Double-coupling inductor Cascode ultra-wideband low-noise amplifier
By using a low-noise amplifier with a dual-coupled inductor Cascode structure, and introducing mid-to-high frequency zeros and LC matching networks, the problems of narrow operating bandwidth and insufficient gain in existing technologies are solved, achieving the effects of bandwidth expansion and high gain.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-04
- Publication Date
- 2026-03-13
AI Technical Summary
Existing low-noise amplifiers have a narrow operating bandwidth in the millimeter-wave band, which cannot cover the 5G+ extended band, and their gain is insufficient, making it difficult to meet the requirements of ultra-wideband.
The dual-coupled inductor Cascode structure is adopted, including an input matching network, a first amplifier, an interstage matching network, and an output matching network. By introducing unstable factors, a zero point is introduced at mid-to-high frequencies to improve the gain, and broadband matching is achieved through an LC matching network.
It achieves a wider operating frequency band, with a gain exceeding 15dB even above 40GHz, meeting the requirements of ultra-wideband and reducing design complexity.
Smart Images
Figure CN121664124A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of radio frequency integrated circuit design technology, and in particular to a dual-coupled inductor Cascode ultrawideband low-noise amplifier. Background Technology
[0002] With continuous research and exploration of communication systems and integrated circuits, communication technology has made great strides, evolving from the first-generation mobile communication technology (1G) in the 20th century to the current fifth-generation mobile communication technology (5G) and sixth-generation mobile technology (6G), bringing about tremendous changes to people's lives. Currently, due to the urgent need for high-speed wireless transmission of large amounts of data in applications such as wireless 8K ultra-high-definition video transmission, the Internet of Things, VR (virtual reality), and AR (augmented reality), fifth-generation mobile communication technology has had to expand from the sub-6GHz operating frequency band to 20GHz-90GHz to obtain more channels.
[0003] As the first-stage amplifier in a wireless receiving front-end system, the low-noise amplifier needs to operate in a frequency band of >20GHz and ultra-wideband (>10GHz) to achieve multi-channel transmission and a gain of over 10dB in order to meet the high-speed transmission of large amounts of data in 5G / 6G mobile communication technology. This enables high-speed transmission of weak signal data.
[0004] Therefore, in recent years, how to broaden the operating bandwidth of low-noise amplifiers and improve their gain in the millimeter-wave band has become a primary research issue for researchers both domestically and internationally. However, in existing technologies, the amplifiers implemented by researchers either utilize more than two amplifier stages, resulting in relatively low bandwidth, or their operating bandwidth cannot exceed 30GHz. Furthermore, their operating frequency bands are 1.6-28GHz, 0.4-30GHz, 65-83.5GHz, and 62.5-92.5GHz respectively, failing to include the 20-40GHz 5G+ extended band. Summary of the Invention
[0005] This application provides a dual-coupled inductor Cascode ultrawideband low-noise amplifier. To solve the above-mentioned technical problems, this application adopts the following technical methods: This application provides a dual-coupled inductor Cascode ultrawideband low-noise amplifier, comprising an input matching network, a first amplifier, an interstage matching network, a second amplifier, and an output matching network connected in sequence; The first amplifier includes a first RC negative feedback loop, a first source negative feedback inductor, and a first dual-coupled inductor loop; The second amplifier includes a second RC negative feedback loop, a second source negative feedback inductor, and a second dual-coupled inductor loop.
[0006] Optionally, the input matching network includes a first capacitor, a first inductor, and a second inductor; the positive terminal of the first capacitor is connected to the RF input terminal, the negative terminal of the first capacitor is connected to one end of the first inductor, the other end of the first inductor and the input terminal of the first amplifier are both connected to one end of the second inductor, and the other end of the second inductor is connected to the first bias terminal.
