A Dual Mode Dual Frequency Secondary Current Multiplexing Low Noise Amplifier

Abstract

The invention discloses a dual-mode dual-band secondary current multiplexing low noise amplifier, comprising a resistance feedback automatic biasing current multiplexing input level amplifier circuitwhich is used for carrying out amplification an input radio frequency signal; an output level amplifier circuit which is used for carrying out secondary amplification on the input radio frequency signal; a gain adjustment module which is used for realizing DC current separation, thereby controlling a DC current of an output NMOS transistor to change the gain of the output level amplifier circuit and control gain high and low modes; a band adjustment module which is used for changing a capacitance value of a variable capacitance diode by changing a capacitance control voltage value of the variable capacitance diode, wherein the variable capacitance diode is connected with a feedback capacitor in series, so the capacitance value of an input matching network is changed to realize different-band input matching, and whether a second load capacitor is connected or not is decided by switching on or switching off a digital control switch, thereby changing the capacitance value of an output matching network; and a control voltage module which is used for selectively outputting different voltages under the control of selection signals, thereby controlling the gain adjustment module and the band adjustment module to realize gain selection and band selection.

Description

technical field [0001] The invention relates to a low-noise amplifier, in particular to a dual-mode, dual-frequency secondary current multiplexing low-noise amplifier. Background technique [0002] As the first module of a radio frequency receiver, LNA's noise performance NF is crucial to the sensitivity of the receiving system, and an optimized design is required. In addition, with the development of communication technology, radio frequency devices are required to support multi-mode, multi-frequency and low-power applications to save PCB space and reduce costs. [0003] Figure 1-Figure 3 It is a structural schematic diagram of three traditional LNAs (Low Noise Amplifier, low noise amplifier). figure 1 The input-stage amplifying circuit of the LNA shown is composed of an input DC blocking capacitor Cg, a bias inductor Lg, a compensation capacitor Cex, a source negative feedback inductor Ls, and an input NMOS transistor Min. The bias inductor Lg is connected to the bias v...

AI Technical Summary

Problems solved by technology

[0004] The LNAs in the prior art all use source inductance negative feedback, which belongs to narrow-band noise power matching. Although current multiplexing is used, the gain is limited and fixed, and the input and output matching networks are all narrow-band matching, which is not suitable for multi-mode and multi-frequency applications.

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