Source: http://www.google.com/patents/US7366486?ie=ISO-8859-1&dq=5893120
Timestamp: 2015-10-06 02:35:54
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Matched Legal Cases: ['in fine', 'in fine', 'in fine', 'in fine', 'Application No. 60', 'Application No. 60', 'Application No. 60']

Patent US7366486 - System and method for coarse/fine PLL adjustment - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsAn integrated receiver with channel selection and image rejection substantially implemented on a single CMOS integrated circuit is described. A receiver front end provides programable attenuation and a programable gain low noise amplifier. Frequency conversion circuitry advantageously uses LC filters...http://www.google.com/patents/US7366486?utm_source=gb-gplus-sharePatent US7366486 - System and method for coarse/fine PLL adjustmentAdvanced Patent SearchPublication numberUS7366486 B2Publication typeGrantApplication numberUS 10/440,085Publication dateApr 29, 2008Filing dateMay 19, 2003Priority dateNov 12, 1998Fee statusPaidAlso published asDE69920273D1, DE69920273T2, EP1145430A2, EP1145430B1, US6285865, US6377315, US6504420, US6549766, US6591091, US6865381, US6879816, US7092043, US7109781, US7199664, US7236212, US7423699, US7515895, US7729676, US7821581, US8045066, US8111095, US8195117, US20010007151, US20010008430, US20010011013, US20020140869, US20030022646, US20030107427, US20030162521, US20030194978, US20050107055, US20050153677, US20070013433, US20070077908, US20070120605, US20080284919, US20100237884, US20110067083, WO2000028664A2, WO2000028664A3, WO2000028664A8Publication number10440085, 440085, US 7366486 B2, US 7366486B2, US-B2-7366486, US7366486 B2, US7366486B2InventorsPieter Vorenkamp, Klaas Bult, Frank CarrOriginal AssigneeBroadcom CorporationExport CitationBiBTeX, EndNote, RefManPatent Citations (30), Non-Patent Citations (4), Referenced by (18), Classifications (107), Legal Events (2) External Links: USPTO, USPTO Assignment, EspacenetSystem and method for coarse/fine PLL adjustment
US 7366486 B2Abstract
1. A method of tuning a receiver, comprising:
mixing said plurality of channels with a first differential local oscillator signal to produce a first IF signal;
filtering said first IF signal in a first bandpass filter;
coarsely adjusting a frequency of said first differential local oscillator signal so that a selected channel and at least one other channel in said first IF signal falls in a passband of said first bandpass filter;
mixing said first IF signal with a second differential local oscillator signal to produce a second IF signal; and
finely adjusting a frequency of said second differential local oscillator signal so said selected channel falls in a passband of a second bandpass filter.
2. The method of claim 1, wherein said step of mixing said first IF signal with a second differential local oscillator signal includes the step of performing image rejection.
3. The method of claim 1, further comprising the step of filtering said second IF signal to recover said selected channel.
4. The method of claim 1, further comprising the step of lowpass filtering said plurality of channels prior to said step of mixing said plurality of channels with said first differential local oscillator signal.
5. The method of claim 1, wherein said plurality of channels are television channels.
a substrate providing a physical medium on which a portion of the receiver is disposed;
a first differential local oscillator that is adjustable in coarse frequency steps;
a second differential local oscillator that is adjustable in fine frequency steps;
a first differential mixer, disposed on said substrate and coupled to said first differential local oscillator, that generates a first IF signal including a plurality of channels;
a first differential IF filter, coupled to said first differential mixer that removes at least one of said plurality of channels from said first IF signal; and
a second differential mixer, disposed on said substrate and coupled to said second differential local oscillator, that generates a second IF signal from an output of said first differential mixer; and
a second differential IF filter, coupled to said second differential mixer;
wherein a frequency of said first differential local oscillator signal is coarsely adjusted so that a selected channel and at least one other channel in said first IF signal falls in a passband of said first differential IF filter, and said frequency of said second differential local oscillator signal is finely adjusted so that said selected channel falls in a passband of said second differential IF filter.
7. A method of tuning a receiver, comprising:
(1) receiving a channel to be tuned;
(2) mixing said channel with a first differential local oscillator signal to approximately obtain a first intermediate frequency (IF), said first differential local oscillator being adjustable in coarse steps;
(3) filtering said channel at said first IF using a first differential bandpass filter wherein said first differential bandpass filter has a passband sufficiently wide to pass said channel and a portion of another channel; and
(4) mixing said channel at said first if with a second differential local oscillator signal to obtain a second IF, said second differential local oscillator being adjustable in fine steps relative to said first differential local oscillator, wherein said channel falls in a passband of a second differential bandpass filter.
