QUADRATURE VOLTAGE CONTROLLED OSCILLATOR FOR L-BAND WIRELESS APPLICATIONS

摘要

The current-mode approach has become popular in analog integrated circuit design due to its advantages such as wider dynamic range and bandwidth and lower power consumption over its voltage-mode counterparts and various active current mode blocks, including Compound Current Conveyors (CCII), Operational Transconductance Amplifiers (OTA), Current Differencing Buffered Amplifiers (CDBA) and Current Differencing Transconductance Amplifiers (CDTA). The current-mode method is actually a modular design method. Current-mode quadrature oscillators (QOs) consist of two integrator loop quadrature oscillators (second-order QO) and three or more integrator loop quadrature oscillators (ring QO). All these QOs are completely inductorless, and the current-mode theory of designing oscillators is well established. However, the frequency limit of these existing current-mode QOs is very low (no more than 100MHz), so they can't meet the demands of modern communication systems.