Integrated circuit tuner with broad tuning range

• US 7,187,913 B1
• Filed: 01/24/2003
• Issued: 03/06/2007
• Est. Priority Date: 01/25/2002
• Status: Expired due to Fees

• Current Assignee: Intellectual Ventures Holding 75 LLC (Intellectual Ventures LLC)
• Original Assignee: SIGE Semiconductor Incorporated (Skyworks Solutions Incorporated)
• Inventors: Fulga, Stefan, Rahn, David
• Primary Examiner(s): Vuong, Quochien B.
• Application Number:
  US10/349,931
• Time in Patent Office: 1,502 Days
• Field of Search: 455/188.1, 455/188.2, 455/191.1, 455/192.1, 455/192.2, 455/227, 455/266, 455/179.1, 455/182.3, 455/307, 455/333, 455/339, 455/197.2, 348/725, 348/731
• US Class Current: 455/188.1
• CPC Class Codes: H03J 1/005 in a loop
• CPC Class Codes: H03J 3/08 by varying a second parameter simultaneously with the tuning, e.g. coupling bandpass filter
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes
• CPC Class Codes: H04N 21/4263 involving specific tuning arrangements, e.g. two tuners
• CPC Class Codes: H04N 5/50 Tuning indicators; Automatic tuning control

Abstract

An integrated front end filter for a tuner provides an array of from several to a multitude of passbands, each for passing at least one but less than all channels designated in a band of frequencies. Each passband is exclusively selectable. The integrated front end filter can include at least one active filter unit with an active reactance element in either of fixed and variable filter configurations and a decoder coupled to said at least one active filter unit and being responsive to a control signal for selecting a one of the passbands. In one example, a multitude of active filter units of fixed filter configuration provide the multitude of passbands. In another example, a plurality of data corresponds to a like plurality of selectable passbands in combination with a filter element of the variable filter configuration. Each data is stored at a predetermined location and reproduced in response to a corresponding control data signal from a tuner controller. Each data characterizes one of the plurality of passbands. The filter element is switchable from one passband to another in response to the control data signal. Lower power dissipation and lesser requirements of an on-following integrated circuitry tuner permit a reduction of “off chip” connections and cost.

Claims

1. A tuner for receiving information signals within a channel selected from within a plurality of channels and being within a predesignated frequency band, the tuner comprising:

a first filter for providing a plurality of passbands each being exclusively selectable in response to a filter selection signal designating a corresponding one of the plurality of passbands, each of said passbands being characterized by a bandwidth being sufficiently broad to admit signals in at least one of the plurality of channels with lesser attenuation than other signals;

an input port for receiving information signals and conducting the received information signals to the filter;

an output port for conducting any signals having been admitted by the first filter;

superheterodyne circuitry including a mixer and a second filter for processing any signals coupled thereto via the output port and discriminating the received information signals within the selected channel;

wherein,

at least one of the first and second filters is a pass band filter integrated within a semiconductor substrate and comprising;

a filter selection signal port for receiving a filter selection signal;

a frequency data table for converting the filter selection signal to corresponding bias data signals; and

,

a capacitance D/A bias converter and an inductance D/A bias converter, being coupled to a variable capacitance and an active inductance respectively and being responsive respective ones of the bias data signals for adjusting the effective values of the reactance elements to effect a passband filter function as designated by the filter selection signal.

2. A tuner as defined in claim 1 wherein the other of the first and second filters is integrated within the semiconductor substrate and comprises:

a switching filter selection signal port for receiving a switching filter selection signal; and

,

a plurality of bandpass filters each including a switch controlled by data representing the switching filter selection signal for exclusively activating the bandpass filter.

3. A tuner as defined in claim 1 wherein the other of the first and second filters is integrated within the semiconductor substrate and comprises:

a plurality of lowpass and highpass filters, each comprising;

a passband filter selection signal port for receiving a passband filter selection signal; and

,

a switch responsive to data representing the passband filter selection signal, whereby ones of said highpass and lowpass filters are activatable in pairs.

