A millimeter wave broadband distributed matching circuit and power amplifier circuit thereof

Abstract

The present invention discloses a millimeter wave broadband distributed matching circuit and a power amplifier circuit thereof, wherein the millimeter wave broadband distributed matching circuit comprises a distributed transmission network, a lossy network, a first bias network and a second bias network; the distributed transmission network is composed of a plurality of first microstrip lines connected in series with a first capacitor, the lossy network is connected between the distributed transmission network and a reference potential ground for setting the millimeter wave circuit, the first bias network is connected between an output terminal of the distributed transmission network and a terminal of an external power supply, and the second bias network is connected between a terminal where the first section of the first microstrip line and the second section of the first microstrip line in the distributed transmission network are connected and an external power supply. The circuit structure of the present invention is simple, easy to be integrated on a single chip, and is less affected by process fluctuations. It can achieve good impedance matching within a wider frequency range of millimeter waves, and can be applied to millimeter wave power amplifier circuits to greatly improve the working bandwidth of the amplifier and improve the production yield rate.

Description

Technical Field

[0001] The present invention relates to the field of millimeter wave technology, and in particular to a millimeter wave broadband distributed matching circuit and a power amplifier circuit thereof. Background Art

[0002] In the millimeter wave field, the demand for broadband operation in systems such as high-speed communications, instrumentation, drive modules, and high-precision radars is growing. Broadband RF electronic systems can have higher sensitivity, broadband communication satellites have higher transmission rates, and broadband instrumentation can further improve the performance and dexterity of electronic systems, which is conducive to forming an integrated compatible platform, improving the measurement capabilities of instruments, and reducing system complexity, volume, weight, etc. As a key component in high-end systems, broadband amplifiers are indispensable. However, in the millimeter wave frequency band, it is extremely challenging to achieve broadband impedance matching, especially the design of broadband inter-stage matching circuits in multi-stage cascade amplifiers. First, in order to achieve the complex matching network used for broadband impedance matching, there are complex parasitic effects, crosstalk, coupling, etc. at high frequencies, which makes the simulation design accuracy of the circuit lower and lower with the increase of the operating frequency, making it difficult to give full play to the potential of the process and devices; secondly, the matching circuit based on traditional lumped elements at high frequencies is greatly affected by process fluctuations due to the small value of the matching elements and the corresponding small layout size, and the millimeter wave circuit production yield is low. Summary of the invention

[0003] Purpose of the invention: In view of the defects of the prior art that the millimeter-wave broadband matching circuit is complex in parasitic effects, difficult to accurately simulate and design, and greatly affected by process fluctuations when applied to amplifiers, the present invention discloses a millimeter-wave broadband distributed matching circuit and its power amplifier circuit, which have the advantages of simple circuit structure, high simulation design accuracy, and low sensitivity to process fluctuations. It can achieve better impedance matching within the wider frequency band of millimeter waves. When applied to millimeter-wave power amplifier circuits, it can greatly improve the working bandwidth of the amplifier and improve the production yield.

[0004] Technical solution: To achieve the above-mentioned purpose, the present invention adopts the following technical solution.

[0005] A millimeter wave broadband distributed matching circuit comprises a distributed transmission network, a lossy network, a first network and a second bias network; the distributed transmission network is composed of a plurality of first microstrip lines connected in series with a first capacitor; the lossy network is composed of a resistor, a second microstrip line and a second capacitor connected in series, and the lossy network is connected between the distributed transmission network and a reference potential ground for setting a millimeter wave circuit; the first bias network is composed of a third microstrip line and a third capacitor, and the bias network is connected between an output terminal of the distributed transmission network and a terminal of an external power supply; the second bias network is composed of a fourth microstrip line and a fourth capacitor, and the bias network is connected between a terminal where a first section of the first microstrip line and a second section of the first microstrip line are connected in the distributed transmission network and a terminal of an external power supply.

