Four-band reconfigurable balanced low noise amplifier structure and regulation method

Abstract

The application provides a four-frequency-band reconfigurable balanced low noise amplifier structure and a regulation method thereof. The structure is based on a balanced amplifier structure and a reconfigurable low noise amplifier, and a four-frequency-band reconfigurable balanced low noise amplifier is constructed. The four-frequency-band configuration is realized by switching a capacitor array in the reconfigurable low noise amplifier matching structure. Meanwhile, a configurable matching network with a wave-trap function is provided, and the high selection function of each frequency band is realized. The regulation method of the four-frequency-band reconfigurable balanced low noise amplifier is provided, which is convenient for effective implementation of the application. The application solves the problems of high cost, large power consumption and the like caused by the use of multiple different frequency band low noise amplifiers or wideband low noise amplifiers in a multi-frequency-band electronic system, and the problems of single-chip reconfigurable standing wave difference and large area, improves the power resistance and reliability of circuit operation, and is conducive to the construction of a reconfigurable electronic system meeting the requirements of low noise and high power resistance. The circuit architecture can widely meet the application requirements of mobile communication, satellite communication and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radio frequency integrated circuits, in particular to the field of reconfigurable amplifier microwave solid-state circuit design. BACKGROUND

[0002] With the rapid development of wireless communication technology, spectrum resources become increasingly strained, and reconfigurable radio frequency front-ends can quickly adapt to different communication protocols through software-defined methods, reducing the frequency of hardware replacement, and flexibly switching between different frequency bands to maximize the use of limited spectrum resources. Low noise amplifiers (LNAs) play a crucial role in reconfigurable radio frequency receiver front-ends and need to be adjusted according to different operating frequency bands to support the normal operation of the receiver.

[0003] Currently, low noise amplifiers for reconfigurable radio frequency receiver front-ends mainly include wideband low noise amplifiers, multiple low noise amplifiers with different frequencies, and reconfigurable low noise amplifiers. However, when building a reconfigurable radio frequency receiver front-end, using a wideband low noise amplifier can introduce high power consumption and high noise, and using multiple low noise amplifiers can introduce high cost, large area, and long design time, etc. Therefore, a single-chip reconfigurable amplifier can solve the problems encountered when using a wideband low noise amplifier or multiple low noise amplifiers in combination, but a single-chip reconfigurable low noise amplifier still has room for improvement in terms of chip area and input / output standing wave, etc. At present, there is no corresponding solution that enables a reconfigurable low noise amplifier to have low power consumption, low noise, small area, and good input / output standing wave, etc. SUMMARY

[0004] The present application provides a four-frequency-band reconfigurable balanced low noise amplifier structure and a control method to overcome the shortcomings of the prior art. The structure is based on a balanced amplifier structure and a reconfigurable low noise amplifier to build a four-frequency-band reconfigurable balanced low noise amplifier. The four-frequency-band configuration is achieved by switching the capacitor array in the reconfigurable low noise amplifier matching structure. A configurable matching network with a notch function is also provided to achieve high selectivity in each frequency band. The control method for the four-frequency-band reconfigurable balanced low noise amplifier is also provided to facilitate the effective implementation of the present application. The present application solves the problems of high cost, high power consumption, etc. caused by the use of multiple low noise amplifiers with different frequencies or wideband low noise amplifiers in multi-frequency-band electronic systems, and the problems of poor standing wave and large area in single-chip reconfigurable amplifiers. The present application improves the power tolerance and reliability of the circuit operation. In addition, the circuit architecture is conducive to building a reconfigurable electronic system that meets the requirements of low noise and high power tolerance, and can widely meet the application requirements of mobile communication, satellite communication, etc.

[0005] To achieve the above-mentioned purpose, the present application provides a four-frequency-band reconfigurable balanced low noise amplifier structure, which comprises:

[0006] The 90-degree hybrid coupler is arranged at the input end and the output end, the through port and the coupling port of the input 90-degree hybrid coupler and the output 90-degree hybrid coupler are connected with the two-way reconfigurable low noise amplifier, and the isolation port is connected with a 50-ohm load and then grounded.

