AM receiver
First Claim
Patent Images
1. An AM receiver, comprising:
- at least one IF filter with a fixed IF bandwidth; and
at least one down-conversion stage to shift the signal input thereto into an IF range,wherein said at least one down-conversion stage has a variable oscillation frequency which is adjustable to detune a wanted center frequency of a wanted signal part from a center frequency of said at least one IF filter so that an unwanted signal part adjacent to said wanted signal part lies outside said fixed IF bandwidth, andsaid AM receiver is configured and adapted for adjusting said variable oscillation frequency on the basis of a feedback signal supplied downstream from said down-conversion stage in order to shift said wanted center frequency toward a higher frequency within a passband of said at least one IF filter so as to have more of a higher frequency unwanted signal part to lie substantially outside the passband of the IF filter.
2 Assignments
0 Petitions
Accused Products
Abstract
An AM receiver with at least one IF filter with a fixed IF bandwidth comprises at least one downconversion stage (3, 4, 5) to shift the signal input thereto into an IF range (IF1) having a variable oscillation frequency (fLO1) which is adjustable to detune a wanted center frequency (fC1) of a wanted signal part (30) from a center frequency (fIF1) of the at least one IF filter so that an unwanted signal part (31b) adjacent to the wanted signal part (30) lies outside the fixed IF bandwidth.
36 Citations
44 Claims
-
1. An AM receiver, comprising:
-
at least one IF filter with a fixed IF bandwidth; and at least one down-conversion stage to shift the signal input thereto into an IF range, wherein said at least one down-conversion stage has a variable oscillation frequency which is adjustable to detune a wanted center frequency of a wanted signal part from a center frequency of said at least one IF filter so that an unwanted signal part adjacent to said wanted signal part lies outside said fixed IF bandwidth, and said AM receiver is configured and adapted for adjusting said variable oscillation frequency on the basis of a feedback signal supplied downstream from said down-conversion stage in order to shift said wanted center frequency toward a higher frequency within a passband of said at least one IF filter so as to have more of a higher frequency unwanted signal part to lie substantially outside the passband of the IF filter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method to process a received and optionally processed AM signal, comprising the steps of
detuning, by means of a down conversion stage, a wanted center frequency of a wanted signal part from a center frequency used during at least one IF filtering with a fixed IF bandwidth so that an unwanted signal part adjacent to said wanted signal part lies outside said fixed IF bandwidth; - and
adjusting, on the basis of a feedback signal obtained downstream from said down-conversion stage, a frequency to which said wanted center frequency is detuned, such that said wanted center frequency is shifted toward a higher frequency within a passband of said fixed IF bandwidth to have more of a higher frequency unwanted signal part to lie substantially outside the passband of the IF filter. - View Dependent Claims (12, 13, 14, 15)
- and
-
16. An AM receiver comprising:
-
an IF filter having a fixed bandwidth and a predetermined center frequency; a down-conversion stage, arranged upstream from said IF filter, configured and adapted to receive an input signal having a desired signal component having a center frequency; and a feedback path for supplying a control signal to said down-conversion stage on the basis of a feedback signal obtained downstream from said down-conversion stage, wherein said AM receiver is configured and adapted for shifting, by means of said down-conversion stage, said input signal into an IF range on the basis of said control signal such that said center frequency of said shifted input signal is detuned from said center frequency of said IF filter in order to shift said wanted center frequency toward a higher frequency within a passband of said at least one IF filter so as to have more of a higher frequency unwanted signal part to lie substantially outside the passband of the IF filter. - View Dependent Claims (17, 18, 19)
-
-
20. An AM receiver comprising:
-
an IF filter having a fixed bandwidth; a down-conversion stage, arranged upstream from said IF filter, configured and adapted to receive an input signal having a desired signal component and an undesired signal component adjacent said desired signal component in the frequency domain; and a feedback path for supplying a control signal to said down-conversion stage on the basis of a feedback signal obtained downstream from said down-conversion stage, wherein said AM receiver is configured and adapted for shifting, by means of said down-conversion stage, said input signal into an IF range on the basis of said control signal such that said undesired signal component lies at least partially outside said bandwidth of said IF filter, such that said wanted center frequency is shifted toward a higher frequency within a passband of said IF filter to have more of a higher frequency unwanted signal part to lie substantially outside the passband of the IF filter. - View Dependent Claims (21, 22)
-
-
23. An AM receiver, comprising:
-
at least one IF filter with a fixed IF bandwidth; and at least one down-conversion stage to shift the signal input thereto into an IF range, wherein said at least one down-conversion stage has a variable oscillation frequency which is adjustable to detune a wanted center frequency of a wanted signal part from a center frequency of said at least one IF filter so that an unwanted signal part adjacent to said wanted signal part lies outside said fixed IF bandwidth, and said AM receiver is configured and adapted for adjusting said variable oscillation frequency on the basis of a feedback signal supplied downstream from said down-conversion stage in order to shift said wanted center frequency toward a higher or lower edge of the passband of said at least one IF filter so as to have more of a higher frequency unwanted signal part to lie substantially outside the passband of the IF filter. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32)
-
-
33. A method to process a received and optionally processed AM signal, comprising the steps of
detuning, by means of a down conversion stage, a wanted center frequency of a wanted signal part from a center frequency toward a higher or lower edge of the passband of said at least one IF bandwidth so that an unwanted signal part adjacent to said wanted signal part lies outside said fixed IF bandwidth; - and
adjusting, on the basis of a feedback signal obtained downstream from said down-conversion stage, a frequency to which said wanted center frequency is detuned, such that said wanted center frequency is shifted toward a higher frequency within a passband of said fixed IF bandwidth to have more of a higher frequency unwanted signal part to lie substantially outside the passband of the IF filter. - View Dependent Claims (34, 35, 36, 37)
- and
-
38. An AM receiver comprising:
-
an IF filter having a fixed bandwidth and a predetermined center frequency; a down-conversion stage, arranged upstream from said IF filter, configured and adapted to receive an input signal having a desired signal component having a center frequency; and a feedback path for supplying a control signal to said down-conversion stage on the basis of a feedback signal obtained downstream from said down-conversion stage, wherein said AM receiver is configured and adapted for shifting, by means of said down-conversion stage, said input signal into an IF range on the basis of said control signal such that said center frequency of said shifted input signal is detuned from said center frequency of said IF filter in order to shift said wanted center frequency toward a higher frequency within a passband of said at least one IF filter so as to have more of a higher frequency unwanted signal part to lie substantially outside the passband of the IF filter. - View Dependent Claims (39, 40, 41)
-
-
42. An AM receiver comprising:
-
an IF filter having a fixed bandwidth; a down-conversion stage, arranged upstream from said IF filter, configured and adapted to receive an input signal having a desired signal component and an undesired signal component adjacent said desired signal component in the frequency domain; and a feedback path for supplying a control signal to said down-conversion stage on the basis of a feedback signal obtained downstream from said down-conversion stage, wherein said AM receiver is configured and adapted for shifting, by means of said down-conversion stage, said input signal into an IF range on the basis of said control signal such that said undesired signal component lies at least partially outside said bandwidth of said IF filter, such that said wanted center frequency toward a higher or lower edge of the passband of said at least one IF filter signal to have more of a higher frequency unwanted signal part to lie substantially outside the passband of the IF filter. - View Dependent Claims (43, 44)
-
Specification