[0006] Preferably, the first capacitor in the distributed transmission network is connected in series between the first bias network and the second bias network.

[0007] Preferably, the resistor, the second microstrip line and the second capacitor in the lossy network are connected in series in sequence, the second capacitor is connected to the reference potential of the millimeter wave circuit, and the resistor is connected to the distributed transmission network; or the second microstrip line, the resistor and the second capacitor are connected in series in sequence, the second capacitor is connected to the reference potential of the millimeter wave circuit, and the second microstrip line is connected to the distributed transmission network. Preferably, the second capacitor in the lossy network adopts a metal-insulator-metal capacitor, and one of the metal plates is connected to the reference potential ground of the millimeter wave circuit.

[0008] Preferably, the third capacitor and the fourth capacitor in the first bias network and the second bias network are fan-shaped capacitors or metal-insulator-metal capacitors.

[0009] Preferably, the constituent material of the microstrip line is gold, copper or other conductor alloys. A power amplifier circuit, the power amplifier circuit comprising an input matching circuit, n transistors, n-1 millimeter-wave broadband distributed matching circuits as described above, and an output matching circuit, n being a positive integer greater than or equal to 2, wherein after the n transistors are sequentially connected in series, a millimeter-wave broadband distributed matching circuit is connected in series between two adjacent transistors. Preferably, the physical structure type of the transistor is a junction field effect transistor, a metal-oxide-semiconductor field effect transistor, a heterojunction field effect transistor, a bipolar junction transistor, and a heterojunction bipolar transistor.

[0010] Preferably, the millimeter wave power amplifier circuit is implemented as a monolithic integrated circuit or a hybrid integrated circuit. Beneficial Effects

[0011] 1. The circuit structure of the present invention is simple, easy to integrate on a single chip, and less affected by process fluctuations. It can achieve good impedance matching within a wide frequency band of millimeter waves. When applied to millimeter wave power amplifier circuits, it can greatly increase the working bandwidth of the amplifier and improve the production yield.

[0012] 2. The millimeter wave broadband distributed matching circuit of the present invention is suitable for wide-band millimeter wave applications and has no special requirements for the amplifier, which can be a power amplifier, a low-noise amplifier or a frequency multiplier. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of a millimeter wave broadband distributed matching circuit according to an embodiment of the present invention;

[0014] Figure 2 To adopt Figure 1 Two-stage millimeter-wave power amplifier circuit of millimeter-wave broadband distributed matching circuit;

[0015] Figure 3 for Figure 1 Smith circle diagram of impedance conversion between stages in the embodiment;

[0016] Figure 4 for Figure 1 Inter-stage impedance matching simulation result diagram in the embodiment;

[0017] Figure 5 for Figure 1 A simulation result diagram of the amplifier gain curve in the embodiment;

[0018] Figure 6 for Figure 1 Schematic diagram of a millimeter wave broadband distributed matching circuit with one microstrip line added in the embodiment;

[0019] Figure 7 for Figure 1 Schematic diagram of a millimeter-wave broadband distributed matching circuit with two microstrip lines added in the embodiment. DETAILED DESCRIPTION

[0020] The following is a further description of a millimeter-wave broadband distributed matching circuit and a power amplifier circuit thereof of the present solution in combination with the accompanying drawings and embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art fall within the scope defined by the claims attached to this application.

[0021] As attached Figure 1As shown, a millimeter-wave broadband distributed matching circuit includes a distributed transmission network, a lossy network, a first bias network and a second bias network; the distributed transmission network is composed of four first microstrip lines 1-4 connected in series with a first capacitor C9; the lossy network is composed of a resistor R8, a second microstrip line 5, and a second capacitor C10 connected in series, and the branch is connected between the distributed transmission network and a reference potential ground for setting the millimeter-wave circuit; the first bias network is composed of a third microstrip line 6 and a third capacitor C11, and the branch is connected between the output terminal of the distributed transmission network and the terminal of an external power supply; the second bias network is composed of a fourth microstrip line 7 and a fourth capacitor C12, and the branch is connected between the terminal where the first section of the first microstrip line 1 and the second section of the first microstrip line 2 in the distributed transmission network are connected and the terminal of the external power supply.

