The present invention offers significant improvements in the performance of a radio receiver operating in an environment with high desired band interference. The present invention comprises a high selectivity RF circuit that is located between the antenna and the radio receiver, and utilizes superheterodyne technology to filter adjacent channel interference in the desired band frequency spectrum. This type of interference is problematic for IEEE 802.11 radio receivers that are implemented with the popular direct conversion radio receiver architectures. The present invention may be utilized in many types of radio receivers. The high selectivity RF circuit comprises channel select filters, a down-converter, an up-converter and a programmable local oscillator. The radio receiver provides control signals to the high selectivity RF circuit that permits the selection of an appropriate channel select filter and permits the generation of a local oscillator that subsequently generates the proper intermediate frequency in a mixer.