CN117081542A - Filter bank - Google Patents

Abstract

The application relates to the field of filters, in particular to a filter bank, which comprises a radio frequency input end RF1 and a radio frequency output end RF2; comprising the following steps: seven band-pass filter units: a first band-pass filter unit, a second band-pass filter unit, a third band-pass filter unit, a fourth band-pass filter unit, a fifth band-pass filter unit, a sixth band-pass filter unit, and a seventh band-pass filter unit; six single pole three throw switching circuits: the first single-pole three-throw switch circuit S1, the second single-pole three-throw switch circuit S2, the third single-pole three-throw switch circuit S3, the fourth single-pole three-throw switch circuit S4, the fifth single-pole three-throw switch circuit S5 and the sixth single-pole three-throw switch circuit S6; for selecting any one of the seven band-pass filter units, filtering out frequency signals outside the band-pass filter units; and a control unit for controlling the respective selection paths of the six single pole three throw switch circuits. The application has the effect of selectable filtering.

Description

filter bank

Technical field

The present application relates to the field of filters, and in particular to a filter bank.

Background technique

At present, in radar systems, especially in receiving systems, a filter is usually required to filter out the received signals outside a specific frequency band. LC filter is also called passive filter, which does not require additional power supply and is widely used in fields such as harmonic suppression. Traditional LC filters are usually built using discrete components. This method has the disadvantages of high cost, large size, poor performance consistency, and can usually only filter signals outside a single frequency band.

With the continuous improvement of LC filter performance in 2-18GHz radar systems, it is often necessary to filter signals in different frequency ranges. The traditional LC filter can only filter signals outside a single frequency and cannot satisfy such systems. requirements.

Contents of the invention

In order to filter signals in multiple frequency bands, this application provides a filter bank.

The filter bank provided by this application adopts the following technical solution:

A filter bank is provided, including a radio frequency input terminal RF1 and a radio frequency output terminal RF2; including:

Seven band-pass filter units: the first band-pass filter unit, the second band-pass filter unit, the third band-pass filter unit, the fourth band-pass filter unit, the fifth band-pass filter unit, the sixth band-pass filter unit a bandpass filter unit and a seventh bandpass filter unit;

Six single pole three throw switch circuits: the first single pole three throw switch circuit S1, the second single pole three throw switch circuit S2, the third single pole three throw switch circuit S3, the fourth single pole three throw switch circuit S4, the fifth single pole three throw switch circuit S4 Circuit S5 and sixth single-pole three-throw switch circuit S6; used to select any one of the seven band-pass filter units and filter out frequency signals other than the band-pass filter unit;

Control units respectively connected to the six single-pole three-throw switch circuits and controlling respective selection paths of the six single-pole three-throw switch circuits;

The input terminal of the first single-pole three-throw switch circuit S1 is connected to the radio frequency input terminal RF1, and the three output terminals of the first single-pole three-throw switch circuit S1 are selectively connected to the second single-pole three-throw switch circuit S2 and the third single-pole three-throw switch circuit S2. Respective input terminals of the three-throw switch circuit S3 or the fourth band-pass filter unit;

The three output terminals of the second single-pole three-throw switch circuit S2 are selectively connected to the respective input terminals of the first band-pass filter unit, the second band-pass filter unit or the third band-pass filter unit; the third band-pass filter unit The three input terminals of the four single-pole three-throw switch circuit S4 are selectively connected to the respective output terminals of the first band-pass filter unit, the second band-pass filter unit or the third band-pass filter unit; the second The band-pass filter unit selected by the single-pole three-throw switch circuit S2 and the fourth single-pole three-throw switch circuit S4 remains consistent;

The three output terminals of the third single-pole three-throw switch circuit S3 are selectively connected to the respective input terminals of the fifth band-pass filter unit, the sixth band-pass filter unit or the seventh band-pass filter unit; the third The three input terminals of the five single-pole three-throw switch circuit S5 are selectively connected to the respective output terminals of the fifth band-pass filter unit, the sixth band-pass filter unit or the seventh band-pass filter unit; the third The band-pass filter unit selected by the single-pole three-throw switch circuit S3 and the fifth single-pole three-throw switch circuit S5 remains consistent;

The three input terminals of the sixth single-pole three-throw switch circuit S6 are selectively connected to the output terminal of the fourth single-pole three-throw switch circuit S4, the output terminal of the fourth band-pass filter unit or the fifth single-pole three-throw switch circuit S4. The respective output terminals of the throw switch S5; the output terminal of the sixth single-pole three-throw switch S6 is connected to the radio frequency output terminal RF2;

When the first single-pole three-throw switch circuit S1 selects the input terminal of the second single-pole three-throw switch circuit S2, the sixth single-pole three-throw switch circuit S6 selects the output terminal of the fourth single-pole three-throw switch circuit S4;

When the first single-pole three-throw switch circuit S1 selects the input terminal of the third single-pole three-throw switch circuit S3, the sixth single-pole three-throw switch circuit S6 selects the output terminal of the fifth single-pole three-throw switch circuit S5;

When the first single-pole three-throw switch circuit S1 selects the input terminal of the fourth band-pass filter unit, the sixth single-pole three-throw switch circuit S6 selects the output terminal of the fourth band-pass filter unit.

