Radio frequency switch for switching non-zero direct current bias signal

Abstract

The invention provides a radio frequency switch for switching non-zero direct current bias signals. Each switch branch comprises a plurality of switch units and a charge pump control module for controlling the plurality of switch units; each switch unit comprises a switch tube, a bias resistor of the switch tube and a bidirectional charge pump, the bidirectional charge pump comprises a positive-voltage-starting charge pump and a negative-voltage-stopping charge pump, the positive-voltage-starting charge pump and the negative-voltage-stopping charge pump alternately and selectively work, and source-drain direct-current voltage drop of the switch tube is collected and input into the bidirectional charge pump; and the charge pump is correspondingly switched on or switched off according to a switching-on or switching-off selection signal controlled by the switching tube, and an operation voltage which is used for controlling the switching tube to be switched on or switched off and takes the input switching tube source-drain direct-current voltage drop as a reference and superposes the output voltage of the charge pump is generated so as to control the switching tube to be uniformly switched on and switched off. According to the invention, the problem of radio frequency performance degradation caused by inconsistent turn-on and turn-off degrees or turn-on and turn-off problems when the switching tube transmits and switches the non-zero direct current bias signal is solved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a radio frequency switch for switching a non-zero direct current bias signal. Background Art

[0002] Switches are generally divided into analog switches and RF switches. Analog switches are used to switch DC bias or low-frequency signals of MHz; while RF switches are used to switch RF signals above hundreds of MHz. They generally use stacked switching tubes to utilize the resistor RF floating bias effect and stacked tube voltage division to increase the RF signal transmission swing, and generally transmit RF signals with zero DC bias.

[0003] RF system applications such as power supply selection for power amplifier efficiency optimization, RF transformer driving and signal selection switching require non-zero DC bias or RF signal selection switching and transmission.

[0004] If you use Figure 1 The prior art RF switch shown performs non-zero DC bias signal selection switching, and the DC bias will be distributed and dropped between the source and drain of the stacked switch tube, resulting in inconsistent source-drain DC voltages of different switch tubes. The gate voltages of the switch tubes using fixed control signals are the same, which will lead to inconsistent switching degrees of the switch tubes or problems with switching on and off.

[0005] In order to solve the above problems, it is necessary to propose a new type of RF switch for switching non-zero DC bias signals. Summary of the invention

[0006] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a radio frequency switch for switching a non-zero DC bias signal, which is used to solve the problem in the prior art that the DC bias will be distributed and dropped between the source and drain of the stacked switch tube, resulting in inconsistent source-drain DC voltages of different switch tubes, and the gate voltage of the switch tube using a fixed control signal is the same, which will lead to inconsistent switching degrees of the switch tube or the existence of switching problems.

[0007] To achieve the above-mentioned object and other related objects, the present invention provides a radio frequency switch for switching a non-zero DC bias signal, comprising:

[0008] The switch control system includes a logic control module and a series-parallel RF switch branch;

[0009] The series-parallel RF switch branch is composed of a series switch branch and a parallel switch branch;

[0010] The logic control module sends a control signal, and the series-parallel RF switch branch receives the control signal sent by the logic control module;

[0011] Each switch branch includes a plurality of switch units and a charge pump control module for controlling the plurality of switch units;

[0012] Each switch unit includes a switch tube, a bias resistor of the switch tube and a bidirectional charge pump. The bidirectional charge pump contains a positive voltage charge pump that is turned on and a negative voltage charge pump that is turned off. The positive voltage charge pump and the negative voltage charge pump that are turned on are selected to work alternately. The DC voltage drop from the source to the drain of the switch tube is collected and input into the bidirectional charge pump. The charge pump is turned on or off correspondingly according to the on or off selection signal controlled by the switch tube. An operating voltage that controls the switch tube to be turned on or off is generated based on the input DC voltage drop from the source to the drain of the switch tube and is superimposed with the output voltage of the charge pump, so as to control the uniform on and off of the switch tube.

[0013] Preferably, a source-drain bias resistor is provided between the source and drain ends of each of the switch tubes, and a gate bias resistor is also connected to the gate of each switch tube.