8. The method of claim 7, wherein said first differential local oscillator and said second differential local oscillator are phase lock loops.
9. The method of claim 7, wherein step (3) is accomplished with a surface acoustic wave (SAW) filter.
(5) filtering said channel at said second IF; and
(6) mixing said channel at said second IF with a third differential local oscillator signal to obtain a third IF, said third differential local oscillator having a narrow bandwidth and being adjustable in fine steps relative to said first differential local oscillator.
11. The method of claim 7, wherein, prior to step (1), said channel is passed through a receiver front end that provides a differential output.
12. The method of claim 7, wherein steps (1), (2) and (4) are performed on a single integrated circuit.
13. The method of claim 7, wherein said first differential local oscillator has a wide bandwidth relative to said second differential local oscillator.
a first differential local oscillator (LO) that is adjustable in coarse steps and having a wide bandwidth;
a first differential mixer coupled to said first differential LO for up-converting a received channel to obtain a first intermediate frequency (IF);
a first differential IF filter, coupled to said first differential mixer for filtering said channel at said first IF wherein said first differential IF filter has a sufficiently wide bandwidth to pass said channel and a portion of another channel;
a second differential LO that is adjustable in fine steps and having a narrow bandwidth relative to said wide bandwidth;
a second differential mixer coupled to said first differential IF filter and said second differential LO for down-converting said first IF signal to a second IF signal; and
a second differential IF filter, coupled to said second differential mixer, wherein said second IF signal falls in a passband of the second differential IF filter.
15. The receiver of claim 14, wherein said first differential IF filter is a surface acoustic wave (SAW) filter.
16. The receiver of claim 14, further comprising a receiver front end that provides a differential output to the receiver.
This is application is a continuation of U.S. Non-Provisional Application entitled “System and Method for Coarse/Fine PLL Adjustment,” Ser. No. 09/438,688, filed Nov. 12, 1999, now U.S. Pat. No. 6,591,091 which claims the benefit of U.S. Provisional Application Nos. 60/108,459, 60/108,209, 60/108,210, filed Nov. 12, 1998; U.S. Provisional Application No. 60/117,609, filed Jan. 28, 1999; U.S. Provisional Application Nos. 60/136,115 and 60/136,116, filed May 26, 1999; U.S. Provisional Application No. 60/136,654, filed May 27, 1999; and U.S. Provisional Application No. 60/159,726, filed Oct. 15, 1999; all of which are incorporated herein by reference.
Radio receivers, or tuners, are widely-used in applications requiring the reception of electromagnetic energy. Applications can include broadcast receivers such as radio and television, set top boxes for cable television, receivers in local area networks, test and measurement equipment, radar receivers, air traffic control receivers, and microwave communication links among others. Transmission of the electromagnetic energy may be over a transmission line or by electromagnetic radio waves.
Recriver Front End-programable Attenuator and LNA Figures
When a single frequency called a fundamental 202 is generated, unwanted spurious signals 204 are always generated with this fundamental. The spurious signals produced as a result of generating a single frequency (f) 202 are called harmonics 204 and occur at integer multiples of the fundamental frequency (2f, 3f, . . . ) The signal strength or amplitude of these harmonics decrease with increasing harmonic frequency. Fortunately these distortion products fall one or more octaves away from the desired signal, and can usually be satisfactorily filtered out with a low pass filter that blocks all frequencies above a preselected cut-off frequency. However, if the receiver is a wide band or multi octave bandwidth receiver, these harmonics will fall within the bandwidth of the receiver and cannot be low pass filtered, without also filtering out some of the desired signals. In this case, other methods known to those skilled in the art, such as reducing the distortion products produced, must be used to eliminate this distortion.
Selectivity is a measure of a radio receiver's ability to reject signals outside of the band being tuned by a radio receiver. A way to increase selectivity is to provide a resonant circuit after an antenna and before the receiver's frequency conversion circuitry in a “front end.” For example, a parallel resonant circuit after an antenna and before a first mixer that can be tuned to the band desired will produce a high impedance to ground at the center of the band. The high impedance will allow the antenna signal to develop a voltage a