Transceiver architectures for supporting multi-band radio frequencies are disclosed. According to one aspect of the present invention, a number of processing channels are designed, each for one specified carrier frequency. A number of switching means is provided to ensure that a processing channel is properly selected for a specified carrier frequency. Each of the processing channels includes at least an amplified and a low-pass filter, where the low-pass filter is automatically programmable in response to a wireless standard (e.g., Wi-Fi or WiMAX). A single voltage oscillator (VCO) is used to support operations of each of the processing channels.