Preferably, each of the seven band-pass filter units of different frequency bands includes: a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, which are connected in series in sequence. the fifth capacitor C5, the first inductor L1, the second inductor L2, the third inductor L3, and the fourth inductor L4;

At the connection between the first capacitor C1 and the second capacitor C2, there are provided a fifth inductor L5 and a sixth capacitor C6 which are connected to the ground terminal in sequence;

At the connection between the second capacitor C2 and the third capacitor C3, a sixth inductor L6 and a seventh capacitor C7 connected to the ground terminal in sequence are provided;

At the connection between the third capacitor C3 and the fourth capacitor C4, a seventh inductor L7 and an eighth capacitor C8 connected to the ground terminal in sequence are provided;

At the connection between the fourth capacitor C4 and the fifth capacitor C5, an eighth inductor L8 and a ninth capacitor C9 connected to the ground terminal in sequence are provided;

The tenth capacitor C10, the eleventh capacitor C11, the twelfth capacitor C12 and the thirteenth capacitor C13 are respectively connected in parallel at both ends of the first inductor L1, the second inductor L2, the third inductor L3 and the fourth inductor L4. ;

The fourteenth capacitor C14, the fifteenth capacitor C15, the sixteenth capacitor C16, and the ground terminal are respectively connected from two ends of the first inductor L1, the second inductor L2, the third inductor L3 and the fourth inductor L4 to the ground terminal. The seventeenth capacitor C17 and the eighteenth capacitor C18.

Preferably, in the first bandpass filter unit, the second bandpass filter unit, the third bandpass filter unit, the fourth bandpass filter unit, the fifth bandpass filter unit, and the sixth bandpass filter unit, The respective connections between the filter unit and the seventh bandpass filter unit and the first single-pole three-throw switch circuit S1, the second single-pole three-throw switch circuit S2, and the third single-pole three-throw switch circuit S3 are respectively arranged correspondingly. There are a first attenuator T1, a second attenuator T2, a third attenuator T3, a fourth attenuator T4, a fifth attenuator T5, a sixth attenuator T6, and a seventh attenuator T7.

Preferably, in the first bandpass filter unit, the second bandpass filter unit, the third bandpass filter unit, the fourth bandpass filter unit, the fifth bandpass filter unit, and the sixth bandpass filter unit, The respective connections between the filter unit and the seventh bandpass filter unit and the fourth single-pole three-throw switch circuit S4, the fifth single-pole three-throw switch circuit S5, and the sixth single-pole three-throw switch circuit S6 are respectively arranged correspondingly. There are an eighth attenuator T8, a ninth attenuator T9, a tenth attenuator T10, an eleventh attenuator T11, a twelfth attenuator T12, a thirteenth attenuator T13, and a fourteenth attenuator T14.

Preferably, in the first bandpass filter unit, the second bandpass filter unit, the third bandpass filter unit, the fourth bandpass filter unit, the fifth bandpass filter unit, and the sixth bandpass filter unit, The respective connections between the filter unit and the seventh bandpass filter unit and the first single-pole three-throw switch circuit S1, the second single-pole three-throw switch circuit S2, and the third single-pole three-throw switch circuit S3 are respectively arranged correspondingly. There are a first attenuator T1, a second attenuator T2, a third attenuator T3, a fourth attenuator T4, a fifth attenuator T5, a sixth attenuator T6, and a seventh attenuator T7; in the first bandpass Filter unit, second band-pass filter unit, third band-pass filter unit, fourth band-pass filter unit, fifth band-pass filter unit, sixth band-pass filter unit and seventh band-pass filter The respective connection points of the unit with the fourth single-pole three-throw switch circuit S4, the fifth single-pole three-throw switch circuit S5 and the sixth single-pole three-throw switch circuit S6 are respectively provided with eighth attenuators T8 and ninth attenuators. The attenuator T9, the tenth attenuator T10, the eleventh attenuator T11, the twelfth attenuator T12, the thirteenth attenuator T13, and the fourteenth attenuator T14.

Preferably, the first attenuator T1, the second attenuator T2, the third attenuator T3, the fourth attenuator T4, the fifth attenuator T5, the sixth attenuator T6, the seventh attenuator T7, the eighth attenuator T8, the ninth attenuator T9, the tenth attenuator T10, the eleventh attenuator T11, the twelfth attenuator T12, the thirteenth attenuator T13 and the fourteenth attenuator T14, each including: connected in series The first resistor R1 and the second resistor R2; a third resistor R3 is provided between the connection point of the first resistor R1 and the second resistor R2 and the ground terminal; one end of the first resistor R1 and the selected The single-pole three-throw switch circuit is connected, and one end of the second resistor R2 is connected to the selected band-pass filter unit.

Preferably, each of the six single-pole three-throw switch circuits includes: three conduction switches that receive selection signals.

Preferably, each of the conduction switches includes: a field effect transistor G; the drain of the field effect transistor G is connected to one end of the corresponding attenuator of the single-pole three-throw switch circuit, and the source of the field effect transistor G is The pole is connected to the radio frequency input terminal RF1, the radio frequency output terminal RF2, the first single-pole three-throw switch circuit S1 or the sixth single-pole three-throw switch circuit S6; the gate of the field effect transistor G is controlled by the control unit.