[0007] The two-way reconfigurable low noise amplifier is arranged between the through port and the coupling port of the input 90-degree hybrid coupler and the output 90-degree hybrid coupler, respectively.

[0008] Preferably, the operating bandwidth of the 90-degree hybrid coupler meets the overall bandwidth requirement of each configurable circuit.

[0009] Preferably, the circuit structure and parameters of the two-way reconfigurable low noise amplifier are the same.

[0010] Preferably, the input matching network realizes the noise and gain matching of the front-stage amplification unit; the reconfigurable inter-stage matching network and the reconfigurable output matching network jointly act to divide the input wide frequency band into four non-intersecting operating frequency bands.

[0011] Preferably, the reconfigurable inter-stage matching network is used for matching the inter-stage matching of the front-stage amplification unit and the rear-stage amplification unit in the operating frequency band; and the reconfigurable output matching network is used for matching the gain in each operating frequency band.

[0012] Preferably, the reconfigurable inter-stage matching network is a reconfigurable notch network, which comprises an inter-stage switch capacitor array, an inductor and a resistor; and the reconfigurable output matching network is an L-type matching network, which comprises an output switch capacitor array and an inductor.

[0013] Preferably, the inter-stage switch capacitor array comprises: a capacitor C3, a capacitor C4 connected in sequence, a capacitor C5 and a switch SW1 connected in sequence and in parallel with the capacitor C3, and a switch SW2 and a capacitor C6 connected in sequence and in parallel with the capacitor C4.

[0014] Preferably, the output switch capacitor array comprises: a capacitor C7, a capacitor C8 connected in sequence, a capacitor C9 and a switch SW3 connected in sequence and in parallel with the capacitor C7, and a switch SW4 and a capacitor C10 connected in sequence and in parallel with the capacitor C8.

[0015] The application further provides a modulation method for modulating the four-frequency-band reconfigurable balanced low noise amplifier.

[0016] The working states of the switches SW1 and SW2 in the equivalent circuit corresponding to the adjusting inter-stage switched capacitor array and the switches SW3 and SW4 in the equivalent circuit corresponding to the output switched capacitor array are adjusted to control the four-frequency-band reconfigurable balanced low noise amplifier to work in four frequency bands.

[0017] Preferably, the state modulation method of the switches SW1, SW2, SW3 and SW4 specifically comprises:

[0018] When the switches SW1 and SW2 are closed and the switches SW3 and SW4 are closed, the four-frequency-band reconfigurable balanced low noise amplifier works in the first frequency band.

[0019] When the switches SW1 is closed and the switch SW2 is disconnected, the switch SW3 is closed and the switch SW4 is disconnected, the four-frequency-band reconfigurable balanced low noise amplifier works in the second frequency band.

[0020] When the switch SW1 is disconnected and the switch SW2 is closed, the switch SW3 is disconnected and the switch SW4 is closed, the four-frequency-band reconfigurable balanced low noise amplifier works in the third frequency band.

[0021] When the switch SW1 is disconnected and the switch SW2 is disconnected, the switch SW3 is disconnected and the switch SW4 is disconnected, the four-frequency-band reconfigurable balanced low noise amplifier works in the fourth frequency band.

[0022] The four-frequency-band reconfigurable balanced low noise amplifier structure and the regulation and control method have the following beneficial effects:

[0023] 1. The balanced architecture is formed by using the 90-degree hybrid coupler, so that the performance between the standing wave and the noise is no longer compromised.

[0024] 2. The reconfigurable matching network is formed by using the switched capacitor array, so that the miniaturized reconfigurable network can be realized, and the chip area is small.

[0025] 3. The circuit architecture in the application is also conducive to building a reconfigurable electronic system that meets the requirements of low noise and high power resistance, and can widely meet the application requirements of mobile communication, satellite communication and the like.

