CN210867621U

CN210867621U - Amplitude limiting circuit and wireless receiving device

Info

Publication number: CN210867621U
Application number: CN201921276583.5U
Authority: CN
Inventors: 陆建华; 柳卫天; 王曾祺
Original assignee: Shanghai Archiwave Electronic Technology Co ltd
Current assignee: Shanghai Archiwave Electronic Technology Co ltd
Priority date: 2019-08-08
Filing date: 2019-08-08
Publication date: 2020-06-26
Anticipated expiration: 2029-08-08

Abstract

The utility model discloses an amplitude limiting circuit, this amplitude limiting circuit includes: the signal input end, the signal output end, at least one switching tube and at least one control unit; the at least one control unit is used for controlling the on and off of the at least one switching tube; and the at least one switching tube is used for reducing the power of the radio-frequency signal received by the signal input end and then outputting the radio-frequency signal through the signal output end in a conducting state. The utility model discloses an amplitude limiting circuit adopts switching on and breaking off of power detector control FET, realizes the reduction to signal receiving end signal power, and the switch tube can establish ties, connect in parallel among the amplitude limiting circuit, can be used for making small-size amplitude limiting device.

Description

Amplitude limiting circuit and wireless receiving device

Technical Field

The utility model relates to a radio frequency front end integrated circuit technique among radio communication and the radar technical field especially relates to an amplitude limiting circuit.

Technical Field

In wireless communication, radar, electronic countermeasure systems, etc., a transmitter transmits a radio signal and a receiver receives the radio signal. Generally, the greater the transmitter transmission power, the more advantageous it is for long distance communication and detection, while due to the need for high sensitivity, the lower noise receiver circuitry at the front end of the receiver can withstand very little burn-out power, typically around 10-20 dBm. Therefore, there are two main situations that cause damage to the receiver, one is that an interference signal with large external power is directly received into the receiver by the antenna, and if there is no protection measure in the front stage of the receiver, the large interference signal will burn out the low noise in the receiver, thereby causing damage to the receiver. Another situation is that when a circulator is used as a duplexer in a transceiver module, due to limited isolation of the circulator, when the antenna is too large for transmission, the power of a high-power signal of a transmitter leaking to a receiver channel is too large, which results in damage to the receiver. In order to protect power sensitive devices such as low noise amplifier, a limiter is usually added in front of the devices for protection.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an amplitude limiting circuit, the utility model provides an amplitude limiting circuit is favorable to optimizing traditional limiter circuit, and then provides the basis for the amplitude limiting circuit and the integrated component who reachs low cost, high performance.

In order to solve the technical problem, the utility model discloses a limiting circuit, include: the signal input end, the signal output end, at least one switching tube and at least one control unit;

the at least one control unit is used for controlling the on and off of the at least one switching tube;

the at least one switching tube is used for reducing the power of the radio-frequency signal received by the signal input end and then outputting the radio-frequency signal through the signal output end in a conducting state.

The utility model discloses a limiting circuit adopts the switch-on and the switch-off of power detector control FET, realizes reducing signal power to the signal receiving terminal, compares with traditional structure based on PIN diode, the utility model discloses a limiting circuit can be realized through traditional silicon technology, therefore low cost is fit for extensive volume production; because the utility model discloses an input/output of signal need not blocking electric capacity among the amplitude limiting circuit, therefore this amplitude limiting circuit has excellent ESD performance; because the switch tubes in the amplitude limiting circuit disclosed by the utility model can be connected in series and in parallel, the amplitude limiting circuit occupies small chip area and can be used for manufacturing small-size amplitude limiting devices; simultaneously, because the switch tube can keep less electric capacity at the off-state, make based on the utility model discloses a little, the big but power capacity of bandwidth of amplitude limiting circuit insertion loss is very big.