Preferably, at the connection between the drain of the field effect transistor G and one end of the attenuator corresponding to the single-pole three-throw switch circuit, a switch unit is also provided to prevent signal crosstalk between the seven band-pass filter units; The switching unit is controlled by said control unit.

To sum up, this application includes at least one of the following beneficial technical effects:

1. Integrate signal filtering in multiple frequency bands into one filter bank;

2. Better sideband suppression;

3. Improve the problem of poor consistency between each filter channel of the existing switching filter;

4. Prevent crosstalk problems between each filter channel.

Description of the drawings

Figure 1 is the logical composition diagram of the filter bank;

Figure 2 is a specific circuit diagram of the bandpass filter unit;

Figure 3 is the first connection diagram of the attenuator;

Figure 4 is the second connection diagram of the attenuator;

Figure 5 is a first connection diagram of the switch unit;

Figure 6 is a second connection diagram of the switch unit.

Implementation

In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with reference to the accompanying drawings 1 to 6 and the embodiments. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

The filter bank provided by this application adopts the following technical solution:

A filter bank is provided, as shown in Figure 1, including a radio frequency input terminal RF1 and a radio frequency output terminal RF2; including:

Seven band-pass filter units: first band-pass filter unit BP1, second band-pass filter unit BP2, third band-pass filter unit BP3, fourth band-pass filter unit BP4, fifth band-pass filter unit Unit BP5, sixth band-pass filter unit BP6 and seventh band-pass filter unit BP7;

Six single pole three throw switch circuits: the first single pole three throw switch circuit S1, the second single pole three throw switch circuit S2, the third single pole three throw switch circuit S3, the fourth single pole three throw switch circuit S4, the fifth single pole three throw switch circuit S4 Circuit S5 and sixth single-pole three-throw switch circuit S6; used to select any one of the seven band-pass filter units and filter out frequency signals other than the band-pass filter unit;

Control units respectively connected to the six single-pole three-throw switch circuits and controlling respective selection paths of the six single-pole three-throw switch circuits;

The input terminal of the first single-pole three-throw switch circuit S1 is connected to the radio frequency input terminal RF1, and the three output terminals of the first single-pole three-throw switch circuit S1 are selectively connected to the second single-pole three-throw switch circuit S2 and the third single-pole three-throw switch circuit S2. Respective input terminals of the three-throw switch circuit S3 or the fourth band-pass filter unit;

The three output terminals of the second single-pole three-throw switch circuit S2 are selectively connected to the respective input terminals of the first band-pass filter unit, the second band-pass filter unit or the third band-pass filter unit; the third band-pass filter unit The three input terminals of the four single-pole three-throw switch circuit S4 are selectively connected to the respective output terminals of the first band-pass filter unit, the second band-pass filter unit or the third band-pass filter unit; the second The band-pass filter unit selected by the single-pole three-throw switch circuit S2 and the fourth single-pole three-throw switch circuit S4 remains consistent;

The three output terminals of the third single-pole three-throw switch circuit S3 are selectively connected to the respective input terminals of the fifth band-pass filter unit, the sixth band-pass filter unit or the seventh band-pass filter unit; the third The three input terminals of the five single-pole three-throw switch circuit S5 are selectively connected to the respective output terminals of the fifth band-pass filter unit, the sixth band-pass filter unit or the seventh band-pass filter unit; the third The band-pass filter unit selected by the single-pole three-throw switch circuit S3 and the fifth single-pole three-throw switch circuit S5 remains consistent;

The three input terminals of the sixth single-pole three-throw switch circuit S6 are selectively connected to the output terminal of the fourth single-pole three-throw switch circuit S4, the output terminal of the fourth band-pass filter unit or the fifth single-pole three-throw switch circuit S4. The respective output terminals of the throw switch S5; the output terminal of the sixth single-pole three-throw switch S6 is connected to the radio frequency output terminal RF2;

When the first single-pole three-throw switch circuit S1 selects the input terminal of the second single-pole three-throw switch circuit S2, the sixth single-pole three-throw switch circuit S6 selects the output terminal of the fourth single-pole three-throw switch circuit S4;

When the first single-pole three-throw switch circuit S1 selects the input terminal of the third single-pole three-throw switch circuit S3, the sixth single-pole three-throw switch circuit S6 selects the output terminal of the fifth single-pole three-throw switch circuit S5;

When the first single-pole three-throw switch circuit S1 selects the input terminal of the fourth band-pass filter unit, the sixth single-pole three-throw switch circuit S6 selects the output terminal of the fourth band-pass filter unit.

The operating frequencies of the six single-pole three-throw switch circuits are all DC-20GHz. Among the seven bandpass filter units, their respective frequency bands are 2-3.2GHz, 2.2-3.7GHz, 2.7-4.6GHz, 3.6-6.1GHz, 5.1-8.9GHz, 7.9-13.8GHz, and 12.8-18GHz.