[0022] The first capacitor C9 in the distributed transmission network is connected in series between the first bias network and the second bias network, and is a reactance regarded as a short circuit within the operating frequency range of the matching circuit.

[0023] In the lossy network, resistor R8, microstrip line 5 and capacitor C10 are connected in series in sequence, capacitor C10 is connected to the reference potential of the set millimeter wave circuit, and resistor R8 is connected to the distributed transmission network; or microstrip line 5, resistor R8 and capacitor C10 are connected in series in sequence, capacitor C10 is connected to the reference potential of the set millimeter wave circuit, and microstrip line 5 is connected to the distributed transmission network.

[0024] The capacitor C10 in the lossy network is a metal-insulator-metal (MIM) capacitor, and one of the metal plates is connected to the reference potential ground of the millimeter wave circuit, which is regarded as a short-circuit reactance within the operating frequency range of the matching circuit.

[0025] The capacitors C11 and C12 in the first bias network and the second bias network may be in the form of fan-shaped capacitors or MIM capacitors, which are reactances regarded as short circuits or near short circuits within the operating frequency range of the matching circuit.

[0026] Microstrip lines are made of gold, copper or other conductor alloys.

[0027] A millimeter wave power amplifier circuit comprises an input matching circuit, n transistors, n-1 millimeter wave broadband distributed matching circuits as described above, and an output matching circuit, wherein n is a positive integer greater than or equal to 2, wherein after the n transistors are connected in series in sequence, a millimeter wave broadband distributed matching circuit is connected in series between two adjacent transistors.

[0028] The transistor is a junction field effect transistor, a metal-oxide-semiconductor field effect transistor, a heterojunction field effect transistor, a bipolar junction transistor or a heterojunction bipolar transistor.

[0029] The millimeter wave power amplifier circuit is implemented in the form of a monolithic integrated circuit or a hybrid integrated circuit. Example

[0030] As attached Figure 2 As shown, a power amplifier circuit with a frequency range of 60-140 GHz includes a transistor M1, a transistor M2, an input matching circuit, an inter-stage matching circuit and an output matching circuit, wherein the inter-stage matching network is Figure 1 In a millimeter-wave broadband distributed matching circuit shown in the figure, the gate of transistor M1 is connected to the common connection point of microstrip line 4 and microstrip line 6 in the inter-stage matching circuit, the drain of transistor M2 is connected to microstrip line 1 in the inter-stage matching circuit, the first bias network composed of microstrip line 6 and capacitor C11 provides direct current to the gate of transistor M1, and the second bias network composed of microstrip line 7 and capacitor C12 provides direct current to the drain of transistor M2.

[0031] Attached Figure 3 Yes Figure 1 The active input impedance of transistor M1 in the millimeter wave power amplifier circuit is converted to the load input impedance of transistor M2 through the impedance of the interstage broadband matching network. Since the output of the power amplifier adopts the maximum output power impedance matching method, the output impedance is matched by the impedance obtained by the active transistor load pull, that is, the output impedance is continuously adjusted according to the active transistor load pull method to find the output impedance that maximizes the output power of the active transistor. Figure 2 From the Smith circle diagram in FIG. 1 , it can be seen that the load input impedance forms a good match with the active output impedance of the active transistor M2.

[0032] Attached Figure 4 Provided with Figure 1 The impedance conversion simulation results of the inter-stage matching circuit of the mid-millimeter wave power amplifier circuit. As can be seen from the figure, the return loss S11 of the inter-stage matching circuit is ≤-8dB in the operating frequency range of 75-135GHz.

