A broadband high linearity reconfigurable low noise amplifier

Abstract

The invention discloses a broadband high linearity reconfigurable low noise amplifier, which belongs to the technical field of integrated circuit design, and comprises an A channel switch unit, a B channel switch unit, a first balun, a second balun, a first cascode AMP and a second cascode AMP; the broadband high linearity reconfigurable low noise amplifier provided by the invention has the advantages of high linearity, high second harmonic suppression, low noise coefficient, small chip area and low cost, etc.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated circuit design, and in particular relates to a broadband high-linearity reconfigurable low-noise amplifier. Background Art

[0002] With the rapid development of the 5G communication market, RF front-end reception is also required to develop in the direction of high integration, low noise, large bandwidth and high linearity.

[0003] As an important module of the receiver, the RF and microwave low-noise amplifier is the device that plays the most critical role in noise in the entire receiver. It has relatively high noise requirements and compact structure. When using integrated circuit technology to design and implement the low-noise amplifier chip circuit, its performance and cost are subject to certain constraints, which are mainly reflected in the following aspects:

[0004] (1) The linearity performance of traditional low-noise amplifiers is average: With the development of semiconductor technology and the trend of proportional reduction in transistor size, the gate length of transistors has become shorter and shorter, resulting in a decrease in breakdown voltage and an increase in knee voltage, which limits the transistor drain output voltage swing and, in turn, the power capacity of a single transistor. At the same time, the linearity of the transistor is also greatly limited. With the development of communication technology, the linearity requirements for amplifiers are further improved, and the linearity performance of low-noise amplifiers with traditional structures cannot meet the requirements.

[0005] (2) Low cost and high bandwidth with limited performance: With the development of communication technology, there are higher requirements for the working bandwidth of amplifiers. Traditional amplifiers often have low bandwidth when they have high gain performance. At the same time, the cost of amplifiers is also relatively high, and there is an urgent need to reduce costs.

[0006] Currently, there are many common circuit structures for broadband, low-noise, and high-linearity amplifiers, and it is very difficult to meet the requirements of various parameters at the same time.

[0007] From this, it can be seen that the design difficulties of the millimeter-wave broadband high-linearity reconfigurable low-noise amplifier based on integrated circuit technology are: (1) ultra-wideband high gain is difficult; (2) low noise and high linearity are difficult; (3) the chip area of ​​the traditional millimeter-wave design method is large. Summary of the Invention

[0008] In view of the above-mentioned deficiencies in the prior art, the present invention provides a broadband, high-linearity, reconfigurable low-noise amplifier that solves the above-mentioned problems in the background art.

[0009] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is: a broadband high-linearity reconfigurable low-noise amplifier, comprising an A-channel switch unit, a B-channel switch unit, a first balun, a second balun, a first cascode AMP and a second cascode AMP;

[0010] The A channel switch unit includes a switch SP1T1, a switch SP1T2, a switch SP1T3, a switch SP1T4, a switch SP1T5, a switch SP1T6, a switch SP1T7 and a switch SP1T8;

[0011] The B channel switch unit includes a switch SP2T1 and a switch SP2T2;

[0012] The input end of the switch SP1T1 serves as the first input end Rfin_A of the amplifier and is connected to the input end of the switch SP1T2. The output end of the switch SP1T1 is connected to the input end of the first balun. The first output end of the first balun is connected to the input end of the switch SP1T3. The output ends of the switches SP1T2 and SP1T3 are both connected to the input end of the first cascode AMP. The output end of the first cascode AMP is respectively connected to the input end of the switch SP1T5 and the input end of the switch SP1T7. The output end of the switch SP1T5 is connected to the first input end of the second balun. The output end of the second balun is connected to the input end of the switch SP1T8. The output end of the switch SP1T7 is connected to the output end of the switch SP1T8 and serves as the first output end Rfout_A of the amplifier.