Preferably, as shown in Figure 2, each of the seven band-pass filter units of different frequency bands includes: a first capacitor C1, a second capacitor C2, and a third capacitor C3 connected in series. , the fourth capacitor C4, the fifth capacitor C5, the first inductor L1, the second inductor L2, the third inductor L3, the fourth inductor L4;

At the connection between the first capacitor C1 and the second capacitor C2, there are provided a fifth inductor L5 and a sixth capacitor C6 which are connected to the ground terminal in sequence;

At the connection between the second capacitor C2 and the third capacitor C3, a sixth inductor L6 and a seventh capacitor C7 connected to the ground terminal in sequence are provided;

At the connection between the third capacitor C3 and the fourth capacitor C4, a seventh inductor L7 and an eighth capacitor C8 connected to the ground terminal in sequence are provided;

At the connection between the fourth capacitor C4 and the fifth capacitor C5, an eighth inductor L8 and a ninth capacitor C9 connected to the ground terminal in sequence are provided;

The tenth capacitor C10, the eleventh capacitor C11, the twelfth capacitor C12 and the thirteenth capacitor C13 are respectively connected in parallel at both ends of the first inductor L1, the second inductor L2, the third inductor L3 and the fourth inductor L4. ;

The fourteenth capacitor C14, the fifteenth capacitor C15, the sixteenth capacitor C16, and the ground terminal are respectively connected from two ends of the first inductor L1, the second inductor L2, the third inductor L3 and the fourth inductor L4 to the ground terminal. The seventeenth capacitor C17 and the eighteenth capacitor C18.

Preferably, as shown in Figure 3, in the first band pass filter unit, the second band pass filter unit, the third band pass filter unit, the fourth band pass filter unit, and the fifth band pass filter unit unit, the sixth band-pass filter unit and the seventh band-pass filter unit respectively and the first single-pole three-throw switch circuit S1, the second single-pole three-throw switch circuit S2 and the third single-pole three-throw switch circuit S3. At the connection points, a first attenuator T1, a second attenuator T2, a third attenuator T3, a fourth attenuator T4, a fifth attenuator T5, a sixth attenuator T6, and a seventh attenuator T7 are respectively provided.

Preferably, as shown in Figure 4, in the first band pass filter unit, the second band pass filter unit, the third band pass filter unit, the fourth band pass filter unit, and the fifth band pass filter unit unit, the sixth band-pass filter unit and the seventh band-pass filter unit respectively and the fourth single-pole three-throw switch circuit S4, the fifth single-pole three-throw switch circuit S5 and the sixth single-pole three-throw switch circuit S6 The connections are respectively provided with an eighth attenuator T8, a ninth attenuator T9, a tenth attenuator T10, an eleventh attenuator T11, a twelfth attenuator T12, a thirteenth attenuator T13, and a fourteenth attenuator. Device T14.

Preferably, in the first bandpass filter unit, the second bandpass filter unit, the third bandpass filter unit, the fourth bandpass filter unit, the fifth bandpass filter unit, and the sixth bandpass filter unit, The respective connections between the filter unit and the seventh bandpass filter unit and the first single-pole three-throw switch circuit S1, the second single-pole three-throw switch circuit S2, and the third single-pole three-throw switch circuit S3 are respectively arranged correspondingly. There are a first attenuator T1, a second attenuator T2, a third attenuator T3, a fourth attenuator T4, a fifth attenuator T5, a sixth attenuator T6, and a seventh attenuator T7; in the first bandpass Filter unit, second band-pass filter unit, third band-pass filter unit, fourth band-pass filter unit, fifth band-pass filter unit, sixth band-pass filter unit and seventh band-pass filter The respective connection points of the unit with the fourth single-pole three-throw switch circuit S4, the fifth single-pole three-throw switch circuit S5 and the sixth single-pole three-throw switch circuit S6 are respectively provided with eighth attenuators T8 and ninth attenuators. The attenuator T9, the tenth attenuator T10, the eleventh attenuator T11, the twelfth attenuator T12, the thirteenth attenuator T13, and the fourteenth attenuator T14.

Preferably, the first attenuator T1, the second attenuator T2, the third attenuator T3, the fourth attenuator T4, the fifth attenuator T5, the sixth attenuator T6, the seventh attenuator T7, the eighth attenuator T8, the ninth attenuator T9, the tenth attenuator T10, the eleventh attenuator T11, the twelfth attenuator T12, the thirteenth attenuator T13 and the fourteenth attenuator T14, each including: connected in series The first resistor R1 and the second resistor R2; a third resistor R3 is provided between the connection point of the first resistor R1 and the second resistor R2 and the ground terminal; one end of the first resistor R1 and the selected The single-pole three-throw switch circuit is connected, and one end of the second resistor R2 is connected to the selected band-pass filter unit.

Preferably, as shown in Figure 1, each of the six single-pole three-throw switch circuits includes: three conduction switches that accept selection signals.

Preferably, each of the conduction switches includes: a field effect transistor G; the drain of the field effect transistor G is connected to one end of the corresponding attenuator of the single-pole three-throw switch circuit, and the source of the field effect transistor G is The pole is connected to the radio frequency input terminal RF1, the radio frequency output terminal RF2, the first single-pole three-throw switch circuit S1 or the sixth single-pole three-throw switch circuit S6; the gate of the field effect transistor G is controlled by the control unit.

