Single chip radio receiver with one off-chip filter

A method of operating an integrated circuit radio receiver having an on-chip adaptive filter and a discrete filter, the method comprising the steps of:

• connecting the adaptive filter and the discrete filter to a tuning circuit,
• tuning the adaptive to form a tuned filter which emulates said discrete filter,
• reconnecting the discrete filter and said tuned filter adaptive filter in the radio receiver circuit,
• activating said radio receiver for a period shorter than the stable time period of said adaptive filter,
• deactivating said radio receiver,
• whereby during the active period of said receiver, said adaptive filter and said discrete filter operate in similar fashion.

A radio receiver on an integrated chip said receiver including first on-chip IF filter and a second external IF filter said receiver including;

• means for activating said receiver intermittently, each active period being relatively short,
• on-chip components forming said first on-chip IF filter,
• external components forming said second external IF filter,
• means for adjusting said on-chip IF filter to match said external IF filter prior to each active period of said receiver, whereby said on-chip filter can maintain said setting for said short period of time said receiver is active.