[0026] 4. The structure realizes four working frequency bands with a large span, effectively solves the problems of large power consumption, high noise, large area, standing wave difference and the like of the low noise amplifier, improves the power resistance and reliability of the circuit work, realizes the miniaturization and high performance of the reconfigurable receiving front end, reduces the difficulty of input and output matching of the reconfigurable amplifier, and improves the reliability of the circuit work. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1A schematic diagram of a four-band reconfigurable balanced low noise amplifier structure is provided in the present application.

[0028] Figure 2 A four-band reconfigurable balanced microwave low noise amplifier circuit diagram is provided in the present application.

[0029] Figure 3 A layout schematic diagram of a 90-degree hybrid coupler in an embodiment of the present application is provided.

[0030] Figure 4 A schematic diagram of a single-path broadband low noise amplifier in an embodiment of the present application is provided.

[0031] Figure 5 A schematic diagram of the connection of a coupler and an amplifier in an embodiment of the present application is provided.

[0032] Figure 6 A schematic diagram of the conversion of a capacitor into a capacitor array in an embodiment of the present application is provided. DETAILED DESCRIPTION

[0033] The embodiments of the present application will be described in detail with specific reference felt to the drawings. The skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification. The present application can also be implemented or applied in other different embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0034] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner, and the diagrams only show the components related to the present application without drawing the number, shape and size of the components in actual implementation. The shape, number and ratio of the components in actual implementation can be changed arbitrarily, and the layout pattern of the components can be more complex.

[0035] As shown in Figure 1 The present application provides a four-band reconfigurable balanced low noise amplifier structure (hereinafter referred to as "low noise amplifier"), which comprises: a lange coupler arranged at the input end and the output end, the through end and the coupling end of the input lange coupler and the output lange coupler are connected with two reconfigurable low noise amplifiers, and the isolation end is grounded after being connected with a 50-ohm load. The two reconfigurable low noise amplifiers are respectively arranged between the through end and the coupling end connected with the input lange coupler and the output lange coupler; the reconfigurable low noise amplifier comprises an input matching network, a first-stage amplification unit, a reconfigurable inter-stage matching network, a second-stage amplification unit and a reconfigurable output matching network connected in sequence.

[0036] Specifically, the low-noise amplifier 90-degree hybrid coupler constitutes a balanced architecture, wherein the 90-degree hybrid coupler is preferably a lange coupler, so that the performance between the standing wave and the noise is no longer compromised; a switch capacitor array is used to constitute a reconfigurable matching network, so as to realize miniaturization of the reconfigurable network, and further realize a smaller chip area. The low-noise amplifier effectively solves the problems of large power consumption, high noise, large area, and poor standing wave of the low-noise amplifier, and the problems of single-chip reconfigurable standing wave and large area, improves the power tolerance and reliability of the circuit operation, realizes miniaturization and high performance of the reconfigurable receive front end. The circuit architecture of the low-noise amplifier is also conducive to building a reconfigurable electronic system that meets the low-noise and high-power tolerance, and can widely meet the application requirements of mobile communication, satellite communication and the like.

[0037] In the present application, the lange coupler is arranged at both ends of the two-way amplifier, which can process the input and output reflected signals of the two-way amplifier, so that the overall circuit has a good standing wave ratio.

[0038] Among them, the 90-degree hybrid coupler aims to cover the bandwidth of the configurable low-noise amplifier, therefore, a lange coupler is adopted to realize it, the lange coupler can effectively couple the energy from the input end to the output end, usually showing a coupling efficiency as high as 90%, and can work in a wide frequency range, suitable for multi-frequency band application, maintaining stable coupling characteristics, especially suitable for wideband signal transmission, in addition, the lange coupler is more compact than other coupler structures, suitable for use in high-density integrated circuits, facilitating miniaturization and integration design. Under the action of the lange coupler, the reflected signals of the two-way reconfigurable low-noise amplifier will be cancelled due to the 180° phase difference, so that there is no return loss at the input port and the output port, and good matching is realized, therefore, the balanced reconfigurable low-noise amplifier can reduce the requirement for return loss when designing a single-way reconfigurable low-noise amplifier, and focus more on noise matching, at the same time, due to the characteristics of the lange coupler, the power demand of each reconfigurable low-noise amplifier is halved in the case of high-power signal, and the reflected high-power signal is cancelled, therefore, it has good high-power processing capability and reliability.