Preferably, as shown in Figures 5 and 6, at the connection point between the drain of the field effect transistor G and one end of the attenuator corresponding to the single-pole three-throw switch circuit, there is also a band-pass filter unit to prevent one of the seven band-pass filter units from being connected. A switch unit for signal crosstalk; the switch unit is controlled by the control unit. In this technical solution, each of the switching units includes two field effect transistors; and the drain of each field effect transistor is connected to one end of the attenuator, and the other end of the attenuator is connected to the corresponding The bandpass filter unit is connected; the source of each field effect transistor is connected to the ground terminal; the gate of each field effect transistor is connected to the control unit and is controlled by the control unit. As shown in Figure 5, the switch unit specifically includes: G5, G6, G8, G9, G11, G12, G20, G21, G23, G24, G26, and G27; as shown in Figure 6, the switch unit specifically includes: G32, G33, G35, G36, G38, G39, G47, G48, G50, G51, G53, G54.

Working principle of the filter bank of this application: The present invention is a new type of broadband switching filter bank single-chip circuit and mature product based on GaAs process high electron mobility transistor (PHEMT). It aims to solve the following problems of existing similar products in the existing technology: the existing filter frequency is single and fixed, and the circuit made of a mixture of discrete single-pole multi-throw switch chips and filter devices is high in cost, large in size, and difficult to control. Relatively complex problems cannot meet the application requirements of related systems;

In order to achieve the above purpose, the circuit scheme proposed by the present invention is as follows: including six single-pole three-throw switch circuits S1, S2, S3, S4, S5, S6 with a frequency of DC-20GHz using GaAs high electron migration transistor PHEMT process. Seven The frequency bands are 2-3.2GHz, 2.2-3.7GHz, 2.7-4.6GHz, 3.6-6.1GHz, 5.1-8.9GHz, 7.9-13.8GHz, 12.8-18GHz band-pass filter circuit and control unit. For the above six DC-20GHz single-pole three-throw switch circuits, a PHEMT tube series-parallel circuit structure is adopted. The three switch circuits S1, S2, and S3 are connected through H1 and H2, and H3 and H4 to achieve the single-pole seven-throw switch. In the same way, the three switch circuits S4, S5 and S6 are connected through H5 and H6, H7 and H8 to achieve the above effect. At the same time, attenuators T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, and T14 circuit units are added after each branch of the two sets of single-pole seven-throw switch units to improve the above-mentioned The mentioned problem of poor consistency between each filter channel of the existing switching filter. The topology and component parameters of the two sets of single-pole seven-throw switches are exactly the same. Through theoretical calculation and ADS simulation performance optimization, the optimal values of each component parameter of this circuit are obtained.

In view of the above-mentioned problems of low matrix coefficients and poor sideband suppression performance of traditional LC filters. The above mentioned 2-3.2GHz, 2.2-3.7GHz, 2.7-4.6GHz, 3.6-6.1GHz, 5.1-8.9GHz, 7.9-13.8GHz, 12.8-18GHz band pass filter circuits all use new LC filter circuits structure. Designed to optimize sideband suppression performance and significantly improve the matrix coefficients of this filter. The seven groups of LC filter circuits all use the same circuit topology, but the parameters of each component are different. The optimal values of the parameters of each LC filter component are obtained through theoretical calculation and ADS simulation optimization.

In this technical solution, the gate and drain of the series-connected PHEMT tubes G1, G2, G28, and G29 in the first bandpass filter unit path of the broadband switching filter chip are at high potential, so the above-mentioned series-connected PHEMT tubes are turned on; the parallel-connected PHEMT tubes G3, G4, The gate-drain voltage of G5, G6, G30, G31, G32, and G33 is at low potential, so the above-mentioned parallel PHEMT tubes are turned off, and the gate-drain voltages of the other path PHEMT tubes are in a complementary state, so the first bandpass filter unit path is turned on. All other pathways are closed. One end of the 3.6-6.1GHz band LC filter is connected to one end of the first bandpass filter unit, and the other end is connected to the other end of the first bandpass filter unit. Therefore, at this time, the broadband switching filter chip of the invention allows 3.6- Signals within 6.1GHz pass through, and signals outside this frequency band are filtered out.

In this technical solution, the gate and drain of the series-connected PHEMT tubes G1, G7, G28, and G34 in the second bandpass filter unit path of the broadband switching filter chip are at high potential, so the above-mentioned series-connected PHEMT tubes are turned on; the parallel-connected PHEMT tubes G3, G4, The gate-drain voltages of G8, G9, G30, G31, G35, and G36 are at low potential, so the above-mentioned parallel PHEMT tubes are turned off, and the gate-drain voltages of the other PHEMT tubes in the other paths are in a complementary state, so the paths of the second bandpass filter unit are turned on. All other pathways are closed. One end of the 7.9-13.8GHz band LC filter is connected to one end of the second bandpass filter unit, and the other end is connected to the other end of the second bandpass filter unit. Therefore, at this time, the invented broadband switching filter chip allows 7.9-13.8 Signals within the GHz pass through, and signals outside the frequency band are filtered out.