Drawings

Fig. 1 discloses a circuit diagram of a clipping circuit, according to some embodiments of the present invention;

fig. 2 discloses a circuit diagram of an NMOS transistor as a clipping circuit for a switching tube, according to some embodiments of the present invention;

fig. 3 discloses a circuit diagram of a limiting circuit employing a high resistance device and a voltage source to provide a control voltage, according to some embodiments of the present invention;

fig. 4 discloses a circuit diagram of a limiting circuit employing switches and a voltage source to provide a control voltage, in accordance with some embodiments of the present invention;

fig. 5 discloses a circuit diagram of a limiting circuit employing a power detector to provide a control voltage, in accordance with some embodiments of the present invention;

fig. 6 discloses a circuit diagram of a clipping circuit employing a diode and a resistor as a power detector, according to some embodiments of the present invention;

fig. 7 discloses a circuit diagram of a clipping circuit employing a coupler and a diode as a power detector, according to some embodiments of the present invention;

fig. 8 discloses a circuit diagram of a limiting circuit that employs an amplifier to amplify a control signal, in accordance with some embodiments of the present invention;

fig. 9 discloses a circuit diagram of a clipping circuit using switching tubes in series, according to some embodiments of the present invention;

fig. 10 discloses a circuit diagram of a clipping circuit employing a series connection of switches, in accordance with some embodiments of the present invention;

fig. 11 discloses a circuit diagram of a limiting circuit employing multiple switching tubes in parallel, according to some embodiments of the present invention;

fig. 12 discloses a circuit diagram of a limiting circuit employing two switching tube sets in parallel with each other, according to some embodiments of the present invention;

fig. 13 discloses an exemplary diagram of a chip structure of a clipping circuit according to some embodiments of the present invention;

fig. 14 discloses a chip assembly schematic diagram of a clipping circuit according to some embodiments of the present invention;

fig. 15 discloses a clipping characteristic test chart based on the clipping circuit of the present disclosure, according to some embodiments of the present invention.

Detailed Description

Illustrative embodiments of the present invention include, but are not limited to, a clipping circuit.

The present disclosure will use terminology commonly employed by those skilled in the art to describe various aspects of the illustrative embodiments in order to convey the substance of their work to others skilled in the art. It will be apparent, however, to one skilled in the art that some alternative embodiments may be practiced using portions of the described aspects. For purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the illustrative embodiments. It will be apparent, however, to one skilled in the art that alternative embodiments may be practiced without the specific details. In other instances, well-known features are omitted or simplified in order not to obscure the illustrative embodiments.

In order to make the objects, technical solutions and advantages of the present invention clearer, embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

According to the utility model discloses an embodiment discloses an amplitude limiting circuit. Fig. 1 is a circuit diagram of the limiter circuit. Specifically, as shown in fig. 1, the rf signal enters the limiter circuit from the input terminal and is output from the output terminal. The actual function of the switching tube in the circuit may be equivalent to the switch 103 connected between the input terminal 101 and the output terminal 102 in the figure, the on and off of which is controlled by the control voltage provided by the control unit 104. When the control voltage provided by the control unit 104 is small, the switch 103 is turned off and assumes a high-impedance state, which does not substantially affect the transmission of signals. When the control voltage provided by the control unit 104 exceeds the preset threshold, the switch 103 is turned on, and is in a low-resistance state, which is equivalent to a small resistor connected in parallel to the ground, and the resistance value of the resistor is reduced along with the increase of the control voltage provided by the control unit 104, and the radio frequency signal passes through the resistor to the ground, so that the output signal power is greatly reduced. Therefore, when the control voltage provided by the control unit 104 is large enough, the output signal power can be limited within a safe range.

In some embodiments, the switch tube may be implemented by a Field Effect Transistor (FET), and specifically includes a Junction Field-Effect Transistor (JFET), a High Electron Mobility Transistor (HEMT), a Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET), and the like.

