System and method for coarse/fine PLL adjustment

• US 7,366,486 B2
• Filed: 05/19/2003
• Issued: 04/29/2008
• Est. Priority Date: 11/12/1998
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Vorenkamp, Pieter, Bult, Klaas, Carr, Frank
• Primary Examiner(s): SOBUTKA, PHILIP
• Application Number:
  US10/440,085
• Publication Number:
  US 20030194978A1
• Time in Patent Office: 1,807 Days
• Field of Search: 455/179.1, 455/182.3, 455/190.1, 455/191.1, 455/192.3, 455/196.1, 455/197.1, 455/208, 455/209, 455313-316, 455/318, 455/323, 455/326, 455/334, 455/339, 455/77
• US Class Current: 455/182.3
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 2017/0053 with means to reduce eddy currents
• CPC Class Codes: H01F 2021/125 Printed variable inductor with taps, e.g. for VCO
• CPC Class Codes: H01F 27/34 Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
• CPC Class Codes: H01F 27/40 Structural association with built-in electric component, e.g. fuse
• CPC Class Codes: H01F 27/42 Circuits specially adapted for the purpose of modifying, or compensating for, electric characteristics of transformers, reactors, or choke coils circuits for controlling transformers, reactors or choke coils, for the purpose of obtaining a desired output H02P13/00; impedance networks H03H
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 27/0248 for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection
• CPC Class Codes: H01L 27/0251 for MOS devices
• CPC Class Codes: H01L 27/08 including only semiconductor components of a single kind
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H03B 5/04 Modifications of generator to compensate for variations in physical values, e.g. power supply, load, temperature
• CPC Class Codes: H03B 5/364 the amplifier comprising field effect transistors H03B5/366 takes precedence
• CPC Class Codes: H03D 3/18 by means of synchronous gating arrangements
• CPC Class Codes: H03D 7/161 all the frequency changers being connected in cascade
• CPC Class Codes: H03D 7/18 Modifications of frequency-changers for eliminating image frequencies H03D7/16 takes precedence
• CPC Class Codes: H03F 1/26 Modifications of amplifiers to reduce influence of noise generated by amplifying elements
• CPC Class Codes: H03F 1/3211 : in differential amplifiers
• CPC Class Codes: H03F 2200/111 : the amplifier being a dual or triple band amplifier, e.g. 900 and 1800 MHz, e.g. switched or not switched, simultaneously or not
• CPC Class Codes: H03F 2200/294 : the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/372 : Noise reduction and elimination in amplifier
• CPC Class Codes: H03F 2200/447 : the amplifier being protected to temperature influence
• CPC Class Codes: H03F 2200/63 : the amplifier being suitable for CATV applications
• CPC Class Codes: H03F 2203/45264 : the dif amp comprising frequency or phase stabilisation means
• CPC Class Codes: H03F 2203/45286 : the temperature dependence of a differential amplifier being controlled
• CPC Class Codes: H03F 3/195 : in integrated circuits
• CPC Class Codes: H03F 3/45183 : Long tailed pairs H03F3/4521, H03F3/45237 take precedence
• CPC Class Codes: H03F 3/45188 : Non-folded cascode stages
• CPC Class Codes: H03F 3/68 : Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602
• CPC Class Codes: H03F 3/72 : Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal
• CPC Class Codes: H03G 1/0023 : in emitter-coupled or cascode amplifiers H03G1/0029 takes precedence
• CPC Class Codes: H03G 1/0029 : using FETs
• CPC Class Codes: H03G 3/3052 : in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver H03G3/32, H03G3/34 take precedence
• CPC Class Codes: H03H 11/04 : Frequency selective two-port networks
• CPC Class Codes: H03H 11/1291 : Current or voltage controlled filters
• CPC Class Codes: H03H 11/53 : simulating resistances; simulating resistance multipliers
• CPC Class Codes: H03H 11/54 : Modifications of networks to reduce influence of variations of temperature
• CPC Class Codes: H03H 19/004 : Switched capacitor networks
• CPC Class Codes: H03H 7/25 : comprising an element controlled by an electric or magnetic variable H03H7/27 takes precedence
• CPC Class Codes: H03J 1/0075 : where the receiving frequencies of the stations are stored in a permanent memory, e.g. ROM
• CPC Class Codes: H03J 2200/10 : Tuning of a resonator by means of digitally controlled capacitor bank
• CPC Class Codes: H03J 3/04 : Arrangements for compensating for variations of physical values, e.g. temperature
• CPC Class Codes: H03J 3/08 : by varying a second parameter simultaneously with the tuning, e.g. coupling bandpass filter
• CPC Class Codes: H03J 3/185 : with varactors, i.e. voltage variable reactive diodes
• CPC Class Codes: H03L 2207/06 : Phase locked loops with a controlled oscillator having at least two frequency control terminals
• CPC Class Codes: H03L 7/103 : the additional signal being a digital signal
• CPC Class Codes: H03L 7/183 : a time difference being used for locking the loop, the counter counting between fixed numbers or the frequency divider dividing by a fixed number H03L7/1806 takes precedence
• CPC Class Codes: H03L 7/23 : with pulse counters or frequency dividers

Abstract

An 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 integrated onto the substrate in conjunction with image reject mixers to provide sufficient image frequency rejection. Filter tuning and inductor Q compensation over temperature are performed on chip. The filters utilize multi track spiral inductors. The filters are tuned using local oscillators to tune a substitute filter, and frequency scaling during filter component values to those of the filter being tuned. In conjunction with filtering, frequency planning provides additional image rejection. The advantageous choice of local oscillator signal generation methods on chip is by PLL out of band local oscillation and by direct synthesis for in band local oscillator. The VCOs in the PLLs are centered using a control circuit to center the tuning capacitance range. A differential crystal oscillator is advantageously used as a frequency reference. Differential signal transmission is advantageously used throughout the receiver.

Claims

1. A method of tuning a receiver, comprising:

receiving a plurality of channels;

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.

6. A receiver, comprising:

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.

10. The method of claim 7, further comprising:

(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.

14. A receiver comprising:

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.