High-power amplitude limiter with filtering characteristic

Abstract

The invention provides a high-power amplitude limiter with a filtering characteristic. The high-power amplitude limiter comprises a first amplitude limiting module connected with an input port, a second amplitude limiting module connected with an output port and an intermediate cascade module. The first amplitude limiting module comprises a first amplitude limiting circuit and a first reactance module; the first amplitude limiting circuit and the first reactance module are connected in series to a main transmission line of the amplitude limiter. The second amplitude limiting module comprises a second amplitude limiting circuit and a second reactance module; the second amplitude limiting circuit and the second reactance module are connected in series to the main transmission line of the amplitude limiter; the two ends of the middle cascade module are connected in series with inductive reactance elements and then connected to the amplitude limiter main transmission line, and the middle of the middle cascade module is connected in parallel with capacitive elements and then grounded. According to the technical scheme, the original in-band excellent electromagnetic protection characteristic of the amplitude limiter can be ensured while the filtering characteristic is realized, the performance deterioration of a radio frequency receiving signal caused by cascade mismatch of the amplitude limiter and a radio frequency channel post-stage filter is avoided, and the total volume ratio of a radio frequency channel electromagnetic protection device is effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetic protection, and in particular relates to a high-power limiter with filtering characteristics. Background Art

[0002] Electromagnetic protection refers to the protective measures taken to eliminate the impact or even harm of electromagnetic environmental effects (or electromagnetic hazard sources) on equipment and people. As an adaptive device for power control, the limiter can effectively attenuate the input high-power signal to a safe range to prevent strong electromagnetic signals from damaging the receiver.

[0003] Traditional limiters often use hybrid integration technology to interconnect discrete components through wires and bonding wires. This type of limiter has high withstand power and can withstand strong electromagnetic pulses. However, due to the use of discrete devices for circuit construction, the size of a single limiter is large, which is not conducive to integration in compact equipment or systems. In addition, traditional limiters designed with discrete devices also face problems such as difficulty in debugging and unsuitability for broadband operation. In particular, their insertion loss is relatively high. Using them in the RF front end will reduce the signal-to-noise ratio of the signal, thereby reducing the quality of the received signal.

[0004] In contrast, the monolithic integrated circuit limiter packages various components on one chip, making it almost impossible to connect components, and the parasitic parameters of the circuit are less affected. It has the characteristics of high operating frequency, wide frequency range, and low circuit loss. Since the monolithic integrated circuit limiter integrates multiple functional components on one chip, the structure is more compact and can effectively meet the requirements of modern highly integrated RF microsystems.

[0005] Therefore, how to improve a high-power limiter with filtering characteristics to ensure the excellent electromagnetic protection characteristics of the limiter's original band, avoid the performance deterioration of the RF receiving signal caused by the cascade mismatch between the limiter and the filter, and effectively reduce the overall volume share of the RF channel electromagnetic protection devices has become a technical problem that needs to be solved urgently. Summary of the invention

[0006] The embodiment of the present invention provides a high-power limiter with filtering characteristics, which can ensure the excellent electromagnetic protection characteristics of the original band of the limiter, avoid the performance deterioration of the RF receiving signal caused by the cascade mismatch between the limiter and the filter, and effectively reduce the overall volume proportion of the RF channel electromagnetic protection device.

[0007] In an embodiment of the present invention, a high-power limiter with filtering characteristics is provided, comprising: a first limiter module 1 connected to an input port, a second limiter module 2 connected to an output port, and an intermediate cascade module 3.

[0008] The first amplitude limiting module 1 comprises: a first amplitude limiting circuit 11 composed of a PIN tube and a first reactance module 12; the first amplitude limiting circuit 11 and the first reactance module 12 are connected in series to the main transmission line of the amplitude limiter.