[0007] Optionally, the first RC negative feedback circuit includes a first feedback resistor and a first feedback capacitor; the first dual-coupled inductor circuit includes a first transistor, a third inductor, a fourth inductor, a second transistor, a fifth inductor, and a sixth inductor; one end of the first feedback capacitor and the gate of the first transistor are both connected to the input terminal of the first amplifier; the other end of the first feedback capacitor is connected to one end of the first feedback resistor; the other end of the first feedback resistor, one end of the fifth inductor, and one end of the sixth inductor are all connected to the output terminal of the first amplifier; the other end of the sixth inductor is connected to the power supply terminal; the other end of the fifth inductor is connected to the drain of the second transistor; one end of the fourth inductor is connected to the gate of the second transistor, and the other end of the fourth inductor is connected to the power supply terminal; one end of the third inductor is connected to the source of the second transistor, and the other end of the third inductor is connected to the drain of the first transistor; one end of the first source negative feedback inductor is connected to the source of the first transistor; the other end of the first source negative feedback inductor is grounded.
[0008] Optionally, the interstage matching network includes a second capacitor, a seventh inductor, and a bias resistor; one end of the second capacitor is connected to the output terminal of the first amplifier, and the other end of the second capacitor is connected to one end of the seventh inductor; the other end of the seventh inductor and one end of the bias resistor are connected to the output terminal of the interstage matching network; the other end of the bias resistor is connected to the bias terminal.
[0009] Optionally, the second RC negative feedback circuit includes a second feedback resistor and a second feedback capacitor; the second dual-coupled inductor circuit includes a third transistor, an eighth inductor, a ninth inductor, a fourth transistor, a tenth inductor, and an eleventh inductor; one end of the second feedback capacitor and the gate of the third transistor are both connected to the input terminal of the second amplifier; the other end of the second feedback capacitor is connected to one end of the second feedback resistor; the other end of the second feedback resistor, one end of the tenth inductor, and one end of the eleventh inductor are all connected to the output terminal of the first amplifier; the other end of the eleventh inductor is connected to the power supply terminal; the other end of the tenth inductor is connected to the drain of the fourth transistor; one end of the ninth inductor is connected to the gate of the fourth transistor; the other end of the ninth inductor is connected to the power supply terminal; one end of the eighth inductor is connected to the source of the fourth transistor; the other end of the eighth inductor is connected to the drain of the third transistor; one end of the second source negative feedback inductor is connected to the source of the third transistor; the other end of the second source negative feedback inductor is grounded.
[0010] Optionally, the output matching network includes a twelfth inductor and a third capacitor, one end of the third capacitor being connected to the output terminal of the second amplifier; one end of the third capacitor and one end of the twelfth inductor are both connected to the RF output terminal, and the other end of the twelfth inductor is grounded.
[0011] This application has the following beneficial effects: The amplifier proposed in this application improves the high-frequency gain of the low-noise amplifier by introducing unstable factors at the intermediate and high frequencies, thereby widening the operating bandwidth and maintaining a high gain. Attached Figure Description
[0012] Figure 1 A schematic diagram of the structure of a dual-coupled inductor Cascode ultrawideband low-noise amplifier provided in an embodiment of this application; Figure 2 A schematic diagram of the small-signal equivalent model of the main structure of a dual-coupled inductor Cascode ultrawideband low-noise amplifier provided in an embodiment of this application; Figure 3 This is a schematic diagram illustrating the structure of the input matching network function provided in the embodiments of this application; Figure 4 The simulation comparison results are shown in the figure provided for the embodiments of this application.