[0013] The second output terminal of the first balun is connected to the input terminal of the second cascode AMP through the switch SP1T4, and the output terminal of the second cascode AMP is connected to the second input terminal of the second balun through the switch SP1T6;

[0014] The input end of the switch SP2T1 serves as the second input end Rfin_B of the amplifier, the output end of the switch SP2T1 is connected to the input end of the second Cascode AMP, the output end of the second Cascode AMP is also connected to the input end of the switch SP2T2, and the output end of the switch SP2T2 serves as the second output end Rfout_B of the amplifier.

[0015] Furthermore, the switch SP2T1 and the switch SP2T2 are respectively connected to a 50-ohm load.

[0016] Furthermore, the first Cascode AMP and the second Cascode AMP are gate-source feedback stacked amplifier networks.

[0017] Furthermore, the first Cascode AMP and the second Cascode AMP have the same circuit structure, both including a transistor M1 and a transistor M2;

[0018] The gate of the transistor M1 is connected to one end of the resistor R2. The other end of the resistor R2 is respectively connected to one end of the resistor R1, the grounded resistor R3, the grounded capacitor C3, one end of the resistor R4, and one end of the capacitor C2. The other end of the resistor R4 is connected to a reference voltage Vbias. The other end of the resistor R1 is respectively connected to one end of the inductor L1, the drain of the transistor M1, and one end of the capacitor C1. The other end of the inductor L1 is connected to a power supply VDD. The other end of the capacitor C1 serves as an output end of the first cascode AMP or the second cascode AMP.

[0019] The other end of the capacitor C2 is respectively connected to the other end of the capacitor C4 and the gate of the transistor M2. The drain of the transistor M2 is connected to the source of the transistor M1. The source of the transistor M2 is connected to the ground inductor L2. The other end of the capacitor C4 serves as the input end of the first cascode AMP or the second cascode AMP.

[0020] Furthermore, the switch SP1T1 , the switch SP1T2 , the switch SP1T3 , the switch SP1T4 , the switch SP1T5 , the switch SP1T6 , the switch SP1T7 , the switch SP1T8 , the switch SP2T1 , and the switch SP2T2 are all high-isolation radio frequency switches.

[0021] Furthermore, the operating modes of the amplifier include a high harmonic suppression mode and a dual-channel mode.

[0022] Furthermore, when the operating mode of the amplifier is the high harmonic suppression mode, the switches SP1T1, SP1T3, SP1T4, SP1T5, SP1T6, SP1T8, SP1T2, and SP1T7 in the A-channel switch unit are turned on; and the switches SP2T1 and SP2T2 in the B-channel switch unit are switched to connect to a 50-ohm load.

[0023] Furthermore, when the operating mode of the amplifier is dual-channel mode, switches SP1T1, SP1T3, SP1T4, SP1T5, SP1T6, and SP1T8 in the A-channel switch unit are closed, switches SP1T2 and SP1T7 are opened, and switches SP2T1 and SP2T2 in the B-channel switch are switched to the RF channel and connected to the second output terminal RfoutB of the amplifier.

[0024] The beneficial effects of the present invention are:

[0025] (1) The broadband high linearity reconfigurable low noise amplifier provided by the present invention has the advantages of high linearity, high second harmonic suppression, low noise figure, small chip area and low cost.

[0026] (2) The broadband balun used in the present invention converts the RF signal into a pair of balanced signals with equal amplitudes and a phase difference of 180°. The second harmonic generated by the amplifier is offset by the broadband balun, thereby achieving high harmonic suppression.

[0027] (3) The present invention adopts a gate-source feedback stacked amplifier network to curb the instability phenomenon of traditional transistor stacked structure amplifiers in millimeter waves, so that the gate-source feedback stacked amplifier can achieve good power matching while also taking into account impedance matching. This structure also improves the linearity of the amplifier and has a lower noise coefficient. In addition, it retains the advantages of the stacked structure amplifier, such as saving chip area, achieving good broadband characteristics, avoiding the low breakdown voltage characteristics of the integrated circuit process, and improving the stability and reliability of the circuit.