[0039] In the present application, the circuit structure and parameters of the two-way reconfigurable low-noise amplifier are the same.

[0040] Specifically, the reconfigurable low noise amplifiers for the two paths of 0° and 90° adopt the same circuit structure and parameters, which can ensure that the two paths of reconfigurable low noise amplifiers have the same working parameters, the same reflection characteristics and gain, so that the reflected signals can be offset after passing through the lange coupler, and the overall circuit has good echo characteristics. During debugging, maintaining the consistency of the parameters of the reconfigurable low noise amplifiers for the two paths of 0° and 90° can reduce the complexity of debugging and make fault elimination simpler. During manufacturing, using the same parameters and structure means that the element characteristics of the reconfigurable low noise amplifiers are similar, which helps to improve the reliability and consistency of the entire system, reduce performance fluctuations caused by element differences, and maintain consistent performance under different temperature conditions.

[0041] The four-band reconfigurable balanced microwave low noise amplifier circuit provided by the application is shown in the following figure. Figure 2

[0042] The input matching network includes a capacitor C1, an inductor, a capacitor C2 connected between the capacitor C1 and the inductor L1, and an inductor L2 connected between the other end of the inductor L1 and the first-stage amplifier Stage1 and grounded at the other end. The first-stage amplification unit Stage1 includes a first-stage amplification MOS transistor M1 and a drain bias network composed of a resistor Rd1 and an inductor Ld1 connected in sequence.

[0043] The reconfigurable low noise amplifier includes: an inductor L3, an inductor L4, a resistor R1, a capacitor C11 and an inter-stage switching capacitor array connected in sequence at the drain of the first-stage amplification MOS transistor M1. The inter-stage switching capacitor array includes: a capacitor C3 and a capacitor C4 connected in sequence with the inductor L4 and the resistor R1, a capacitor C5 and a switch M3 connected in sequence in parallel with the capacitor C3, and a switch M4 and a capacitor C6 connected in sequence in parallel with the capacitor C4. The gate of the switch M3 receives a gate voltage V SW1 through a resistor Rb3, the gate of the switch M4 receives a gate voltage V SW2 through a resistor Rb5, and the source of the switch M3 is connected to the drain of the switch M4 and grounded after being connected to a resistor Rb6. The resistor Rb2, the resistor Rb3, the resistor Rb4, the resistor Rb5 and the resistor Rb6 are bias resistors of the switch M3 and the switch M4. The inter-stage switching capacitor array can be equivalent to: a capacitor C3, a capacitor C4, a capacitor C5 and a switch SW1 connected in sequence and in parallel with the capacitor C3, and a switch SW2 and a capacitor C6 connected in sequence and in parallel with the capacitor C4.

[0044] ​The second-stage amplification unit Stage2 includes a second-stage amplification MOS transistor M2, the drain electrode of which is provided with a drain electrode biasing network composed of an inductor and a resistor Rd1 connected in sequence, and the gate electrode of the second-stage amplification MOS transistor M2 is connected with a biasing resistor Rb1. One path of the reconfigurable output matching network is connected to the drain electrode of the second-stage amplification MOS transistor M2 and the coupling end of the output Lange coupler, and the other path is connected to the through end of the Lange coupler. Each path of the reconfigurable output matching network includes an output switched-capacitor array and an inductor L5, and the structure of the output switched-capacitor array is the same as that of the inter-stage switched-capacitor array, which includes capacitors C7, C8, C9, C10, resistors Rb7-Rb11, switches M5 and M6.

[0045] The inter-stage switched-capacitor array (reconfigurable inter-stage matching capacitor) can be equivalent to: capacitors C3 and C4 connected in sequence, capacitor C5 and switch SW1 connected in sequence and in parallel with capacitor C3, and switch SW2 and capacitor C6 connected in sequence and in parallel with capacitor C4.