[0013] Explanation of reference numerals in the attached figures First capacitor C1, first inductor L1, and second inductor L4; first source negative feedback inductor L... D1 Second source negative feedback inductor L D2 First bias terminal bias1 and second bias terminal bias2; first feedback resistor RFB1 and the first feedback capacitor C FB1 Second capacitor C B Seventh inductor L S and bias resistor R1; first transistor M1, third inductor L S1 Fourth inductor L G1 Second transistor M2, fifth inductor L P1 and the sixth inductor L C1 ; Second feedback capacitor R FB2 Second feedback capacitor C FB2 Third transistor M3, eighth inductor L S2 Ninth Inductor L G2 Fourth transistor M4, tenth inductor L P2 And the eleventh inductor L C2 The twelfth inductor L3 and the third capacitor C2. Detailed Implementation
[0014] To facilitate understanding by those skilled in the art, the present application will be further described below in conjunction with embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present application.
[0015] Therefore, in order to solve the problems mentioned in the prior art, such as Figure 1 As shown, this application proposes a dual-coupled inductor Cascode (common source, common gate) ultrawideband low-noise amplifier, comprising an input matching network, a first amplifier, an interstage matching network, a second amplifier, and an output matching network connected in sequence. The first amplifier includes a first RC negative feedback loop and a first source negative feedback inductor L. D1 The first dual-coupled inductor circuit; the second amplifier includes a second RC negative feedback circuit and a second source negative feedback inductor L. D2 The second dual-coupled inductor circuit.
[0016] The input matching network includes a first capacitor C1, a first inductor L1, and a second inductor L4. The positive terminal of the first capacitor C1 is connected to the RF input terminal RFIN, the negative terminal of the first capacitor C1 is connected to one end of the first inductor L1, the other end of the first inductor L1 and the input terminal of the first amplifier are both connected to one end of the second inductor L4, and the other end of the second inductor L4 is connected to the first bias terminal bias1.
[0017] The first RC negative feedback circuit includes a first feedback resistor R. FB1 and the first feedback capacitor C FB1 The first dual-coupled inductor circuit includes a first transistor M1 and a third inductor L. S1 Fourth inductor L G1 Second transistor M2, fifth inductor LP1 and the sixth inductor L C1 The first feedback capacitor C FB1 One end of the capacitor and the gate of the first transistor M1 are both connected to the input terminal of the first amplifier, and the first feedback capacitor C... FB1 The other end is connected to the first feedback resistor R FB1 One end; the first feedback resistor R FB1 The other end, the fifth inductor L P1 One end, and the sixth inductor L C1 One end of each inductor is connected to the output of the first amplifier; the sixth inductor L C1 The other end is connected to the power supply; the fifth inductor L P1 The other end is connected to the drain of the second transistor M2, and the fourth inductor L G1 One end is connected to the gate of the second transistor M2, and the fourth inductor L G1 The other end is connected to the power supply; the third inductor L S1 One end is connected to the source of the second transistor M2, and the third inductor L S1 The other end is connected to the drain of the first transistor M1; the first source negative feedback inductor L D1 One end is connected to the source of the first transistor M1; the first source negative feedback inductor L D1 The other end is grounded.
[0018] The interstage matching network includes a second capacitor C. B Seventh inductor L S and bias resistor R1; second capacitor C B One end of the capacitor is connected to the output of the first amplifier, and the second capacitor C B The other end is connected to the seventh inductor L S One end; the seventh inductor L S The other end of the resistor and one end of the bias resistor R1 are connected to the output of the interstage matching network; the other end of the bias resistor R1 is connected to the second bias terminal bias2.
[0019] The second RC negative feedback circuit includes a second feedback resistor R. FB2 Second feedback capacitor C FB2 The second dual-coupled inductor circuit includes a third transistor M3 and an eighth inductor L. S2 Ninth Inductor L G2 Fourth transistor M4, tenth inductor L P2 And the eleventh inductor L C2 One end of the second feedback capacitor and the gate of the third transistor M3 are both connected to the input terminal of the second amplifier. The second feedback capacitor C FB2 The other end is connected to the second feedback resistor R FB2 One end; the second feedback resistor RFB2 The other end, the tenth inductor L P2 One end, and the eleventh inductor L C2 One end of each inductor is connected to the output of the first amplifier; the eleventh inductor L C2 The other end is connected to the power supply; the tenth inductor L P2 The other end is connected to the drain of the fourth transistor M4, and the ninth inductor L G2 One end is connected to the gate of the fourth transistor M4, and the ninth inductor L G2 The other end is connected to the power supply; the eighth inductor L S2 One end of the inductor is connected to the source of the fourth transistor M4, and the other end of the eighth inductor M4 is connected to the drain of the third transistor M3; the second source negative feedback inductor L D2 One end is connected to the source of the third transistor M3; the second source negative feedback inductor L D2 The other end is grounded.
