Low-noise amplifier in multi-mode navigation type radiofrequency chip

Abstract

The invention relates to a low-noise amplifier in a multi-mode navigation type radiofrequency chip, which is technically characterized by comprising two amplifying tubes Q1 and Q2 and a diode chain. The amplifying tubes Q1 and Q2 are in cascode connection structure, a base electrode of the amplifying tube Q1 is connected with the radiofrequency input signal RFin, the radiofrequency output signal RFout is outputted from an emitter electrode of the amplifying tube Q2, and the diode chain is connected between the base electrode of the amplifying tube Q1 and the emitter electrode of the amplifying tube Q2. The low-noise amplifier having the cascode connection structure is reasonable in design, and the diode chain is connected in a feedback network between the output end and the input end, and thus the satisfactory wideband characteristic can be achieved, enough gain can be obtained with lower direct-current power consumption, and interference resistance is improved.

Description

technical field [0001] The invention belongs to the field of radio frequency integrated circuits, in particular to a low-noise amplifier in a multi-mode navigation radio frequency chip. Background technique [0002] At present, satellite navigation receivers are used more and more widely. The satellite navigation receiver relies on the received weak radio frequency satellite signal to work. The frequency of the satellite navigation signal is B1 (1561.098±2.046)MHz, the frequency point of L1: (1575.42±1.023)MHz, and the input receiving level: -110dBm~- 65dBm. Since the satellite navigation signal is susceptible to interference, resulting in the reduction of navigation accuracy, the accurate positioning function cannot be realized. Therefore, an amplifier needs to be installed at the front end of the satellite navigation receiver to amplify the weak radio frequency satellite signal. [0003] Existing amplifiers usually use a low-gain low-noise amplifier (LNA) to improve syst...

AI Technical Summary

Problems solved by technology

Since the satellite navigation signal is susceptible to interference, resulting in the reduction of navigation accuracy, the accurate positioning function cannot be realized. Therefore, an amplifier needs to be installed at the front end of the satellite navigation receiver to amplify the weak radio frequency satellite signal

[0003] Existing amplifiers usually use a low-gain low-noise amplifier (LNA) to improve system linearity and power consumption. However, the low-gain LNA requires a mixer with a lower noise figure in order to maintain the overall system noise performance. Such a mixer would likely dissipate more power and require a large LO amplitude, i.e., cascading a low-gain LNA with a low-noise Compared with the mixer cascade, it does not reflect the practical advantage in the total power consumption

For the satellite navigation signal itself, the nonlinearity of the front end is not a very important problem. The received signal strength is actually very weak and contains mainly thermal noise. The linearity requirements of the system are mainly limited by external interference. signal, so the requirements for linearity will be slightly relaxed, but the requirements for low noise characteristics of the receiving system will be improved

Therefore, low-gain low-noise amplifiers (LNAs) are not suitable for amplifying weak RF satellite signals

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