In some embodiments, the switch is implemented using an N-type Field Effect Transistor (NMOS FET) or a P-type Field Effect Transistor (PMOS FET). As shown in fig. 2, which is a specific embodiment implemented by using an NMOS, when the control voltage provided by the control unit 204 is less than the threshold voltage of the switching tube 203, the switching tube 203 is in an off state, which is equivalent to a high-impedance state, and no current flows at this time, so that the rf signal can pass through with low insertion loss. When the control voltage provided by the control unit 204 is greater than the threshold voltage of the switching tube 203, the switching tube 203 is in a conducting state, which is equivalent to a low-resistance state, and the impedance of the switching tube 203 decreases with the increase of the control voltage provided by the control unit 204, which is equivalent to a voltage-controlled current source. When the control voltage provided by the control unit 204 is large enough, the switch 203 is fully turned on, and is located in the triode region, and the on-resistance is also small enough, so that most of the rf signals pass through the resistor to the ground, thereby realizing the amplitude limiting effect.

In addition, it is understood that in other embodiments, the switching tube may be implemented by other transistors, which is not limited herein.

In some embodiments, the control unit of the switch tube in the circuit may be provided in a variety of ways, as shown in FIG. 3, the impedance of the high resistance device 304 (which may be a resistor, an inductor, or a combination thereof) is generally much greater than the parasitic capacitance between node ① and node ②, and the parasitic capacitance between node ① and node ③, such that the voltage magnitude at node ① is proportional to the voltage magnitude at node ②. at the same time, the impedance of the high resistance device 304 is sufficiently large to prevent RF signals from leaking through the high resistance device 304. as shown in FIG. 4, the switch 404 is connected between the first electrode of the switch tube 403 and the voltage source 405. when the switch 404 is in the on state, the voltage from the voltage source 405 is conducted to the first electrode of the switch tube 403, and then the switch 404 is turned off, the voltage at the first electrode of the switch tube 403 is maintained.

In some embodiments, the voltage source may be replaced with the power detector 505 shown in FIG. 5. The power detector 505 is connected to the input terminal 101 of the rf signal at one end, and is connected to the switch tube 503 via the high impedance device 504 at the other end. The power detector 505 can detect the power of the rf signal inputted from the input terminal 101 and generate a corresponding dc voltage to control the on/off of the switch 503. When the power of the input rf signal is small, the dc voltage output by the power detector 505 is 0 or the output dc voltage is small, and the output voltage is not enough to turn on the switching tube 503, which is equivalent to a high impedance state, so that the rf signal can pass through with low insertion loss. When the power of the input rf signal is large enough, the dc voltage output by the power detector 505 exceeds the threshold of the switch tube 503, so that the switch tube 503 is in a conducting state and the on-resistance is small enough, and most of the input rf signal passes through the resistor to ground, so that the power of the signal reaching the output terminal 102 is reduced. The power detector 505 is used for detecting the power of the input radio frequency signal, and the whole limiter circuit can monitor the power of the input radio frequency signal in real time, and the switch tube 503 is in a high resistance state or a low resistance state according to the power of the input radio frequency signal, so that the purpose of limiting is achieved, and the control voltage value provided by the control unit does not need to be manually set in the whole process.

In some embodiments, there are multiple implementations of the power detector. As shown in fig. 6, the power detector 605 is composed of a diode 606 and a resistor 607. The anode of the diode 606 is connected to the input terminal 101, and the cathode of the diode 606 is connected to one end of the high-resistance device 604. Resistor 607 has one end connected to the cathode of diode 606 and the other end connected to ground. When the power of the radio frequency signal input by the input terminal 101 is small, the diode 606 is not enough to be turned on, the diode 606 is in a high-impedance state, and the control voltage of the corresponding control switch tube 603 is small, and the switch tube 603 is not enough to be turned on, so that the radio frequency signal can pass through with low insertion loss. When the power of the input rf signal is larger, the diode 606 starts to conduct and rectifies the input rf signal, generating a dc signal that increases as the input rf power increases. When the input rf signal power is large enough, the dc signal generated by the diode 606 is enough to turn on the switch 603, and the on-resistance is small enough, and most of the rf signal goes to ground through the resistor 607. However, the disadvantage of this structure is that the parasitic capacitance of the diode 606 affects the insertion loss of the amplitude limiting circuit, and the diode 606 is directly connected to the input terminal 101, so that the diode 606 is easily burned out when the power of the input rf signal is large. Fig. 7 shows a power detector 705 having an improved structure including a diode 706, a resistor 707, and a power coupler 708. A power coupler 708 is provided near the input 101, the amount of coupling being dependent on the characteristics of the diode 706 selected. The diode 706 has the same function as the diode 606 in fig. 6, and the power coupler 708 has a suitable coupling amount and has a small influence on the insertion loss of the limiter circuit. Meanwhile, because the power of the signal coupled through the power coupler 708 is much smaller than that of the input section 101, the diode 706 is not easily burned due to excessive current. The disadvantage of the structure of fig. 7 is that the power coupled from the power coupler 708 to the diode 706 is usually small, and it is difficult for the diode 706 to detect a large dc signal to turn on the switch tube 703. Fig. 8 shows a power detector 805 with a further improved structure, which is based on the structure of the power detector 705, and an amplifier 809 is connected between a diode 806 and a high-resistance device 804, where the amplifier 809 is used to amplify a dc signal detected by the diode 806, so that the switching tube 803 can be turned on as soon as possible to implement clipping, that is, the clipping level of the clipping circuit is reduced, and the driving capability is enhanced to reduce the response recovery time.

