Design Of Multi-band Reconfigurable Low Noise Amplifier For Radar T/R Module

The first stage of a radar is typically a low noise amplifier(LNA),whose main function is to provide sufficient gain to reduce the noise of subsequent stages(e.g.mixers)while adding as little noise as possible.At the same time,an LNA should maintain linear operation even in the presence of large input signals and present a specific input or output impedance,such as 50?.With the advancement of radar technology,multi-mode and multi-standard radio frequency(RF)receiver is becoming more and more important,it is necessary to design an LNA which can be used for multiple bands.In this paper,the idea of reconfigurable theory is employed to design multi-band LNA.The reconfiguration refers to switch the components such as capacitance or inductance to make other parts of the circuit can be reused for different frequency bands.The main results obtained are as follows:(1)Single-band low noise amplifier design:Based on the analysis of noise theory,matching network and the inductively-degenerated common source(IDCS)structure,three low noise amplifiers working in three single frequency bands are designed and studied.Those bands are L-band,S-band and C-band respectively.The results have important guiding significance for reconfigurable design.(2)Dual-band reconfigurable low noise amplifier design:Based on the analysis of single-band LNA,a dual-band reconfigurable low noise amplifier for L/S band is designed using switchable inductor and switchable capacitor.Both the input matching network and the output matching network of LNA are reconfigurable.(3)Tri-band reconfigurable low noise amplifier design:Based on reconfigurable biasing circuit,reconfigurable inter-stage matching network and reconfigurable input-output matching network,a new tri-band reconfigurable LNA for L/S/C band is designed.In this paper,based on SMIC 0.13um CMOS process,two reconfigurable low noise amplifiers are designed.The simulation results and layout of these circuits are given subsequently.The dual-band reconfigurable LNA for L/S band can be switched freely in the L-band(center frequency 1.3GHz)and the S-band(center frequency 3.2GHz).The tri-band reconfigurable LNA for L/S/C band can operate in the L-band,S-band and C-band(center frequency of 6.4GHz),this LNA can achieve better noise figure and gain in these three bands.The layout post-simulation shows the gain is higher than 17dB,the noise figure is less than 3.0dB,S11 and S22 are less than-10dB,input third-order intercept point is higher than-10dBm,The core circuit power consumption is less than 16mW.