In this technical solution, the gate-drain of the series-connected PHEMT tubes G1, G10, G28, and G37 in the third bandpass filter unit path of the broadband switching filter chip is at a high potential, so the above-mentioned series-connected PHEMT tubes are turned on; the parallel-connected PHEMT tubes G3, G4, The gate-drain voltages of G11, G12, G30, G31, G38, and G39 are at low potential, so the above-mentioned parallel PHEMT tubes are turned off, while the gate-drain voltages of the other PHEMT tubes in the other paths are in a complementary state, so the third band-pass filter unit path is turned on. All other pathways are closed. One section of the LC filter in the 2.2-3.7GHz band is connected to one end of the third band-pass filter unit, and the other end is connected to the other end of the third band-pass filter unit. Therefore, at this time, the wideband switching filter chip of the invention allows 2.2- Signals within 3.7GHz pass through, and signals outside this frequency band are filtered out.

In this technical solution, the gate and drain of the series-connected PHEMT tubes G13 and G40 in the fourth band-pass filter unit path of the broadband switching filter chip are at high potential, so the above-mentioned series-connected PHEMT tubes are conductive; the gates and drains of the parallel-connected PHEMT tubes G14, G15, G41, and G42 are at high potential. The drain is at a low potential, so the above-mentioned parallel PHEMT tube is turned off, and the gate-drain voltages of the PHEMT tubes in other paths are in a complementary state, so the path of the fourth bandpass filter unit is turned on, and the other paths are turned off. One section of the LC filter in the 12.8-18GHz band is connected to one end of the fourth bandpass filter unit, and the other end is connected to the fourth bandpass filter unit. Therefore, at this time, the broadband switching filter chip of the invention allows signals within 12.8-18GHz to pass through , to filter out signals outside the frequency band.

The gate and drain of the series-connected PHEMT tubes G16, G19, G43, and G46 in the fifth bandpass filter unit path of the broadband switching filter chip of this technical solution are at high potential, so the above-mentioned series-connected PHEMT tubes are conductive; the parallel-connected PHEMT tubes G17, G18, and G20 , G21, G44, G45, G47, and G48 have a low gate-drain potential, so the above-mentioned parallel PHEMT tubes are turned off, and the gate-drain voltages of the other PHEMT tubes in the other paths are in a complementary state, so the fifth band-pass filter unit path is turned on, and the other PHEMT tubes are in a complementary state. All paths are closed. One section of the 2-3.2GHz band LC filter is connected to one end of the fifth bandpass filter unit, and the other end is connected to the other end of the fifth bandpass filter unit. Therefore, at this time, the broadband switching filter chip of the invention allows 2- Signals within 3.2GHz pass through, and signals outside this frequency band are filtered out.

The gate and drain of the series-connected PHEMT tubes G16, G22, G43, and G49 in the sixth bandpass filter unit path of the broadband switching filter chip of this technical solution are at high potential, so the above-mentioned series-connected PHEMT tubes are conductive; the parallel-connected PHEMT tubes G17, G18, and G23 , G24, G44, G45, G50, and G51 have a low gate-drain potential, so the above-mentioned parallel PHEMT tubes are turned off, and the gate-drain voltages of the other PHEMT tubes in the other paths are in a complementary state, so the sixth band-pass filter unit path is turned on, and the other PHEMT tubes are in a complementary state. All paths are closed. One section of the 5.1-8.9GHz frequency band LC filter is connected to one end of the sixth bandpass filter unit, and the other end is connected to the other end of the sixth bandpass filter unit. Therefore, at this time, the wideband switching filter chip of the invention allows 5.1- Signals within 8.9GHz pass through, and signals outside this frequency band are filtered out.

The gate-drain of the series-connected PHEMT tubes G16, G25, G43, and G52 in the seventh bandpass filter unit path of the broadband switching filter chip of this technical solution is at high potential, so the above-mentioned series-connected PHEMT tubes are conductive; the parallel-connected PHEMT tubes G17, G18, and G26 , G27, G44, G45, G53, and G54 have a low gate-drain potential, so the above-mentioned parallel PHEMT tubes are turned off, and the gate-drain voltages of the other PHEMT tubes in the other paths are in a complementary state, so the seventh band-pass filter unit path is turned on, and the other PHEMT tubes are in a complementary state. All paths are closed. One section of the LC filter in the 2.7-4.6GHz band is connected to one end of the seventh bandpass filter unit, and the other end is connected to the other end of the seventh bandpass filter unit. Therefore, at this time, the wideband switching filter chip of the invention allows 2.7- Signals within 4.6GHz pass through, and signals outside this frequency band are filtered out.

The above technical solution solves the problem that traditional LC filters can only filter signals outside a single frequency and cannot meet relevant system requirements.

At the same time, we have successfully developed existing products for the broadband switching filter chip in this technical solution, and conducted on-chip probe testing on the 2-18GHz broadband switching filter bare chip. It was found that when switching the 2-3.2GHz filter, the out-of-band suppression was >40dB@1.5GHz&3.8GHz; it was found that when the 2.2-3.7GHz filter was switched, the out-of-band suppression was >40dB@1.7GHz&4.4GHz; it was found that when switching the 2.7 -4.6GHz filter, out-of-band suppression >40dB@2.2GHz&5.4GHz; found when switching 3.6-6.1GHz filter, out-of-band suppression >40dB@2.9GHz&7.2GHz; found when switching 5.1-8.9GHz filter When switching the 7.9-13.8GHz filter, the out-of-band suppression is >40dB@4.2GHz&10.2GHz; when switching the 7.9-13.8GHz filter, the out-of-band suppression is >40dB@6.6GHz&15.6GHz; when switching the 12.8-18GHz filter, the out-of-band suppression is found Suppression >40dB@11GHz&21.5GHz. According to the above, it can be seen that the wideband open filter chip of the invention has good out-of-band suppression performance in different frequency bands.

