RF switch for switching non-zero DC bias signals
By combining the logic control module and the bidirectional charge pump control module, the problem of inconsistent switching tubes when the RF switch switches non-zero DC bias signals is solved, the RF performance and isolation are improved, and the uniformity of the switch on and off is improved.
Patent Information
- Application Number
- CN202411630666.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2044-11-15
AI Technical Summary
When existing RF switches switch non-zero DC bias signals, the source-drain DC voltage of the switch tube becomes inconsistent, resulting in inconsistent on-off levels of the switch tube and causing RF performance degradation.
A logic control module and a series-parallel RF switch branch are used in combination with a bidirectional charge pump control module. By turning on the positive voltage and turning off the negative voltage charge pump alternately, the switch tube is turned on and off according to the source-drain DC voltage drop of the switch tube to ensure uniformity.
The switch tube is uniformly turned on and off when switching non-zero DC bias signals, which improves the RF performance and improves the isolation and harmonic characteristics.
Smart Images
Figure CN119602775B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductor technology, and in particular to a radio frequency switch for switching non-zero DC bias signals. 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. The DC bias will be distributed and dropped between the source and drain of the stacked switch tube, resulting in inconsistent source and drain DC voltages of different switch tubes. 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.
[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 with 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 switching tube, resulting in inconsistent source-drain DC voltages of different switching tubes, and the gate voltage of the switching tube using a fixed control signal is the same, which will lead to inconsistent switching degrees of the switching tube or the existence of switching problems.
[0007] To achieve the above-mentioned and other related purposes, 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 radio frequency switch branch;
[0009] The series-parallel radio frequency switch branch consists 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 switching unit includes a switching tube, a bias resistor of the switching 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 alternately selected to work. The DC voltage drop from the source to the drain of the switching tube is collected and input into the bidirectional charge pump. The charge pump is turned on or off according to the on or off selection signal controlled by the switching tube. An operating voltage for controlling the switching tube to turn on or off is generated based on the DC voltage drop from the source to the drain of the input switching tube and superimposed with the output voltage of the charge pump, so as to control the uniform opening and closing of the switching tube.
[0013] Preferably, a source-drain bias resistor is provided between the source and drain terminals of each switching tube, and a gate bias resistor is also connected to the gate of each switching tube.
[0014] Preferably, the substrate electrode of the switching tube is further connected to a diode.
[0015] Preferably, the source-drain DC voltage drop of the switching tube is collected through a source-drain bias resistor tap.
[0016] Preferably, the bidirectional charge pump includes: 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, 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 startup, the second end of the second capacitor is connected to a positive clock signal for startup, the second end of the third capacitor is connected to a positive clock signal for shutdown, and the second end of the fourth capacitor is connected to a negative clock signal for shutdown; 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 four 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 a start-up 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 a start-up 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 a shut-down 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 a shut-down 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 non-zero DC bias signals of the present invention and the prior art is shown. DETAILED DESCRIPTION
[0024] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different perspectives 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 radio frequency switch branch;
[0027] The series-parallel radio frequency switch branch consists 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 switching unit includes a switching tube, a bias resistor of the switching 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 alternately selected to work. The DC voltage drop from the source to the drain of the switching tube is collected and input into the bidirectional charge pump. The charge pump is turned on or off according to the on or off selection signal controlled by the switching tube. An operating voltage for controlling the switching tube to turn on or off is generated based on the DC voltage drop from the source to the drain of the input switching tube and superimposed with the output voltage of the charge pump, so as to control the uniform opening and closing of the switching tube, thereby solving the problem of RF performance degradation caused by inconsistent opening and closing degrees of the switching tube or opening and closing 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 switching tube is collected through a source-drain bias resistor tap.
[0034] In the embodiments of the present invention, see Figure 2The bidirectional charge pump includes: a first and second PMOS, a first and second NMOS, and a first and second capacitor constituting a positive voltage charge pump, wherein the gate of the first PMOS Mp1 and the gate of the first NMOS Mn1 are connected to the first end of the second capacitor C2, and the gate of the second PMOS Mp2 and the gate of the second NMOS Mn2 are connected to the first end of the first capacitor C1; a third and fourth PMOS, a third and fourth NMOS, and a third and fourth capacitor constituting a negative voltage charge pump, wherein the gate of the third PMOS Mp3 and the gate of the third NMOS Mn3 are connected to the first end of the third capacitor C3, and the gate of the fourth PMOS Mp4 and the gate of the fourth NMOS Mn4 are connected to the first end of the fourth capacitor C4; the second end of the first capacitor C1 is connected to the negative clock signal ON CLK-, the second end of the second capacitor C2 is connected to the positive clock signal ON CLK+, the second end of the third capacitor C3 is connected to the positive clock signal OFFCLK+, and the second end of the fourth capacitor C4 is connected to the 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, see 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- and is connected to the second terminal 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+ and is connected to the second terminal 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- and is connected to the second terminal 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 a comparison between the simulation of the RF switch design for switching non-zero DC bias signals of the present invention and the prior art. The simulation results of the isolation and harmonics when the RF switch branch is turned off and the signal tolerance with non-zero DC bias is performed 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 schematically illustrate the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.
[0038] In summary, the present invention addresses the issue of RF performance degradation caused by inconsistent on / off states or issues with on / off switching when a switch transmits a non-zero DC bias signal. Therefore, the present invention effectively overcomes the shortcomings of the prior art and possesses high industrial 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 skilled in 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 one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to 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 radio frequency switch branch; The series-parallel radio frequency switch branch consists 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 switching unit includes a switching tube, a bias resistor of the switching 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 alternately selected to work. The DC voltage drop from the source to the drain of the switching tube is collected and input into the bidirectional charge pump. The charge pump is turned on or off according to the on or off selection signal controlled by the switching tube. An operating voltage for controlling the switching tube to turn on or off is generated based on the DC voltage drop from the source to the drain of the input switching tube and superimposed with the output voltage of the charge pump, so as to control the uniform opening and closing of the switching tube.
2. The radio frequency switch for switching a non-zero DC bias signal according to claim 1, wherein: A source-drain bias resistor is provided between the source and drain ends of each switching tube, and a gate bias resistor is also connected to the gate of each switching tube.
3. The radio frequency switch for switching a non-zero DC bias signal according to claim 1, wherein: The substrate electrode of the switch tube is further connected to a diode.
4. The radio frequency switch for switching a non-zero DC bias signal according to claim 2, wherein: The source-drain DC voltage drop of the switching tube is collected through the source-drain bias resistor tap.
5. The radio frequency switch for switching a non-zero DC bias signal according to claim 1, wherein: The bidirectional charge pump includes: 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, 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 startup, the second end of the second capacitor is connected to a positive clock signal for startup, the second end of the third capacitor is connected to a positive clock signal for shutdown, and the second end of the fourth capacitor is connected to a negative clock signal for shutdown; 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 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 a start-up 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 a start-up 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 a shut-down 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 a shut-down positive clock signal connected to the second end of the third capacitor in each bidirectional charge pump.