A multi-frequency multi-mode low noise amplifier

Abstract

The present invention discloses a multi-frequency multiplexing low-noise amplifier, comprising: an integrated broadband input stage, used for performing input signal matching and amplifying the antenna receiving signal transmitted by the antenna selection switch in all frequency bands; a multi-channel multiplexing frequency band selection module, used for performing frequency band selection on the input signal and outputting the signal to each narrowband output stage amplifier of the low-noise amplifier; and a multi-channel narrowband output stage amplifier module, used for further amplifying the multi-channel narrowband signals output by the multi-channel multiplexing frequency band selection module and transmitting the signals to a subsequent receiver after narrowband matching.

Description

Technical Field

[0001] The present invention relates to a low noise amplifier, in particular to a multi-frequency multiplexing low noise amplifier. Background Art

[0002] Low noise amplifiers are widely used in RF front-end signal receiving links to provide sufficiently high power gain and reduce system noise to improve system receiving sensitivity. Figure 1 As shown, the traditional multi-band RF front-end receiving chain includes an antenna, an antenna selection switch, and a multi-band multiplexing and low-noise amplifier module. The antenna is used to transmit and receive RF signals. The antenna selection switch is used to transmit the RF signal received by the antenna to the multi-band multiplexing and low-noise amplifier under system control for selection and amplification before transmitting it to the receiver for further processing such as demodulation, or to transmit the RF power signal output by the transmission chain to the antenna for transmission. Typically, the multi-band multiplexing and low-noise amplifier module consists of a multiplexer module and multiple low-noise amplifiers with different frequency bands. The low-noise amplifier shown in the figure consists of a low-frequency narrowband output stage amplifier LNA f L and high frequency narrowband output stage amplifier LNA f H Composition, low frequency narrow band output stage amplifier LNA f L and high frequency narrowband output stage amplifier LNA f H Each has independent input and output stage amplifiers.

[0003] Traditional multi-band multiplexing and low-noise amplifier modules have numerous problems: The high hardware cost and difficulty in integration of the multiplexer's frequency band selection hinder the trend toward low-cost RF front-end SOC or SIP technologies; the high insertion loss of the pre-multiplexer degenerates the noise figure of the receiving link, thereby affecting sensitivity; and the independent operation of the low-noise amplifiers in each frequency band results in high DC power consumption at both the input and output stages, impacting system energy efficiency. Summary of the Invention

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a multi-frequency multiplexing low-noise amplifier, which solves the problems of high hardware cost and difficulty in integration of independent multiplexers, thereby reducing system costs; firstly amplifying the input-stage broadband signal and then performing multiplexing frequency band selection, thereby saving DC power consumption of multiple independent input stages and improving energy efficiency; and solving the problem of insertion loss degradation of the receiving link noise figure caused by pre-multiplexing frequency band selection, thereby improving the noise figure and increasing sensitivity.

[0005] To achieve the above and other objectives, the present invention provides a multi-frequency multiplexing low noise amplifier, comprising:

[0006] An integrated broadband input stage is used to match and amplify the antenna receive signal transmitted from the antenna selector switch across all frequency bands;

[0007] A multiplexed frequency band selection module, used to select the frequency band of the input signal and output it to each narrow-band output stage amplifier of the multi-channel narrow-band output stage amplifier module;

[0008] The multi-channel narrowband output stage amplifier module is used to further amplify the multi-channel narrowband signals output by the multiplexed frequency band selection module and transmit them to subsequent receivers after narrowband matching.

[0009] Preferably, the broadband input stage comprises:

[0010] Broadband input matching is used to complete the input RF signal (RF in ) broadband matching and access input bias voltage (Vgb);

[0011] The input stage is used to convert the input RF signal (RF in ) for preliminary amplification.

[0012] Preferably, the multiplex frequency band selection module includes multiplex frequency band selection (21-2n) with different frequency bands, which is used to select signals in each frequency band.

[0013] Preferably, the multi-channel narrowband output stage amplifier module includes multiple narrowband output stage amplifiers (31-3n) with different frequency bands, respectively connected to each multiplexed frequency band selection (21-2n) of the multi-channel multiplexed frequency band selection module, so as to further amplify the narrowband signals output by each multiplexed frequency band selection (21-2n) of the multi-channel multiplexed frequency band selection module and transmit them to a subsequent receiver after performing narrowband matching.