To sum up, this application includes at least one of the following beneficial technical effects:

1. Integrate signal filtering in multiple frequency bands into one filter bank;

2. Better sideband suppression;

3. Improve the problem of poor consistency between each filter channel of the existing switching filter;

4. Prevent crosstalk problems between each filter channel.

The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Any feature disclosed in this specification (including the abstract and the drawings), unless specifically stated, can be replaced by other equivalent or similar features. Replace it with the alternative characteristics of the purpose. That is, unless otherwise stated, each feature is only one example in a series of equivalent or similar features.

Claims (9)

1. A filter bank, including a radio frequency input terminal RF1 and a radio frequency output terminal RF2; characterized in that it includes: Seven band-pass filter units: the first band-pass filter unit, the second band-pass filter unit, the third band-pass filter unit, the fourth band-pass filter unit, the fifth band-pass filter unit, the sixth band-pass filter unit a bandpass filter unit and a seventh bandpass filter unit; Six single pole three throw switch circuits: the first single pole three throw switch circuit S1, the second single pole three throw switch circuit S2, the third single pole three throw switch circuit S3, the fourth single pole three throw switch circuit S4, the fifth single pole three throw switch circuit S4 Circuit S5 and sixth single-pole three-throw switch circuit S6; used to select any one of the seven band-pass filter units and filter out frequency signals other than the band-pass filter unit; Control units respectively connected to the six single-pole three-throw switch circuits and controlling respective selection paths of the six single-pole three-throw switch circuits; The input terminal of the first single-pole three-throw switch circuit S1 is connected to the radio frequency input terminal RF1, and the three output terminals of the first single-pole three-throw switch circuit S1 are selectively connected to the second single-pole three-throw switch circuit S2 and the third single-pole three-throw switch circuit S2. Respective input terminals of the three-throw switch circuit S3 or the fourth band-pass filter unit; The three output terminals of the second single-pole three-throw switch circuit S2 are selectively connected to the respective input terminals of the first band-pass filter unit, the second band-pass filter unit or the third band-pass filter unit; the third band-pass filter unit The three input terminals of the four single-pole three-throw switch circuit S4 are selectively connected to the respective output terminals of the first band-pass filter unit, the second band-pass filter unit or the third band-pass filter unit; the second The band-pass filter unit selected by the single-pole three-throw switch circuit S2 and the fourth single-pole three-throw switch circuit S4 remains consistent; The three output terminals of the third single-pole three-throw switch circuit S3 are selectively connected to the respective input terminals of the fifth band-pass filter unit, the sixth band-pass filter unit or the seventh band-pass filter unit; the third The three input terminals of the five single-pole three-throw switch circuit S5 are selectively connected to the respective output terminals of the fifth band-pass filter unit, the sixth band-pass filter unit or the seventh band-pass filter unit; the third The band-pass filter unit selected by the single-pole three-throw switch circuit S3 and the fifth single-pole three-throw switch circuit S5 remains consistent; The three input terminals of the sixth single-pole three-throw switch circuit S6 are selectively connected to the output terminal of the fourth single-pole three-throw switch circuit S4, the output terminal of the fourth band-pass filter unit or the fifth single-pole three-throw switch circuit S4. The respective output terminals of the throw switch circuit S5; the output terminal of the sixth single-pole three-throw switch circuit S6 is connected to the radio frequency output terminal RF2; When the first single-pole three-throw switch circuit S1 selects the input terminal of the second single-pole three-throw switch circuit S2, the sixth single-pole three-throw switch circuit S6 selects the output terminal of the fourth single-pole three-throw switch circuit S4; When the first single-pole three-throw switch circuit S1 selects the input terminal of the third single-pole three-throw switch circuit S3, the sixth single-pole three-throw switch circuit S6 selects the output terminal of the fifth single-pole three-throw switch circuit S5; When the first single-pole three-throw switch circuit S1 selects the input terminal of the fourth band-pass filter unit, the sixth single-pole three-throw switch circuit S6 selects the output terminal of the fourth band-pass filter unit. 2. The filter bank according to claim 1, characterized in that each of the seven band-pass filter units includes: a first capacitor C1 and a second capacitor C2 connected in series. , the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, the first inductor L1, the second inductor L2, the third inductor L3, the fourth inductor L4; At the connection between the first capacitor C1 and the second capacitor C2, there are provided a fifth inductor L5 and a sixth capacitor C6 which are connected to the ground terminal in sequence; At the connection between the second capacitor C2 and the third capacitor C3, a sixth inductor L6 and a seventh capacitor C7 connected to the ground terminal in sequence are provided; At the connection between the third capacitor C3 and the fourth capacitor C4, a seventh inductor L7 and an eighth capacitor C8 connected to the ground terminal in sequence are provided; At the connection between the fourth capacitor C4 and the fifth capacitor C5, an eighth inductor L8 and a ninth capacitor C9 connected to the ground terminal in sequence are provided; The tenth capacitor C10, the eleventh capacitor C11, the twelfth capacitor C12 and the thirteenth capacitor C13 are respectively connected in parallel at both ends of the first inductor L1, the second inductor L2, the third inductor L3 and the fourth inductor L4. ; The fourteenth capacitor C14, the fifteenth capacitor C15, the sixteenth capacitor C16, and the ground terminal are respectively connected from two ends of the first inductor L1, the second inductor L2, the third inductor L3 and the fourth inductor L4 to the ground terminal. The seventeenth capacitor C17 and the eighteenth capacitor C18. 