[0009] The second amplitude limiting module 2 comprises: a second amplitude limiting circuit 21 composed of a PIN tube and a second reactance module 22; the second amplitude limiting circuit 21 and the second reactance module 22 are connected in series to the main transmission line of the amplitude limiter;

[0010] The intermediate cascade module 3 is a T-type low-pass filter structure. The two ends of the intermediate cascade module 3 are connected in series with inductive elements and then connected to the main transmission line of the limiter. The middle of the intermediate cascade module 3 is connected in parallel with a capacitive element and then grounded. Among them, the number of intermediate cascade modules 3 is less than the number of the first limiting modules 1 and the second limiting modules 2.

[0011] Furthermore, the first amplitude limiting circuit 11 is a diode reverse parallel structure, including N pairs of identical PIN tube parallel branches;

[0012] Each pair of parallel branches includes two PIN tube series branches, which are formed by M identical PIN tubes connected in series in the same direction, with the anode of the PIN tube of one series branch being grounded and the cathode of the PIN tube of the other series branch being grounded; wherein M and N are both positive integers.

[0013] Furthermore, the first reactance module 12 is an inductive module, and forms an m-derivative filter section with the capacitive first limiter circuit 11 to achieve strong attenuation of out-of-band high-frequency signals.

[0014] Furthermore, the first limiting module 1 comprises: a first limiting circuit 11 composed of 12 PIN tubes and a first inductor module 12 providing filter characteristics;

[0015] When the limiter is working, the radio frequency conductivity modulation effect of the PIN tube reduces the on-resistance of the diode to achieve the limiting function; the 12 PIN tubes are divided into two pairs of PIN tubes connected in reverse parallel, and multiple branches are connected in parallel to achieve the high power capacity of the limiting circuit. Each pair of parallel branches includes two strings of PIN tube series branches connected in reverse series, and each series branch includes three identical PIN tubes. When the limiting is working, the two series PIN tubes provide each other with an inductive DC circuit.

[0016] Furthermore, the second amplitude limiting circuit 21 adopts a diode anti-parallel structure, including two anti-directional PIN tubes, wherein the anode of one PIN tube is grounded, and the cathode of the other PIN tube is grounded.

[0017] Furthermore, the second reactance module 22 is an inductive module, adopts a spiral inductor structure, and forms an m-derivative filter section with the second limiting circuit 21 having capacitance, so as to achieve strong attenuation of out-of-band high-frequency signals.

[0018] Furthermore, the limiter is designed as a monolithic integrated circuit using a GaAs PIN tube.

[0019] The beneficial effects brought by the present invention are as follows:

[0020] It can be seen from the above scheme that the embodiment of the present invention provides a high-power limiter with filtering characteristics, including: a first limiting module connected to the input port, a second limiting module connected to the output port and an intermediate cascade module. The first limiting module includes: a first limiting circuit composed of a PIN tube and a first reactance module; the first limiting circuit and the first reactance module are connected in series to the main transmission line of the limiter. The second limiting module includes: a second limiting circuit composed of a PIN tube and a second reactance module; the second limiting circuit and the second reactance module are connected in series to the main transmission line of the limiter; the intermediate cascade module is a T-type low-pass filter structure, and the two ends of the intermediate cascade module are connected to the main transmission line of the limiter after the inductive reactance elements are connected in series, and the middle of the intermediate cascade module is connected in parallel with the capacitive element and then grounded. The technical solution of the present invention can ensure the original excellent electromagnetic protection characteristics of the limiter in the band while realizing the filtering characteristics, avoid the performance deterioration of the RF receiving signal caused by the cascade mismatch between the limiter and the post-stage filter of the RF channel, and effectively reduce the overall volume proportion of the RF channel electromagnetic protection device through integrated design. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram showing the electrical structure of a high-power limiter with filtering characteristics according to an embodiment of the present invention;

[0022] Figure 2 An equivalent circuit diagram showing a high-power limiter with filtering characteristics according to an embodiment of the present invention;

[0023] Figure 3 A schematic diagram showing a comparison of insertion losses between a high-power limiter with filtering characteristics according to an embodiment of the present invention and a conventional fixed-k-type structure limiter;

[0024] In the figure, 1 is the first limiting module, 11 is the first limiting circuit, 12 is the first reactance module, 2 is the second limiting module, 21 is the limiting circuit, 22 is the second reactance module, and 3 is the intermediate cascade module. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] At present, both the traditional limiter and the new monolithic integrated circuit limiter need to be cascaded with the filter to complete the comprehensive protection of the RF channel, which will lead to further increase in the insertion loss at the input end of the RF channel and the size of the electromagnetic protection device.