[0014] Preferably, each multiplexer band selector includes a band selection capacitor, a band selection inductor, a decoupling capacitor and an inter-stage coupling matching and isolating capacitor. The first common end of the parallel band selection capacitor and the band selection inductor is connected to the output end of the broadband input stage, the second common end of the parallel band selection capacitor and the band selection inductor is connected to one end of the decoupling capacitor and the corresponding narrowband output stage amplifier of the multi-channel narrowband output stage amplifier module, the middle tap end of the band selection inductor is connected to one end of the inter-stage coupling matching and isolating capacitor, the other end of the inter-stage coupling matching and isolating capacitor is connected to the corresponding narrowband output stage amplifier of the multi-channel narrowband output stage amplifier module, and the other end of the decoupling capacitor is grounded.

[0015] Preferably, each narrowband output stage amplifier comprises:

[0016] The narrowband output stage is used to further amplify the frequency band signal selected and output by the corresponding multiplexed frequency band;

[0017] Narrowband output matching is used to achieve narrowband output matching for the frequency band signal output by the narrowband output stage.

[0018] Preferably, the narrowband output stage includes an output bias resistor and an output NMOS amplifier tube, the source of the output NMOS amplifier tube is connected to the second common end of the parallel band selection capacitor and the band selection inductor of the corresponding multi-band selection and its decoupling capacitor, the gate is connected to the corresponding inter-stage coupling matching DC blocking capacitor of the multi-band selection and one end of the output bias resistor, the drain is connected to the corresponding narrowband output matching, and the other end of the output bias resistor is connected to the output bias voltage.

[0019] Preferably, the narrowband output matching includes a load inductor and an output DC-isolating matching capacitor, one end of the load inductor is connected to the drain of the corresponding output NMOS amplifier tube, the other end is connected to the power supply, and the middle tap end is connected to one end of the corresponding output DC-isolating matching capacitor, and the other end of the output DC-isolating matching capacitor outputs a narrowband output RF signal.

[0020] Preferably, the broadband input matching includes an input DC blocking capacitor (C in ), input bias resistor (R gb ), input bias bypass adjustment capacitor (C gb ), input matching inductor (L g ), input degeneration inductance (L s ) and input matching capacitor (C ex ), the input RF signal (RFin) is bypassed by the input bias adjustment capacitor (C gb ) is connected to the input matching inductor (L g ) at one end, input matching inductor (L g ) is connected to the input stage and the input matching capacitor (C ex ), the input bias voltage (Vgb) is connected to the parallel input bias resistor (R gb ) and the input bias bypass capacitor (C gb ) in parallel with the input bias resistor (R gb ) and the input bias bypass capacitor (C gb ) is connected to the second common terminal of the input matching inductor (L g ) middle tap end, input matching capacitor (C ex ) is connected to the other end of the input degeneration inductor (L s ) of the middle tap terminal.

[0021] Preferably, the input stage includes an input NMOS amplifier tube M in , the input NMOS amplifier tube M in The source of the input degeneration inductor (L s) is grounded, and the gate is connected to the input matching inductor (L g ) and the input matching capacitor (C ex ), the drain is connected to the input end of each multiplexed frequency band selection of the multiplexed frequency band selection module.

[0022] Compared with the prior art, the multi-frequency multiplexing low-noise amplifier of the present invention solves the problem of high hardware cost and difficulty in integration of independent multiplexers by integrating the functions of a broadband input stage, a multiplexer and multiple (≥2) low-noise amplifiers with different frequency bands, thereby reducing system costs; the broadband signal is first amplified to solve the problem of insertion loss degradation of the receiving link noise figure during multiplexing frequency band selection, thereby improving the noise figure and increasing sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a circuit diagram of a traditional multi-frequency RF front-end receiving link;

[0024] Figure 2 A structural diagram of a radio frequency front-end receiving link including the multi-frequency multiplexing low noise amplifier of the present invention;

[0025] Figure 3 Schematic diagram of the structure of the multi-frequency multiplexing low noise amplifier of the present invention;

[0026] Figure 4 A detailed structural diagram of a multi-frequency multiplexing low noise amplifier in a specific embodiment of the present invention;

[0027] Figure 5 The simulated gain and reflection coefficient of the specific embodiment of the present invention;

[0028] Figure 6 Comparison of simulated noise figures of the embodiment of the present invention and the prior art. DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present invention using specific examples and accompanying drawings. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through other different specific examples, and the details in this specification may be modified and altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0030] Figure 2 This is a structural diagram of a radio frequency front-end receiving link including the multi-frequency multiplexing low noise amplifier of the present invention, which is composed of an antenna, an antenna selection switch, and the multi-frequency multiplexing low noise amplifier of the present invention. Figure 3 This is a schematic diagram of the structure of the multi-frequency multi-mode low noise amplifier of the present invention. Figure 4 FIG is a detailed structural diagram of a multi-frequency multiplexing low noise amplifier in a specific embodiment of the present invention. Figure 2 、 Figure 3 、 Figure 4 As shown, the multi-frequency multiplexing low noise amplifier of the present invention includes: an integrated broadband input stage 10, a multi-channel multiplexing frequency band selection module 20 and a multi-channel narrowband output stage amplifier module 30.

