Design of MedRadio RF Mixer by Utilizing Subthreshold Biasing and Bleeding Circuit Techniques

The mixer's role is frequency conversion, in which the frequency of input signal is translated into output signal with different frequency. The MedRadio transceiver must operate with low power to prolong the battery lifetime. However, there is a challenge to improve the mixer's performance with low power. This paper presents the low power down-converter mixer for the MedRadio application using 0.18 μm CMOS technology. The current bleeding technique is used to improve the performance of the transconductance stage. The subthreshold biasing technique's utilization provides better current efficiency to improve the Conversion Gain, CG by maintaining low power consumption. The proposed mixer is designed and simulated in Cadence software and provides 14.24 dB of conversion gain, 9.02 dB of noise figure, -26.2 dBm of IP1dB, and -16.5 dBm of IIP3 for pre-layout simulation. In the post-layout simulation, the conversion gain and noise figure are 12.34 dB and 12.4 dBm, respectively. IP1dB and IIP3 are -23.6 dBm and -15.2 dBm respectively. All the results were obtained to achieve the targeted design specifications with overall DC power consumption of 0.495 mW based on the DC simulation using Cadence.