In some embodiments, in certain specific processes, such as SOI process, high resistance silicon process, multi-well CMOS process or gallium arsenide process, FETs are well isolated from each other, allowing FETs to be connected in series, in such processes, multiple switch tubes in a limiter circuit according to the present invention may also be connected in series, taking two switch tubes connected in series as an example, a limiter circuit according to the present invention is shown in fig. 9, wherein the second electrode of the switch tube 903 is connected to the input terminal 101, the third electrode is connected to the second electrode of the switch tube 905, and the third electrode of the switch tube 905 is grounded, where the switching on and off of the switch tube 903 is controlled by the control voltage provided by the control unit 904, and the switching tube 905 is controlled by the control voltage provided by the control unit 906, the maximum withstand voltage of the series of switch tubes is the maximum withstand voltage of the switch tube is the Vmax, for example, the maximum withstand voltage of a single switch tube physically withstand voltage is the Vmax, the maximum withstand voltage of the switch tube is the Vmax, the switch tube is connected in series, the switch tube is connected to the switch tube 1005, and the switch tube is connected to the switch tube 1003, the switch tube 1005, and the switch tube 1005 is connected to the switch tube 1005, the switch tube 1003 is connected to the switch tube 1005, and the switch tube 1005.

In some embodiments, a plurality of switch tubes in the limiter circuit according to the present invention may also be connected in parallel, as shown in fig. 11, the switch tube 1103 is connected in parallel with the switch tube 1105, and the on/off of the switch tube 1103 is controlled by the control voltage provided by the control unit 1104, and the on/off of the switch tube 1105 is controlled by the control voltage provided by the control unit 1106. Similar to the above limiter circuit including a plurality of switching tubes connected in series, when a plurality of switching tubes are connected in parallel, the on/off of each switching tube may be controlled by the control voltage provided by the respective control unit, or may be controlled by the control voltage provided by the same control unit.

In some embodiments, a plurality of switching tube sets formed by connecting a plurality of switching tubes in series can also be connected in parallel, the structure has the advantages that the parasitic capacitance of a single switching tube can be distributed to the plurality of switching tube sets, distributed matching is easy to realize, the bandwidth is improved, and in the design of the multi-tube set, the consideration emphasis of each tube set can be different so as to realize better performance. For example, the number of series connections for different tube sets may be different, and a tube set with a large number of series connections may be able to withstand greater power but have a longer response recovery time. And the tube set with small serial number can quickly respond and recover although the power borne by the tube set is small. In practical application, the tubes with large serial number and the tubes with small serial number are used in parallel, so that the device can not only quickly respond, but also bear high power. Fig. 12 shows an example of a switching tube based limiter circuit, which combines the above-mentioned technologies and structures, and mainly includes a radio frequency signal transmission line 1204 for transmitting radio frequency signals; the control unit 1203 is configured to detect a power level of the rf signal input by the input end 101, and then generate a corresponding control voltage to control on/off of the first switching transistor set 1201 and the second switching transistor set 1202. The first switching transistor set 1201 does not affect signal transmission in the off state, and limits the amplitude of an input signal in the on state; the second switch tube set 1202 forms an LC filter with the first switch tube set and the radio frequency signal transmission line 1204 in the off state, thereby ensuring low-loss transmission of the input signal. When the second switching transistor set 1202 is turned on, the input signal is further limited, and the limiting level is reduced.