[0020] The output matching network includes a twelfth inductor L3 and a third capacitor C2. One end of the third capacitor C2 is connected to the output of the second amplifier. One end of the third capacitor C2 and one end of the twelfth inductor L3 are both connected to the RF output. The other end of the twelfth inductor L3 is grounded.
[0021] The first and second amplifiers of this application are respectively equipped with L... G1 L S1 and L G2 L S2 Disrupting large parasitic capacitance nodes, the small-signal model of the circuit containing parasitic capacitance is as follows: Figure 2 As shown, this introduces two zeros in the intermediate and high frequencies, causing the stability coefficient Kf in the intermediate and high frequencies to produce two minimum values, thereby improving the gain in the intermediate and high frequencies. Gmax still exceeds 15dB when it exceeds 40GHz.
[0022] The interstage matching network in this application allows the two-stage amplifier to be treated as a single-stage amplifier for input and output matching, significantly reducing design complexity. For a two-stage amplifier, interstage matching primarily serves to adjust the overall input and output impedance.
[0023] The input matching network in this application, viewed from the amplifier body, can be represented by an impedance equivalent to a network of a resistor and a capacitor in series. Thus, the input matching network and the amplifier input impedance constitute a dual-resonant cavity structure, as shown below. Figure 3As shown, at low frequencies, C1 and L1 exhibit capacitive effects, while L4 and the input capacitor CIN exhibit inductive effects, forming an LC matching network. At high frequencies, C1 and L1 exhibit inductive effects, while L4 and CIN exhibit capacitive effects, forming another LC matching network. Therefore, this dual-resonant cavity structure can achieve good matching at two different frequency points, namely low and high frequencies, thus realizing wideband input matching.
[0024] Finally, there's the output matching network, which primarily focuses on compensating for gain. This is because the amplifier achieves its highest gain when the input and output are simultaneously matched. Observing the Gmax trend of a two-stage amplifier, we find that Gmax tends to be low at both ends and high in the middle. Therefore, the main function of the output matching network is to achieve dual-frequency matching at low and high frequencies. In this embodiment, an LC matching network with a series capacitor and a parallel inductor is used to construct the output matching network, achieving dual-frequency matching at 20 and 40 GHz (second harmonics).
[0025] Simulation Experiment To verify the effectiveness of the above-mentioned method of this application, this application uses the corresponding parameter table shown in Table 1 for simulation.
[0026] Table 1 ; The Gmax simulation comparison results of ordinary Cascode, existing circuits, and the dual-coupled inductor Cascode structure proposed in this application are as follows: Figure 4 As shown in the figure, it is clear that the dual-coupled inductor Cascode structure has a significant advantage in improving the mid- and high-frequency gain compared to ordinary Cascode and existing circuits.
[0027] In summary, the amplifier proposed in this application improves the high-frequency gain of the low-noise amplifier by introducing unstable factors at the intermediate and high frequencies, thereby widening the operating bandwidth and maintaining a high gain.
[0028] The above embodiments are preferred implementations of this application. In addition, this application can be implemented in other ways. Any obvious substitutions without departing from the concept of this technical solution are within the protection scope of this application.
[0029] To facilitate understanding by those skilled in the art of the improvements made by this application compared to the prior art, some of the accompanying drawings and descriptions have been simplified, and for clarity, some other elements have been omitted from this application. Those skilled in the art should realize that these omitted elements may also constitute the content of this application.