[0028] (4) The high isolation switch used in the present invention completes the selection of the signal flow direction when the amplifier operating mode is changed, so that the amplifier can complete the normal switching between the high harmonic suppression mode and the dual-channel mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural block diagram of a broadband, high-linearity, reconfigurable low-noise amplifier provided in an embodiment of the present invention.

[0030] Figure 2 This is a circuit structure diagram of the first Cascode AMP and the second Cascode AMP provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0032] The embodiment of the present invention provides a broadband high linearity reconfigurable low noise amplifier, such as Figure 1 As shown, it includes an A-channel switch unit, a B-channel switch unit, a first balun, a second balun, a first cascode AMP, and a second cascode AMP;

[0033] The A channel switch unit includes a switch SP1T1, a switch SP1T2, a switch SP1T3, a switch SP1T4, a switch SP1T5, a switch SP1T6, a switch SP1T7 and a switch SP1T8;

[0034] The B channel switch unit includes a switch SP2T1 and a switch SP2T2;

[0035] The input end of the switch SP1T1 serves as the first input end Rfin_A of the amplifier and is connected to the input end of the switch SP1T2. The output end of the switch SP1T1 is connected to the input end of the first balun. The first output end of the first balun is connected to the input end of the switch SP1T3. The output ends of the switches SP1T2 and SP1T3 are both connected to the input end of the first cascode AMP. The output end of the first cascode AMP is respectively connected to the input end of the switch SP1T5 and the input end of the switch SP1T7. The output end of the switch SP1T5 is connected to the first input end of the second balun. The output end of the second balun is connected to the input end of the switch SP1T8. The output end of the switch SP1T7 is connected to the output end of the switch SP1T8 and serves as the first output end Rfout_A of the amplifier.

[0036] The second output terminal of the first balun is connected to the input terminal of the second cascode AMP through the switch SP1T4, and the output terminal of the second cascode AMP is connected to the second input terminal of the second balun through the switch SP1T6;

[0037] The input end of the switch SP2T1 serves as the second input end Rfin_B of the amplifier, the output end of the switch SP2T1 is connected to the input end of the second Cascode AMP, the output end of the second Cascode AMP is also connected to the input end of the switch SP2T2, and the output end of the switch SP2T2 serves as the second output end Rfout_B of the amplifier.

[0038] exist Figure 1 In the embodiment of the present invention, the switch SP2T1 and the switch SP2T2 are also connected to a 50-ohm load respectively.

[0039] The first Cascode AMP and the second Cascode AMP in the embodiment of the present invention are gate-source feedback stacked amplifier networks, and their circuit structures are the same, such as Figure 2 As shown, both include a transistor M1 and a transistor M2;

[0040] The gate of the transistor M1 is connected to one end of the resistor R2. The other end of the resistor R2 is respectively connected to one end of the resistor R1, the grounded resistor R3, the grounded capacitor C3, one end of the resistor R4, and one end of the capacitor C2. The other end of the resistor R4 is connected to a reference voltage Vbias. The other end of the resistor R1 is respectively connected to one end of the inductor L1, the drain of the transistor M1, and one end of the capacitor C1. The other end of the inductor L1 is connected to a power supply VDD. The other end of the capacitor C1 serves as an output end of the first cascode AMP or the second cascode AMP.

[0041] The other end of the capacitor C2 is respectively connected to the other end of the capacitor C4 and the gate of the transistor M2. The drain of the transistor M2 is connected to the source of the transistor M1. The source of the transistor M2 is connected to the ground inductor L2. The other end of the capacitor C4 serves as the input end of the first cascode AMP or the second cascode AMP.

[0042] The two cascode AMPs in the embodiment of the present invention are composed of two gate-source feedback stacked amplifier networks, both of which adopt a transistor structure composed of a stacked source-drain connection. In each gate-source feedback stacked amplifier network, the drain of each common-gate transistor and the source of the common-source transistor are connected through a capacitor and a resistor to form a feedback loop, which effectively curbs the instability of traditional transistor stack structure amplifiers at millimeter waves, while also improving the linearity of the amplifier and improving impedance matching.

