چكيده به لاتين
This thesis presents two ultra low power mixers in CMOS technology, suitable for ultra wideband media and fifth-generation (5G) mobile telecommunication systems. Following the initial simulation of each mixer, layout in TSMC CMOS 180-nm technology design kit was designed and post-layout results were used to obtain a more realistic model of the design.
Bulk injection structure was used in the first mixer to obtain voltage and power reduction. However, bulk injection mixers are noisier than conventional Gilbert cell topologies. Consequently, P Channel transistors were used in mixer core to reduce the noise. Regarding that, P channel transistors provide lower voltage gains compared to N channel transistors. gm boosting buffers were used in IF Band in order to increase conversion gain. In addition, transistors were biased in weak inversion region in order to reduce power consumption. Low chip area is the advantage of the aforementioned mixer, which was provided sans usage of wideband inductor. Post-layout simulation results show that this mixer presents maximum conversion gain of 10.9 dB, minimum noise figure of 13.9 dB, maximum IIP3 of 4 dBm, and port-to-port isolation better than 43 dBm with moderate LO signal power of 2 dBm. Total power consumption of this mixer was 214 µW from a 1 V voltage supply voltage in frequency band of 3~11 GHz.
In the second design, an ultra low power mixer with high linearity in frequency band of 22-32 GHz is presented. In order to achieve maximal conversion gain with low power consumption, current-reuse structure was used in push-pull amplifier in order to increase the transconductance. Applying local oscillator signal aids the source in reduction of necessity for LO signal range. In addition, applying of cross differential LO signal, may result in reduction of supply voltage, whereas output voltage swing remains high, therefore conversion gain and linearity are increased. MOS components were biased in weak inversion region to further reduction of current and power consumption. Also, IIP3 will increase further regarding minuscule non-linearity second order transconductance coefficient. The proposed millimeter wave mixer post-layout results present maximum conversion gain of 13.4 dB, minimum noise figure of 15.1 dB, maximum IIP3 of 17.4 dB, port-to-port isolation better than 42 dB with LO signal power of 0 dB, with solely 33 µW DC power usage.