4. A tuner as defined in claim 1 further comprising:

a signal processor for providing a composite video signal and for providing tuning error signal representing a tuning error in response to received information signals from the superheterodyne circuitry; and

,

a synthesizer for providing at least one local oscillator signal for operation of the superheterodyne circuitry, the local oscillator signal being of a frequency substantially corresponding to a predetermined frequency for discriminating signals within the selected channel, and being responsive to a tuning error signal for adjusting the frequency of the local oscillator signal toward eliminating the tuning error.

5. A tuner as defined in claim 1 wherein the other of the first and second filters is a second pass band filter integrated within the semiconductor substrate and comprising:

a second filter selection signal port for receiving a second filter selection signal;

a second frequency data table for converting the second filter selection signal to corresponding second bias data signals; and

,

a second capacitance D/A bias converter and an second inductance D/A bias converter, being coupled to the second variable capacitance and the second active inductance respectively and being responsive respective ones of the second bias data signals for adjusting the effective values of the reactance elements to effect a second passband filter function as designated by the second filter selection signal.

6. A tuner as defined in claim 1 wherein at least one of the filters comprises:

active and passive elements including an active inductance being integrated within a semiconductor substrate.

7. A tuner for receiving information signals within a channel selected from within a plurality of channels and being within a predesignated frequency band, the tuner comprising:

a first filter for providing a plurality of passbands each being exclusively selectable in response to a filter selection signal designating a corresponding one of the plurality of passbands, each of said passbands being characterized by a bandwidth being sufficiently broad to admit signals in at least one of the plurality of channels with lesser attenuation than other signals;

an input port for receiving information signals and conducting the received information signals to the filter;

an output port for conducting any signals having been admitted by the first filter;

superheterodyne circuitry including a mixer and a second filter for processing any signals coupled thereto via the output port and discriminating the received information signals within the selected channel;

wherein,

at least one of the first and second filters comprises;

a filter selection signal port for receiving a filter selection signal; and

,

a plurality of bandpass filters each including a decoder being responsive to the filter selection signal designating a corresponding one of the plurality of passbands for asserting a switch ON signal and a switch for activating the bandpass filter in response to the switch ON signal from the decoder and otherwise maintaining the bandpass filter in an OFF state.

8. A tuner for receiving information signals within a channel selected from within a plurality of channels and being within a predesignated frequency band, the tuner comprising:

a first filter for providing a plurality of passbands each being exclusively selectable in response to a filter selection signal designating a corresponding one of the plurality of passbands, each of said passbands being characterized by a bandwidth being sufficiently broad to admit signals in at least one of the plurality of channels with lesser attenuation than other signals;

an input port for receiving information signals and conducting the received information signals to the filter;

an output port for conducting any signals having been admitted by the first filter;

superheterodyne circuitry including a mixer and a second filter for processing any signals coupled thereto via the output port and discriminating the received information signals within the selected channel;

wherein

at least one of the first and second filters is integrated within a semiconductor substrate and comprises;

a plurality of bandpass filters, each comprising;

a filter selection signal port for receiving a filter selection signal; and

,

a switch and a digital to analog converter, the switch being responsive to data representing the filter selection signal for activating the bandpass filter and the digital to analog converter and the activated digital to analog converter being responsive to said data for generating a bias voltage for selecting a passband of operation in the activated bandpass filter.

9. A tuner as defined in claim 8 wherein each of the bandpass filters further comprises:

a frequency table for converting a data representing the filter selection signal to a passband selection signal for use by the digital to analog converter, whereby a selected filter is switchable to any of a plurality of predesignated passbands.

