| In the current space environment,multiple modes and standards of radio waves coexist widely,which makes the transceiver system compatible with2 G / 3G / 4G / 5G,WLAN,Bluetooth,UWB and other communication modes and standards become a hot research area.Mixer and low noise amplifier are the key components in the RF front-end of multi standard receiver,which also put forward more stringent design requirements.It is very important to design mixer and LNA which can be used in software radio or multi standard RF receiver system.Based on the research of RF front-end circuit,mixer and low noise amplifier,two new structures of mixer and low noise amplifier are proposed.The main innovative work of this paper can be summarized as follows:(1)In this paper,TSMC 65 nm RF CMOS process is used to design a high gain and low noise wideband folded-switching down conversion mixer?The input transconductance stage of the mixer adopts A differential complimentary common source/common gate(CS/CG)hybrid topology to increase the effective transconductance.Compared with the traditional common-source or common-gate input transconductance structure,it can achieve high conversion gain and low noise coefficient at the same power consumption.Using a transformer to replace conventional planar spiral inductors in the source nodes of the complimentary CS/CG transistors can save the chip area and realize the broadband input impedance matching.The input transconductance stage of mixer and the local oscillator switch stage are connected by AC coupling capacitor folding,which can realize the optimization of the DC bias current of the input transconductance stage and the local oscillator switch stage.The simulation results show that the power consumption of the mixer is only 2.72 m W at 0.8V power supply voltage.the mixer exhibits a conversion gain of 12.2?17.9 d B and a double-sideband noise figure of 2.6?6.1 d B between RF frequencies from 3.0 to 7.0 GHz.At the RF frequency of 5.0 GHz,the input third-order interchange point(IIP3)is-6.5 d Bm.The chip area is only 0.55 mm×0.65 mm.(2)In this paper,TSMC 180 RF CMOS process is used to design a wideband low noise amplifier based on double noise cancellation technology.The input stage of the low noise amplifier adopts a common gate(CG)structure and a common source(CS)structure in parallel.The common source structure is responsible for noise suppression.As a noise canceling stage,the common gate structure is used to provide input matching.Compared with the traditional common source or common gate input stage structure,this input stage structure provides ideal input impedance matching and noise performance.The intermediate stage compensates for the low gain of the front stage by using the common source common gate with inductance peak technique and extends the bandwidth at the same time.The parasitic capacitance of common source structure and common gate structure will lead to the increase of circuit noise coefficient at high frequency.The noise cancellation technology can eliminate the contribution of common gate transistors and improve the noise performance.The simulation results show that in the frequency range of 3.3?10.1GHz,the maximum power gain of the low noise amplifier is 18.5 d B,the minimum noise coefficient is 1.9 d B,the reflection coefficient of input and output is less than-10 d B,and the reverse isolation degree is kept below-70 d B.and the power consumption is only 7.2m W when the power supply voltage is 1.8V. |
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