[0043] The switch SP1T1 , switch SP1T2 , switch SP1T3 , switch SP1T4 , switch SP1T5 , switch SP1T6 , switch SP1T7 , switch SP1T8 , switch SP2T1 , and switch SP2T2 in the embodiment of the present invention are all high-isolation radio frequency switches.

[0044] Based on the above circuit structure, the operating modes of the amplifier in the embodiment of the present invention include a high harmonic suppression mode and a dual-channel mode;

[0045] In this embodiment, when the operating mode of the amplifier is the high harmonic suppression mode, the switches SP1T1, SP1T3, SP1T4, SP1T5, SP1T6, SP1T8, SP1T2, and SP1T7 in the A-channel switch unit are turned on; the switches SP2T1 and SP2T2 in the B-channel switch unit are switched to connect to a 50-ohm load;

[0046] Specifically, when the amplifier operates in high-harmonic suppression mode, the RF input signal enters the amplifier through input terminals Rfin_A and Rfin_B. Channel A switches SP1T1, SP1T3, SP1T4, SP1T5, SP1T6, and SP1T8 are turned on, while SP1T2 and SP1T7 are turned off. Channel B switches SP2T1 and SP2T2 are switched to a 50-ohm load. The Channel A signal is input to the first balun via SP1T1. After passing through the balun, a pair of differential signals with equal amplitudes and a 180° phase difference are generated. These differential signals then enter the same two low-noise, high-linearity amplifiers for amplification. The amplified signals then pass through SP1T5 and SP1T6, respectively, and enter the output balun for synthesis. After synthesis, they pass through switch SP1T8 to form the RF output signal, which reaches output terminal Rfout_A.

[0047] The first balun in this embodiment converts the RF signal into a pair of balanced signals with equal amplitude and opposite phase. In the amplifier of this invention, the input signal passes through the balun to produce a pair of balanced signals. These signals then pass through two identical amplifiers, generating a second harmonic component due to the amplifier's nonlinearity. This second harmonic component then passes through the second balun at the output, canceling out the second harmonic components generated by the two amplifiers and achieving high-harmonic suppression.

[0048] In this embodiment, when the operating mode of the amplifier is the dual-channel mode, the switches SP1T1, SP1T3, SP1T4, SP1T5, SP1T6, and SP1T8 in the A-channel switch unit are closed, the switches SP1T2 and SP1T7 are opened, and the switches SP2T1 and SP2T2 in the B-channel switch are switched to the RF channel and connected to the second output terminal Rfout_B of the amplifier.

[0049] Specifically, when the amplifier operates in dual-channel mode, the RF input signal enters the amplifier through input terminals Rfin_A and Rfin_B. Switches SP1T1, SP1T3, SP1T4, SP1T5, SP1T6, and SP1T8 in the A-channel switch unit are closed, while SP1T2 and SP1T7 are opened. Switches SP2T1 and SP2T2 in the B-channel switch unit are switched to the RF channel. The A-channel signal is output via SP1T2 to low-noise, high-linearity amplifier A for amplification. The amplified signal then passes through SP1T7, ultimately forming the RF output signal that reaches output terminal Rfout_A. The B-channel signal is output via SP2T1 to low-noise, high-linearity amplifier B for amplification. The amplified signal then passes through SP2T2, ultimately forming the RF output signal that reaches output terminal Rfout_B.

[0050] Specific embodiments are used in the present invention to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

[0051] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art can make various other specific variations and combinations based on the technical teachings disclosed in the present invention without departing from the essence of the present invention, and such variations and combinations are still within the scope of protection of the present invention.