[0027] like Figure 1 and Figure 2 As shown, Figure 1 A schematic diagram showing the electrical structure of a high-power limiter with filtering characteristics according to an embodiment of the present invention; Figure 2 An equivalent circuit diagram of a high-power limiter with filtering characteristics according to an embodiment of the present invention is shown.

[0028] Figure 1 A high-power limiter with filtering characteristics includes: a first limiter module 1 connected to an input port, a second limiter module 2 connected to an output port, and an intermediate cascade module 3.

[0029] The first amplitude limiting module 1 comprises: a first amplitude limiting circuit 11 composed of a PIN tube and a first reactance module 12; the first amplitude limiting circuit 11 and the first reactance module 12 are connected in series to the main transmission line of the amplitude limiter.

[0030] The second amplitude limiting module 2 comprises: a second amplitude limiting circuit 21 composed of a PIN tube and a second reactance module 22; the second amplitude limiting circuit 21 and the second reactance module 22 are connected in series to the main transmission line of the amplitude limiter;

[0031] The intermediate cascade module 3 is a T-type low-pass filter structure, the two ends of the intermediate cascade module 3 are connected in series with the inductive reactance elements and then connected to the main transmission line of the limiter, and the middle of the intermediate cascade module 3 is connected in parallel with the capacitive element and then grounded. Among them, the number of intermediate cascade modules 3 is less than the number of the first limiting module 1 and the second limiting module 2.

[0032] In the embodiment of the present invention, the first limiter circuit 11 is a diode reverse parallel structure, including N pairs of identical PIN tube parallel branches;

[0033] Each pair of parallel branches includes two PIN tube series branches, which are formed by M identical PIN tubes connected in series in the same direction, with the anode of the PIN tube of one series branch being grounded and the cathode of the PIN tube of the other series branch being grounded; wherein M and N are both positive integers.

[0034] In another embodiment of the present invention, the first reactance module 12 is an inductive module, which forms an m-derivative filter section with the capacitive first limiter circuit 11 to achieve strong attenuation of out-of-band high-frequency signals.

[0035] In another embodiment of the present invention, the first amplitude limiting module 1 includes: a first amplitude limiting circuit 11 composed of 12 PIN tubes and a first inductor module 12 providing filter characteristics;

[0036] When the limiter is working, the radio frequency conductivity modulation effect of the PIN tube reduces the on-resistance of the diode to achieve the limiting function; the 12 PIN tubes are divided into two pairs of PIN tubes connected in reverse parallel, and multiple branches are connected in parallel to achieve the high power capacity of the limiting circuit. Each pair of parallel branches includes two strings of PIN tube series branches connected in reverse series, and each series branch includes three identical PIN tubes. When the limiting is working, the two series PIN tubes provide each other with an inductive DC circuit.

[0037] In another embodiment of the present invention, the second amplitude limiting circuit 21 adopts a diode anti-parallel structure, including two anti-parallel PIN tubes, wherein the anode of one PIN tube is grounded, and the cathode of the other PIN tube is grounded.

[0038] In another embodiment of the present invention, the second reactance module 22 is an inductive module, adopts a spiral inductor structure, and forms an m-derivative filter section with the second limiting circuit 21 having capacitance to achieve strong attenuation of out-of-band high-frequency signals.

[0039] In another embodiment of the present invention, the limiter is designed as a monolithic integrated circuit using a GaAs PIN transistor.

[0040] Compared with the prior art, in the technical embodiment of the present invention, the integrated design of the limiter and the filter can achieve the suppression of out-of-band interference signals while ensuring the original excellent electromagnetic protection characteristics of the limiter in the band through only a simple circuit structure, and has excellent filtering characteristics. The technical solution of the present invention can effectively avoid the performance deterioration of the RF receiving signal caused by the cascade mismatch between the limiter and the filter, ensure that the RF front end has wide bandwidth and low insertion loss characteristics, facilitate the further stacking of PIN tubes, and enable the limiter to have high power handling capacity.