[0046] The single-path LNA discretely divides four non-intersecting narrow frequency bands from the wide frequency band covered by the coupler, and the four frequency bands are realized by the reconfigurable inter-stage matching network and the reconfigurable output matching network. In the single-path amplifier, the input matching network realizes the noise matching of the first-stage amplification unit in the wide band; the reconfigurable inter-stage matching network realizes the inter-stage matching of the first-stage amplification unit and the second-stage amplification unit in each frequency band, and the network is composed of an inter-stage switched-capacitor array, an inductor and a resistor to form a reconfigurable notch network, which introduces a notch outside the upper band of each frequency band to enhance the passband selectivity of each frequency band of the amplifier, and at the same time, the frequency in the frequency band is lower than the resonant frequency, so the LC resonant notch network is inductive and can be used for inter-stage matching. The reconfigurable output matching network is composed of an output switched-capacitor array and an inductor to form an L-type matching network, which realizes the gain matching in each frequency band. The reconfigurable inter-stage matching network and the reconfigurable output matching network work together to realize high gain and low noise while the circuit is configurable.

[0047] The output switched-capacitor array (reconfigurable output matching capacitor) can be equivalent to: capacitors C7 and C8 connected in sequence, capacitor C9 and switch SW3 connected in sequence and in parallel with capacitor C7, and switch SW4 and capacitor C10 connected in sequence and in parallel with capacitor C8. Among them, the reconfigurable capacitor array composed of switches M3 and M4, resistors Rb2, Rb3, Rb4, Rb5 and Rb6 in the inter-stage switched-capacitor array is simplified as switches SW1 and SW2; and the reconfigurable capacitor array composed of switches M5 and M6, resistors Rb7, Rb8, Rb9, Rb10 and Rb11 in the output switched-capacitor array is simplified as switches SW3 and SW4.

[0048] The application further provides a modulation method for modulating the four-band reconfigurable balanced low noise amplifier, and the specific steps include: adjusting the working states of the switch SW1 and the switch SW2 in the equivalent circuit corresponding to the inter-stage switched capacitor array, and the switch SW3 and the switch SW4 in the equivalent circuit corresponding to the output switched capacitor array, so as to control the four-band reconfigurable balanced low noise amplifier to work in the four frequency bands.

[0049] The state modulation method of the switches SW1, SW2, SW3 and SW4 specifically includes:

[0050] When the switch SW1 is closed, the switch SW2 is closed, the switch SW3 is closed, and the switch SW4 is closed, the four-band reconfigurable balanced low noise amplifier works in the first frequency band.

[0051] When the switch SW1 is closed, the switch SW2 is opened, the switch SW3 is closed, and the switch SW4 is opened, the four-band reconfigurable balanced low noise amplifier works in the second frequency band.

[0052] When the switch SW1 is opened, the switch SW2 is closed, the switch SW3 is opened, and the switch SW4 is closed, the four-band reconfigurable balanced low noise amplifier works in the third frequency band.

[0053] When the switch SW1 is opened, the switch SW2 is opened, the switch SW3 is opened, and the switch SW4 is opened, the four-band reconfigurable balanced low noise amplifier works in the fourth frequency band.

[0054] In summary, the four-band reconfigurable balanced microwave low noise amplifier provided in the application solves the problems of high cost, large size, high noise and large power consumption caused by the use of multiple different frequency band low noise amplifiers or wideband low noise amplifiers in a multi-band electronic system, and the problems of poor single-chip reconfigurable standing wave and large area, improves the power endurance and reliability of the circuit operation, and improves the power endurance and reliability of the circuit operation. The circuit architecture proposed in the application is conducive to building a reconfigurable electronic system that meets the requirements of low noise and high power endurance, and can widely meet the application requirements of mobile communication, satellite communication and the like.

[0055] To better illustrate the above structure and modulation method, the application provides an embodiment, that is, a four-band reconfigurable balanced low noise amplifier structure and modulation method, and the steps are as follows:

[0056] Step 1: The lange coupler has the feature of equally dividing the input signal into two orthogonal signals with a phase difference of 90°.