[0014] Preferably, the substrate electrode of the switch tube is also connected to a diode.

[0015] Preferably, the source-drain DC voltage drop of the switch tube is collected through a source-drain bias resistor tap.

[0016] Preferably, the bidirectional charge pump comprises: a first and a second PMOS, a first and a second NMOS and a first and a second capacitor constituting a positive voltage charge pump, the gate of the first PMOS and the gate of the first NMOS are connected to the first end of the second capacitor, and the gate of the second PMOS and the gate of the second NMOS are connected to the first end of the first capacitor; a third and a fourth PMOS, a third and a fourth NMOS and a third and a fourth capacitor constituting a negative voltage charge pump that is turned off, the gate of the third PMOS and the gate of the third NMOS are connected to the first end of the third capacitor, and the gate of the fourth PMOS and the gate of the fourth NMOS are connected to the first end of the fourth capacitor; the second end of the first capacitor is connected to a negative clock signal that is turned on, the second end of the second capacitor is connected to a positive clock signal that is turned on, the second end of the third capacitor is connected to a positive clock signal that is turned off, and the second end of the fourth capacitor is connected to a negative clock signal that is turned off; the source of the first and the second PMOS and the drain of the third and the fourth NMOS are connected to the output end of the bidirectional charge pump; the source of the third and the fourth PMOS and the drain of the first and the second NMOS are connected to the output end of the bidirectional charge pump.

[0017] Preferably, the charge pump control module includes a first inverter and first to fourth AND gates; the control signal forms an inverted phase signal of the control signal through the second inverter; one input terminal of the first AND gate is connected to the negative clock signal, and the other input terminal is connected to the inverted phase signal of the control signal through the first inverter, and the output terminal forms an on-state negative clock signal connected to the second end of the first capacitor in each bidirectional charge pump; one input terminal of the second AND gate is connected to the inverted phase signal of the control signal through the first inverter, and the other input terminal is connected to the positive clock signal, and the output terminal generates an on-state positive clock signal connected to the second end of the second capacitor in each bidirectional charge pump; one input terminal of the third AND gate is connected to the negative clock signal, and the other input terminal is connected to the inverted phase signal of the control signal, and the output terminal forms an off-state negative clock signal connected to the second end of the fourth capacitor in each bidirectional charge pump; one input terminal of the fourth AND gate is connected to the inverted phase signal of the control signal, and the other input terminal is connected to the positive clock signal, and the output terminal forms an off-state positive clock signal connected to the second end of the third capacitor in each bidirectional charge pump.

[0018] As described above, the radio frequency switch for switching a non-zero DC bias signal of the present invention has the following beneficial effects:

[0019] The present invention solves the problem of radio frequency performance degradation caused by inconsistent on / off levels or on / off problems when a switch tube transmits and switches a non-zero DC bias signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Shown is a schematic diagram of a radio frequency switch of the prior art;

[0021] Figure 2 Shown is a schematic diagram of the bidirectional charge pump circuit structure of the present invention;

[0022] Figure 3 Shown is a schematic diagram of a radio frequency switch of the present invention;

[0023] Figure 4 A schematic diagram showing a comparison of the design simulation of the radio frequency switch for switching a non-zero DC bias signal of the present invention and the prior art. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0025] See also Figure 3 The present invention provides a radio frequency switch for switching a non-zero DC bias signal, comprising:

[0026] The switch control system includes a logic control module and a series-parallel RF switch branch;

[0027] The series-parallel RF switch branch is composed of a series switch branch and a parallel switch branch;

[0028] The logic control module sends a control signal, and the series-parallel RF switch branch receives the control signal sent by the logic control module;

[0029] Each switch branch includes a plurality of switch units and a charge pump control module for controlling the plurality of switch units;

[0030] Each switch unit includes a switch tube, a bias resistor of the switch tube and a bidirectional charge pump. The bidirectional charge pump contains a positive voltage charge pump for turning on and a negative voltage charge pump for turning off. The positive voltage charge pump and the negative voltage charge pump are switched on and off to work alternately. The DC voltage drop from the source to the drain of the switch tube is collected and input into the bidirectional charge pump. The charge pump is switched on or off correspondingly according to the on or off selection signal controlled by the switch tube. An operating voltage for controlling the switch tube to turn on or off is generated based on the DC voltage drop from the source to the drain of the input switch tube and superimposed with the output voltage of the charge pump, so as to control the uniform on and off of the switch tube, thereby solving the problem of RF performance degradation caused by inconsistent on and off degrees of the switch tube or on and off problems.