[0041] Among them, the limiter has filtering characteristics, and the electromagnetic protection process of the RF front end no longer relies on a separate filter to suppress out-of-band interference signals, which effectively reduces the overall volume share of the RF channel electromagnetic protection devices, which is beneficial to the current miniaturization design needs of the RF front end.

[0042] In another embodiment of the present invention, a high-power limiter with filtering characteristics is provided. The limiter is designed as a monolithic integrated circuit using a GaAs PIN tube and is designed to be applied to a radio frequency band of 0-8 GHz. Figure 1 As shown, the limiter is a two-stage limiter structure, including a limiter module 1 connected to the input port, a limiter module 2 connected to the output port, and an intermediate cascade module 3.

[0043] The limiting module 1 includes a limiting circuit 11 composed of twelve PIN tubes and an inductance module 12 providing filter characteristics. The power processing of the limiter is mainly completed by the first-stage limiting circuit. The limiting circuit 11 adopts twelve identical PIN tubes to realize the reverse parallel structure design. The size of each PIN tube is 70um×20um. When the limiter is working, the radio frequency conductivity modulation effect of the PIN tube reduces the on-resistance of the diode to realize the limiting function. These twelve large-size PIN tubes are divided into two pairs of PIN tubes in reverse parallel connection. The high power capacity of the limiting circuit is realized by using multi-branch parallel connection. Each pair of parallel branches includes two series of PIN tube series branches in reverse series connection. Each series branch includes three identical PIN tubes. When the limiting is working, the two series of PIN tubes provide each other with an inductance DC circuit.

[0044] The first reactance module 12 has inductance characteristics and adopts a spiral inductor structure. The high-power limiter circuit composed of twelve PIN tubes is connected in series with the spiral inductor to the main transmission line of the limiter. The traditional limiter mainly adopts a fixed k-type circuit structure. Although the low-pass design of the limiter can be realized, the power attenuation at the cut-off frequency is low, and it does not have effective filtering characteristics for high-frequency signals outside the working frequency band.

[0045] like Figure 3 As shown, Figure 3 A schematic diagram showing a comparison of insertion losses between a high-power limiter with filtering characteristics according to an embodiment of the present invention and a traditional fixed-k structure limiter is shown.

[0046] It is understandable that in other implementations of the present invention, the number of PIN tubes in the first reactance module 12 can be adjusted according to specific needs and is not specifically limited herein.

[0047] The limiter provided by the present invention is improved in circuit design. Figure 2 This is the equivalent circuit diagram of this example. As shown in the figure, the inductor module and the first limiting circuit 11 form an m-derived filter section. After optimizing other reactance structures, an improved m-derived low-pass filter design can be achieved. While ensuring excellent transmission characteristics of 0-8GHz, it can achieve strong attenuation of out-of-band high-frequency signals and have high-frequency filtering characteristics.

[0048] The limiting module 2 includes a second limiting circuit 21 composed of two PIN tubes and a second reactance module 22. The second limiting module 22 is composed of two PIN tubes of the same size connected in reverse parallel. The size of the PIN tube is 35um×20um. The second reactance module 22 has an inductance characteristic and adopts a spiral inductance structure. The limiting circuit 21 is connected in series with the spiral inductor to the main transmission line of the limiter. The equivalent circuit of this module is similar to the first-stage limiting circuit, and is also equivalent to an m-derived low-pass filter structure. In the embodiment of the present invention, both the two-stage limiting modules adopt an m-derived filter section, the first-stage reactance module 12 adopts a spiral inductor with a relatively low inductance value, and the second-stage reactance module 22 adopts a spiral inductor with a relatively high inductance value. While providing high filtering characteristics and strong attenuation for out-of-band high-frequency signals, it avoids the limiter size being too large due to the series inductance.