[0031] The broadband input stage 10 is composed of a broadband input matching stage 101 and an input stage 102, and is used to match and amplify the antenna receiving signal transmitted from the antenna selection switch in all frequency bands. The multiplexer frequency band selection module 20 integrates frequency band selection, signal coupling, and shared DC bias current AC isolation functions, and is composed of multiplexer frequency band selections 21-2n with different frequency bands. Figure 2 The figure shows two channels, namely, a multiplexer band selector L (21) and a multiplexer band selector H (22), which are used to select the frequency band of the input signal and output it to each narrow-band output stage amplifier of the multiple narrow-band output stage amplifier 30, where n≥2; the multiple narrow-band output stage amplifier 30 is composed of multiple output stage amplifiers with different frequency bands, namely, narrow-band output stage amplifiers 31-3n. Figure 2 The figure shows a 2-way low-frequency narrow-band output amplifier LNA f L (31) and high-frequency narrow-band output stage amplifier LNA f H (32), further, the low frequency narrowband output stage amplifier LNA f L (31) consists of a narrowband output stage L (311) and a narrowband output matching L (312), a high-frequency narrowband output stage amplifier LNA f H (32) consists of a narrowband output stage H (321) and a narrowband output matching stage H (322), and is used to further amplify the multi-channel narrowband signals output by the multi-channel multiplexing band selection module 20 and transmit them to the subsequent receiver after narrowband matching, n≥2.

[0032] Specifically, the broadband input matching 101 is composed of the input DC blocking capacitor C in , input bias resistor R gb , Input bias bypass adjustment capacitor C gb , input matching inductor L g , input degeneration inductance L s and input matching capacitor C ex Composition, used to complete the input radio frequency signal RF in The input stage 102 is an input NMOS amplifier tube M in , used to convert the broadband matched input RF signal RF in Perform initial zoom.

[0033] The multiplexer band selection L (21) is composed of a first band selection capacitor C3, a first band selection inductor L1, a first decoupling capacitor C1 and a first inter-stage coupling matching blocking capacitor C5, and is used to select signals in the first frequency band (low frequency band L); the multiplexer band selection H (22) is composed of a second band selection capacitor C4, a second band selection inductor L2, a second decoupling capacitor C2 and a second inter-stage coupling matching blocking capacitor C6, and is used to select signals in the second frequency band (high frequency band H).

[0034] The narrowband output stage L (311) is connected to the first output bias resistor R gL and the first output NMOS amplifier tube M L is composed of a first load inductor L and a first frequency band signal. dL And the first output DC blocking matching capacitor C oL is composed of a second output bias resistor R gH And the second output NMOS amplifier tube M H is composed of a second load inductor L and a second load inductor L. dH and the second output DC blocking matching capacitor C oH Composition, used to complete the narrowband output matching of the second frequency band.

[0035] Specifically, the input RFin signal is adjusted by the input bias bypass capacitor C gb Connect to the input matching inductor L g One end of the input matching inductor L g The other end is connected to the input NMOS amplifier tube M in The gate and input matching capacitor C ex One end of the input bias voltage Vgb is connected to the parallel input bias resistor R gb and input bias bypass adjustment capacitor C gb The first common terminal is connected in parallel with the input bias resistor R gb and input bias bypass adjustment capacitor C gb The second common terminal is connected to the input matching inductor L g The middle tap end of the input NMOS amplifier tube M in The source of the input degeneration inductor L s Ground, input matching capacitor C ex The other end is connected to the input degeneration inductor L s The middle tap end of the input NMOS amplifier tube M inThe drain of the multiplexer is connected to the input end of the multiplexer band selection module 20, namely, the first common end of the first band selection capacitor C3 and the first band selection inductor L1 connected in parallel, and the first common end of the second band selection capacitor C4 and the second band selection inductor L2 connected in parallel;

