Adaptively extending tunable range of frequency in a closed loop

• US 6,885,873 B2
• Filed: 12/19/2002
• Issued: 04/26/2005
• Est. Priority Date: 12/19/2002
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Soumyanath, Krishnamurthy, Banerjee, Gaurab, Ravi, Ashoke
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): Chang, Joseph
• Application Number:
  US10/324,686
• Publication Number:
  US 20040119547A1
• Time in Patent Office: 859 Days
• Field of Search: 331/182, 331/17, 331/25, 331/36.C, 455/517, 455/524
• US Class Current: 455/517
• CPC Class Codes: H03L 7/0898 the source or sink current values being variable H03L7/0896 takes precedence
• CPC Class Codes: H03L 7/093 using special filtering or amplification characteristics in the loop H03L7/087 - H03L7/091 take precedence
• CPC Class Codes: H03L 7/107 using a variable transfer function for the loop, e.g. low pass filter having a variable bandwidth
• CPC Class Codes: H03L 7/18 using a frequency divider or counter in the loop H03L7/20, H03L7/22 take precedence

Abstract

A semiconductor device or a circuit includes a controllable oscillator and circuitry that senses a voltage which may control the controllable oscillator and digitally controls a gain compensation, adaptively compensating for a drop in a gain against overall loop gain within a closed loop. In one embodiment, a single supply source may be used to power the closed loop while a variable gain stage that is digitally controllable may adjust the gain in a feed-forward manner based on the drop.

Claims

1. A communication system comprising:

a wireless interface to communicate over a wireless local area network;

a controllable oscillator coupled to an interface; and

a device operably coupled to said controllable oscillator to extend a tunable range of frequency within a closed loop by compensating for a drop in a gain of said controllable oscillator in the closed loop.

2. The communication system of claim 1, wherein said wireless interface further comprising:

an interface to receive a reference frequency from a source external to said wireless interface; and

a supply source to power said wireless interface.

3. The communication system of claim 2, wherein said wireless interface further comprising:

a compensation circuit operably coupled between said interface and said controllable oscillator to form the closed loop, sense a voltage that controls said controllable oscillator and digitally control a gain compensation, said compensation circuit including;

a sensing logic that detects a voltage that controls said controllable oscillator and provides digital controls for a gain compensation; and

a variable gain stage coupled to said sensing logic to adaptively compensate for the drop in the gain based on the gain compensation.

4. The communication system of claim 1, further comprising:

a radio frequency transceiver operably coupled to said device to receive and transmit a wireless communication via the wireless local area network within said tunable range of frequency.