In some embodiments, the input end of the control unit 1203 is connected to the input end of the rf signal transmission line 1204, and the output end is connected to the control ends of the first switching tube set 1201 and the second switching tube set 1202, so as to control the on/off of the switching tubes in the tube set. One end of the first switching transistor set 1201 is connected to the rf signal transmission line 1204, and the other end is grounded. The second switch tube set 1202 has one end connected to the rf signal transmission line 1204 and the other end grounded.

In some embodiments, the rf signal transmission line 1204 between the input terminal 101 and the output terminal 102 is mainly composed of 4 sections of high-

impedance microstrip lines

12041, 12042, 12043, and 12044, and is formed by stacking two thick metals in a silicon process, and has a large width and thickness to withstand high rf power, the transmission line input and output have pads for gold bonding wires, and the pad size 100um × 100 um. adjusts the width and length of the

microstrip lines

12041, 12042, 12043, and 12044 to optimize small signal S parameters of the limiter circuit, so as to meet design requirements.

In some embodiments, the control unit 1203 mainly includes a pickup diode 12031, a resistor 12032, and a control port 12033. Wherein the anode of the detector diode 12031 is connected to the input terminal of the rf signal transmission line 1204, and the cathode is connected to the resistor 12032 and the control terminals of the switching

transistor sets

1201, 1202. Resistor 12032 has one end connected to the negative terminal of the detector diode and the other end connected to ground. Control port 12033 leads from the control port of the switching manifold. When the input signal power is small, the detector diode 12031 is non-conductive. When the power of the input signal is greater than a certain value, the detector diode 12031 is turned on, and the output voltage signal is used for controlling the on-state of each switching tube, so that the amplitude limiting effect is realized. When the input signal returns to a normal value, the detector diode 12031 is turned off, the control terminal voltage is reduced by discharging the switching tubes through the resistor 12032, the switching tubes are turned off, and the output signal also returns to a normal value. In addition, the control port 12033 has two application modes, one mode is that a control signal can be accessed from the outside to control the on-off of the switch tube, and at the moment, the internal high-power switch is controlled by the external control signal. Another application mode is to suspend the control port, and the internal power detector generates a control signal to control the on/off of the high power switch.

In some embodiments, the first set of switching tubes includes switching

tubes

12011, 12013, 12015, 12017, 12019 connected in series with each other and

resistors

12010, 12012, 12014, 12016, 12018 connected to the first electrodes of the switching tubes, respectively, and the series connection can withstand greater power. It should be understood that, only 5 switching tubes are connected in series for illustration, and the number of the switching tubes connected in series in the switching tube set is not limited, and the specific number needs to be selected according to the power required to be borne in the actual application and the small signal S parameter index requirement. The

resistors

12010, 12012, 12014, 12016, 12018 connected to the electrodes are connected to the first electrodes of the corresponding switch tubes to isolate the rf signals and reduce the insertion loss. In addition, the switching

tubes

12011, 12013, 12015, 12017, and 12019 do not need to have the same size, and may be specifically designed according to the voltage distribution and the index requirement. Likewise, the

resistors

12010, 12012, 12014, 12016, 12018 are not required to be the same size. When a radio-frequency signal passes through the first switch tube set 1201, if the signal voltage amplitude is smaller than the conduction voltage of the medium wave diode 12031 in the control unit 1203, each switch tube in the switch tube set 1201 is in a disconnected state, which is equivalent to a capacitor connected to the ground in parallel, and the radio-frequency signal passes through; when the amplitude of the signal voltage is larger than the conduction voltage of the detection diode 12031 in the control unit 1203, each switch tube in the switch tube set 1201 is in a conduction state, which is equivalent to a small resistor connected in parallel to the ground, and the radio-frequency signal passes through the switch tube to the ground, so that the output signal power is greatly reduced.