[0031] In an embodiment of the present invention, a source-drain bias resistor is provided between the source and drain terminals of each switch tube, and a gate bias resistor is also connected to the gate of each switch tube.

[0032] In an embodiment of the present invention, the substrate electrode of the switch tube is further connected to a diode.

[0033] In an embodiment of the present invention, the source-drain DC voltage drop of the switch tube is collected through a source-drain bias resistor tap.

[0034] In the embodiments of the present invention, please refer to Figure 2The bidirectional charge pump comprises: a first and a second PMOS, a first and a second NMOS and a first and a second capacitor constituting a positive voltage charge pump, a gate of the first PMOS Mp1 and a gate of the first NMOS Mn1 are connected to a first end of the second capacitor C2, a gate of the second PMOS Mp2 and a gate of the second NMOS Mn2 are connected to a first end of the first capacitor C1; a third and a fourth PMOS, a third and a fourth NMOS and a third and a fourth capacitor constituting a negative voltage charge pump that is turned off, a gate of the third PMOS Mp3 and a gate of the third NMOS Mn3 are connected to a first end of the third capacitor C3, a gate of the fourth PMOS Mp4 and a gate of the fourth NMOS Mn4 are connected to a first end of the fourth capacitor C4; a second end of the first capacitor C1 is connected to a negative clock signal ON CLK-, a second end of the second capacitor C2 is connected to a positive clock signal ON CLK+, a second end of the third capacitor C3 is connected to a positive clock signal OFFCLK+, and a second end of the fourth capacitor C4 is connected to a negative clock signal OFF CLK-; the sources of the first and second PMOS and the drains of the third and fourth NMOS are connected to the output end of the bidirectional charge pump; the sources of the third and fourth PMOS and the drains of the first and second NMOS are connected to the output end of the bidirectional charge pump.

[0035] In the embodiments of the present invention, please refer to Figure 3 The logic control module includes a first inverter and first to fourth AND gates; the control signal forms an inverted phase signal of the control signal through the second inverter; one input terminal of the first AND gate &1 is connected to the negative clock signal CLK-, and the other input terminal is connected to the inverted phase signal of the control signal through the first inverter, and the output terminal forms an on-negative clock signal ON CLK- connected to the second end of the first capacitor C1 in each bidirectional charge pump; one input terminal of the second AND gate &2 is connected to the inverted phase signal of the control signal through the first inverter, and the other input terminal is connected to the positive clock signal CLK+, and the output terminal generates an on-positive clock signal ON CLK+ connected to the second end of the second capacitor C2 in each bidirectional charge pump; one input terminal of the third AND gate &3 is connected to the negative clock signal CLK-, and the other input terminal is connected to the inverted phase signal of the control signal, and the output terminal forms an off-negative clock signal OFF CLK- connected to the second end of the fourth capacitor C4 in each bidirectional charge pump; one input terminal of the fourth AND gate &4 is connected to the inverted phase signal of the control signal, and the other input terminal is connected to the positive clock signal CLK+, and the output terminal forms an off-positive clock signal OFF CLK+ is connected to the second end of the third capacitor C3 in each bidirectional charge pump.

[0036] See also Figure 4 , which shows the comparison of the RF switch design simulation for switching non-zero DC bias signals of the present invention and the prior art. The isolation and harmonic simulation results of the signal tolerance with non-zero DC bias when the RF switch branch is turned off show that the isolation and harmonics of the RF switch design for switching non-zero DC bias signals are significantly improved.