[0057] As shown in FIG. 3, if port 1 is the input end, then port 2 is the coupling end, port 3 is the isolation end, and port 4 is the straight-through end. The input signal enters port 1, and the equal-amplitude orthogonal signals are output from ports 2 and 4.

[0058] In this example, the design of the Lange coupler is carried out by microstrip line, the working frequency band of the coupler is controlled by controlling the length L of the coupler, the coupling strength and the through loss are controlled by controlling the coupling line spacing S and the coupling line width W, so that the through loss and the coupling strength are close to each other and close to 3dB in the required frequency band, and the impedance of ports 1, 2 and 4 is matched with 50Ω. Port 3 is an isolation port, which can withstand power load, usually a 50Ω resistor.

[0059] Step 2: Design a single low-noise amplifier, evaluate the indicators expected by the circuit, select a two-stage common-source amplifier structure, then evaluate the MOS characteristics, and select appropriate size MOS tubes, bias, and matching network to build a single low-noise amplifier.

[0060] In this embodiment, as shown in Figure 4 A two-stage common-source amplifier structure is used to design a single low-noise amplifier. In the figure, M1 and M2 are the first-stage and second-stage amplification MOS tubes, respectively, VG and VD are the gate and drain bias voltages, respectively, and appropriate size amplification MOS tubes M1 and M2 are selected, as well as appropriate voltages VG1, VG2, VD1 and VD2, to meet the noise, gain, linearity, gain flatness and other indicators in the preliminary design of the single low-noise amplifier. Capacitor C2, inductor L1 and inductor L2 are input matching, which matches the source impedance from 50 ohms to the best noise impedance to achieve the best noise of the first-stage amplification unit. Inductor L3, inductor L4, resistor R1 and capacitor Cadj1 are inter-stage matching and inter-stage notch network. Capacitor Cadj2 and inductor L5 are output matching, which ensures sufficient and flat gain in the frequency band of 4GHz-11GHz. Inductor Ld1 and inductor Ld2 are the first-stage and second-stage drain choke inductors, respectively, and resistor Rd1 and resistor Rd2 are the first-stage and second-stage drain resistors, respectively, which are used to improve the stability of the circuit and reduce the matching difficulty. Resistor Rb1 is a gate bias resistor used to prevent signal leakage to the DC end. Capacitor C1 and capacitor C11 are DC blocking capacitors and do not participate in matching.

[0061] Step 3: Combine the Lange coupler with the amplifier and further optimize the device parameters to obtain a balanced low-noise amplifier.

[0062] The connection method is as shown in Figure 5As shown, the input signal enters the first lange coupler (input lange coupler), and an output straight-through signal and a coupled signal are output, the straight-through signal enters the coupling end of the second lange coupler (output lange coupler) after passing through the low-noise amplifier, and the coupled signal enters the straight-through end of the second lange coupler after passing through the low-noise amplifier. The signal after the coupled signal lags the straight-through signal by 90°, as can be observed from the figure, both signals undergo a 90° phase lag, so the phase is the same at the final output, and the output gain is equal to the gain of the single-ended low-noise amplifier. When the lange coupler output port and the low-noise amplifier impedance are not matched, a reflected signal is generated. Taking the first lange coupler as an example, the signal at the coupling end will again experience coupling back to the input end, and the signal at the straight-through end will again experience the straight-through end back to the input end. Therefore, at the input end, the reflected signals of the two are 180° out of phase and cancel each other out, thus improving the input standing wave ratio. Similarly, the output standing wave ratio is also improved.

[0063] Step 4: The inter-stage matching and output matching of the above-mentioned step circuit are designed and modified to form a configurable inter-stage matching and a configurable output matching, frequency band switching is performed through a switch, and then the parameters of the overall circuit components are iteratively optimized to obtain a final balanced reconfigurable four-frequency band MMIC low-noise amplifier.

