Abstract
To provide a more comfortable and secure environment, the high data rate communication systems has been needed hungrilyare with high demands. The common applications of the high data rate communication could be usedare the in Gb/s wireless data transmission, real-time video streaming, automotive anti-collision radars, and medical image sensor, and etc. There have are two ways to touch achieve the goal of the high-speed communication could be implement by,. iImproving the operation communication bandwidth or . It would be easier to get larger bandwidth when operating at a high er frequency could improve the data rate.. The higher frequency could send larger data per second. (re-write this part. High frequency does not necessary provide high data rate. High bandwidth is the key point.) Therefore, a W-band transmitter is implemented to realize the Gb/s communication. We choose the second one in this thesis. The advantage of W-band (75~110 GHz) is that there is so far no officially defined standard to be used and the wavelength is short enough to have some characteristics which could be used on security or medical treatment. The cell would have different behavior under this frequency.(what characteristics?) A W-band transmitter is presented in this thesis. This transmitter is composed with a Gilbert cell upconversion mixer and a differential power amplifier (PA). This work focuses on the design of the power amplifier (PA) since it dominates the power consumption, the power efficiency, the linearity, and the output power of the transmitter. Three distinct power amplifiers are discussed in details in this thesis. In the beginning, aA differential common-source power amplifier has firstly been design. This structure suppresses the noise and common-mode interferences. It also provides a larger output power compared with its single-ended counterpart. The saturation output power (P_sat) is 12.35 dBm with a power gain of 8.25 dB of power gain in the post-layout simulation. It achieves a high output 1-dB compression point (P_1dB) of 9.11 dBm, and a power-added-efficieny (PAE) of 7.26%, with a chip size of 0.18 × 0.55 〖mm〗^2. To improve the gain budget of the first power amplifier, the second power amplifier has been designed with higher drivability. By adding a cross-coupled pair at the inter-stage of the PA, power gain is increased. The inserted cCross-coupled pair technology could provides circuit negative resistance, which could offsetcompensates the extra extra resistance in from transformer. Therefore, the gain of the PA is largely improved. This PA achieves a post-layout simulated P_sat of 12.6 dBm, a P_1dB of 9.2 dBm, a PAE of 7.4%, and a linear power gain of 8.5 dB, with a chip size of 0.18 × 0.58 〖mm〗^2. In the third PA design, cross-coupled capacitors at the power stage are inserted to enhance the f_max of the transistors and hence the output power. Switches at the output port are designed to change the output impedance to improve the saturation output power at each operating frequency. This PA achieves a post-layout simulated P_sat of 13.9 dBm, a P_1dB of 9.9 dBm, a PAE of 6.3%, and a linear gain of 10 dB, with a chip size of 0.13 × 0.505 〖mm〗^2. Lastly, a CMOS W-band transmitter is designed and implemented. The PA and the mixer in the transmitter will be discussed individually. Transformers are used extensively in the power amplifier and the mixer to facilitate compact power combining, impedance matching networks, and DC feeds. The transmitter provides a saturation output power of 11.3 dBm with a power consumption of 237 mW. The peak conversion gain is 14.8 dB and the 3-dB bandwidth is 13.3 GHz. The core circuit occupies an area of 0.2 mm x 0.52 mm〖mm〗^2.