[0037] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner. Therefore, the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0038] In summary, the present invention solves the problem of RF performance degradation when the switch tube transmits and switches non-zero DC bias signals with inconsistent on / off levels or on / off problems. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0039] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A radio frequency switch for switching a non-zero DC bias signal, characterized in that: At least: The switch control system includes a logic control module and a series-parallel RF switch branch; The series-parallel RF switch branch is composed of a series switch branch and a parallel switch branch; The logic control module sends a control signal, and the series-parallel RF switch branch receives the control signal sent by the logic control module; Each switch branch includes a plurality of switch units and a charge pump control module for controlling the plurality of switch units; Each switch unit includes a switch tube, a bias resistor of the switch tube and a bidirectional charge pump. The bidirectional charge pump contains a positive voltage charge pump that is turned on and a negative voltage charge pump that is turned off. The positive voltage charge pump and the negative voltage charge pump that are turned on are selected to work alternately. The DC voltage drop from the source to the drain of the switch tube is collected and input into the bidirectional charge pump. The charge pump is turned on or off correspondingly according to the on or off selection signal controlled by the switch tube. An operating voltage that controls the switch tube to be turned on or off is generated based on the input DC voltage drop from the source to the drain of the switch tube and is superimposed with the output voltage of the charge pump, so as to control the uniform on and off of the switch tube.

2. The radio frequency switch for switching a non-zero DC bias signal according to claim 1, characterized in that: A source-drain bias resistor is provided between the source and drain ends of each switch tube, and a gate bias resistor is also connected to the gate of each switch tube.

3. The radio frequency switch for switching a non-zero DC bias signal according to claim 1, characterized in that: The substrate electrode of the switch tube is also connected to a diode.

4. The radio frequency switch for switching a non-zero DC bias signal according to claim 2, characterized in that: The source-drain DC voltage drop of the switch tube is collected through a source-drain bias resistor tap.

5. The radio frequency switch for switching a non-zero DC bias signal according to claim 1, characterized in that: The bidirectional charge pump comprises: a first and a second PMOS, a first and a second NMOS and a first and a second capacitor constituting a positive voltage charge pump, wherein the gate of the first PMOS and the gate of the first NMOS are connected to the first end of the second capacitor, and the gate of the second PMOS and the gate of the second NMOS are connected to the first end of the first capacitor; a third and a fourth PMOS, a third and a fourth NMOS and a third and a fourth capacitor constituting a negative voltage charge pump being turned off, wherein the gate of the third PMOS and the gate of the third NMOS are connected to the first end of the third capacitor, and the gate of the fourth PMOS and the gate of the fourth NMOS are connected to the first end of the fourth capacitor; the second end of the first capacitor is connected to a negative clock signal for turning on, the second end of the second capacitor is connected to a positive clock signal for turning on, the second end of the third capacitor is connected to a positive clock signal for turning off, and the second end of the fourth capacitor is connected to a negative clock signal for turning off; the source of the first and the second PMOS and the drain of the third and the fourth NMOS are connected to the output end of the bidirectional charge pump; the source of the third and the fourth PMOS and the drain of the first and the second NMOS are connected to the output end of the bidirectional charge pump.

6. The radio frequency switch for switching a non-zero DC bias signal according to claim 5, characterized in that: The charge pump control module includes a first inverter and first to fourth AND gates; the control signal forms an inverted phase signal of the control signal through the second inverter; one input end of the first AND gate is connected to the negative clock signal, the other input end is connected to the inverted phase signal of the control signal through the first inverter, and the output end forms an open negative clock signal connected to the second end of the first capacitor in each bidirectional charge pump; one input end of the second AND gate is connected to the inverted phase signal of the control signal through the first inverter, the other input end is connected to the positive clock signal, and the output end generates an open positive clock signal connected to the second end of the second capacitor in each bidirectional charge pump; one input end of the third AND gate is connected to the negative clock signal, the other input end is connected to the inverted phase signal of the control signal, and the output end forms a shutoff negative clock signal connected to the second end of the fourth capacitor in each bidirectional charge pump; one input end of the fourth AND gate is connected to the inverted phase signal of the control signal, the other input end is connected to the positive clock signal, and the output end forms a shutoff positive clock signal connected to the second end of the third capacitor in each bidirectional charge pump.

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