[0064] In this embodiment, the inter-stage matching network is specifically designed as follows:

[0065] The inter-stage matching network and the output matching network are designed so that the values of the capacitors Cadj1 and Cadj2 are variable, and the cooperative change of the two can enable the single-path low-noise amplifier to work in four narrow bands f1, f2, f3, and f4 from low to high.

[0066]

[0067]

[0068]

[0069]

[0070] wherein f out is a frequency deviating from the working frequency band, the value is selected as 4GHz, Cadj11-Cadj14 are the capacitance values when the single-path low-noise amplifier works at frequencies f1, f2, f3, and f4, L4 is the inductance value of the inductor L4, and R1 is the resistance value of the resistor R1.

[0071] According to the output impedance, the value of the capacitor Cadj2 that enables the amplifier to work in four narrow bands can be calculated as follows:

[0072]

[0073]

[0074]

[0075]

[0076] The designed capacitance value is converted into a bridge type switch capacitor array, Cadj21~Cadj24 are the capacitance values when the single low noise amplifier works at frequencies f1, f2, f3, f4, and L5 is the inductance value of inductor L5. As shown in the following formula: Figure 6

[0077] The capacitor Cadj1 is replaced by a capacitor array composed of capacitors C3, C4, C5, C6, switch SW1, and switch SW2. According to the capacitor calculation formula:

[0078] When the switch SW1 is closed and the switch SW2 is closed,

[0079] When the switch SW1 is closed and the switch SW2 is opened,

[0080] When the switch SW1 is opened and the switch SW2 is closed,

[0081] When the switch SW1 is opened and the switch SW2 is opened,

[0082] The capacitor Cadj1 is replaced by a capacitor array composed of capacitors C3, C4, C5, C6, switch SW3, and switch SW4. According to the capacitor calculation formula:

[0083] When the switch SW3 is closed and the switch SW4 is closed,

[0084] When the switch SW3 is closed and the switch SW4 is opened,

[0085] When the switch SW3 is opened and the switch SW4 is closed,

[0086] When the switch SW3 is opened and the switch SW4 is opened,

[0087] Wherein, C3, C4, C5, C6 are the corresponding capacitance values of capacitors C3, C4, C5, C6.

[0088] ​The simultaneous equations (1), (2), (3), (4), (9), (10), (11), (12) can be solved to obtain the capacitances C3, C4, C5, C6;

[0089] The simultaneous equations (5), (6), (7), (8), (13), (14), (15), (16) can be solved to obtain the capacitances C7, C8, C9, C10;

[0090] The value of each discrete capacitor in the capacitor array is obtained through the above calculation. Since the various parasitic effects of the transistor and the various parasitic effects when the switch is opened and closed are ignored during the calculation, the calculated discrete capacitor value can only serve as the initial value of the capacitor array. The accurate discrete capacitor value needs to be optimized by overall simulation of the circuit using simulation software, so as to obtain the final capacitance of each capacitor.

[0091] The final balanced reconfigurable four-band MMIC low noise amplifier schematic diagram is shown in Figure 2 The input matching network includes capacitors C1, C2, inductors L1, L2; the reconfigurable inter-stage matching network includes inductors L3, L4, resistor R1, capacitors C11, C3, C4, C5, C6, switches M3, M4; the reconfigurable output matching network includes capacitors C7, C8, C9, C10, switches M5, M6, inductor L5; the remaining devices are shown: M1 is a first-stage amplification unit MOS transistor, M2 is a second-stage amplification unit MOS transistor, resistor Rd1, inductor Ld1 are first-stage MOS transistor drain biases, resistor Rd2, inductor Ld2 are second-stage MOS transistor drain biases, resistor Rb1 is a second-stage MOS transistor gate bias, resistors Rb2, Rb3, Rb4, Rb5, Rb6 are bias resistors of switches M3 and M4, resistors Rb7, Rb8, Rb9, Rb10, Rb11 are bias resistors of switches M3 and M4.

[0092] Through the above four-band balanced reconfigurable low noise amplifier design method, four working frequency bands with a large span are realized, and the contradiction between bandwidth and gain, noise in the design of a wideband amplifier is avoided; the difficulty of reconfigurable amplifier input and output matching is reduced, and the reliability of the circuit operation is improved.