In some embodiments, the second set 1202 of switching tubes includes switching

tubes

12021, 12023, and 12025, and

resistors

12020, 12022, and 12024, respectively, coupled to the first electrodes of the switching tubes, which are coupled in the same series configuration as the switching tubes in the first set 1201 of switching tubes. The quantity of the switch tubes in the second switch tube set can be smaller than that of the first switch tube set, so that when radio-frequency signals pass through the second switch tube set, due to the fact that the number of the switch tubes in the second switch tube set is small, the radio-frequency signals can respond quickly, power spikes are eliminated, and amplitude limiting levels are further reduced. It should be understood that, the exemplary illustration is only that 3 switching tubes are connected in series, and the specific number of the switching tubes in the second switching tube set is not limited.

The schematic diagram of the chip of the amplitude limiting circuit according to the present invention is shown in fig. 13. Preferably, the length of the single chip is 950um, the width thereof is 1650um, the positions of the pressure point of the input terminal 1301, the pressure point of the output terminal 1302 and the pressure point of the control terminal 1303 are shown in the figure, and meanwhile, the single chip is marked with characters, wherein RFin represents an input terminal interface of a radio frequency signal, RFout represents an output terminal interface of the radio frequency signal, and VCTRL represents a control terminal interface. In addition, the control terminal 1303 has two application modes, one mode is that a control signal can be accessed from the outside to control the on-off of the switch tube, and at the moment, the internal high-power switch is controlled by the external control signal. Another application mode is to suspend the control port, and the internal rf power detector generates a control signal to control the on/off of the high power switch.

The chip assembly diagram of the limiting circuit according to the present invention is shown in fig. 14. The chip can be bonded by conductive adhesive, and the input terminal 1301 and the output terminal 1302 can be connected by gold wires and external microstrip lines. Preferably, two gold wires can be used for connection, and the shorter the length of the gold wire, the better. The control terminal 1303 may be connected to an external microstrip line by using a gold wire, or may be directly connected to an external control pin by using a gold wire. It is noted that the input of the amplitude circuit must correspond to the direction of transmission of the signal during assembly.

In some embodiments, fig. 15 shows a relationship curve between the input power Pin and the output power Pout when a continuous wave power signal is input into the limiter circuit according to the present invention. The whole curve can be divided into two regions: a, linear region. In the region, the input signal power Pin is small, the output signal power Pout and the input signal power Pin are almost the same, and the signals pass through almost without attenuation; and B, a limiting zone. In this region, the output signal power Pout begins to decay as the input signal power Pin is above a threshold level, i.e., above about 13dBm, and then substantially within a designed safe range as the input signal power Pin increases. From the test results, it can be seen that when the input signal power Pin is less than or equal to 43dBm, the maximum leakage level of the disclosed clipping circuit is less than 15 dBm.

In some embodiments, the utility model discloses a wireless receiving device includes the amplitude limiting circuit in above-mentioned embodiment, wireless receiving device's structure adopt among the prior art commonly used can realize carrying out the wireless receiving device of amplitude limiting to input radio frequency signal can, mainly include parts such as receiving arrangement front end, demodulator, amplitude limiter and device shell. Wherein, the limiter among the wireless receiving device is through using the utility model discloses an amplitude limiting circuit reduces the power of the radio frequency signal received, avoids the low noise in the receiver to put and is burnt to the realization is to the protection of wireless signal receiver. It should be understood that the wireless receiving device including the amplitude limiting circuit disclosed in the present invention is only illustrated here, and the specific structure and application environment of the wireless receiving device are not limited, and the specific structure and parameters of the wireless receiving device can be selected and adjusted according to actual needs.