Claims
1. A dual-coupled inductor Cascode ultrawideband low-noise amplifier, characterized in that, It includes an input matching network, a first amplifier, an interstage matching network, a second amplifier, and an output matching network connected in sequence; The first amplifier includes a first RC negative feedback loop, a first source negative feedback inductor, and a first dual-coupled inductor loop; The second amplifier includes a second RC negative feedback loop, a second source negative feedback inductor, and a second dual-coupled inductor loop.
2. The amplifier according to claim 1, characterized in that, The input matching network includes a first capacitor, a first inductor, and a second inductor; the positive terminal of the first capacitor is connected to the RF input terminal, the negative terminal of the first capacitor is connected to one end of the first inductor, the other end of the first inductor and the input terminal of the first amplifier are both connected to one end of the second inductor, and the other end of the second inductor is connected to the first bias terminal.
3. The amplifier according to claim 2, characterized in that, The first RC negative feedback circuit includes a first feedback resistor and a first feedback capacitor; the first dual-coupled inductor circuit includes a first transistor, a third inductor, a fourth inductor, a second transistor, a fifth inductor, and a sixth inductor; one end of the first feedback capacitor and the gate of the first transistor are both connected to the input terminal of the first amplifier; the other end of the first feedback capacitor is connected to one end of the first feedback resistor; the other end of the first feedback resistor, one end of the fifth inductor, and one end of the sixth inductor are all connected to the output terminal of the first amplifier; the other end of the sixth inductor is connected to the power supply terminal; the other end of the fifth inductor is connected to the drain of the second transistor; one end of the fourth inductor is connected to the gate of the second transistor, and the other end of the fourth inductor is connected to the power supply terminal; one end of the third inductor is connected to the source of the second transistor, and the other end of the third inductor is connected to the drain of the first transistor; one end of the first source negative feedback inductor is connected to the source of the first transistor. The other end of the first source negative feedback inductor is grounded.
4. The amplifier according to claim 3, characterized in that, The interstage matching network includes a second capacitor, a seventh inductor, and a bias resistor; one end of the second capacitor is connected to the output terminal of the first amplifier, and the other end of the second capacitor is connected to one end of the seventh inductor; the other end of the seventh inductor and one end of the bias resistor are connected to the output terminal of the interstage matching network; the other end of the bias resistor is connected to the bias terminal.
5. The amplifier according to claim 4, characterized in that, The second RC negative feedback circuit includes a second feedback resistor and a second feedback capacitor; the second dual-coupled inductor circuit includes a third transistor, an eighth inductor, a ninth inductor, a fourth transistor, a tenth inductor, and an eleventh inductor; one end of the second feedback capacitor and the gate of the third transistor are both connected to the input terminal of the second amplifier; the other end of the second feedback capacitor is connected to one end of the second feedback resistor; the other end of the second feedback resistor, one end of the tenth inductor, and one end of the eleventh inductor are all connected to the output terminal of the first amplifier; the other end of the eleventh inductor is connected to the power supply terminal; the other end of the tenth inductor is connected to the drain of the fourth transistor; one end of the ninth inductor is connected to the gate of the fourth transistor, and the other end of the ninth inductor is connected to the power supply terminal; one end of the eighth inductor is connected to the source of the fourth transistor, and the other end of the eighth inductor is connected to the drain of the third transistor; one end of the second source negative feedback inductor is connected to the source of the third transistor. The other end of the second source negative feedback inductor is grounded.
6. The amplifier according to claim 5, characterized in that, The output matching network includes a twelfth inductor and a third capacitor. One end of the third capacitor is connected to the output terminal of the second amplifier. One end of the third capacitor and one end of the twelfth inductor are both connected to the RF output terminal, and the other end of the twelfth inductor is grounded.