveyed by a third control line C2; and

(2) a second depletion-mode shunt (D-Sh) circuit operatively coupled to receive the second RF signal, wherein the second D-Sh circuit selectively conveys the second RF signal to ground, and wherein the second D-Sh circuit is controlled by control signals conveyed by a fourth control line C2x.

22. The SPDT RF switch of claim 21, wherein when the switch is not provided with operating power it operates in an UNPOWERED-STATE, and wherein when the switch is provided with operating power it operates in a POWERED-STATE, further comprising at least one bleeder circuit operatively coupled to ground and to at least one of the control lines, wherein the at least one bleeder circuit has a first impedance between ground and the at least one of the control lines when the RF switch operates in the POWERED-STATE, and wherein the at least one bleeder circuit has a second impedance between ground and the at least one of the control lines when the RF switch operates in the UNPOWERED-STATE, and wherein the second impedance is less than the first impedance.

23. The SPDT RF switch of claim 21, wherein at least one of the first E-Sw circuit, first D-Sh circuit, second E-Sw circuit and second D-Sh circuit components comprises one or more transistors coupled together in a stacked or serial configuration.

24. The SPDT RF switch of claim 23, wherein the one or more transistors are configured in a symmetrically stacked configuration.

25. The SPDT RF switch of claim 23, wherein the one or more transistors are configured in an asymmetrically stacked configuration.

26. The SPDT RF switch of claim 21, wherein the SPDT RF switch is fabricated using at least one of the following technologies:

SIMOX, bonded wafers having a thin silicon layer bonded to an insulating layer, silicon-on-sapphire, ultrathin silicon-on-sapphire, and GaAs.

27. The SPDT RF switch of claim 21, wherein at least one of the E-D RF switches comprises a plurality of E-D RF switches coupled together in a cascaded series-shunt configuration.