The utility model also discloses some embodiments, specifically:

embodiment 1 may include a clipping circuit, the circuit comprising: the signal input end, the signal output end, at least one switching tube and at least one control unit;

Embodiment 2 may include the circuit of embodiment 1, wherein the limiter circuit further includes at least one resistor corresponding to each of the at least one switching tube, a first electrode of the switching tube is connected to a first end of the corresponding resistor, and a second end of the resistor is connected to the control unit.

Embodiment 3 may include the circuit of embodiment 1 or 2, wherein the limiter circuit includes a switch tube, a first electrode of the switch tube is connected to the control unit, a second electrode of the switch tube is connected to the signal input terminal and the signal output terminal, and a third electrode of the switch tube is grounded.

Embodiment 4 may include the circuit of any of embodiments 1 to 3, wherein the clipping circuit includes at least two switching tubes connected in parallel with each other.

Embodiment 5 may include the circuit of any of embodiments 1 to 4, wherein the second electrodes of the at least two switching tubes are connected to the signal input terminal and the signal output terminal, and the third electrodes of the at least two switching tubes are grounded.

Embodiment 6 may include the circuit of any one of embodiments 1 to 5, wherein the first electrodes of the at least two switching tubes are respectively connected to two control units.

Embodiment 7 may include the circuit of any of embodiments 1 to 5, wherein the first electrodes of the at least two switching tubes are connected to the same control unit.

Embodiment 8 may include the circuit of any of embodiments 1 to 3, wherein the clipping circuit includes at least two switching tubes connected in series with each other.

Embodiment 9 may include the circuit of embodiment 8, wherein a second electrode of a first switch tube of the at least two switch tubes is connected to the signal input terminal and the signal output terminal, and a third electrode of a second switch tube of the at least two switch tubes is grounded.

Embodiment 10 may include the circuit of embodiment 8 or 9, wherein the first electrodes of the at least two switching tubes are respectively connected to two control units.

Embodiment 11 may include the circuit of embodiment 8 or 9, wherein the first electrodes of the at least two switching tubes are connected to the same control unit.

Embodiment 12 may include the circuit of any of embodiments 1-11, the clipping circuit comprising a first switch tube set and a second switch tube set connected in parallel with each other;

the first switch tube set comprises at least two switch tubes which are connected in series, and the second switch tube set comprises at least two switch tubes which are connected in series.

Embodiment 13 may include the circuit of any of embodiments 1-12, wherein a second electrode of one of the first set of switching tubes is connected to the signal input and the signal output, and a third electrode is connected to a second electrode of a switching tube in series with the switching tube.

Embodiment 14 may include the circuit of any of embodiments 1-12, wherein the third electrode of one of the first set of switching tubes is connected to ground and the second electrode is connected to the third electrode of a switching tube connected in series with the switching tube.

Embodiment 15 may include the circuit of any of embodiments 1-12, wherein a second electrode of one of the second set of switching tubes connects the signal input and the signal output, and a third electrode connects the second electrodes of the switching tubes in series with the switching tube.

Embodiment 16 may include the circuit of any of embodiments 1-12, wherein the third electrode of one of the second set of switching tubes is connected to ground and the second electrode is connected to the third electrode of a switching tube connected in series with the switching tube.

Embodiment 17 may include the circuit of any of embodiments 1-16, wherein the first electrodes of the different switching tubes included in the first and second switching tube sets are connected to the same control unit.

Embodiment 18 may include the circuit of any of embodiments 1-16, wherein the first electrodes of the different switching tubes included in the first and second switching tube sets are connected to different control units.

Embodiment 19 may include the circuit of any of embodiments 1-18, wherein the control unit is a voltage source.

Embodiment 20 may include the circuit of any of embodiments 1-18, wherein the control unit is a power detector.

Embodiment 21 may include the circuit of embodiment 20, wherein the power detector is capable of generating a corresponding dc voltage to control the on/off of the switching tube according to the detected power of the signal input terminal.

Embodiment 22 may include the circuit of any of embodiments 1-21, wherein the switching transistor is a field effect transistor.

Embodiment 23 may include a wireless receiving apparatus including the clipping circuit of any one of embodiments 1 to 22.