[0036] The second common end of the first frequency band selection capacitor C3 and the first frequency band selection inductor L1 connected in parallel is connected to one end of the first decoupling capacitor C1 and the first output NMOS amplifier tube M L The source of the first band selection inductor L1, the middle tap end of the first band selection inductor L1 is connected to one end of the first inter-stage coupling matching blocking capacitor C5, and the other end of the first inter-stage coupling matching blocking capacitor C5 is connected to the first output NMOS amplifier tube M L The gate and first output bias resistor R gL The second common end of the second band selection capacitor C4 and the second band selection inductor L2 connected in parallel is connected to one end of the second decoupling capacitor C2 and the second output NMOS amplifier tube M H The source of the second band selection inductor L2, the middle tap end of the second band selection inductor L2 is connected to one end of the second inter-stage coupling matching blocking capacitor C6, and the other end of the second inter-stage coupling matching blocking capacitor C6 is connected to the second output NMOS amplifier tube M H The gate and second output bias resistor R gH One end of the second decoupling capacitor C2 is grounded.

[0037] The first output bias resistor R gL The other end is connected to the first output bias voltage Vgb L , the first output NMOS amplifier tube M L The drain is connected to the first load inductor L dL One end of the first load inductor L dL The other end is connected to the power supply Vdd, the first load inductor L dL The middle tap end is connected to the first output DC blocking matching capacitor C oL One end of the first output DC blocking matching capacitor C oL The other end is the first narrowband output RF signal RFout L ; Second output bias resistor R gH The other end is connected to the second output bias voltage Vgb H , the second output NMOS amplifier tube M H The drain is connected to the second load inductor L dH One end of the second load inductor L dH The other end is connected to the power supply Vdd, the second load inductor L dH The middle tap end is connected to the second output DC blocking matching capacitor C oHOne end of the second output DC blocking matching capacitor C oH The other end is the second narrowband output RF signal RFout H .

[0038] Depend on Figure 3 It can be seen that the broadband input stage and the multiple narrowband output stages share the DC bias current, which reduces the system DC power consumption and improves the system energy efficiency. Figure 4 It can be seen that the first narrowband bias current I L Through the first load inductor L dL , the first output NMOS amplifier tube M L , the first frequency band selection inductor L1 flows into the input NMOS amplifier tube M in , the second narrowband bias current I H Through the second load inductor L dH , the second output NMOS amplifier tube M H , the second frequency band selection inductor L2 flows into the input NMOS amplifier tube M in , the first narrowband bias current I L and the second narrowband bias current I H The sum of the input NMOS amplifier tube M in The bias current I IN .

[0039] Figure 5 The simulation gain and reflection coefficient of the specific embodiment of the present invention, the upper left is the low frequency band gain fL Gain, the upper right is the high frequency band gain fH Gain, and the bottom is the reflection coefficient S11 of the entire frequency band. It can be seen from the figure that in the low frequency band f L The center frequency of 1.8GHz has a gain of 21dB, and in the high frequency band f H A 20dB gain is obtained near the center frequency of 2.4GHz. Correspondingly, the reflection coefficients are -27dB and -24dB at 1.8GHz and 2.4GHz respectively.

[0040] Figure 6 The figure shows a comparison of the simulated noise figures of the embodiment of the present invention and the prior art. The upper curve is the simulated data NF of the prior art, and the lower curve is the simulated data NF of the present invention. As can be seen from the figure, the noise figure is improved by 0.2dB.

[0041] It can be seen that in the present invention, the input stage broadband signal amplification is performed first and then the multi-band selection is performed, which saves the DC power consumption of multiple independent input stages, and the broadband input stage and the multiple narrowband output stages share the DC bias current, which reduces the system DC power consumption and improves the system energy efficiency: in =I L +I HThe present invention integrates the functions of a broadband input stage, a multiplexer, and multiple (≥2) low-noise amplifiers with different frequency bands, solving the high hardware cost and difficulty in integration of independent multiplexers, thereby reducing system costs. Furthermore, the present invention pre-amplifies the broadband signal, solving the problem of insertion loss degrading the noise figure of the receiving link due to pre-multiplexing frequency band selection, thereby improving the noise figure and increasing sensitivity.

[0042] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any skilled artisan may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be as set forth in the appended claims.