[0033] Attached Figure 5The simulation results of the gain curve of the millimeter-wave power amplifier circuit in the embodiment are given. As can be seen from the figure, the power amplifier circuit using the millimeter-wave broadband distributed matching circuit of the present invention obtains a relatively flat gain in the frequency range of 75-135GHz, and the corresponding working bandwidth reaches 60GHz, which greatly improves the working bandwidth of the amplifier. Moreover, since the main components in the matching circuit are microstrip lines, the process controllability is stronger, the influence of process fluctuations is small, and the electromagnetic field simulation design accuracy is higher, thereby improving the design accuracy and design efficiency of the millimeter-wave amplifier circuit, and also improving the production yield. The millimeter-wave broadband distributed matching circuit in the present invention is suitable for wide-band millimeter-wave applications, and there are no special requirements for the amplifier, which can be a power amplifier, a low-noise amplifier or a frequency multiplier, etc.

[0034] Figure 6 for Figure 1 In the embodiment, a millimeter wave broadband distributed matching circuit and a millimeter wave power amplifier circuit structure are added with one microstrip line. Figure 7 for Figure 1 In the embodiment, a millimeter-wave broadband distributed matching circuit and a millimeter-wave power amplifier circuit structure with two microstrip lines are added, and these structures maintain the performance consistent with the description in the first embodiment.

Claims

1. A millimeter wave broadband distributed matching circuit, characterized in that: It includes a distributed transmission network, a lossy network, a first network, and a second bias network; the distributed transmission network is composed of a plurality of first microstrip lines connected in series with a first capacitor; the lossy network is composed of a resistor, a second microstrip line, and a second capacitor connected in series, and the lossy network is connected between the distributed transmission network and a reference potential ground for setting a millimeter wave circuit; the first bias network is composed of a third microstrip line and a third capacitor, and the bias network is connected between an output terminal of the distributed transmission network and a terminal of an external power supply; the second bias network is composed of a fourth microstrip line and a fourth capacitor, and the bias network is connected between a terminal where the first section of the first microstrip line and the second section of the first microstrip line in the distributed transmission network are connected and an external power supply; A first capacitor in the distributed transmission network is connected in series between the first bias network and the second bias network; The resistor, the second microstrip line and the second capacitor in the lossy network are connected in series in sequence, the second capacitor is connected to the reference potential of the millimeter wave circuit, and the resistor is connected to the distributed transmission network; or the second microstrip line, the resistor and the second capacitor are connected in series in sequence, the second capacitor is connected to the reference potential of the millimeter wave circuit, and the second microstrip line is connected to the distributed transmission network; The second capacitor in the lossy network is a metal-insulator-metal capacitor, and one of the metal plates is connected to a reference potential ground for setting the millimeter wave circuit.

2. The millimeter wave broadband distributed matching circuit according to claim 1, characterized in that: The third capacitor and the fourth capacitor in the first bias network and the second bias network are fan-shaped capacitors or metal-insulator-metal capacitors.

3. The millimeter wave broadband distributed matching circuit according to claim 1, characterized in that: The microstrip line is made of gold, copper or other conductor alloys.

4. A power amplifier circuit, characterized in that: The power amplifier circuit includes an input matching circuit, n transistors, n-1 millimeter-wave broadband distributed matching circuits as described in any one of claims 1 to 3, and an output matching circuit, wherein n is a positive integer greater than or equal to 2, wherein after the n transistors are connected in series in sequence, a millimeter-wave broadband distributed matching circuit is connected in series between two adjacent transistors.

5. A power amplifier circuit according to claim 4, characterized in that: The transistor is a junction field effect transistor, a metal-oxide-semiconductor field effect transistor, a heterojunction field effect transistor, a bipolar junction transistor or a heterojunction bipolar transistor.

6. A power amplifier circuit according to claim 4, characterized in that: The power amplifier circuit is implemented in the form of a monolithic integrated circuit or a hybrid integrated circuit.

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