Claims

1. A broadband high linearity reconfigurable low noise amplifier, characterized in that: It includes an A channel switch unit, a B channel switch unit, a first balun, a second balun, a first cascode AMP and a second cascode AMP; The A channel switch unit includes a switch SP1T1, a switch SP1T2, a switch SP1T3, a switch SP1T4, a switch SP1T5, a switch SP1T6, a switch SP1T7 and a switch SP1T8; The B channel switch unit includes a switch SP2T1 and a switch SP2T2; The input end of the switch SP1T1 serves as the first input end Rfin_A of the amplifier and is connected to the input end of the switch SP1T2. The output end of the switch SP1T1 is connected to the input end of the first balun. The first output end of the first balun is connected to the input end of the switch SP1T3. The output end of the switch SP1T2 and the output end of the switch SP1T3 are both connected to the input end of the first CascodeAMP. The output end of the first CascodeAMP is respectively connected to the input end of the switch SP1T5 and the input end of the switch SP1T7. The output end of the switch SP1T5 is connected to the first input end of the second balun. The output end of the second balun is connected to the input end of the switch SP1T8. The output end of the switch SP1T7 is connected to the output end of the switch SP1T8 and serves as the first output end Rfout_A of the amplifier. The second output terminal of the first balun is connected to the input terminal of the second Cascode AMP through the switch SP1T4, and the output terminal of the second Cascode AMP is connected to the second input terminal of the second balun through the switch SP1T6; The input end of the switch SP2T1 serves as the second input end Rfin_B of the amplifier, the output end of the switch SP2T1 is connected to the input end of the second Cascode AMP, the output end of the second Cascode AMP is also connected to the input end of the switch SP2T2, and the output end of the switch SP2T2 serves as the second output end Rfout_B of the amplifier; The first Cascode AMP and the second Cascode AMP have the same circuit structure, and both include a transistor M1 and a transistor M2; The gate of the transistor M1 is connected to one end of the resistor R2, the other end of the resistor R2 is respectively connected to one end of the resistor R1, the grounding resistor R3, the grounding capacitor C3, one end of the resistor R4 and one end of the capacitor C2, the other end of the resistor R4 is connected to the reference voltage Vbias, the other end of the resistor R1 is respectively connected to one end of the inductor L1, the drain of the transistor M1 and one end of the capacitor C1, the other end of the inductor L1 is connected to the power supply VDD, and the other end of the capacitor C1 serves as the output end of the first Cascode AMP or the second Cascode AMP; The other end of the capacitor C2 is respectively connected to the other end of the capacitor C4 and the gate of the transistor M2, the drain of the transistor M2 is connected to the source of the transistor M1, the source of the transistor M2 is connected to the ground inductor L2, and the other end of the capacitor C4 serves as the input end of the first Cascode AMP or the second Cascode AMP.

2. The broadband high linearity reconfigurable low noise amplifier according to claim 1, characterized in that: The switch SP2T1 and the switch SP2T2 are also connected to a 50-ohm load respectively.

3. The broadband high linearity reconfigurable low noise amplifier according to claim 1, characterized in that: The first Cascode AMP and the second Cascode AMP are gate-source feedback stacked amplifier networks.

4. The broadband high linearity reconfigurable low noise amplifier according to claim 1, characterized in that: The switch SP1T1 , switch SP1T2 , switch SP1T3 , switch SP1T4 , switch SP1T5 , switch SP1T6 , switch SP1T7 , switch SP1T8 , switch SP2T1 , and switch SP2T2 are all high-isolation radio frequency switches.

5. The broadband high linearity reconfigurable low noise amplifier according to claim 4, characterized in that: The working modes of the amplifier include a high harmonic suppression mode and a dual-channel mode.

6. The broadband high linearity reconfigurable low noise amplifier according to claim 5, characterized in that: When the working mode of the amplifier is the high harmonic suppression mode, switches SP1T1, SP1T3, SP1T4, SP1T5, SP1T6, SP1T8, SP1T2 and SP1T7 in the A channel switch unit are turned on; switches SP2T1 and SP2T2 in the B channel switch unit are switched to connect to a 50 ohm load.

7. The broadband high linearity reconfigurable low noise amplifier according to claim 5, characterized in that: When the working mode of the amplifier is the dual-channel mode, switches SP1T1, SP1T3, SP1T4, SP1T5, SP1T6, and SP1T8 in the A channel switch unit are closed, switches SP1T2 and SP1T7 are opened, and switches SP2T1 and SP2T2 in the B channel switch are switched to the RF channel and connected to the second output terminal RfoutB of the amplifier.

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