10. An integrated circuit tuner, responsive to a tuner controller signal, for receiving information modulated signals from a designated one of a multitude of channels in a predesignated band of frequencies, comprising:

at least several switchable bandpass filters each being selectable for admitting signals in at least one of several channels in adjacent frequency bands in response to the control signal;

an input port for receiving signals and conducting the received signals to said at least several bandpass filters;

an output port for coupling any signals having been admitted via any of said at least several bandpass filters;

a superheterodyne circuit for discriminating the received information signals within the selected channel; and

,

a tuner controller port for receiving the tuner controller signal;

said at least several bandpass filters each having a pass band characteristic being defined by a mutually exclusive central frequency and a bandwidth sufficiently broad to admit at least one of said channels with a substantially flat gain there being sufficient bandpass filters within said at least several bandpass filters to admit information signals within any designated channel;

said at least several bandpass filters each including a switch for enabling the bandpass filter with energizing power, the switch being responsive to the tuner controller signal; and

at least one of the several bandpass filters is integrated within a semiconductor substrate and comprises;

a bandpass filter selection signal port for receiving a bandpass filter selection signal;

a frequency data table for converting the filter selection signal to corresponding bias data signals; and

,

a capacitance D/A bias converter and an inductance D/A bias converter, being coupled to a variable capacitance and an active inductance respectively and being responsive respective ones of the bias data signals for adjusting the effective values of the reactance elements to effect a passband filter function as designated by the bandpass filter selection signal.

11. An integrated circuit tuner as defined in claim 10 wherein the bandpass characteristic of each of the several bandpass filters are defined by a parallel resonant active circuit in a feedback path in combination with an inverting amplifier.

12. An integrated circuit tuner as defined in claim 10 wherein the pass band characteristic of each of the several bandpass filters is between about 5% and 10% of a central frequency of the respective passband.

13. An integrated circuit tuner as defined in claim 10 wherein the pass band characteristics are defined by lowpass and highpass filter circuits being switchably selectable in pairs.

14. An integrated circuit tuner as defined in claim 13 wherein the pass band characteristic of each of the selectable in pairs is about one octave in the predesignated band of frequencies.

15. A television signal receiving appliance for receiving TV program information signals within a channel selected via a tuner controller, the receiving appliance comprising:

an input port for receiving TV program information signals;

a filter selection signal port for receiving a filter selection signal;

a tuner including a first filter for providing a plurality of passbands each being exclusively selectable in response to the filter selection signal designating a corresponding one of the plurality of passbands, each of said passbands being characterized by a bandwidth being sufficiently broad to admit signals in at least one of the plurality of channels with lesser attenuation than other signals in response to an activating control signal from the tuner controller, the tuner also including superheterodyne circuitry with a mixer and a second filter for discriminating the received information signals within the selected channel; and

,

detection and processing circuitry being responsive to the discriminated signals for generating a video signal and an audio signal; and

at least one of

an apparatus for visual display and sound reproduction of the video and audio signals and a recording apparatus for storing at least one of the video and audio signals as it occurs over a period of time, for future use

wherein at least one of the first and second filters includes a tunable filter element, the tunable filter element comprising;

a variable parallel resonant circuit with a bias voltage responsive capacitance element and a bias voltage responsive active inductance element,

an inverting amplifier with a feedback loop including the variable parallel resonant circuit; and

,

respective digital to analog converters each being responsive to reproduced data for generating said bias voltages.

16. A television signal receiving appliance as defined in claim 15 wherein each of said passbands is further characterized by a bandwidth being sufficiently narrow to admit signals in a minority of channels of adjacent channel frequencies in the plurality of channels with lesser attenuation than other signals.

17. A television signal receiving appliance as defined in claim 15 wherein the tuner is an integrated circuit.

18. A television signal receiving appliance as defined in claim 15 wherein the tuner and the detection and processing circuitry are integrated within a semiconductor substrate.

19. A television signal receiving appliance as defined in claim 15 further comprising:

a tuner controller port for receiving a control data signal; and

,

a memory for storing channel selection data, wherein the first filter is provided by a plurality of data corresponding to the selectable channels in combination with the tunable filter element, each data from the plurality being stored at a predetermined location within the memory and reproduced in response to a corresponding control data signal, each data characterizing one of a plurality of passbands each of a bandwidth being sufficiently broad to admit at least one of the plurality of channels in the received information signal with lesser attenuation than others of the plurality of channels, the tunable filter element being switchable from one passband to another in response to the control data signal.