[0093] Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

Claims

1. A quad-band reconfigurable balanced low noise amplifier, characterized by, The application relates to a four-frequency-band reconfigurable balanced low-noise amplifier. The four-frequency-band reconfigurable balanced low-noise amplifier comprises: 90-degree hybrid couplers arranged at input ends and output ends, and two-way reconfigurable low-noise amplifiers connected to through ends and coupling ends of the input 90-degree hybrid couplers and the output 90-degree hybrid couplers; the isolation ends are grounded after being connected to 50-ohm loads. The two-way reconfigurable low-noise amplifiers are arranged between the through ends and the coupling ends of the input 90-degree hybrid couplers and the output 90-degree hybrid couplers respectively; the reconfigurable low-noise amplifier comprises an input matching network, a first-stage amplification unit, a reconfigurable inter-stage matching network, a second-stage amplification unit and a reconfigurable output matching network which are sequentially connected. The circuit structures and parameters of the two-way reconfigurable low-noise amplifiers are the same. The reconfigurable inter-stage matching network is a reconfigurable wave trap network which comprises an inter-stage switch capacitor array, an inductor and a resistor; and the reconfigurable output matching network is an L-shaped matching network which comprises an output switch capacitor array and an inductor. The inter-stage switch capacitor array comprises: a capacitor C3, a capacitor C4, a capacitor C5 and a switch SW1 which are sequentially connected and in parallel with the capacitor C3, and a switch SW2 and a capacitor C6 which are sequentially connected and in parallel with the capacitor C4. The output switch capacitor array comprises: a capacitor C7, a capacitor C8, a capacitor C9 and a switch SW3 which are sequentially connected and in parallel with the capacitor C7, and a switch SW4 and a capacitor C10 which are sequentially connected and in parallel with the capacitor C8.

2. The quad-band reconfigurable balanced low noise amplifier of claim 1, wherein, The working bandwidth of the 90-degree hybrid coupler needs to meet the overall bandwidth requirement of each configurable circuit.

3. The quad-band reconfigurable balanced low noise amplifier of claim 1, wherein, The input matching network is used for matching the gain and noise of a front-stage amplification unit in a wide band; the reconfigurable inter-stage matching network and the reconfigurable output matching network jointly act to discretize the input wide band into four non-intersecting working frequency bands.

4. The quad-band reconfigurable balanced low noise amplifier of claim 3, wherein, The reconfigurable inter-stage matching network is used for matching the inter-stage matching of a front-stage amplification unit and a rear-stage amplification unit in the working frequency bands; and the reconfigurable output matching network is used for matching the gain in each working frequency band.

5. A modulation method for modulating the quad-band reconfigurable balanced low noise amplifier according to any one of claims 1-4, characterized in that, The specific steps comprise: The working states of the switches SW1 and SW2 in the inter-stage switch capacitor array and the switches SW3 and SW4 in the output switch capacitor array are adjusted to control the four-frequency-band reconfigurable balanced low-noise amplifier to work in the four frequency bands.

6. The modulation method of claim 5, wherein, The state modulation method of the switches SW1, SW2, SW3 and SW4 specifically comprises: When the switches SW1 and SW2 are closed and the switches SW3 and SW4 are closed, the four-frequency-band reconfigurable balanced low-noise amplifier works in a first frequency band; When the switches SW1 is closed and the switch SW2 is disconnected, the switch SW3 is closed and the switch SW4 is disconnected, the four-frequency-band reconfigurable balanced low-noise amplifier works in a second frequency band; When the switch SW1 is disconnected and the switch SW2 is closed, the switch SW3 is disconnected and the switch SW4 is closed, the four-frequency-band reconfigurable balanced low-noise amplifier works in a third frequency band; When the switch SW1 is disconnected, the switch SW2 is disconnected, the switch SW3 is disconnected and the switch SW4 is disconnected, the four-frequency-band reconfigurable balanced low-noise amplifier works in a fourth frequency band.

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