The embodiments of the present invention have been described in detail with reference to the drawings, but the present invention is not limited to the above embodiments, and various changes made without departing from the spirit and scope of the present invention should be construed as falling within the scope of the present invention.

In the drawings, some features of the structures or methods may be shown in a particular arrangement and/or order. However, it is to be understood that such specific arrangement and/or ordering may not be required. Rather, in some embodiments, the features may be arranged in a manner and/or order different from that shown in the illustrative figures. In addition, the inclusion of a structural or methodical feature in a particular figure is not meant to imply that such feature is required in all embodiments, and in some embodiments, may not be included or may be combined with other features.

It is noted that, in the examples and descriptions of the present invention, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the use of the verb "comprise a" to define an element does not exclude the presence of another, same element in a process, method, article, or apparatus that comprises the element.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims

1. A clipping circuit, comprising: the signal input end, the signal output end, at least one switching tube and at least one control unit;

2. The circuit of claim 1, wherein the clipping circuit further comprises at least one resistor corresponding to each of the at least one switching tube, a first electrode of the switching tube is connected to a first end of the corresponding resistor, and a second end of the resistor is connected to the control unit.

3. The circuit of claim 1, wherein the clipping circuit comprises a switch tube, wherein a first electrode of the switch tube is connected to the control unit, a second electrode of the switch tube is connected to the signal input terminal and the signal output terminal, and a third electrode of the switch tube is grounded.

4. The circuit of claim 1, wherein the clipping circuit comprises at least two switching tubes, the at least two switching tubes being connected in parallel with each other.

5. The circuit of claim 4, wherein the second electrodes of the at least two switching tubes are connected to the signal input terminal and the signal output terminal, and the third electrodes of the at least two switching tubes are grounded.

6. The circuit of claim 5, wherein the first electrodes of the at least two switching tubes are respectively connected with two control units.

7. The circuit of claim 5, wherein the first electrodes of the at least two switching tubes are connected to the same control unit.

8. The circuit of claim 1, wherein the clipping circuit comprises at least two switching tubes, and wherein the at least two switching tubes are connected in series with each other.

9. The circuit of claim 8, wherein a second electrode of a first switch tube of the at least two switch tubes is connected to the signal input terminal and the signal output terminal, and a third electrode of a second switch tube of the at least two switch tubes is connected to ground.

10. The circuit of claim 9, wherein the first electrodes of the at least two switching tubes are respectively connected to two control units.

11. The circuit of claim 9, wherein the first electrodes of the at least two switching tubes are connected to the same control unit.

12. The circuit of claim 1, wherein the clipping circuit comprises a first switch tube set and a second switch tube set connected in parallel with each other;

13. The circuit of claim 12, wherein a second electrode of one of the first set of switching tubes is connected to the signal input and signal output, and a third electrode is connected to a second electrode of a switching tube connected in series with the switching tube.

14. The circuit of claim 12, wherein the third electrode of one of the first switching tubes is connected to ground, and the second electrode is connected to the third electrode of the switching tube connected in series with the switching tube.

15. The circuit of claim 12, wherein a second electrode of one of the second set of switching tubes is connected to the signal input and the signal output, and a third electrode is connected to a second electrode of a switching tube connected in series with the switching tube.

16. The circuit of claim 12, wherein the third electrode of one of the second set of switching tubes is connected to ground, and the second electrode is connected to the third electrode of the switching tube connected in series with the switching tube.

17. The circuit of claim 12, wherein the first electrodes of the different switching tubes included in the first and second switching tube sets are connected to the same control unit.

18. The circuit of claim 12, wherein the first electrodes of the different switching tubes included in the first and second switching tube sets are connected to different control units.

19. The circuit of claim 1, wherein the control unit is a voltage source.

20. The circuit of claim 1, wherein the control unit is a power detector.

21. The circuit of claim 20, wherein the power detector is capable of generating a corresponding dc voltage to control the on and off of the switching tube according to the detected power of the signal input terminal.

22. The circuit of claim 1, wherein the switching transistor is a field effect transistor.

23. A radio receiving apparatus comprising the limiter circuit according to any one of claims 1 to 22.