[0049] The middle cascade module 3 is a T-type low-pass filter structure, with spiral inductors connected in series at both ends to the main transmission line, and a parallel capacitor in the middle to ground. The T-type structure reduces the length of the limiter's main transmission line, effectively reduces transmission losses, and ensures that the limiter can still achieve wide-band small signal transmission after completing the high-power limiting design.

[0050] In the embodiment of the present invention, the limiter may be designed by hybrid integration process using a PIN tube of discrete components.

[0051] The technical solution of the present invention is a high-power limiter with filtering characteristics, which can ensure the excellent electromagnetic protection characteristics of the original band of the limiter, avoid the performance deterioration of the radio frequency receiving signal caused by the cascade mismatch between the limiter and the filter, and effectively reduce the overall volume proportion of the electromagnetic protection device of the radio frequency channel.

[0052] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A high-power limiter with filtering characteristics, characterized in that: The limiter comprises: a first limiter module (1) connected to an input port, a second limiter module (2) connected to an output port, and an intermediate cascade module (3); The first amplitude limiting module (1) comprises: a first amplitude limiting circuit (11) composed of a PIN tube and a first reactance module (12); the first amplitude limiting circuit (11) and the first reactance module (12) are connected in series to a main transmission line of the amplitude limiter; The second amplitude limiting module (2) comprises: a second amplitude limiting circuit (21) composed of a PIN tube and a second reactance module (22); the second amplitude limiting circuit (21) and the second reactance module (22) are connected in series to the main transmission line of the amplitude limiter; The intermediate cascade module (3) is a T-type low-pass filter structure, the two ends of the intermediate cascade module (3) are connected in series with inductive reactance elements and then connected to the main transmission line of the limiter, and the middle of the intermediate cascade module (3) is connected in parallel with a capacitive element and then grounded; wherein the number of the intermediate cascade modules (3) is respectively less than the number of the first limiter modules (1) and the second limiter modules (2).

2. A high-power limiter with filtering characteristics according to claim 1, characterized in that: The first amplitude limiting circuit (11) is a diode reverse parallel structure, comprising N pairs of identical PIN tube parallel branches; Each pair of parallel branches includes two PIN tube series branches, which are formed by M identical PIN tubes connected in series in the same direction, with the anode of the PIN tube of one series branch being grounded and the cathode of the PIN tube of the other series branch being grounded; wherein M and N are both positive integers.

3. A high-power limiter with filtering characteristics according to claim 2, characterized in that: The first reactance module (12) is an inductive module, and forms an m-derivative filter section with the first limiting circuit (11) having capacitance, thereby achieving strong attenuation of out-of-band high-frequency signals.

4. A high-power limiter with filtering characteristics according to claim 2, characterized in that: The first amplitude limiting module (1) comprises: the first amplitude limiting circuit (11) composed of 12 PIN tubes and the first inductance module (12) providing filter characteristics; When the limiter is working, the radio frequency conductivity modulation effect of the PIN tube reduces the on-resistance of the diode to achieve the limiting function; the 12 PIN tubes are divided into two pairs of PIN tubes connected in reverse parallel, and multiple branches are connected in parallel to achieve the high power capacity of the limiting circuit. Each pair of parallel branches includes two strings of PIN tube series branches connected in reverse series, and each series branch includes three identical PIN tubes. When the limiting is working, the two series PIN tubes provide each other with an inductive DC circuit.

5. A high-power limiter with filtering characteristics according to claim 1, characterized in that: The second amplitude limiting circuit (21) adopts a diode reverse parallel structure and comprises two reverse PIN tubes, wherein the anode of one PIN tube is grounded and the cathode of the other PIN tube is grounded.

6. A high-power limiter with filtering characteristics according to claim 1, characterized in that: The second reactance module (22) is an inductive module, adopts a spiral inductor structure, and forms an m-derivative filter section with the second limiting circuit (21) having capacitance, so as to achieve strong attenuation of out-of-band high-frequency signals.

7. A high-power limiter with filtering characteristics according to any one of claims 1 to 6, characterized in that: The limiter adopts GaAs PIN tube to carry out single chip integrated circuit design.

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