Abstract
The revolutionary advances in solid-states and VLSI technology have brought the world of wireless communications into a completely brand-new era. However, the success of the wireless communication products depends on the low cost, low power and high performance transceivers. Direct conversion is a very promising architecture for high integration. Unlike conventional superheterodyne receiver, it constructs without applying any IF stage. Its minimum circuit blocks operated at high-speed enable the goal of highly integration. The main problems in the direct conversion architecture are listed below. The effects due to devices mismatches and self-mixing result in DC offset at low frequency. And that will saturate the following stages. In addition, inherent MOS 1/f noise will deteriorate the downconverted signal at DC. In-band interrupts from high power interferences, and AM disturbance due to burst blockers will greatly degrade the system sensitivity. In this thesis, the emphasis is primarily put on the solution of reducing flicker noise of the mixer for direct conversoin receiver. Different approaches of reducing flicker noise and the detailed noise derivation of mixer are discussed in this thesis. The modified Gilbert mixer has been implemented and steps of the measurement are described clearly.