초록 ▼

The present invention provides an improved single chip radio receiver which has less external components than do previous similar receivers. With the present invention the integrated circuit which includes the radio receiver also has an on-chip adaptive filter. The radio receiver is designed for use

The present invention provides an improved single chip radio receiver which has less external components than do previous similar receivers. With the present invention the integrated circuit which includes the radio receiver also has an on-chip adaptive filter. The radio receiver is designed for use in a radio pager which is only active for a very short time slot during a relative long repeat cycle. Thus the adaptive filter only need remain stable for a short period after its coefficients are adjusted to the desired values. The radio receiver includes an external filter which has the same frequency response as desired from the adaptive filter. Immediately prior to activating the radio receiver, the circuit is activated to adjust the parameters of the adaptive filter so that the adaptive filter matches the external filter. The radio receiver is then activated using both filters in series thereby producing the desired radio reception. The adaptive filter quickly changes characteristics; however, since the radio receiver is only active for a short period of time, operation of the system is not affected.

대표청구항 ▼

A single chip radio receiver designed for use in a radio pager said radio receiver having first and second filters which operate within a set of specifications to form an IF filter, said radio pager only being active for a very short time slot during a relative long repeat cycle, comprising, an inte

A single chip radio receiver designed for use in a radio pager said radio receiver having first and second filters which operate within a set of specifications to form an IF filter, said radio pager only being active for a very short time slot during a relative long repeat cycle, comprising, an integrated circuit chip having radio receiver components thereon, including components connected to form said first filter which comprises capacitors and gyrators, an external off-chip filter connected to form said second filter, means for adjusting said on-chip filter to match said off-chip filter when said receiver is not operating, means for connecting said on-chip and said off-chip filters together as said IF filter, whereby said receiver can operate for a short period of time before said on-chip components drift out of said specification.