Claims

1. A multi-frequency multi-mode low noise amplifier, comprising: An integrated broadband input stage is used to match and amplify the antenna receive signal transmitted from the antenna selector switch across all frequency bands; A multiplex frequency band selection module is used to select the frequency band of the input signal and output it to each narrow-band output stage amplifier of the multiple narrow-band output stage amplifier module, wherein the multiplex frequency band selection module includes multiplex frequency band selection (21-2n) with different frequency bands, which is used to select signals in each frequency band; A multi-channel narrowband output stage amplifier module is used to further amplify the multi-channel narrowband signals output by the multi-channel multiplexing frequency band selection module and transmit them to a subsequent receiver after narrowband matching, wherein the multi-channel narrowband output stage amplifier module includes multiple narrowband output stage amplifiers (31-3n) with different frequency bands, respectively connected to each multiplexing frequency band selection (21-2n) of the multi-channel multiplexing frequency band selection module, so as to further amplify the narrowband signals output by each multiplexing frequency band selection (21-2n) of the multi-channel multiplexing frequency band selection module, perform narrowband matching, and transmit them to a subsequent receiver; Each multiplexer band selector includes a band selection capacitor, a band selection inductor, a decoupling capacitor and an inter-stage coupling matching and isolating capacitor. The first common end of the parallel band selection capacitor and the band selection inductor is connected to the output end of the broadband input stage, the second common end of the parallel band selection capacitor and the band selection inductor is connected to one end of the decoupling capacitor and the corresponding narrowband output stage amplifier of the multi-channel narrowband output stage amplifier module, the middle tap end of the band selection inductor is connected to one end of the inter-stage coupling matching and isolating capacitor, the other end of the inter-stage coupling matching and isolating capacitor is connected to the corresponding narrowband output stage amplifier of the multi-channel narrowband output stage amplifier module, and the other end of the decoupling capacitor is grounded.

2. The multi-frequency multiplexing low noise amplifier according to claim 1, wherein: The broadband input stage comprises: Broadband input matching is used to complete the input RF signal (RF in ) broadband matching and access input bias voltage (Vgb); The input stage is used to convert the input RF signal (RF in ) for preliminary amplification.

3. The multi-frequency multiplexing low noise amplifier according to claim 1, wherein: Each narrowband output stage amplifier includes: The narrowband output stage is used to further amplify the frequency band signal selected and output by the corresponding multiplexed frequency band; Narrowband output matching is used to achieve narrowband output matching for the frequency band signal output by the narrowband output stage.

4. The multi-frequency multiplexing low noise amplifier according to claim 3, wherein: The narrowband output stage includes an output bias resistor and an output NMOS amplifier tube. The source of the output NMOS amplifier tube is connected to the second common end of the parallel band selection capacitor and the band selection inductor of the corresponding multi-band selection and its decoupling capacitor, the gate is connected to the corresponding inter-stage coupling matching DC blocking capacitor of the multi-band selection and one end of the output bias resistor, the drain is connected to the corresponding narrowband output matching, and the other end of the output bias resistor is connected to the output bias voltage.

5. The multi-frequency multiplexing low noise amplifier according to claim 4, wherein: The narrowband output matching includes a load inductor and an output DC-isolating matching capacitor. One end of the load inductor is connected to the drain of the corresponding output NMOS amplifier tube, and the other end is connected to the power supply. The middle tap end is connected to one end of the corresponding output DC-isolating matching capacitor. The other end of the output DC-isolating matching capacitor outputs a narrowband output RF signal.

6. The multi-frequency multiplexing low noise amplifier according to claim 5, characterized in that: The broadband input matching includes an input DC blocking capacitor (C in ), input bias resistor (R gb ), input bias bypass adjustment capacitor (C gb ), input matching inductor (L g ), input degeneration inductance (L s ) and input matching capacitor (C ex ), the input RF signal (RFin) is bypassed by the input bias adjustment capacitor (C gb ) is connected to the input matching inductor (L g ) at one end, input matching inductor (L g ) is connected to the input stage and the input matching capacitor (C ex ), the input bias voltage (Vgb) is connected to the parallel input bias resistor (R gb ) and the input bias bypass capacitor (C gb ) in parallel with the input bias resistor (R gb ) and the input bias bypass capacitor (C gb ) is connected to the second common terminal of the input matching inductor (L g ) middle tap end, input matching capacitor (C ex ) is connected to the other end of the input degeneration inductor (L s ) of the middle tap terminal.

7. The multi-frequency multiplexing low noise amplifier according to claim 6, characterized in that: The input stage includes an input NMOS amplifier tube M in , the input NMOS amplifier tube M in The source of the input degeneration inductor (L s ) is grounded, and the gate is connected to the input matching inductor (L g ) and the input matching capacitor (C ex ), the drain is connected to the input end of each multiplexed frequency band selection of the multiplexed frequency band selection module.

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