20. An integrated front end filter in a tuner, comprising:

a tuner controller port for receiving a control data signal from a tuner controller; and

,

a memory for storing a plurality of data corresponding to the selectable channels in combination with a tunable filter element, each data being stored at predetermined location within the memory and reproduced in response to the corresponding control data signal from a tuner controller, each data characterizing one of a plurality of passbands each of a bandwidth being sufficiently broad to admit at least one of the plurality of channels in the received information signal with lesser attenuation than others of the plurality of channels, the tunable filter element being switchable from one passband to another in response to the control data signal;

wherein,

the tunable filter element comprises;

a variable parallel resonant circuit with a bias voltage responsive capacitance element and a bias voltage responsive active inductance element;

an inverting amplifier with a feedback loop including the variable parallel resonant circuit; and

,

respective digital to analog converters each being responsive to reproduced data for generating said bias voltages.

21. An integrated front-end filter in a tuner according to claim 20 wherein the front-end filter comprises;

at least the front end filter in an integrated circuit form;

an electronic memory;

the electronic memory for storing each of the plurality of data at a storage location being addressable by a corresponding one of the control data signals, such that in subsequent use, the tunable filter element is switchable from one passband to another in response to the control data signal.

22. An integrated front-end filter in a tuner according to claim 21 wherein the storing of each of the plurality of data comprises

channel testing the tuner'"'"'s performance by operating the tuner with a channel test signal selected from a plurality of channel test signals;

and,

if a result of the channel test is less than a predetermined standard, amending the data characterizing the passband to urge the result toward the predetermined standard; and

otherwise,

repeating the channel testing step with each channel test signal until each of the channel test signals has been selected.

23. A method of receiving RF information modulated signals from a designated one of a multitude of channels in a predesignated band of frequencies, comprising the steps of:

providing a plurality of switchably selectable bandpass filters each being selectable for admitting signals in at least one of several channels in adjacent frequency bands;

determining a desired channel from the multitude of channels;

generating a tuning signal in dependence upon the determined channel;

receiving the tuning signal by the plurality switchably selectable bandpass filters;

comparing the tuning signal to predetermined data within the plurality switchably selectable bandpass filters;

enabling a single switchably selectable bandpass filter from the plurality of switchably selectable bandpass filters for which the tuning signal compares to the predetermined data; and

,

disabling the plurality of switchably selectable bandpass filters that are other than the single enabled switchably selectable bandpass filter;

wherein,

providing at least one of the plurality of switchably selectable bandpass filters is by providing a pass band filter integrated within a semiconductor substrate;

the pass band filter comprising;

a filter selection signal port for receiving a filter selection signal;

a frequency data table for converting the filter selection signal to corresponding bias data signals; and

,

a capacitance D/A bias converter and an inductance D/A bias converter, being coupled to a variable capacitance and an active inductance respectively and being responsive respective ones of the bias data signals for adjusting the effective values of the reactance elements to effect a passband filter function as designated by the filter selection signal.

24. A method according to claim 23 wherein the tuning signal is an analog tuning signal.

25. A method according to claim 24 wherein the predetermined data comprises analog voltage data.

26. A method according to claim 25 further comprising the step of:

providing a comparator circuit for performing the step of comparing the analog tuning signal to the analog voltage data.

27. A method according to claim 23 wherein the tuning signal is a digital tuning signal.

28. A method according to claim 27 wherein the predetermined data comprises digital data.

29. A method according to claim 23 wherein the enabled single switchably selectable bandpass filter comprises the desired channel within the at least one of several channels in adjacent frequency bands.

30. A method according to claim 23 further comprising;

providing a memory circuit having an output port coupled to each switch port from a plurality of switchably selectable bandpass filters each being selectable for admitting signals in at least one of several channels in adjacent frequency bands, the memory circuit having instructions contained therein for performing the steps of;

determining a desired channel having information modulated signals therein from a multitude of channels each having information modulated signals therein;

generating a tuning voltage in dependence upon the determined channel; and

, providing a tuning voltage to the output port coupled to the each switch port of the plurality switchably selectable bandpass filters.