3. The filter bank according to claim 1, characterized in that, in the first band-pass filter unit, the second band-pass filter unit, the third band-pass filter unit and the fourth band-pass filter unit, unit, the fifth band-pass filter unit, the sixth band-pass filter unit and the seventh band-pass filter unit are respectively connected with the first single-pole three-throw switch circuit S1, the second single-pole three-throw switch circuit S2 and the third single-pole three-throw switch circuit S2. The connections of the three single-pole three-throw switch circuits S3 are respectively provided with a first attenuator T1, a second attenuator T2, a third attenuator T3, a fourth attenuator T4, a fifth attenuator T5, and a sixth attenuator T6. , the seventh attenuator T7. 4. The filter bank according to claim 1, characterized in that, in the first band-pass filter unit, the second band-pass filter unit, the third band-pass filter unit and the fourth band-pass filter unit, unit, the fifth band-pass filter unit, the sixth band-pass filter unit and the seventh band-pass filter unit respectively and the fourth single-pole three-throw switch circuit S4, the fifth single-pole three-throw switch circuit S5 and the third single-pole three-throw switch circuit S5. The connections of the six single-pole three-throw switch circuits S6 are respectively provided with an eighth attenuator T8, a ninth attenuator T9, a tenth attenuator T10, an eleventh attenuator T11, a twelfth attenuator T12, and a thirteenth attenuator. Attenuator T13, fourteenth attenuator T14. 5. The filter bank according to claim 1, characterized in that, in the first band-pass filter unit, the second band-pass filter unit, the third band-pass filter unit and the fourth band-pass filter unit, unit, the fifth band-pass filter unit, the sixth band-pass filter unit and the seventh band-pass filter unit are respectively connected with the first single-pole three-throw switch circuit S1, the second single-pole three-throw switch circuit S2 and the third single-pole three-throw switch circuit S2. The connections of the three single-pole three-throw switch circuits S3 are respectively provided with a first attenuator T1, a second attenuator T2, a third attenuator T3, a fourth attenuator T4, a fifth attenuator T5, and a sixth attenuator T6. , the seventh attenuator T7; in the first band-pass filter unit, the second band-pass filter unit, the third band-pass filter unit, the fourth band-pass filter unit, the fifth band-pass filter unit, The respective connections between the sixth bandpass filter unit and the seventh bandpass filter unit and the fourth single-pole three-throw switch circuit S4, the fifth single-pole three-throw switch circuit S5, and the sixth single-pole three-throw switch circuit S6 , respectively provided with an eighth attenuator T8, a ninth attenuator T9, a tenth attenuator T10, an eleventh attenuator T11, a twelfth attenuator T12, a thirteenth attenuator T13, and a fourteenth attenuator T14. . 6. The filter set according to claim 5, characterized in that the first attenuator T1, the second attenuator T2, the third attenuator T3, the fourth attenuator T4, the fifth attenuator T5, the Six attenuators T6, seventh attenuator T7, eighth attenuator T8, ninth attenuator T9, tenth attenuator T10, eleventh attenuator T11, twelfth attenuator T12, thirteenth attenuator T13 and The fourteenth attenuator T14 each includes: a first resistor R1 and a second resistor R2 connected in series; a third resistor R3 is provided between the connection point of the first resistor R1 and the second resistor R2 and the ground terminal. ; One end of the first resistor R1 is connected to the selected single-pole three-throw switch circuit, and one end of the second resistor R2 is connected to the selected band-pass filter unit. 7. The filter set according to claim 6, wherein each of the six single-pole three-throw switch circuits includes: three conduction switches that accept selection signals. 8. The filter group according to claim 7, characterized in that each of the conduction switches includes: a field effect transistor G; the drain of the field effect transistor G corresponds to the single-pole three-throw switch circuit. One end of the attenuator is connected, and the source of the field effect transistor G is connected to the radio frequency input terminal RF1, the radio frequency output terminal RF2, the first single pole three throw switch circuit S1 or the sixth single pole three throw switch circuit S6; the field effect transistor G The gate of G is controlled by the control unit. 9. The filter group according to claim 8, characterized in that, at the connection between the drain of the field effect transistor G and one end of the attenuator corresponding to the single-pole three-throw switch circuit, there is also a device to prevent seven bands. A switching unit for signal crosstalk between filter units; the switching unit is controlled by the control unit.